Presence Of IL-2 Research Articles

Long-term survival without graft-versus-host-disease following infusion of allogeneic myeloma-specific V\u03b2 T cell families

BackgroundDespite chemo-induction therapy and autologous stem cell transplantation (ASCT), the vast majority of patients with Multiple Myeloma (MM) relapse within 7 years and the disease remains incurable. Adoptive Allogeneic T-cell therapy (ATCT) might be curative for MM, however current ATCT protocols often lead to graft versus host disease (GvHD). Transplanting only tumor reactive donor T cells that mediate a graft-versus-myeloma (GvM) but not GvHD may overcome this problem.MethodsWe used an MHC-matched/miHA-disparate B10.D2 → Balb/c bone marrow transplantation (BMT) murine model and MOPC315.BM MM cells to develop an ATCT protocol consisting of total body irradiation, autologous-BMT and infusion of selective, myeloma-reactive lymphocytes of T cell receptor (TCR) Vβ 2, 3 and 8.3 families (MM-auto BMT ATCT).ResultsPre-stimulation ex vivo of allogeneic T cells by exposure to MOPC315.BM MM cells in the presence of IL-2, anti-CD3 and anti-CD28 resulted in expansion of the myeloma-reactive T cell TCRVβ 2, 3 and 8.3 subfamilies. Their isolation and infusion into MM-bearing mice resulted in a vigorous GvM response without induction GvHD and long-term survival. Repeated infusion of naïve myeloma-reactive T cell TCRVβ 2, 3 and 8.3 subfamilies was also effective.ConclusionsThese data demonstrate that a transplantation protocol involving only selective tumor-reactive donor T cell families is an effective immunotherapy and results in long-term survival in a mouse model of human MM. The results highlight the need to develop similar ATCT strategies for MM patients that result in enhanced survival without symptoms of GvHD.

The Combination of Dexamethasone and Ruxolitinib Synergistically Attenuates Disease Manifestations in a Preclinical Model of Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe immunologic syndrome characterized by a failure of CD8 T-cells to appropriately terminate immune responses, leading to excessive activation of immune cells that mediate life-threatening organ damage. Many patients with HLH are refractory to front-line therapy consisting primarily of the glucocorticoid dexamethasone (DEX) and the chemotherapeutic agent etoposide, resulting in five-year survival rates of only 62%. Therefore, novel strategies are needed to enhance the efficacy of frontline therapy in order to improve clinical outcomes. Hypercytokinemia is a hallmark feature of HLH due to the persistent activation of immune cells. CD8 T-cells both secrete and respond to these cytokines, making them important cellular targets of HLH therapy. Many HLH-associated cytokines activate the JAK/STAT pathway, and the JAK1/2 inhibitor ruxolitinib (RUX) has shown efficacy in murine models of HLH and in clinical case reports of refractory HLH. Importantly, JAK/STAT signaling has been shown in other disease contexts to induce DEX resistance. We therefore hypothesized that cytokine-mediated JAK/STAT signaling might contribute to DEX resistance in HLH and that this could be overcome by combination treatment with RUX. To test this hypothesis, we infected Prf1-/- mice with lymphocytic choriomeningitis virus (LCMV) to generate an in vivo model of primary HLH. Beginning on day four post-infection, mice were treated with vehicle control, DEX, RUX, or the combination of DEX and RUX and examined for signs of HLH. The Bliss independence model of synergy was applied to quantify the combinatorial effects of these drugs on disease parameters. Combined treatment with DEX and RUX synergistically lessened signs of systemic inflammation, including splenomegaly, numbers of inflammatory cells, including neutrophils and CD8 T-cells, and circulating levels of inflammatory cytokines. The mechanistic basis for these findings was then interrogated ex vivo. First, activated murine and human CD8 T-cells were exposed to DEX or etoposide in the presence of HLH-associated cytokines and were evaluated for cell viability. This revealed that the JAK-dependent cytokines IL-2 and IL-12 confer resistance specifically to DEX, but not to etoposide. IL-2 and IL-12 receptor signaling converge to activate STAT5. Consistent with this, exposure to RUX attenuated STAT5 activation in response to IL-2 or IL-12 stimulation. Furthermore, DEX and RUX synergized to induce cell death in the presence of IL-2 or IL-12. Mechanistic studies revealed that cytokine exposure did not inhibit nuclear translocation of ligand-activated glucocorticoid receptor (GR) or activation of GR transcriptional targets, suggesting that IL-2 and IL-12 act downstream of GR activity to confer DEX resistance. To interrogate this further, we quantified expression of BCL-2 family members in CD8 T-cells exposed to IL-2 or IL-12 and found significant upregulation of BCL-2 and BCL-XL. Using BH3 profiling, we functionally interrogated the intrinsic apoptotic pathway and found that cytokine exposure significantly suppressed the apoptotic potential of CD8 T-cells, such that DEX alone was no longer sufficient to induce apoptotic priming. However, concomitant exposure to RUX effectively restored apoptotic priming in response to DEX by inhibiting cytokine-induced upregulation of BCL-2 and BCL-XL. Finally, we performed BH3 profiling on cells from Prf1-/- mice following in vivo treatment with DEX +/- RUX. Similar to the ex vivo findings, LCMV infection and the subsequent onset of HLH significantly reduced the apoptotic potential of CD8 T-cells relative to cells from naïve mice, consistent with elevated levels of circulating cytokines in vivo. Combined treatment with DEX and RUX was more effective than either agent alone at inducing apoptotic priming, suggesting that both ex vivo and in vivo, cytokine exposure inhibits DEX-induced cell death by altering the cellular apoptotic potential. Taken together, this study reveals a mechanism of cytokine-mediated DEX resistance in HLH and provides rationale for combining DEX and RUX as a means to augment DEX sensitivity and improve clinical outcomes for patients with HLH. Figure Disclosures Nichols: Incyte: Research Funding.

Manipulation of Induced Foxp3+ Regulatory T Cells for Prevention of Mouse Acute Graft-Versus-Host Disease

