Co-inhibitory Molecules Research Articles

PD-1H/VISTA expressed on host myeloid cells regulates acute graft-versus-host disease (aGVHD)

Abstract Programmed Death-1 Homolog (PD-1H, also known as VISTA) is a co-inhibitory molecule of the immunoglobulin superfamily and broadly found in hematopoietic cells. We previously demonstrated that PD-1H agonists prevent aGVHD in a murine MHC mismatched bone marrow (BM) transplantation model. aGVHD occurs when donor T cells are primed and activated by host antigen-presenting cells (APCs). PD-1H agonism suppressed donor allogeneic T cell activation leading to the suppression of aGVHD. However, it remains unknown whether PD-1H agonists also suppress host myeloid APCs, in which PD-1H is highly expressed. To test this, we adoptively transferred wildtype (WT) C57B/L6 (B6) BM into either PD-1H knock-out (KO) or WT BALB/c mice as hosts. PD-1H KO host mice had more severe aGVHD clinical scores and a worse survival rate when compared to WT host mice. To determine whether PD-1H agonism impacts host immune cells, we transferred B6 PD-1H KO BM into BALB/c WT host mice and treated host recipients with or without PD-1H agonists. Consistent with prior data, host mice treated with PD-1H agonists suppressed aGVHD and extended survival compared with isotype control treated mice. To test which cell subsets expressing PD-1H in host mice regulate aGVHD, we transferred WT BALB/c BM into myeloid lineage specific KO of PD-1H or WT littermate hosts. Interestingly, the myeloid lineage specific KO mice host had significantly worse survival rates and worse aGVHD symptoms compared with WT littermates. Our studies indicate that PD-1H expression on host myeloid cells regulates aGVHD in addition to donor T cell PD-1H. Finding new mechanisms of PD-1H agonism on aGVHD enables development of future therapeutic approaches for aGVHD treatment, such as myeloid APC suppression. Supported by an Edward P. Evans Foundation Young Investigator Award, a Conquer Cancer Foundation American Society of Clinical Oncology Career Development Grant, and an American Cancer Society Clinician Scientist Development Grant

Transcription Factor c-Maf Promotes Immunoregulation of Programmed Cell Death 1-Expressed CD8+ T Cells in Multiple Sclerosis.

Background and ObjectivesMultiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. CD8+ T cells are prominently found at inflammatory sites. Recent advances in understanding checkpoint molecules, including programmed cell death 1 (PD-1), expressed on CD8+ T cells, highlight the immune regulatory roles of this T-cell subset; however, the role of CD8+ T cells in MS is unclear. Thus, we aimed to reveal the characteristics of PD-1–expressed (PD-1+) CD8+ T cells in MS.MethodsWe performed a cohort, case-control study for phenotyping analysis of PD-1+CD8+ T cells in disease remission and flare states using CSF and peripheral blood samples of 45 patients with MS or clinically isolated syndrome and 12 healthy subjects. We further analyzed the transcriptome of sorted PD-1+CD8+ T cells obtained from interferon (IFN)-β–treated patients and validated their regulatory machinery using in vitro cell culture assays with lentiviral gene transfer.ResultsIn the disease remission state, PD-1+CD8+ T cells were decreased in the peripheral blood of patients with MS and resolved in patients treated with IFN-β treatment who showed immune regulatory cytokine interleukin (IL)-10 expression. In the disease flare state, we found that PD-1+CD8+ T cells were enriched in the CSF, which predicted a good response to subsequent IV steroid therapy. Transcriptome analysis of sorted PD-1+CD8+ T cells revealed the transcription factor c-Maf as a potential major regulator of the gene module, including multiple coinhibitory molecules. Furthermore, c-Maf expressed in CD8+ T cells induced PD-1 expression and production of IL-10 as well as suppressed alloactivated CD4+ T-cell survival.DiscussionThis study uncovered a favorable role of PD-1+CD8+ T cells against MS and demonstrated that c-Maf–driven IL-10 is an immune regulatory machinery.

Microbiota-dependent activation of the myeloid calcineurin-NFAT pathway inhibits B7H3- and B7H4-dependent anti-tumor immunity in colorectal cancer

Bacterial sensing by intestinal tumor cells contributes to tumor growth through cell-intrinsic activation of the calcineurin-NFAT axis, but the role of this pathway in other intestinal cells remains unclear. Here, we found that myeloid-specific deletion of calcineurin in mice activated protective CD8+ Tcell responses and inhibited colorectal cancer (CRC) growth. Microbial sensing by myeloid cells promoted calcineurin- and NFAT-dependent interleukin 6 (IL-6) release, expression of the co-inhibitory molecules B7H3 and B7H4 by tumor cells, and inhibition of CD8+ Tcell-dependent anti-tumor immunity. Accordingly, targeting members of this pathway activated protective CD8+ Tcell responses and inhibited primary and metastatic CRC growth. B7H3 and B7H4 were expressed by the majority of human primary CRCs and metastases, which was associated with low numbers of tumor-infiltrating CD8+ Tcells and poor survival. Therefore, a microbiota-, calcineurin-, and B7H3/B7H4-dependent pathway controls anti-tumor immunity, revealing additional targets for immune checkpoint inhibition in microsatellite-stable CRC.

