Cytokine-producing CD4 Research Articles

CD8+ T Cell Immunity Is Compromised by Anti-CD20 Treatment and Rescued by Interleukin-17A.

Treatment with anti-CD20, used in many diseases in which B cells play a pathogenic role, has been associated with susceptibility to intracellular infections. Here, we studied the effect of anti-CD20 injection on CD8+ T cell immunity using an experimental model of Trypanosoma cruzi infection, in which CD8+ T cells play a pivotal role. C57BL/6 mice were treated with anti-CD20 for B cell depletion prior to T. cruzi infection. Infected anti-CD20-treated mice exhibited a CD8+ T cell response with a conserved expansion phase followed by an early contraction, resulting in a strong reduction in total and parasite-specific CD8+ T cell numbers at 20 days postinfection. Anti-CD20 injection increased the frequency of apoptotic CD8+ T cells, decreased the number of effector and memory CD8+ T cells, and reduced the frequency of proliferating and cytokine-producing CD8+ T cells. Accordingly, infected anti-CD20-treated mice presented lower cytotoxicity of T. cruzi peptide-pulsed target cells in vivo All of these alterations in CD8+ T cell immunity were associated with increased tissue parasitism. Anti-CD20 injection also dampened the CD8+ T cell response, when this had already been generated, indicating that B cells were involved in the maintenance rather than the induction of CD8+ T cell immunity. Anti-CD20 injection also resulted in a marked reduction in the frequency of interleukin-6 (IL-6)- and IL-17A-producing cells, and recombinant IL-17A (rIL-17A) injection partially restored the CD8+ T cell response in infected anti-CD20-treated mice. Thus, anti-CD20 reduced CD8+ T cell immunity, and IL-17A is a candidate for rescuing deficient responses either directly or indirectly.IMPORTANCE Monoclonal antibody targeting the CD20 antigen on B cells is used to treat the majority of non-Hodgkin lymphoma patients and some autoimmune disorders. This therapy generates adverse effects, notably opportunistic infections and activation of viruses from latency. Here, using the infection murine model with the intracellular parasite Trypanosoma cruzi, we report that anti-CD20 treatment affects not only B cell responses but also CD8+ T cell responses, representing the most important immune effectors involved in control of intracellular pathogens. Anti-CD20 treatment, directly or indirectly, affects cytotoxic T cell number and function, and this deficient response was rescued by the cytokine IL-17A. The identification of IL-17A as the cytokine capable of reversing the poor response of CD8+ T cells provides information about a potential therapeutic treatment aimed at enhancing defective immunity induced by B cell depletion.

Homologous prime-boost with Zika virus envelope protein and poly (I:C) induces robust specific humoral and cellular immune responses

The recent outbreaks of Zika virus (ZIKV) infection and the potential association with Guillain-Barré syndrome in adults and with congenital abnormalities have highlighted the urgency for an effective vaccine. The ZIKV Envelope glycoprotein (EZIKV) is the most abundant protein on the virus surface, and has been evaluated together with the pre-membrane protein (prM) of the viral coat as a vaccine candidate in clinical trials. In this study, we performed a head-to-head comparison of the immune response induced by different EZIKV-based vaccine candidates in mice. We compared different platforms (DNA, recombinant protein), adjuvants (poly (I:C), CpG ODN 1826) and immunization strategies (homologous, heterologous).The hierarchy of adjuvant potency showed that poly (I:C) was a superior adjuvant than CpG ODN. While poly (I:C) assisted immunization reached a plateau in antibody titers after two doses, the CpG ODN group required an extra immunization dose. Besides, the administration of poly (I:C) induced higher EZIKV-specific cellular immune responses than CpG ODN. We also show that immunization with homologous prime-boost EZIKV protein + poly (I:C) regimen induced a more robust humoral response than homologous DNA (pVAX-EZIKV) or heterologous regimens (DNA/protein or protein/DNA). A detailed analysis of cellular immune responses revealed that homologous (EZIKV + poly (I:C)) and heterologous (pVAX-EZIKV/EZIKV + poly (I:C)) prime-boost regimens induced the highest magnitude of IFN-γ secreting cells and cytokine-producing CD4+ T cells.Overall, our data demonstrate that homologous EZIKV + poly (I:C) prime-boost immunization is sufficient to induce more robust specific-EZIKV humoral and cellular immune responses than the other strategies that contemplate homologous DNA (pVAX-EZIKV) or heterologous (pVAX-EZIKV/EZIKV + poly (I:C), and vice-versa) immunizations.