Background Foxp3+ regulatory T cells (Tregs) comprise of natural (n) and induced (i) Treg subsets play an important role in immune system. Currently, isolation of nTregs and in vitro-expanded nTregs was shown to be an effective therapy to GVHD patients. However, shortage of nTregs in peripheral blood and time consumption of expansion in vitro may eventually limit the clinical application. Conversely, iTregs can be generated in vitro from naïve T cells and to a large number of iTregs in short time. As we known, regulatory T cells would decay after a period of time, in vivo or in vitro. Keeping a certain number of iTregs during the GVHD treatment is necessary, it should be the best to provide iTregs to the patient more than single usage. Aim Manipulated supplements of TGF-β1-induced Foxp3+ regulatory T cells should be a good way for prevention from acute graft-versus-host disease within a short time. Investigation was performed via animal model. Methods Splenocytes from C57BL/6 mice were used as a source of naïve T cells by a CD4+ naïve T cell isolation Kit. To induce Foxp3+ regulatory T cells (iTregs), the CD4+ naïve T cells were incubated with anti-CD3/CD28 coated 24-well plate in the presence of IL-2 (20U/ml) and TGF-b1 (50ng/ml) for 3 days. Foxp3+iTregs were harvested and identified as the expressions of CD4+/CD25+/FoxP3+/CD127- via flow cytometry (Fig.1). In this experiment, recipients (BALB/c) were irradiated with 800cGy and then infused with donor (C57BL/6) bone marrow cells with (TCD-BM+CD4T) or without donor T cells (TCD-BM) by intravenous injection. TCD-BM+CD4T cells mice would appear aGVHD phenotype. 8x106 Foxp3+ iTregs were injected into the TCD-BM with donor T cell mouse one or twice (TCD-BM+CD4 T +iTreg) for immunosuppression assay as shown in Fig.2. Mouse GVHD phenotype, body weights and survival rates were investigated lasting for over 90 days. Tissue sections were stained with haematoxylin-eosin. Results According to our preliminary data, it indicated the injection of iTregs in the prevention of aGVHD should be feasible (Fig.3). Consequently, we have tried to investigate preventative efficiency of repeated iTregs supplements in TCD-BM mice. First of all, we compared the single-dose of iTregs with the repetition-dose of iTregs in aGVHD prevention. The data showed in Fig.4. The data showed that the survival rate was 73.3% in repeated treatment in mice, however, the survival rate was only 45.8% in single-dose of iTregs mice within 24 days. As the TCD-BM survival rate was 76.1%. It indicated that the repetition-dose of iTregs would prevent the occurrence of aGVHD, and the survival rate was similar as the bone marrow transplantation mice. The BM-CD4T mice with aGVHD phenotype could survive no more than 10 days. Furthermore, we investigated the survival time of the continual iTreg supplements mice. The data showed in Fig.5. After 90 days later, the body weight of iTregs treated mice could maintain the recovery efficiency to 83.8±2.1% and the survival rate to 78%, comparing with the TCD-BM mice was 88.8±0.6% and 73%. All of these mice could keep alive more than 90 days. Using histographic staining, we confirmed the aGVHD prevention with repeated supplement of Foxp3+iTregs to the CD4T mice (Fig.6). The mice, administration of CD4T cells with bone marrow cells, failed to survival for the serious damage of intestine villi (Fig.6A) and Peyer's patches (Fig.6B). In contrast, CD4T mice with Foxp3+-iTregs (iTregs) could survival more than 90 days and intestine villi were recovered after 90 days (Fig.6A). Peyer's patches are an important gut associated lymphoid tissue in small intestine and play a crucial role in immune response. Therefore, we have investigated the changes of Peyer's patches (Fig.6B). As the recovery of mice with iTregs for twice, the Peyer's patches reappeared after 90 days later. It indicated that keeping more iTregs in vivo could more efficient on prevention of aGVHD. It indicated that more alive iTregs to prevent GVHD occurrence more efficient and may provide the information pre-clinically. Conclusion We showed that repetition supplement of iTreg cells to TCD-BM+CD4T-treated mice, could maintain the mice in high survival rate. Therefore, we may provide more of the functional iTregs to GVHD patients, continuously. It's a good way to prevent the occurrence of GVHD. The result should develop a novel-cell based approach for potentially reducing the risk of acute GVHD clinically. Disclosures No relevant conflicts of interest to declare.

Towards Safer Allogeneic HSCT in Autoimmunity: Proof of Concept in Diabetes-Prone Mice

R.S.K and B.N.L contributed equally to this study. The induction of tolerance towards pancreas autoantigens is a promising approach in the treatment of type 1 diabetes mellitus (T1DM). This goal can be partially attained by immuno-ablation followed by autologous HSCT which mitigates the immune reaction leading to diabetes, at least temporarily, if performed soon after diagnosis. However, most T1DM patients transplanted with autologous HSCT eventually relapse (E Snarski et al., Bone marrow Transplantation; 2016; 51, 398-402). Thus, developing methodologies for allogeneic HSCT, to provide a durable non-autoimmune TCR repertoire, could be a promising treatment approach provided that such protocols can safely achieve donor type chimerism. Accordingly, transplantation of T cell-depleted allogeneic HSCT (TD-HSCT) under mild conditioning, associated with minimal toxicity and reduced risk of GVHD, offers an attractive therapeutic option. However, overcoming rejection after reduced conditioning in T1DM represents a major challenge. We previously demonstrated in wild type mice that rejection of TD-HSCT can be prevented using donor-derived veto cells. Here, we show proof of concept of the safety and efficacy of veto cell mediated non-myeloablative mismatched allogeneic TD-HSCT, in the established NOD mouse T1DM model. Veto activity, first defined by Miller (Miller, R. G; Nature; 1980; 287; 544-54), is based on the ability of specific cell populations to attack host CTL-precursors (CTLp) that are directed against the antigens presented by the veto cells themselves. This response spares cells that are not targeted against the veto cells, including those recognizing pathogens. Among different veto cell populations described in the literature, central memory CD8 T cells exhibit the most robust veto activity upon transplantation, but are also endowed with marked GvH activity. We overcame GvH reactivity by expanding naïve or memory CD8 T cells against 3rd party MHC or viral antigens, under culture conditions favoring expression of the central memory phenotype. Such anti-3rd party central memory CD8 T cells (Tcm) are endowed with marked veto activity, while effectively depleted of GVH reactivity in fully mis-matched recipients (Reviewed in Reisner Y, Or-Geva N. Semin. Hematol. 2019; 56(3): 173-182). In this study, Tcm veto cells were generated from splenocytes obtained from Balb/c donors (H2d) cultured against irradiated third-party splenocytes (FVB; H2q), under cytokine deprivation. The selective expansion of CD8 mouse T cells against 3rd party stimulators under these conditions leads to selective 'death by neglect' of bystander anti-host T cell clones that could mediate GvHD; such cells are further diluted out by subsequent expansion of anti-3rd party T clones during further culture in the presence of IL15. In addition to causing selective loss of GvH reactive T cells, these culture conditions induce a central memory phenotype shown to be crucial for robust veto activity in vivo. To evaluate the safety and efficacy of such a transplant for diabetes therapy, 8 week old NOD mice (before diabetes onset) were treated with 4.5 Gy TBI conditioning at day -1, anti-3rd party veto Tcm and megadose nude bone marrow (NuBM) on day 0, and Rapamycin treatment from day -1 to day +4 (Scheme 1). Controls were untreated or received conditioning with no transplant. In four independent experiments (n= 35 NOD mice in the transplanted group), high chimerism from 83.5% to 99.6 % was found in all transplanted mice at 6 months post-transplant. Notably, with a follow-up of 200 days, 72.4% mice in the untreated group, and 96% in the conditioned group died of diabetes, while only 8.5% diabetes-associated mortality (Fig.1A) and no GvHD or other transplant-related mortality was observed in the transplanted mice (Fig.1B). Our results demonstrate a proof of concept for the safety and efficacy of non-myeloablative allogeneic TD-HSCT in type 1 diabetes. A clinical protocol testing the safety and efficacy of anti-3rd party veto cells in the context of low toxicity non-myeloablative TD-HSCT in hematological malignancies is commencing at MD Anderson Cancer Center. If successful, our results support further extension of this platform to autoimmune diabetes and other autoimmune diseases. Disclosures Lustig: Yeda Ltd.: Patents & Royalties. Reisner:Cell Source, Inc.: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