High Levels of CD244 Rather Than CD160 Associate With CD8+ T-Cell Aging.

Aging leads to functional dysregulation of the immune system, especially T cell defects. Previous studies have shown that the accumulation of co-inhibitory molecules plays an essential role in both T cell exhaustion and aging. In the present study, we showed that CD244 and CD160 were both up-regulated on CD8+ T cells of elderly individuals. CD244+CD160- CD8+ T cells displayed the increased activity of β-GAL, higher production of cytokines, and severe metabolic disorders, which were characteristics of immune aging. Notably, the functional dysregulation associated with aging was reversed by blocking CD244 instead of CD160. Meanwhile, CD244+CD160+ CD8+ T cells exhibited features of exhaustion, including lower levels of cytokine, impaired proliferation, and intrinsic transcriptional regulation, compared to CD244+CD160- population. Collectively, our findings demonstrated that CD244 rather than CD160 acts as a prominent regulator involved in T cell aging, providing a solid therapeutic target to improve disorders and comorbidities correlated to immune system aging.

Recombinant human interleukin-7 reverses T cell exhaustion ex vivo in critically ill COVID-19 patients

BackgroundLymphopenia is a hallmark of severe coronavirus disease 19 (COVID-19). Similar alterations have been described in bacterial sepsis and therapeutic strategies targeting T cell function such as recombinant human interleukin 7 (rhIL-7) have been proposed in this clinical context. As COVID-19 is a viral sepsis, the objectives of this study were to characterize T lymphocyte response over time in severe COVID-19 patients and to assess the effect of ex vivo administration of rhIL-7.ResultsPeripheral blood mononuclear cells from COVID-19 patients hospitalized in intensive care unit (ICU) were collected at admission and after 20 days. Transcriptomic profile was evaluated through NanoString technology. Inhibitory immune checkpoints expressions were determined by flow cytometry. T lymphocyte proliferation and IFN-γ production were evaluated after ex vivo stimulation in the presence or not of rhIL-7. COVID-19 ICU patients were markedly lymphopenic at admission. Mononuclear cells presented with inhibited transcriptomic profile prevalently with impaired T cell activation pathways. CD4 + and CD8 + T cells presented with over-expression of co-inhibitory molecules PD-1, PD-L1, CTLA-4 and TIM-3. CD4 + and CD8 + T cell proliferation and IFN-γ production were markedly altered in samples collected at ICU admission. These alterations, characteristic of a T cell exhaustion state, were more pronounced at ICU admission and alleviated over time. Treatment with rhIL-7 ex vivo significantly improved both T cell proliferation and IFN-γ production in cells from COVID-19 patients.ConclusionsSevere COVID-19 patients present with features of profound T cell exhaustion upon ICU admission which can be reversed ex vivo by rhIL-7. These results reinforce our understanding of severe COVID-19 pathophysiology and opens novel therapeutic avenues to treat such critically ill patients based of immunomodulation approaches. Defining the appropriate timing for initiating such immune-adjuvant therapy in clinical setting and the pertinent markers for a careful selection of patients are now warranted to confirm the ex vivo results described so far.Trial registration ClinicalTrials.gov identifier: NCT04392401 Registered 18 May 2020, http:// clinicaltrials.gov/ct2/show/NCT04392401.

Inhibitor of glutamine metabolism V9302 promotes ROS-induced autophagic degradation of B7H3 to enhance antitumor immunity

Despite the enormous successes of anti-PD-1/PD-L1 immunotherapy in multiple other cancer types, the overall response rates of breast cancer remain suboptimal. Therefore, exploring additional immune checkpoint molecules for potential cancer treatment is crucial. B7H3, a T-cell coinhibitory molecule, is specifically overexpressed in breast cancer compared with normal breast tissue and benign lesions, making it an attractive therapeutic target. However, the mechanism by which B7H3 contributes to the cancer phenotype is unclear. Here we show that the expression of B7H3 is negatively related to the number of CD8+ T cells in breast tumor sites. In addition, analysis of the differentially expressed B7H3 reveals that it is inversely correlated to autophagic flux both in breast cancer cell lines and clinical tumor tissues. Furthermore, block of autophagy by bafilomycin A1 (Baf A1) increases B7H3 levels and attenuates CD8+ T cell activation, while promotion of autophagy by V9302, a small-molecule inhibitor of glutamine metabolism, decreases B7H3 expression and enhances granzyme B (GzB) production of CD8+ T cells via regulation of reactive oxygen species (ROS) accumulation. We demonstrate that combined treatment with V9302 and anti-PD-1 monoclonal antibody (mAb) enhances antitumor immunity in syngeneic mouse models. Collectively, our findings unveil the beneficial effect of V9302 in boosting antitumor immune response in breast cancer and illustrate that anti-PD-1 together with V9302 treatment may provide synergistic effects in the treatment of patients insensitive to anti-PD-1 therapy.