Immune Phenotype and Functionality of Mtb-Specific T-Cells in HIV/TB Co-Infected Patients on Antiretroviral Treatment.

The performance of host blood-based biomarkers for tuberculosis (TB) in HIV-infected patients on antiretroviral therapy (ART) has not been fully assessed. We evaluated the immune phenotype and functionality of antigen-specific T-cell responses in HIV positive (+) participants with TB (n = 12) compared to HIV negative (−) participants with either TB (n = 9) or latent TB infection (LTBI) (n = 9). We show that the cytokine profile of Mtb-specific CD4+ T-cells in participants with TB, regardless of HIV status, was predominantly single IFN-γ or dual IFN-γ/ TNFα. Whilst ESAT-6/CFP-10 responding T-cells were predominantly of an effector memory (CD27−CD45RA−CCR7−) profile, HIV-specific T-cells were mainly of a central (CD27+CD45RA−CCR7+) and transitional memory (CD27+CD45RA+/−CCR7−) phenotype on both CD4+ and CD8+ T-cells. Using receiving operating characteristic (ROC) curve analysis, co-expression of CD38 and HLA-DR on ESAT-6/CFP-10 responding total cytokine-producing CD4+ T-cells had a high sensitivity for discriminating HIV+TB (100%, 95% CI 70–100) and HIV−TB (100%, 95% CI 70–100) from latent TB with high specificity (100%, 95% CI 68–100 for HIV−TB) at a cut-off value of 5% and 13%, respectively. TB treatment reduced the proportion of Mtb-specific total cytokine+CD38+HLA-DR+ CD4+ T-cells only in HIV−TB (p = 0.001). Our results suggest that co-expression of CD38 and HLA-DR on Mtb-specific CD4+ T-cells could serve as a TB diagnosis tool regardless of HIV status.

Identification of VIMP as a Gene Inhibiting Cytokine Production in Human CD4+ Effector T Cells

Many players regulating the CD4+ T cell-mediated inflammatory response have already been identified. However, the critical nodes that constitute the regulatory and signaling networks underlying CD4 T cell responses are still missing. Using a correlation-network-guided approach, here we identified VIMP (VCP-interacting membrane protein), one of the 25 genes encoding selenocysteine in humans, as a gene regulating the effector functions of human CD4 T cells, especially production of several cytokines including IL2 and CSF2. We identified VIMP as an endogenous inhibitor of cytokine production in CD4 effector T cells via both, the E2F5 transcription regulatory pathway and the Ca2+/NFATC2 signaling pathway. Our work not only indicates that VIMP might be a promising therapeutic target for various inflammation-associated diseases, but also shows that our network-guided approach can significantly aid in predicting new functions of the genes of interest.

Natural Killer and CD8 T Cells Contribute to Protection by Formalin Inactivated Respiratory Syncytial Virus Vaccination under a CD4-Deficient Condition.

Respiratory syncytial virus (RSV) causes severe pulmonary disease in infants, young children, and the elderly. Formalin inactivated RSV (FI-RSV) vaccine trials failed due to vaccine enhanced respiratory disease, but the underlying immune mechanisms remain not fully understood. In this study, we have used wild type C57BL/6 and CD4 knockout (CD4KO) mouse models to better understand the roles of the CD4 T cells and cellular mechanisms responsible for enhanced respiratory disease after FI-RSV vaccination and RSV infection. Less eosinophil infiltration and lower pro-inflammatory cytokine production were observed in FI-RSV vaccinated CD4KO mice after RSV infection compared to FI-RSV vaccinated C57BL/6 mice. NK cells and cytokine-producing CD8 T cells were recruited at high levels in the airways of CD4KO mice, correlating with reduced respiratory disease. Depletion studies provided evidence that virus control was primarily mediated by NK cells whereas CD8 T cells contributed to IFN-γ production and less eosinophilic lung inflammation. This study demonstrated the differential roles of effector CD4 and CD8 T cells as well as NK cells, in networking with other inflammatory infiltrates in RSV disease in immune competent and CD4-deficient condition.