Proof of Concept for Repair of Sickle Cell Disease By Non-Myeloablative MHC Disparate T Cell Depleted HSCT Combined with Donor-Derived Veto Cells

Although life extending medical treatments are available for sickle cell disease (SCD), allogenic hematopoietic stem cell transplantation (HSCT) is considered a treatment of choice (Ozdogu et al., Bone Marrow Transplant 2018; 53(7): 880-890). However, HSCT is associated with several limitations, including conditioning-related toxicity and graft-versus-host disease (GvHD), especially when using MHC disparate transplants. Thus, the development of safe transplantation protocols for MHC disparate HSCT in sickle cell disease is vital. While the risk of GvHD and conditioning toxicity can be effectively reduced by the use of T-cell-depleted HSCT (TD-HSCT) under reduced intensity conditioning (RIC), rejection of TD-HSCT remains a challenge. We previously demonstrated in wild type mice that this barrier can be overcome using donor-derived veto cells. Here, we demonstrate the safety and efficacy of this approach in a well-defined murine model for sickle cells disease. Veto activity is based on the ability of certain cells to attack host CTL-precursors (CTLp) which are directed against antigens expressed on the veto cells themselves, sparing cells that are not targeted against the veto cells including T cells needed for defense against pathogens. Central memory CD8 T cells exhibit the most robust veto activity upon transplantation; however, these cells are also endowed with marked GvH activity. We overcame this issue by expanding naïve or memory CD8 T cells against 3rd party MHC or viral antigens, respectively, under culture conditions favoring expression of central memory phenotype. Such anti-3rd party central memoryCD8 T cells (Tcm), which are endowed with marked veto activity, also exhibit reduced risk for GvHD in fully mis-matched recipients (Reviewed in Reisner Y, Or-Geva N. Semin Hematol. 2019; 56(3): 173-182.) To generate Tcm veto cells, splenocytes obtained from Balb/c donors (H2d) were cultured against irradiated third-party splenocytes (FVB; H2q) under cytokine deprivation. The selective expansion of CD8 mouse T cells against 3rd party stimulators leads to selective 'death by neglect' of bystander anti-host T cell clones potentialy mediating GvHD, and these are further diluted out by subsequent expansion of anti-3rd party T clones during continued culture in the presence of IL-15. Apart from selective loss of GvH reactive T cells, these culture conditions induce a central memory phenotype shown to be important for attaining robust veto activity in vivo (Ophir et al., Blood. 2013; 121(7): 1220-8). We first calibrated the optimal irradiation dose for sickle mice (Berkeley model, H2b), comparing 4.5 Gy versus 5 Gy TBI in a conditioning protocol also including short term rapmycin treatment (Scheme 1). Higher levels of engraftment and chimerism were found in the group receiving 5Gy TBI (Fig. 1). All mice of both treatment groups survived >140 days with no evidence of GvHD. To further evaluate this treatment approach, 8 week old sickle mice (N=7) were given bone marrow transplants using the protocol described in Scheme 1, including conditioning with 5 Gy TBI (day -1), rapamycin treatment (day -1 to day 4), and transplantation of NuBM (day 0) plus veto cells (day 7; Scheme 1). Notably, at 44 days post-transplant, 6 out of 7 mice receiving NuBM + TCM + Rapa (85.7%) showed donor chimerism in the peripheral blood, ranging between 77-94% (Fig.2A-B), while no chimerism was detected in mice receiving conditioning alone, or conditioning and transplantation with only NuBM or only veto cells . All mice in all groups survived (N=26) , and no GvHD was detected with a follow up of 77 days, even in the transplanted group which exhibited high donor-derived chimerism. Furthermore, reversal of sickle disease symptoms was observed, including reticulocyte levels (p=0.001;Fig.2C) and expression of wild type hemoglobin ( Fig.2D) in all engrafted mice. Our results offer a proof of concept for the treatment of sickle disease by MHC disparate non-myeloablative T cell depleted HSCT in conjunction with anti-3rd party central memory veto CD8 T cells. A clinical trial testing the safety and efficacy of anti-3rd party veto cells in the context of low toxicity non-myeloablative TD-HSCT in hematological malignancies is currently ongoing at MD Anderson Cancer Center. If successful, our present results support further evaluation of this platform for sickle cell disease. Disclosures Lustig: Yeda Ltd.: Patents & Royalties. Reisner:Cell Source, Inc.: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

T Cells Educated By DC/AML Fusions in the Context of 4-1BB Costimulation As a Potent Strategy for Adoptive Cellular Therapy

Introduction: Our group has developed a novel vaccine using patient-derived acute myeloid leukemia (AML) cells and autologous dendritic cells (DCs), capable of presenting a broad array of leukemia antigens. In a phase I/II clinical trial DC/AML vaccination led to an expansion of leukemia-specific T cells. We hypothesized that the fusion vaccine offered a unique platform for ex vivo expansion of functionally potent leukemia specific T cells with broad specificity targeting shared and tumor specific neoantigens. We postulated that incorporating 4-1BB (CD137) mediated co-stimulation would further enhance activation of antigen specific T cells and the development of a crucial memory response as well as promote survival and persistence. Here we describe therapeutic exploration of the use of 4-1BB to augment vaccine-educated T cells for adoptive cellular therapy in an immunocompetent murine model. Methods: DC/AML fusion vaccine was generated using DCs obtained from C57BL/6J mice and syngeneic C1498 AML cells as previously described. T cells were obtained from splenocytes after magnetic bead isolation and cultured with irradiated DC/AML fusion vaccine in the presence of IL-15 and IL-7. Following co-culture, 4-1BB positive T cells were ligated using agonistic 4-1BB antibody (3H3 clone, BioXCell) and further selected with RatIgG2a magnetic beads (Easy Sep). Subsequently T cells were expanded with anti-CD3/CD28 activation beads (Dynabeads). In vivo, mice underwent retro-orbital inoculation with C1498 and vaccination with irradiated fusion cells the following day. Agonistic mouse anti-4-1BB antibody was injected intraperitoneally on day 4 and day 7. In addition, C1498 cells were transduced with Mcherry/luciferase and a reproducible model of disease progression was established. Results: DC/fusion stimulated T cells showed increased immune activation as measured by multichannel flow cytometric analysis. Compared to unstimulated T cells, there was 5-fold increase in CD4+CD25+CD69+, and a 10-fold and 7-fold increase in 4-1BB and intracellular IFNƔ expression on CD8+ cells respectively. Following agonistic 4-1BB ligation and bead isolation, the proliferation rate was increased in the 4-1BB positive fraction as compared to both 4-1BB negative cells and unstimulated T cells. In addition, the 4-1BB positive fraction demonstrated increased cytotoxicity, as measured by a CTL assay detecting granzyme B with 1:10 tumor to effector cells. A shift from naïve to memory T cell phenotype was also observed. Following DC/fusion stimulation, CD44+CD62L- cells comprised 67% of CD8+ cells versus 20% without stimulation, the latter reflecting the effect of cytokines alone. Following 4-1BB ligation and anti-CD3/CD28 bead expansion, this phenotype was retained with the CD4+ and CD8+ effector memory and central memory compartments comprising the majority of T cells. Such findings are significant as presence of memory T cell populations are a critical component for successful adoptive cell transfer. The effect of agonistic 4-1BB antibody following vaccination was evaluated in vivo in an aggressive immunocompetent murine AML model. The combination of DC/AML fusion vaccine with 4-1BB antibody was associated with increased long-term survival (>120 days) of 40% versus 20% of mice treated with vaccine alone while all controls required euthanasia by 40 days. Conclusion: In the current study we have demonstrated the ability of DC/AML fusion vaccine to stimulate T cells ex-vivo as demonstrated by both early-activation (CD25,CD69), upregulation of antigen-specific markers (CD137) and cytokine secretion. Further enhancement of the cellular product using agonistic 4-1BB ligation and isolation simultaneously enriches for antigen-activated cells, as demonstrated by more potent cytotoxicity, as well as promoting memory phenotype and survival. Use of 4-1BB ligation for antigen-specific selection while providing an agonistic co-stimulatory signal is a potentially novel approach for development of non-engineered T cells. Ongoing experiments evaluating the efficacy of 4-1BB selected vaccine educated T cells using bioluminescence monitoring will be reported as well as in vitro use of patient-derived T cells. Disclosures Kufe: Canbas: Consultancy, Honoraria; Victa BioTherapeutics: Consultancy, Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genus Oncology: Equity Ownership; Hillstream BioPharma: Equity Ownership; Reata Pharmaceuticals: Consultancy, Equity Ownership, Honoraria; Nanogen Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Rosenblatt:Dava Oncology: Other: Education; Partner Tx: Other: Advisory Board; Parexel: Consultancy; Celgene: Research Funding; BMS: Research Funding; Amgen: Other: Advisory Board; Merck: Other: Advisory Board; BMS: Other: Advisory Board ; Imaging Endpoint: Consultancy. Avigan:Takeda: Consultancy; Parexel: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees; Partners Tx: Membership on an entity's Board of Directors or advisory committees; Partner Tx: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy.