Group B streptococci infection model shows decreased regulatory capacity of cord blood cells

BackgroundSepsis is one of the leading causes of morbidity and mortality in the neonatal period. Compared to adults, neonates are more susceptible to infections, especially to systemic infections with Group B Streptococcus (GBS). Furthermore, neonates show defects in terminating inflammation. The immunological causes for the increased susceptibility to infection and the prolonged inflammatory response are still incompletely understood.MethodsIn the present study, we aimed to investigate the reaction of cord blood mononuclear cells (MNC) to stimulation with GBS in comparison to that of MNC from adult blood with focus on the proliferative response in an in vitro infection model with heat-inactivated GBS.ResultsWe demonstrate that after stimulation with GBS the proliferation of T cells from adult blood strongly decreased, while the proliferation of cord blood T cells remained unchanged. This effect could be traced back to a transformation of adult monocytes, but not cord blood monocytes, to a suppressive phenotype with increased expression of the co-inhibitory molecule programmed death ligand 1 (PD-L1).ConclusionsThese results point towards an increased inflammatory capacity of neonatal MNC after stimulation with GBS. Targeting the prolonged inflammatory response of neonatal immune cells may be a strategy to prevent complications of neonatal infections.ImpactNeonatal sepsis often leads to post-inflammatory complications.Causes for sustained inflammation in neonates are incompletely understood.We show that cord blood T cells exhibited increased proliferative capacity after stimulation with group B streptococci (GBS) in comparison to adult T cells.Adult monocytes but not cord blood monocytes acquired suppressive activity and expressed increased levels of PD-L1 after GBS stimulation.Increased proliferative capacity of neonatal T cells and decreased suppressive activity of neonatal monocytes during GBS infection may contribute to prolonged inflammation and development of post-inflammatory diseases in newborns.

Functional and molecular characterization of PD1+ tumor-infiltrating lymphocytes from lung cancer patients

ABSTRACT Antibody-mediated cancer immunotherapy targets inhibitory surface molecules, such as PD1, PD-L1, and CTLA-4, aiming to re-invigorate dysfunctional T cells. We purified and characterized tumor-infiltrating lymphocytes (TILs) and their patient-matched non-tumor counterparts from treatment-naïve NSCLC patient biopsies to evaluate the effect of PD1 expression on the functional and molecular profiles of tumor-resident T cells. We show that PD1+ CD8+ TILs have elevated expression of the transcriptional regulator ID3 and that the cytotoxic potential of CD8 T cells can be improved by knocking down ID3, defining it as a potential regulator of T cell effector function. PD1+ CD4+ memory TILs display transcriptional patterns consistent with both helper and regulator function, but can robustly facilitate B cell activation and expansion. Furthermore, we show that expanding ex vivo-prepared TILs in vitro broadly preserves their functionality with respect to tumor cell killing, B cell help, and TCR repertoire. Although purified PD1+ CD8+ TILs generally maintain an exhausted phenotype upon expansion in vitro, transcriptional analysis reveals a downregulation of markers of T-cell dysfunction, including the co-inhibitory molecules PD1 and CTLA-4 and transcription factors ID3, TOX and TOX2, while genes involved in cell cycle and DNA repair are upregulated. We find reduced expression of WNT signaling components to be a hallmark of PD1+ CD8+ exhausted T cells in vivo and in vitro and demonstrate that restoring WNT signaling, by pharmacological blockade of GSK3β, can improve effector function. These data unveil novel targets for tumor immunotherapy and have promising implications for the development of a personalized TIL-based cell therapy for lung cancer.

Roles of Podoplanin in Malignant Progression of Tumor.

Podoplanin (PDPN) is a cell-surface mucin-like glycoprotein that plays a critical role in tumor development and normal development of the lung, kidney, and lymphatic vascular systems. PDPN is overexpressed in several tumors and is involved in their malignancy. PDPN induces platelet aggregation through binding to platelet receptor C-type lectin-like receptor 2. Furthermore, PDPN modulates signal transductions that regulate cell proliferation, differentiation, migration, invasion, epithelial-to-mesenchymal transition, and stemness, all of which are crucial for the malignant progression of tumor. In the tumor microenvironment (TME), PDPN expression is upregulated in the tumor stroma, including cancer-associated fibroblasts (CAFs) and immune cells. CAFs play significant roles in the extracellular matrix remodeling and the development of immunosuppressive TME. Additionally, PDPN functions as a co-inhibitory molecule on T cells, indicating its involvement with immune evasion. In this review, we describe the mechanistic basis and diverse roles of PDPN in the malignant progression of tumors and discuss the possibility of the clinical application of PDPN-targeted cancer therapy, including cancer-specific monoclonal antibodies, and chimeric antigen receptor T technologies.