Adipose‐derived stromal/stem cells successfully attenuate the fibrosis of scleroderma mouse models

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and lung fibrosis. Although SSc has a high mortality risk, an effective treatment for the disease has not been established yet. Mesenchymal stromal/stem cells (MSCs) are multipotential nonhematopoietic progenitor cells that have the ability to regulate immune responses. Adipose-derived stromal/stem cells (ASCs), one of the types of MSCs, have the advantage of accessibility and potent immunomodulatory effects when compared with other MSCs, such as bone marrow-derived MSCs. This study aimed to investigate the antifibrotic effect of ASCs in scleroderma mouse models, including bleomycin-induced scleroderma and sclerodermatous chronic graft-versus-host disease (Scl-cGVHD) models. ASCs were intravenously administered to a bleomycin-induced scleroderma or Scl-cGVHD model on day 0. We compared the skin and lung fibrosis of scleroderma model mice between the ASC-treated group and control group. Administration of ASCs attenuated the skin and lung fibrosis of bleomycin-induced scleroderma and Scl-cGVHD model mice compared to that in the control mice. Immunohistochemical staining showed that ASCs suppressed the infiltration of CD4+ , CD8+ T cells and macrophages into the dermis of bleomycin model mice compared to that in control mice. In addition, ASCs attenuated the messenger RNA expression of collagen and fibrogenic cytokines, such as interleukin (IL)-6 and IL-13, in the skin of bleomycin model mice. ASCs also reduced the frequency of fibrogenic cytokine-producing CD4+ T cells and effector B cells in the spleen of bleomycin model mice. ASCs could prove to be a potential therapeutic agent for use in patients with SSc.

Poly-functional T helper cells in human tonsillar mononuclear cells.

Tonsils are important lymphoid organs in which B cells and T cells complete their maturation and identify cells that are infected by pathogens. However, the functions of T cells in human tonsils remain unclear, especially the characteristics of polyfunctional CD4+ T helper cells. In this study, we used multi-color flow cytometry to analyze the expression or co-expression of effector cytokines in CD4+ T cells from tonsillar tissues. We have demonstrated that tonsillar CD4+ T cell can express various Th effector cytokines after short-term polyclonal stimulation, and that cytokine-producing CD4+ T cells were CD45RO+ T cells. In addition, we analyzed the co-expression of two or more kinds of cytokines at the level of a single cell. The results showed that tonsillar CD4+ T cells exhibited polyfunctionality by co-expressing two to five kinds of cytokines in the same time. These data furnished a basic theory for further understanding the differentiation of polyfunctional Th cells in human tonsils and their functions in resisting invasive microorganisms.

T Cell-Specific Adaptor Protein Regulates Mitochondrial Function and CD4+ T Regulatory Cell Activity In Vivo following Transplantation.

The T cell-specific adaptor protein (TSAd), encoded by the SH2D2A gene, is an intracellular molecule that binds Lck to elicit signals that result in cytokine production in CD4+ T effector cells (Teff). Nevertheless, using Sh2d2a knockout (KO; also called TSAd-/-) mice, we find that alloimmune CD4+ Teff responses are fully competent in vivo. Furthermore, and contrary to expectations, we find that allograft rejection is accelerated in KO recipients of MHC class II-mismatched B6.C-H-2bm12 heart transplants versus wild-type (WT) recipients. Also, KO recipients of fully MHC-mismatched cardiac allografts are resistant to the graft-prolonging effects of costimulatory blockade. Using adoptive transfer models, we find that KO T regulatory cells (Tregs) are less efficient in suppressing Teff function and they produce IFN-γ following mitogenic activation. In addition, pyrosequencing demonstrated higher levels of methylation of CpG regions within the Treg-specific demethylated region of KO versus WT Tregs, suggesting that TSAd, in part, promotes Treg stability. By Western blot, Lck is absent in the mitochondria of KO Tregs, and reactive oxygen species production by mitochondria is reduced in KO versus WT Tregs. Full transcriptomic analysis demonstrated that the key mechanism of TSAd function in Tregs relates to its effects on cellular activation rather than intrinsic effects on mitochondria/metabolism. Nevertheless, KO Tregs compensate for a lack of activation by increasing the number of mitochondria per cell. Thus, TSAd serves as a critical cell-intrinsic molecule in CD4+Foxp3+ Tregs to regulate the translocation of Lck to mitochondria, cellular activation responses, and the development of immunoregulation following solid organ transplantation.