PRDM1 Binds an Extensive Network of Genes to Regulate Human Natural Killer Cell Homeostasis

Natural killer (NK) cells are innate lymphocytes responsible for early defense against infections and malignant cells. Specific transcription factors crucial for NK cell development and function include PRDM1, which also regulates T cell homeostasis and is essential for the terminal differentiation of B cells into plasma cells. Importantly, PRDM1 deletion, methylation and loss-of-function mutations were commonly detected in NK cell malignancies. However, the detailed mechanisms through which PRDM1 regulates NK cell homeostasis are still largely undefined. Here, we employed an in vitro culture system of human NK cells isolated from healthy donors, in which the NK cells were cultured in the presence of IL-2 with or without an engineered feeder cell line, K562-Cl9-mb21, expressing membrane-bound IL-21, 4-1BBL and CD86. The NK cells were able to expand for months when co-cultured with feeder cells, whereas IL-2 alone could only maintain NK cell survival with limited proliferation for one week. We performed ChIP-seq to compare the genome-wide binding profiles of PRDM1 in NK cells grown with or without feeder cells. We found that PRDM1 bound much fewer target genes (802) in NK cells with feeder than in NK cells with IL-2 alone (2880), and 98.5% (790/802) of the binding sites in feeder-stimulated NK cells overlapped with those found in NK cells without feeder. The PRDM1 consensus motifs were almost identical in both conditions. MEME analyses also identified motifs of other transcription factors enriched in the PRDM1 binding sites, such as the RUNX and T-Box families. Interestingly, the RUNX and T-Box motifs, among others, were more enriched in the PRDM1 binding sites lacking the PRDM1 motif than in those with the PRDM1 motif, which indicates that PRDM1 may often bind to DNA indirectly through other transcription factors. PRDM1 bound a large number of genes in the NK or T cell receptor signaling pathway, which are employed during NK cell activation. In addition, several genes encoding immune checkpoints that may restrict NK cell activation such as TIGIT, HAVCR2 (TIM3), and IL-1R8 were targeted by PRDM1. Many genes encoding NK cell inhibitory and activating receptors were also bound by PRDM1. Moreover, PRDM1 was found to target transcription factors that are important for NK cell development and homeostasis, such as the RUNX family, TBX21, MAF, and PRDM1 itself. Despite an extensive overlap of PRDM1 binding sites detected in NK cells grown with or without feeder cells, the most enriched pathways were not exactly the same. Importantly, our RNA-seq data on PRDM1-knockout NK cells validated the regulatory role of PRDM1 on a fraction of these PRDM1-bound genes and interestingly, PRDM1 appeared to be an activator for some of the genes, including those encoding immune checkpoint molecules TIGIT, HAVCR2, and IL-1R8. We also utilized ATAC-seq to examine the chromatin accessibility of NK cells grown with feeder cells or with IL-2 alone. We identified differentially enriched pathways for the NK cells cultured under different conditions. When compared with the PRDM1 ChIP-seq, we found that those PRDM1 binding sites that contain a consensus PRDM1 motif were less likely to be accessible to transposase than those without the PRDM1 motif, thereby confirming the transcriptional repressor role of PRDM1. To further understand how PRDM1 regulates its target genes in NK cells, we performed mass spectrometric analysis on the protein complexes associated with PRDM1. We were able to identify the interaction of PRDM1 with the corepressor Groucho (TLE3) and components from the SIN3, NCoR, and NuRD complex, which have been previously reported in mouse plasma cells. Surprisingly, the protein compositions of the PRDM1-associated complexes from the two NK cell populations were very different. Although PRDM1 is generally associated with transcriptional repression, we also detected the association of PRDM1 with transcriptional activators or coactivators, such as the RUNX-binding protein CBFβ and the T-Box family member EOMES, which may thereby upregulate some of the PRDM1 target genes. In summary, we found that PRDM1 binds and regulates an extensive network of genes responsible for NK cell activation and function. Extrinsic stimuli, as provided by the feeder cells, can alter the extent and profile of PRDM1 binding as well as the associated protein complexes and hence alter its regulatory function in NK cells. Disclosures No relevant conflicts of interest to declare.