SerpinB1 controls encephalitogenic T helper cells in neuroinflammation

SerpinB1, a protease inhibitor and neutrophil survival factor, was recently linked with IL-17-expressing T cells. Here, we show that serpinB1 (Sb1) is dramatically induced in a subset of effector CD4 cells in experimental autoimmune encephalomyelitis (EAE). Despite normal T cell priming, Sb1-/- mice are resistant to EAE with a paucity of T helper (TH) cells that produce two or more of the cytokines, IFNγ, GM-CSF, and IL-17. These multiple cytokine-producing CD4 cells proliferate extremely rapidly; highly express the cytolytic granule proteins perforin-A, granzyme C (GzmC), and GzmA and surface receptors IL-23R, IL-7Rα, and IL-1R1; and can be identified by the surface marker CXCR6. In Sb1-/- mice, CXCR6+ TH cells are generated but fail to expand due to enhanced granule protease-mediated mitochondrial damage leading to suicidal cell death. Finally, anti-CXCR6 antibody treatment, like Sb1 deletion, dramatically reverts EAE, strongly indicating that the CXCR6+ T cells are the drivers of encephalitis.

1009 Optimizing immunological reinvigoration in leukemic cutaneous T-cell lymphoma through use of multiple immune checkpoint inhibitors

We have previously demonstrated that malignant T-cells in leukemic CTCL (L-CTCL) may simultaneously express mulitple immune checkpoint molecules, including PD-1, CTLA4 and TIGIT, possibly contributing to immune evasion and immune exhaustion and these may also have relevance to prognosis. The ability to block signaling of these molecules is likely to be beneficial to clinical outcome which is supported by preliminary data from trials using anti-PD-1 therapy for advanced CTCL. In this study we assessed the use of multiple immune checkpoint inhibitors on the proliferation and Th1 cytokine production of CD4 and CD8 T-cells of patients with L-CTCL. Purified, freshly isolated lymphocytes from 22 patients with L-CTCL were cultured with varying concentrations of anti-PD-1 or anti-TIGIT for 96 hours with assessment of T-cell proliferation, expression of cytolytic molecules and production of IL-2 and interferon gamma. A significant increase in proliferation of both CD4 and CD8 T-cells in response to anti-PD-1 was noted among the cells of 8 patients while the response to TIGIT resulted in increased proliferation of T-cells from 6 patients. Exposure to anti-PD-1 resulted in significant increases in IL-2 production by the cells of 9 patients and increased production of interferon gamma by 5 patients. Anti-TIGIT increased IL-2 production by 5 patients while interferon gamma production was increased among the cells of 4 patients. Combination blockade further enhanced immune responses of 6 patients. These results indicate that different immune checkpoint inhibitors may exert beneficial enhancement of T-cell proliferation and cytokine production among patients with leukemic CTCL and variable responses to each supports the use of combination checkpoint inhibition to improve clinical outcomes.

Long-term immunogenicity and safety of tetravalent dengue vaccine (CYD-TDV) in healthy populations in Singapore and Vietnam: 4-year follow-up of randomized, controlled, phase II trials

ABSTRACT Dengue is prevalent in the Asia-Pacific region. Participants of two immunogenicity and safety phase II studies conducted in Singapore and Vietnam (NCT0088089 and NCT00875524, respectively) were followed for up to four years after third vaccine dose of a recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV). Participants (2–45 years) received three doses of CYD-TDV or control at 0, 6, and 12 months. Dengue plaque reduction neutralization test (PRNT50) antibody titers were measured in both studies. Cytokine-producing antigen-specific CD4+ and CD8+ T-cells were quantified to assess cell-mediated immunity (CMI) in Singapore. Post-hoc analyses were carried out for participants aged <9 and ≥9 years old. Related and fatal serious adverse events (SAEs) were collected during long-term follow-up. Of participants who received ≥1 CYD-TDV injection in Singapore (n = 1198) and Vietnam (n = 180), 87% and 92% participants completed long-term follow-up, respectively. At four years, geometric mean titers (GMTs) in participants who received CYD-TDV ranged from 30.2 1/dil (95% CI 23.9–38.3) to 73.7 (49.3–110) 1/dil in Vietnam and 9.73 1/dil (95% CI 8.28–11.4) to 21.8 (18.9–25.1) 1/dil in Singapore. Interferon and interleukin-13 levels were lower at four years than one year post-vaccination but were still present. Tumor necrosis factor-α levels at four years were similar to those after the third vaccine dose. Seropositivity rates were higher at year four in participants who were seropositive vs. seronegative at baseline in both studies. No safety concerns were identified. CYD-TDV demonstrated long-term immunogenicity and was well-tolerated for four years after the third vaccine dose.

3236 Identification of exhaustive markers in cytotoxic T-cells to guide immune modulation in hepatocellular carcinoma ex vivo

OBJECTIVES/SPECIFIC AIMS: Objective: apply checkpoint inhibitors that are specific to the exhaustive markers expressed on tumor CD8+ T-cells ex vivo in order to improve cytokine release and cytotoxic function in comparison to two control groups: (1.) T-cells that receive no antibodies; (2.) T-cells that receive standard inhibition with PD-1 and CTLA-4 antibodies only. Long-term objective: provide personalized medicine in the treatment of HCC by using checkpoint inhibitors that are specific to the receptors expressed by an individual tumor. METHODS/STUDY POPULATION: The study population includes patients undergoing liver transplantation or surgical resection for HCC. Two grams of tumor, two grams of healthy liver tissue at least one centimeter from the tumor margin, and 50 milliliters of blood will be obtained. Solid tissue will be mechanically and enzymatically disrupted and CD8+ T-cells will be isolated from all sites. Using flow cytometry, the expression of surface receptors PD-1, CTLA-4, LAG-3, TIM-3, BTLA, CD244, and CD160 will be categorized in each tissue to identify which receptors are upregulated in the tumor microenvironment. Up to three antibodies specific to the upregulated receptor(s) on the tumor T-cells will be applied per specimen. The experimental arm will receive these antibodies and co-stimulation with CD3/CD28 and will be compared to two controls. One control will receive only CD3/CD28, and the other will receive CD3/CD28 in addition to the standard combination of PD-1 and CTLA-4 inhibitors. From each condition, flow cytometry will be used to assess the mean production of interleukin-2, tumor necrosis factor-α, interferon-γ, granzyme B, and perforin expression as an assessment of T-cell function. RESULTS/ANTICIPATED RESULTS: Preliminary data from the peripheral blood of healthy controls confirms that the developed flow cytometry panels effectively identify the surface receptors and cytokine production of CD8+ T-cells. Two patients have successfully been enrolled in this study. It is predicted that T-cells extracted from the tumor will express more inhibitory receptors than normal liver or peripheral blood and will have increased function after they are targeted with checkpoint inhibitors that are specific to the inhibitory surface receptors they express. DISCUSSION/SIGNIFICANCE OF IMPACT: HCC is the second leading cause of cancer-related death worldwide and therapeutic options are limited for patients who are not surgical candidates. T-cells are a critical component of the anti-tumor response to HCC. However, T-cells can develop an exhausted phenotype characterized by up-regulated inhibitory receptors (PD-1, CTLA-4, LAG-3, TIM-3, CD-244, CD-160, BTLA) and decreased function, allowing for immune escape. Clinical trials using combined checkpoint inhibition with PD-L1 and CTLA-4 antibodies have been considered a breakthrough for patients with advanced HCC, as up to 25% show an objective tumor response. The explanation for the varied susceptibility to checkpoint inhibition remains unknown and is hypothesized to be secondary to inconsistencies in the expression of surface inhibitory receptors. Although inhibitory receptor expression has been shown to be upregulated under conditions of hepatitis and/or HCC, there has been no single study to effectively investigate the expression of all known inhibitors in order to better explore the interplay between them. It will be of great academic interest and clinical purpose to evaluate individual receptor expression and engage the correlating antibodies given the possibility of synergism between receptors and the need for a more profound anti-tumor T-cell response in HCC.

Constitutively active MyD88/CD40 costimulation enhances expansion and efficacy of chimeric antigen receptor T cells targeting hematological malignancies

Successful adoptive chimeric antigen receptor (CAR) T-cell therapies against hematological malignancies require CAR-T expansion and durable persistence following infusion. Balancing increased CAR-T potency with safety, including severe cytokine-release syndrome (sCRS) and neurotoxicity, warrants inclusion of safety mechanisms to control in vivo CAR-T activity. Here, we describe a novel CAR-T cell platform that utilizes expression of the toll-like receptor (TLR) adaptor molecule, MyD88, and tumor-necrosis factor family member, CD40 (MC), tethered to the CAR molecule through an intentionally inefficient 2A linker system, providing a constitutive signal that drives CAR-T survival, proliferation, and antitumor activity against CD19+ and CD123+ hematological cancers. Robust activity of MC-enhanced CAR-T cells was associated with cachexia in animal models that corresponded with high levels of human cytokine production. However, toxicity could be successfully resolved by using the inducible caspase-9 (iC9) safety switch to reduce serum cytokines, by administration of a neutralizing antibody against TNF-α, or by selecting “low” cytokine-producing CD8+ T cells, without loss of antitumor activity. Interestingly, high basal activity was essential for in vivo CAR-T expansion. This study shows that co-opting novel signaling elements (i.e., MyD88 and CD40) and development of a unique CAR-T architecture can drive T-cell proliferation in vivo to enhance CAR-T therapies.