Microrna-31 Regulates T-Cell Metabolism Via HIF1α and Promotes Effector Function

MicroRNAs (miRs) repress gene expression at the post-transcriptional level via binding target mRNAs subsequently promoting mRNA degradation or impeding translation. Certain miRs influence the survival, differentiation, and function of T cells in cancer, infections, and autoimmunity. Uncontrolled T-cell allogeneic responses contribute to chronic graft-versus-host disease (cGVHD), a major cause of non-relapse mortality following allogeneic hematopoietic stem-cell transplantation (allo-HCT). Dysregulation of miR-31 is implicated in cancer, but how miR-31 impacts allogeneic T-cell response is unclear. Using oligonucleotide array, we found miR-31 was dramatically up-regulated in T cells under alloantigen-driven vs. homeostatic proliferation in recipient mice following bone marrow transplantation (BMT) (Figure 1A-B). To understand how miR-31 regulates T-cell responses to alloantigens, we utilized murine models of allogeneic BMT and donor mice with miR-31 conditional knock-out on their T cells. In a sclerodermatous cGVHD model (B6→BDF1), we observed that the recipients transferred with donor T cells deficient for miR-31 exhibited significantly alleviated disease (Figure 1C), reflected by attenuated fibrosis and pathologic damage in skin. In a bronchiolitis obliterans cGVHD model (B6→B10.BR), we found that the recipients of miR-31-deficient T cells had reduced airway resistance, elastance (Figure 1D) and pathological damage in the lungs as compared with those of WT T cells. The role of miR-31 in promoting T-cell pathogenicity was further confirmed when miR-31 was inhibited by administration of specific antagomir (locked nuclear acid anti-miR-31). We used mass cytometry to analyze donor immune cell reconstitution in recipient spleens after BMT. Consistent with attenuated disease manifestation, the recipients of miR-31-deficient T cells displayed improved reconstitution of donor T- and B- lymphocytes. The follicular T helper cells (TFH) instruct germinal center (GC) B-cell expansion, affinity maturation, and plasma cell differentiation, whereas follicular regulatory T cells (TFR) inhibit TFH -mediated B-cell activation and antibody production. We found that miR-31 deficient T cells differentiated into more TFR, but fewer TFH during alloresponses. As a result, the differentiation and activation of GC B cells and the generation of plasma cells were attenuated in the recipients of miR-31-deficient T cells. Furthermore, miR-31-deficient T cells exhibited defects in proliferation and survival in allogeneic recipients, resulting in fewer donor T cells in recipient thymus, skin and lungs. In the absence of miR-31, T cells differentiated less into Th17 cells but more towards Tregs (Figure 1E) in vivo. Those miR-31-deficient Tregs expressed higher levels of Neuropilin 1 and PD-L1, the markers associated with superior stability and suppressive function of Tregs. While miR-31 played little role on Th1 cell differentiation, it facilitated alloantigen-reactive iTregs losing Foxp3 and producing IFNγ after being transferred into allogeneic recipients. Hypoxia, a hallmark of inflamed and damaged tissue, can drive fibrosis and disease development through immune cell dysregulation. Upon activation, T cells rapidly increase their metabolic rate and switch from oxidative phosphorylation to aerobic glycolysis. We found that miR-31-deficient T cells exhibited reduced hypoxia-inducible factor 1α (HIF1α) signaling (glycolysis promotor), surface GLUT1 expression, and glucose uptake, but increased lipid droplet accumulation in allogeneic recipients, suggesting that miR-31 promotes metabolic switch from fatty acid β-oxidation to aerobic glycolysis in allo-reactive T cells (Figure 1F). Furthermore, under hypoxia (3% oxygen) but not normoxia (21% oxygen) conditions, miR-31 increased Th17 but decreased iTreg differentiation from naïve CD4 T cells in the presence of IL-6 and TGFβ in vitro. Taken together, miR-31 regulates T-cell expansion, differentiation, and metabolism via promoting HIF1α expression and hypoxia adaptation in allo-reactive T cells, which enhances T-cell effector function and pathogenicity after allogeneic BMT. Disclosures No relevant conflicts of interest to declare.

Ruxolitinib Reverses Checkpoint Inhibition By Downregulating PD-L1 and PD-L2 Expression on Both Tumor and Stromal Cells in Multiple Myeloma

Introduction: Multiple myeloma (MM) tumor cells evade host immunity through the interaction of PD-L1 and PD-L2 to PD-1 on T-cells. This creates an immunosuppressive milieu in the bone marrow (BM) microenvironment. The immune inhibitory proteins PD-L1 and PD-L2 are highly expressed in MM BM. Moreover, increased expression of these proteins are associated with resistance to treatment in MM. Ruxolitinib (RUX) is a JAK1/2 inhibitor that is effective for the treatment of myeloproliferative diseases. In this study, we examined PD-L1 and PD-L2 gene and protein expression in the BM of MM patients with progressive disease (PD) or in complete remission (CR). We further investigated the effects of RUX on expression of PD-L1 and PD-L2 in MMBM, and the effect of RUX in combination with anti-MM agents in vitro and in vivo. Material and Methods: BM mononuclear cells (MCs) and serum were collected from MM patients and healthy subjects after obtaining IRB approval. Single-cell suspensions were prepared from human MM LAGκ-1A xenografts which had been grown in the mice. The cells were cultured and treated with or without RUX and then were determined by qPCR, flow cytometric analysis, ELISA, and western blot. Results and Discussion: The results from qPCR and flow cytometric assays showed that PD-L1 and PD-L2 gene expression was markedly increased in BMMCs from MM patients with PD compared with patients in CR or with healthy controls. We further investigated the effects of RUX on PD-L1 and PD-L2 expression in primary and stromal cells from MM patients' BM samples in vitro. RUX treatment markedly reduced PD-L1and PD-L2 gene and protein expression in the MM tumor cells cultured alone or co-cultured with stromal cells in a concentration dependent pattern. We then determined whether RUX can augment the anti-MM effects of T-cells in vitro. RUX (0, 0.1, 0.5, 1, and 5 µM) increased MM cell apoptosis in the presence of IL-2 stimulated T-cells in a concentration dependent fashion, to a similar degree to anti-PD-1 (0, 0.5, 1, 5, and 10 µg/ml) or anti-PD-L1 (0, 0.5, 1, 5, and 10 µg/ml) antibody treatment. Moreover, the combination of RUX with anti-PD-1 or anti-PD-L1 antibody increased T-cell-induced MM cell apoptosis more than the agents alone. To evaluate the efficacy of drugs in vivo, severe combined immune deficient mice implanted with the human MM xenograft LAGκ-2 were treated with RUX (30mg/kg). The results showed PD-L1 expression in the xenograft was significantly decreased in RUX-treated mice compared with the untreated control group. In contrast, RUX had no effect on PD-1 expression on T-cells. Conclusion: The PD-L1/PD-1 pathway delivers inhibitory signals that regulate both peripheral and central tolerance, and inhibit anti-tumor immune-mediated responses. This study demonstrated that the JAK inhibitor RUX downregulated PD-L1 and PD-L2 expression in both MM tumor and stromal cells. We also demonstrated that RUX alone increased T-cell-induced apoptosis of MM cells; and, moreover, the combination of RUX with anti-PD-1 and anti-PD-L1 further increased apoptosis. The results suggest that JAK inhibitors may be effective for treating MM patients through their ability to reduce expression of checkpoint proteins involved in the development of immune resistance. Thus, JAK inhibitors should help overcome the immune resistance generated by these proteins for patients with this B-cell malignancy. Disclosures Chen: Oncotraker Inc: Equity Ownership. Berenson:Amgen: Consultancy, Speakers Bureau; Sanofi: Consultancy; Takeda: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Incyte Corporation.: Consultancy, Research Funding; Sanofi: Consultancy; Amag: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; OncoTracker: Equity Ownership, Other: Officer; Incyte Corporation.: Consultancy, Research Funding; Janssen: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Honoraria, Research Funding; Amag: Consultancy, Speakers Bureau.