Sublingual administration of liposomes enclosing alpha-galactosylceramide as an effective adjuvant of allergen immunotherapy in a murine model of allergic rhinitis

BackgroundSublingual immunotherapy (SLIT) is an established efficacious approach for the treatment of allergic rhinitis (AR). However, SLIT requires a long administration period to establish stable and adequate responses. This study investigated the efficacy of the sublingual administration of an allergen with liposomes enclosing α-GalCer (α-GC-liposome) as a potential adjuvant in mice with AR. MethodsMice with AR induced by OVA received the sublingual administration of OVA, α-GC-liposomes, or OVA plus α-GC-liposomes for 7 days. After nasal re-challenge with OVA, nasal symptoms were evaluated. The serum levels of OVA-specific Ig, the cytokine production of CD4+ T cells in the cultures of cervical lymph node (CLN) cells, and the gene expression of CLNs were analyzed. ResultsAlthough IL-4, IL-5 and IL-13 production from CD4+ T cells in CLN cells was significantly inhibited by the sublingual administration of OVA alone in mice with AR induced by OVA, their nasal symptoms were not significantly diminished. However, the combined sublingual administration of α-GC-liposomes and OVA completely suppressed nasal symptoms, downregulated Th2 and Th17 type cytokine production in CD4+ T cells as well as Th2 and Th17 gene expressions, and upregulated Th1 type cytokine production as well as Th1 gene expressions in CLN cells. Additionally, the serum levels of specific IgG2a were promoted, and specific IgE and IgG1 were inhibited. ConclusionsOur findings suggest that the sublingual administration of an allergen with α-GC-liposomes as an adjuvant might increase the therapeutic efficacy and effectiveness of this treatment method.

Abstract A185: Effective expansion of poly-functional tumor-reactive TILs from NSCLC correlates with an immune-engaged T-cell profile in tumor tissues

Abstract Non-small cell lung cancer (NSCLC) is the second most frequently occurring type of cancer. Because of the high mortality rates with the current treatment regimens, novel therapeutic approaches are warranted. The high mutational rate of the tumors, and the high level of T-cell infiltrates should render NSCLC patients eligible for autologous T-cell therapy. Here we show that tumor-infiltrating lymphocytes (TILs) from treatment naive, stage I-IIIa NSCLC tumors can be effectively expanded and reprogrammed. With an optimized detection essay for tumor-reactive T-cells, we observed that 13/17 tested TIL products (76.5%) from primary NSCLC tumor tissues contained cytokine-producing CD4+ and/or CD8+ T-cells in response to primary tumor digest. Tumor responses ranged from 0.5%-30%, and correlated well with activation markers on CD4+ and CD8+ T-cells. Importantly, 29.4% of the TIL products contained poly-functional T-cells that produced TNF-alfa and/or IL-2 in addition to IFN-gamma, and poly-functional T-cells correlated with high levels of tumor reactivity. Furthermore, high percentages of CD103+CD69+CD8+ T-cells, PD-1+CD4+ T-cells and FoxP3+CD25+CD4+ T-cells in the tumors were good predictors for the generation of highly tumor-reactive TIL products. In conclusion, we show that most NSCLCs contain tumor-specific T-cells that can be efficiently expanded and become highly poly-functional, depending on the initial T-cell profile of TILs. Our findings show the feasibility of culturing tumor-reactive TILs from NSCLC and provide keys to individualize adoptive T-cell therapy. Therefore, autologous T-cell therapy should be reconsidered as treatment for NSCLC patients. Citation Format: Rosa De Groot, Marleen M. van Loenen, Aurélie Guislain, Derk Amsen, John B.A.G. Haanen, Kim Monkhorst, Koen J. Hartemink, Monika C. Wolkers. Effective expansion of poly-functional tumor-reactive TILs from NSCLC correlates with an immune-engaged T-cell profile in tumor tissues [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A185.

Relationships Between Phenotype and Function of Blood CD4+ T-Cells and Ascending Thoracic Aortic Aneurysm: an Experimental Study.

IntroductionNon-familial ascending thoracic aorta dilation and aneurysms (TAAs) are silent diseases in elderly patients. Histopathology revealed that functionally polarized infiltrating CD4+ T-cells play a key role in aortic wall weakening.ObjectiveTo evaluate the possible associations between phenotype and cytokine production of circulating CD4+ T-lymphocytes and the presence of TAA in patients with aortic valve disease (AVD).MethodsWe studied blood samples from 10 patients with TAA and 10 patients with AVD. Flow cytometry was used to quantify: a) CD4+ T-lymphocytes surface expression of CD25, CD28, and chemokine receptors (CCR5, CXCR3, CX3CR1); b) fractions of in vitro stimulated CD4+ T-cells producing cytokines (interferon gamma [IFN-γ], interleukin [IL]-17A, IL-21, IL-10); c) CD4+CD25highFoxP3+ regulatory T-cells (Treg) fraction. Enzyme-linked immunosorbent assays (ELISA) were performed for cytokines (IFN-γ, IL-6, IL-10, IL-17A, IL-23, transforming growth factor beta [TGF-β]) and chemokines (RANTES, CX3CL1).ResultsThe total CD4+CD28±CD4+/CX3CR1+ T-cells fraction was higher (P=0.0323) in AVD (20.452±4.673) than in TAA patients (8.633±2.030). The frequency ratio of CD4+ T-lymphocytes producing IFN-γ vs. IL-17A+IL-21 cytokine-producing CD4+ T-cells was higher (P=0.0239) in AVD (2.102±0.272) than in TAA (1.365±0.123) patients. The sum of CD4+CD28±CD4+/CX3CR1+ T-cells correlated positively with values of the previous cytokine ratio (P=0.0002, R=0.732). The ratio of CD4+CD28±CD4+/CX3CR1+ T-cells vs. Treg was higher (P=0.0008) in AVD (20.859±3.393) than in TAA (6.367±1.277) patients.ConclusionOur results show that the presence of TAA in subjects with AVD is associated with imbalance between phenotypic and cytokine-producing subsets of circulating CD4+ T-lymphocytes, prevalently oriented towards a pro-fibrotic and IFN-γ counteracting effect to functional polarization.

Tacrolimus inhibits Th1 and Th17 responses in MuSK-antibody positive myasthenia gravis patients

Muscle specific tyrosine kinase antibody positive myasthenia gravis (MuSK- MG) is characterized by autoantibodies against the MuSK protein of the neuromuscular junction resulting in weakness of bulbar and proximal muscles. We previously demonstrated that patients with MuSK-MG have increased pro-inflammatory Th1 and Th17 responses. Tacrolimus, an immunosuppressant used in AChR-MG and transplantation patients, inhibits T cell responses through interference with IL-2 transcription. The therapeutic efficacy and immunological effect of tacrolimus in MuSK-MG is unclear. In the current study we examined the proliferation, phenotype and cytokine production of CD4+ and CD8+ T cells in peripheral blood mononuclear cells of MuSK-MG following a 3-day in vitro culture with or without tacrolimus. We determined that tacrolimus profoundly suppressed CD4 and CD8 T cell proliferation and significantly suppressed Th1 and Th17 responses, as demonstrated by a reduced frequency of IFN-γ, IL-2, and IL-17 producing CD4 T cells and reduced frequencies of IFN-γ and IL-2 producing CD8 T cells. Tacrolimus also inhibits pathogenic Th17 cells coproducing IL-17 and IFN-γ. In addition, tacrolimus suppressed follicular T helper cell (Tfh) and regulatory T helper cell (Treg) subsets. These findings provide preliminary support for tacrolimus as a potential alternative immunosuppressive therapy for MuSK-MG.

Pro and Anti-inflammatory Cytokine Production in CD4+ T Lymphocytes in Children with Asthma and Allergic Rhinitis Exposed to the Monocyte Locomotion Inhibitory Factor (MLIF).