A method for the generation of large numbers of dendritic cells from CD34+ hematopoietic stem cells from cord blood

Dendritic cells (DCs) play a central role in regulating innate and adaptive immune responses. It is well accepted that their regulatory functions change over the life course. In order to study DCs function during early life it is important to characterize the function of neonatal DCs. However, the availability of neonatal DCs is limited due to ethical reasons or relative small samples of cord blood making it difficult to perform large-scale experiments. Our aim was to establish a robust protocol for the generation of neonatal DCs from cord blood derived CD34+ hematopoietic stem cells. For the expansion of DC precursor cells we used a cytokine cocktail containing Flt-3 L, SCF, TPO, IL-3 and IL-6. The presence of IL-3 and IL-6 in the first 2 weeks of expansion culture was essential for the proliferation of DC precursor cells expressing CD14. After 4 weeks in culture, CD14+ precursor cells were selected and functional DCs were generated in the presence of GM-CSF and IL-4. Neonatal DCs were then stimulated with Poly(I:C) and LPS to mimic viral or bacterial infections, respectively. Poly(I:C) induced a higher expression of the maturation markers CD80, CD86 and CD40 compared to LPS. In line with literature data using cord blood DCs, our Poly(I:C) matured neonatal DCs cells showed a higher release of IL-12p70 compared to LPS matured neonatal DCs. Additionally, we demonstrated a higher release of IFN-γ, TNF-α, IL-1β and IL-6, but lower release of IL-10 in Poly(I:C) matured compared to LPS matured neonatal DCs derived from cord blood CD34+ hematopoietic stem cells. In summary, we established a robust protocol for the generation of large numbers of functional neonatal DCs. In line with previous studies, we showed that neonatal DCs generated form CD34+ cord blood progenitors have a higher inflammatory potential when exposed to viral than bacterial related stimuli.

326P - Autologous V gamma 9 V delta 2 T cell therapy to target Epstein Barr Virus (EBV)-related malignancies

BackgroundAnalysis of ∼18,000 human tumors across 39 cancers identified tumor infiltrating γδ T cells as the most favorable prognostic immune population. Sharing both innate and adaptive immune properties, γδ T cells are an attractive candidate for direct adoptive cellular therapy as well as utilizing their professional antigen presenting cell (APC) property for ex vivo expansion of antigen-specific CD4+and CD8+ T cells for subsequent adoptive cellular therapy. MethodsHere, we report a Good Manufacturing Method (GMP) expansion protocol of Vγ9Vδ2 T cells from human PBMCs and its functional and transcriptomic characterization. ResultsFollowing cytokine optimization experiments, we found that some combinations of IL-2, IL-15 and IL-21 led to optimal antigen presentation and effector functions. γδ T cells produced in the presence of IL-2 alone or in combination with other cytokines showed increased APC markers compared to IL-15 combinations. In vitro, EBV-LMP2 peptide-pulsed γδ T cells primed a more robust naïve CD3+ T cell proliferation than monocyte-derived Dendritic Cells (moDC). Importantly, EBV-LMP2 peptide-pulsed γδ T cells stimulated less T regulatory cells and exhausted CD8+ and CD4+ T cells compared to moDCs.Through gene expression profiling, we demonstrated that γδ T cells express enhanced levels of markers of cross presentation pathway compared to moDCs which may explain the cross presentation phenotype. Finally, we demonstrated the potential of EBV-LMP2 peptide-pulsed Vγ9Vδ2 T cells as a therapeutic cancer vaccine in an autologous EBV-lymphoblastoid cell line tumor model in vivo. This therapeutic intervention resulted in increased tumor infiltration of gd, CD8+ and CD4+ T cells and improved control of primary tumor growth and metastasis of EBV LCLs tumor model in vivo. ConclusionsIn summary, we demonstrated in our pre-clinical study γδ T cell APC and effector functions in vitro and in vivo, indicating the potential of γδ T cells as therapeutic immunotherapy against EBV-positive cancers. Legal entity responsible for the studyThe authors. FundingTessa Therapeutics. DisclosureP.W.-W. Wang: Advisory / Consultancy: Tessa Therapeutics. H.C. Toh: Leadership role, Travel / Accommodation / Expenses, Shareholder / Stockholder / Stock options: Tessa Therapeutics. All other authors have declared no conflicts of interest.

Dichotomous role of TGF-β controls inducible regulatory T-cell fate in allergic airway disease through Smad3 and TGF-β–activated kinase 1

Inducible CD4+CD25+ regulatory T (iTreg) cells can become pathogenic effector cells, enhancing lung allergic responses. We aimed to define the underlying cellular and molecular pathways activated by TGF-β, which determine the suppressor or enhancing activities of iTreg cells. Sensitized wild-type and CD8-deficient (CD8-/-) mice were challenged with allergen. Isolated CD4+CD25- T cells were activated by using anti-CD3/anti-CD28. To generate suppressor iTreg cells, cells were then differentiated in the presence of TGF-β, whereas IL-17-producing effector T cells were additionally exposed to IL-6. After TGF-β, Smad3 and TGF-β-activated kinase 1 (TAK1) kinase levels were monitored. The consequences of inhibiting either kinase were determined invitro and after transfer into CD8-/- recipients. Quantitative PCR and chromatin immunoprecipitation were used to monitor gene expression and histone modifications at the retinoic acid-related orphan receptor γt (Rorγt) locus. In wild-type mice, iTreg cells suppressed lung allergic responses linked to Smad3-dependent forkhead box P3 (Foxp3) expression and IL-10 production. In the presence of IL-6, iTreg cells converted to TH17 cells, mediating a neutrophil-dependent enhancement of lung allergic responses in CD8-/- mice. Conversion was regulated by TAK1. Inhibition or silencing of TAK1 prevented expression of Rorγt and TH17 differentiation through histone modifications of Rorγt; Foxp3 expression and iTreg cell-mediated suppression remained intact. In the same cell, TGF-β induced coexpression of Smad3 and TAK1 proteins; in the presence of IL-6, expression of Smad3 and Foxp3 but not TAK1 decreased. TGF-β regulates iTreg cell outcomes through 2 distinct signal transduction pathways: one Smad3 dependent and the other TAK1 dependent. The balance of these pathways has important implications in TH17-mediated autoimmune diseases and neutrophil-dependent asthma.

Dynamic Imprinting of the Treg Cell-Specific Epigenetic Signature in Developing Thymic Regulatory T Cells.