Entamoeba histolytica produces, in axenic culture, the monocytes locomotion inhibitory factor (MLIF), a oligopeptide with selective anti-inflammatory properties. We evaluated the effect of MLIF on the expression of pro- and anti-inflammatory cytokines in CD4+ T lymphocytes from children with asthma and allergic rhinitis. Twelve children with severe asthma, 12 children with allergic rhinitis and 6 healthy controls were recruited for this study between May and December 2016. CD4+ T cells were cultured for 24 h at 37°C, 5% CO2 in the presence of MLIF, 1-phorbol 12-myristate 13-acetate (PMA), MLIF+PMA or RPMI. Interleukin-10 (IL-10), IL-4, interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) expression levels were measured in the supernatants of T-cell cultures using the enzyme-linked immunosorbent assay (ELISA). Pro- and anti-inflammatory cytokines were inhibited by MLIF (IFN-γ p=0.0036, TNF-α p<0.001, IL-4 p=0.0082) in asthmatic patients, however IFN-γ was not significantly inhibited (NS) in patients with allergic rhinitis when compared to the RPMI group. In CD4+ T cells treated with PMA+MLIF, the expression levels of IFN-γ, TNF-α and IL-4 were strongly inhibited (p<0.001, p<0.001 and p<0.0094), compared to PMA treatment alone, for both, rhinitis and asthma. IL-10 expression was not affected by MLIF in neither of the two diseases. We conclude that MLIF alters the pro/anti-inflammatory balance and induces inhibition of IL-4, IFN-γ and TNF-α, but does not affect IL-10.

Histone Deacetylases Enhance Ca2+-Activated K⁺ Channel KCa3.1 Expression in Murine Inflammatory CD4⁺ T Cells.

The up-regulated expression of the Ca2+-activated K+ channel KCa3.1 in inflammatory CD4+ T cells has been implicated in the pathogenesis of inflammatory bowel disease (IBD) through the enhanced production of inflammatory cytokines, such as interferon-γ (IFN-γ). However, the underlying mechanisms have not yet been elucidated. The objective of the present study is to clarify the involvement of histone deacetylases (HDACs) in the up-regulation of KCa3.1 in the CD4+ T cells of IBD model mice. The expression levels of KCa3.1 and its regulators, such as function-modifying molecules and transcription factors, were quantitated using a real-time polymerase chain reaction (PCR) assay, Western blotting, and depolarization responses, which were induced by the selective KCa3.1 blocker TRAM-34 (1 μM) and were measured using a voltage-sensitive fluorescent dye imaging system. The treatment with 1 μM vorinostat, a pan-HDAC inhibitor, for 24 h repressed the transcriptional expression of KCa3.1 in the splenic CD4+ T cells of IBD model mice. Accordingly, TRAM-34-induced depolarization responses were significantly reduced. HDAC2 and HDAC3 were significantly up-regulated in the CD4+ T cells of IBD model mice. The down-regulated expression of KCa3.1 was observed following treatments with the selective inhibitors of HDAC2 and HDAC3. The KCa3.1 K+ channel regulates inflammatory cytokine production in CD4+ T cells, mediating epigenetic modifications by HDAC2 and HDAC3.

PD-1 Expression on Mycobacterium tuberculosis-Specific CD4 T Cells Is Associated With Bacterial Load in Human Tuberculosis.

Persistent antigen stimulation in chronic infections has been associated with antigen-specific T cell dysfunction and upregulation of inhibitory receptors, including programmed cell death protein 1 (PD-1). Pulmonary tuberculosis (TB) disease is characterized by high levels of Mycobacterium tuberculosis (Mtb), yet the relationship between bacterial load, PD-1 expression, and Mtb-specific T cell function in human TB has not been well-defined. Using peripheral blood samples from adults with LTBI and with pulmonary TB disease, we tested the hypothesis that PD-1 expression is associated with bacterial load and functional capacity of Mtb-specific T cell responses. We found that PD-1 was expressed at significantly higher levels on Th1 cytokine-producing Mtb-specific CD4 T cells from patients with smear-positive TB, compared with smear-negative TB and LTBI, which decreased after completion of anti-TB treatment. By contrast, expression of PD-1 on Mtb-specific CD8 T cells was significantly lower than on Mtb-specific CD4 T cells and did not differ by Mtb infection and disease status. In vitro stimulation of PBMC with Mtb antigens demonstrated that PD-1 is induced on proliferating Mtb-specific CD4 T cells and that Th1 cytokine production capacity is preferentially maintained within PD-1+ proliferating CD4 T cells, compared with proliferating Mtb-specific CD4 T cells that lack PD-1 expression. Together, these data indicate that expression of PD-1 on Mtb-specific CD4 T cells is indicative of mycobacterial antigen exposure and identifies a population of effector cells with Th1 cytokine production capacity. These studies provide novel insights into the role of the PD-1 pathway in regulating CD4 and CD8 T cell responses in Mtb infection and provide rationale for future studies to evaluate PD-1 expression on antigen-specific CD4 T cells as a potential biomarker for bacterial load and treatment response in human TB.