Regulatory T (Treg) cells mainly develop within the thymus and arise from CD25+Foxp3− (CD25+ TregP) or CD25−Foxp3+ (Foxp3+ TregP) Treg cell precursors resulting in Treg cells harboring distinct transcriptomic profiles and complementary T cell receptor repertoires. The stable and long-term expression of Foxp3 in Treg cells and their stable suppressive phenotype are controlled by the demethylation of Treg cell-specific epigenetic signature genes including an evolutionarily conserved CpG-rich element within the Foxp3 locus, the Treg-specific demethylated region (TSDR). Here we analyzed the dynamics of the imprinting of the Treg cell-specific epigenetic signature genes in thymic Treg cells. We could demonstrate that CD25+Foxp3+ Treg cells show a progressive demethylation of most signature genes during maturation within the thymus. Interestingly, a partial demethylation of several Treg cell-specific epigenetic signature genes was already observed in Foxp3+ TregP but not in CD25+ TregP. Furthermore, Foxp3+ TregP were very transient in nature and arose at a more mature developmental stage when compared to CD25+ TregP. When the two Treg cell precursors were cultured in presence of IL-2, a factor known to be critical for thymic Treg cell development, we observed a major impact of IL-2 on the demethylation of the TSDR with a more pronounced effect on Foxp3+ TregP. Together, these results suggest that the establishment of the Treg cell-specific hypomethylation pattern is a continuous process throughout thymic Treg cell development and that the two known Treg cell precursors display distinct dynamics for the imprinting of the Treg cell-specific epigenetic signature genes.

Differential Modulation of Human Innate Lymphoid Cell (ILC) Subsets by IL-10 and TGF-\u03b2

Using multiparameter flow cytometry human innate lymphoid cell (ILC) subsets can be detected in the circulation, in relatively low frequencies. Despite the low frequency of ILCs in circulation, ex vivo experiments have demonstrated that these ILCs release extremely large per cell quantities of signature ILC cytokines following activation. To determine how activated ILC cytokine production is regulated, ILC subsets were activated in the presence or absence of the immunoregulatory cytokines IL-10 and TGF-β. An examination of circulating ILC subsets revealed surface expression of IL-10Rα and mRNA expression of both IL-10Rα and TGF-βR1 for all ILC subsets. Stimulated ILC1 production of IFN-γ was decreased by TGF-β and not IL-10. Interestingly, ILC2s stimulated in the presence of IL-10 had a marked reduction in cytokine production of IL-5 and IL-13 while TGF-β had no effect on ILC2 cytokine production. Ex vivo activated ILC1 and ILC2 subsets were also found to be a source of the immunoregulatory cytokine IL-10, raising the potential for ILC-mediated regulation of immune cells. These findings demonstrate the differential effects of immunoregulatory cytokines IL-10 and TGF-β on activated ILC1 and ILC2 populations ex vivo.

1184PD - Results of a phase I trial with MART-1 T cell receptor modified T cells in patients with metastatic melanoma

BackgroundAdoptive cell therapy (ACT) with T cell receptor (TCR) gene modified peripheral blood T cells creates large pools of tumor reactive T cells. Based on preclinical validation we have selected a high affinity MART-1-specific TCR for TCR gene therapy in metastatic melanoma (MM). Utilizing a novel GMP production protocol we performed a phase I trial to asses feasibility, safety and efficacy of TCR gene therapy in pts with MM. MethodsHLA-A2*0201+ pts with irresectable stage IIIc/IV melanoma, expressing MART-1 and MHC class I, with no standard treatment options were included. Autologous T cells were isolated via apheresis and transduced with a MP-71 retroviral vector encoding the 1D3HMCys MART-1 TCR and expanded ex vivo in presence of IL-7 and IL-15. Non-myeloablative chemotherapy was given prior to one i.v. infusion of MART-1 TCR transduced T cells in a dose escalating manner after evaluation of adverse events (AEs). Feasibility, safety (CTCAE 4.0) and ORR (RECIST 1.1) were assessed. ResultsTwelve heavily pretreated metastatic cutaneous (n=7) and uveal (n=5) melanoma (mUM) pts were treated with MART-1 TCR transduced T cells across 4 dose cohorts. Transduction efficiency was 42-76%. Viability of the cell product was 92.9-98.5%. Pt 1 received 4.56x109 MART-1 TCR transduced T cells but died 9 days post infusion due to multiple organ failure. Subsequent pts received 5x107 (n=3; cohort (c) 2), 25x107 (n=2; c3) and 10x107 (n=6; c4) cells. On-target AEs were dose-dependent and included dermatitis (10/11) max grade 3, uveitis (3/11) max grade 2 and ototoxicity (4/11) max grade 3, highest in cohort 3. Four pts (n=2 c3; n=2 c4) showed signs of cytokine release syndrome and 3 pts required tocilizumab. Objective PR by RECIST 1.1 was seen in 2 pts (17%), with a DOR of 4.2 (mUM, c4) and 8.4 (c3) months. Persistence of transduced T cells in peripheral blood was correlated with infused cell dose. ConclusionsTreatment with MART-1 TCR transduced peripheral blood T cells expanded in presence of IL-7 and IL-15 led to severe dose-dependent toxicity with a maximum tolerated dose of 10x107 transduced cells. Despite observed responses, toxicity limited further development and use of this MART-1 TCR cellular therapy in MM patients. NCT02654821. Clinical trial identificationNCT02654821. Legal entity responsible for the studyNetherlands Cancer Institute/Antoni van Leeuwenhoek hospital (NKI-AVL). FundingKWF Kankerbestrijding. DisclosureJ.H. Beijnen: Shareholder / Stockholder / Stock options, Full / Part-time employment: Modra Pharmaceuticals BV . J.V. van Thienen: Honoraria (institution), Advisory / Consultancy: Pfizer ; Honoraria (institution), Advisory / Consultancy: Novartis. C.U. Blank: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): BMS; Honoraria (self), Advisory / Consultancy: MSD; Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: GSK; Honoraria (self), Advisory / Consultancy: GenMab; Honoraria (self), Advisory / Consultancy: Pierre Fabre ; Research grant / Funding (institution): NanoString. T.N. Schumacher: Advisory / Consultancy: Adaptive Biotechnologies; Advisory / Consultancy, Shareholder / Stockholder / Stock options: AIMM Therapeutics; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Allogene Therapeutics; Advisory / Consultancy: Amgen; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Merus; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Neon Therapeutics; Advisory / Consultancy: Scenic Biotech; Advisory / Consultancy: Third Rock Ventures; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Bristol-Myers Squibb; Research grant / Funding (institution): Merck KGaA; Shareholder / Stockholder / Stock options: Neogene Therapeutics; Shareholder / Stockholder / Stock options: Scenic Biotech. J.B.A.G. Haanen: Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): BMS; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): MSD; Honoraria (institution), Advisory / Consultancy: Pfizer; Honoraria (institution), Advisory / Consultancy: AZ/MedImmune; Honoraria (institution), Advisory / Consultancy: Roche/Genentech; Honoraria (institution), Advisory / Consultancy: Ipsen; Honoraria (institution), Advisory / Consultancy: Bayer; Honoraria (institution), Advisory / Consultancy: Immunocore; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (institution), Advisory / Consultancy: Seattle Genetics; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Neon Therapeutics; Honoraria (institution), Advisory / Consultancy: Celsius Therapeutics; Honoraria (institution), Advisory / Consultancy: Gadet ; Honoraria (institution), Advisory / Consultancy: GSK. All other authors have declared no conflicts of interest.

NMAAP1 Maintains M1 Phenotype in Macrophages Through Binding to IP3R and Activating Calcium-related Signaling Pathways.

NMAAP1 plays a role in regulating macrophage differentiation to the M1 type and exerting antitumoral functions. It is not clear what role and mechanism NMAAP1 does play in the reversal of macrophages from M1 to M2. We detected the typing of macrophages with high or low expression of NMAAP1 by QPCR and ELISA, and detected the colocalization of NMAAP1 and endogenous IP3R by laser confocal microscopy, and detected the protein expression in cells by Western-blotting. Our study found that knockdown NMAAP1 in RAW264.7 cells induced macrophage polarization to the M2 type and up-regulation of NMAAP1 in RAW264.7 cells maintain M1 Phenotype even in the presence of IL-4, a stronger inducer of the M2 type. Additionally, Coimmunoprecipitation revealed a protein-protein interaction between NMAAP1 and IP3R and then activates key molecules in the PKC-dependent Raf/MEK/ERK and Ca2+/CaM/CaMKII signaling pathways. Activation of PKC (Thr638/641), ERK1/2 (Thr202/Tyr204) and CaMKII (Thr286) is involved in the regulation of cell differentiation. NMAAP1 interacts with IP3R, which in turn activates the PKC-dependent Raf/MEK/ERK and Ca2+/CaM/CaMKII signaling pathways. These results provide a new explanation of the mechanism underlying M1 differentiation.

Interleukin-10 production by B cells is regulated by cytokines, but independently of GATA-3 or FoxP3 expression

The knowledge of mechanisms of regulation of IL-10 production by B cells remains still very limited. We show here that highly purified mouse B cells stimulated with LPS produce significant levels of IL-10, but Bregs in our model do not express detectable level of either Foxp3 or GATA-3. Nevertheless, IL-10 production by B cells is regulated by cytokines. In activated B cells, IL-10 production was significantly enhanced by IFN-γ and decreased in the presence of IL-4 or TGF-β. These findings are in sharp contrast with the observations in T cells, where IL-10 production correlates with GATA-3 or FoxP3 expression, and the cytokines regulate IL-10 production in a reverse manner than in activated B cells. These results thus show that the production of IL-10 by Bregs is regulated by cytokines independently of the expression of GATA-3 and FoxP3, which is clearly different from GATA-3-dependent IL-10 production by activated Th2 cells and FoxP3 expression in IL-10-producing Tregs.

Interleukin-6 selectively induces drug metabolism to potentiate the genotoxicity of dietary carcinogens in mammary cells

Breast cancer is the most commonly diagnosed malignancy in females, the etiology being multifactorial and includes the role of lifestyle exposure to DNA-damaging chemicals such as dietary carcinogens benzo (a) pyrene (BaP) and 2-amino-1-methyl-6-phenylimidazo [4, 5-b] pyridine (PhIP). Both compounds require cytochrome P450 (CYP)-mediated metabolic activation to DNA-damaging species, and both induce transcriptional responses through the nuclear receptors Aryl hydrocarbon receptor (AhR) and estrogen receptor α (ERα). BaP and PhIP are mammary carcinogens in rodents. Clinically, circulating IL-6 expression is linked with poor prognosis of cancer and 35% of the deaths in breast cancer are linked with inflammation. The objective of this work was to investigate the molecular toxicology and local activation of BaP and PhIP in the presence of IL-6. Our laboratory has previously reported that miR27b can regulate CYP1B1 expression in colorectal cells, here we have investigated if this mechanism is working in mammary cell models, MCF-7 and MDA-MB-231 cells. Treatment (24 h) of cells with BaP (10 nM-10 µM) and PhIP (100 nM-100 µM) significantly induced genetic damage (micronuclei formation) in a dose-dependent manner in both cell lines. This effect was potentiated in the presence of human IL-6 at concentrations reported to be expressed in clinical breast cancer. On its own, IL-6 treatment failed to induce micronuclei frequency above the control levels in these cells. Compared to BaP or PhIP treatment alone, IL-6 plus BaP or PhIP selectively induced CYP1B1 significantly in both cell lines. Additionally, miR27b expression was downregulated by IL-6 treatments and transfection with miR27b inhibitor confirmed that miR27b is a regulator of CYP1B1 in both cell lines. These data show that BaP- and PhIP-induced DNA damage in mammary cells is potentiated by the inflammatory cytokine IL-6 and that inflammation-induced CYP expression, specifically CYP1B1 via miR27b, is responsible for this effect.

Characterization of dendritic cell (DC)-10 in recurrent miscarriage and recurrent implantation failure.

During pregnancy, the maternal immune system must tolerate the persistence of semi-allogeneic fetus in the maternal tissue. Inadequate recognition of fetal antigens may lead to pregnancy complications, such as recurrent miscarriage (RM) and recurrent implantation failure (RIF). Dendritic cells (DCs) are key regulators of protective immune responses and the development and maintenance of tolerance. Regarding that DCs are important in the establishment of immune tolerance in human pregnancy, it would be important to study the microenvironment in which DCs reside or are activated may affect their functions toward tolerance rather than active immune response. IL-10 plays a critical role in the maintenance of normal pregnancy, and the increased production of IL-10 is associated with successful pregnancy. In this study, we provide an in-depth comparison of the phenotype and cytokine production by DC-10 and other DC subsets, such as iDC and mDC. CD14+ monocyte-derived DCs were differentiated in the presence of IL-10 (DC-10) in vitro from ten normal fertile controls, six RM women and seven RIF women, and characterized for relevant markers. DC-10 was characterized by relatively low expression of costimulatory molecule CD86, as well as MHC class II molecule HLA-DR, high expression of tolerance molecules HLA-G, ILT2, ILT4 and immunosuppressive cytokine IL-10, but produced little or no proinflammatory cytokines, such as TNF-α, IL-6 and IL-12p70. Our study provides a better understanding of the phenotypical properties of DC-10, which may participate in the complex orchestration that leads to maternal immune tolerance and homeostatic environment in human pregnancy.

Cytokine Profile in Patients with Aseptic Loosening of Total Hip Replacements and Its Relation to Metal Release and Metal Allergy.

Metal release from total hip replacements (THRs) is associated with aseptic loosening (AL). It has been proposed that the underlying immunological response is caused by a delayed type IV hypersensitivity-like reaction to metals, i.e., metal allergy. The purpose of this study was to investigate the immunological response in patients with AL in relation to metal release and the prevalence of metal allergy. THR patients undergoing revision surgery due to AL or mechanical implant failures were included in the study along with a control group consisting of primary THR patients. Comprehensive cytokine analyses were performed on serum and periimplant tissue samples along with metal analysis using inductive coupled plasma mass spectrometry (ICP-MS). Patient patch testing was done with a series of metals related to orthopedic implant. A distinct cytokine profile was found in the periimplant tissue of patients with AL. Significantly increased levels of the proinflammatory cytokines IL-1β, IL-2, IL-8, IFN-γ and TNF-α, but also the anti-inflammatory IL-10 were detected. A general increase of metal concentrations in the periimplant tissue was observed in both revision groups, while Cr was significantly increased in patient serum with AL. No difference in the prevalence of metal sensitivity was established by patch testing. Increased levels of IL-1β, IL-8, and TNF-α point to an innate immune response. However, the presence of IL-2 and IFN-γ indicates additional involvement of T cell-mediated response in patients with AL, although this could not be detected by patch testing.