JAK1 signaling in dendritic cells promotes peripheral tolerance in autoimmunity through PD-L1-mediated regulatory Tcell induction.

Dendritic cells (DCs) induce peripheral Tcell tolerance, but cell-intrinsic signaling cascades governing their stable tolerogenesis remain poorly defined. Janus Kinase 1 (JAK1) transduces cytokine-receptor signaling, and JAK inhibitors (Jakinibs), including JAK1-specific filgotinib, break inflammatory cycles in autoimmunity. Here, we report in heterogeneous DC populations of multiple secondary lymphoid organs that JAK1 promotes peripheral Tcell tolerance during experimental autoimmune encephalomyelitis (EAE). Mice harboring DC-specific JAK1 deletion exhibit elevated peripheral CD4+ Tcell expansion, less regulatory Tcells (Tregs), and worse EAE outcomes, whereas adoptive DC transfer ameliorates EAE pathogenesis by inducing peripheral Tregs, programmed cell death ligand 1 (PD-L1) dependently. This tolerogenic program is substantially reduced upon the transfer of JAK1-deficient DCs. DC-intrinsic IFN-γ-JAK1-STAT1 signaling induces PD-L1, which is required for DCs to convert CD4+ Tcells into Tregs invitro and attenuated upon JAK1 deficiency and filgotinib treatment. Thus, DC-intrinsic JAK1 promotes peripheral tolerance, suggesting potential unwarranted DC-mediated effects of Jakinibs in autoimmune diseases.

Comparing CAR and TCR engineered T cell performance as a function of tumor cell exposure

ABSTRACT Chimeric antigen receptor (CAR) T cell therapies have resulted in profound clinical responses in the treatment of CD19-positive hematological malignancies, but a significant proportion of patients do not respond or relapse eventually. As an alternative to CAR T cells, T cells can be engineered to express a tumor-targeting T cell receptor (TCR). Due to HLA restriction of TCRs, CARs have emerged as a preferred treatment moiety when targeting surface antigens, despite the fact that functional differences between engineered TCR (eTCR) T and CAR T cells remain ill-defined. Here, we compared the activity of CAR T cells versus engineered TCR T cells in targeting the B cell malignancy-associated antigen CD20 as a function of antigen exposure. We found CAR T cells to be more potent effector cells, producing higher levels of cytokines and killing more efficiently than eTCR T cells in a short time frame. However, we revealed that the increase of antigen exposure significantly impaired CAR T cell expansion, a phenotype defined by high expression of coinhibitory molecules and effector differentiation. In contrast, eTCR T cells expanded better than CAR T cells under high antigenic pressure, with lower expression of coinhibitory molecules and maintenance of an early differentiation phenotype, and comparable clearance of tumor cells.

Molecular profile of hepatocellular carcinoma (HCC) in older versus younger adults: Does age matter?

477 Background: HCC is increasingly prevalent in older adults with rising incidence and an aging population worldwide. Retrospective studies show older patients with HCC may have an increased survival compared to younger patients. However, data is lacking regarding the genomic and biologic differences, that if identified, would potentially change how we treat this disease in younger vs. older patients. Hence, there is a need to better characterize the molecular landscape of the disease in an age-specific manner. We analyzed the association of age with genomic alterations and therapeutic response to sorafenib in a cohort of advanced HCC that had undergone comprehensive molecular profiling. Methods: 487 HCC samples (excluding variants) were analyzed using Next Generation Sequencing (592 gene panel, NextSeq), Whole Exome and Whole Transcriptome Sequencing (NovaSeq), and IHC at Caris Life Sciences (Phoenix, AZ). PD-L1 positivity was determined by IHC (SP-142 clone, cutoff ≥1, 1%). Tumor mutational burden (TMB) was a measure of total somatic mutations per Mb. Immune cell populations were determined by Microenvironment Cell Population (MCP) counter analysis of RNA expression data. Overall survival (OS) calculated from tissue collection to last contact and time on treatment (TOT) with sorafenib were extracted from insurance claims and calculated using Kaplan-Meier curves. Statistical analysis was done using Chi-square, Fisher Exact and Wilcoxon rank sum tests, with p values adjusted for multiple comparisons and q<0.05. Results: Differences in the molecular landscape of HCC stratified by patient age were assayed using a ternary classification based on 1 standard deviation from the mean age (mean age=65; <53: A1 (n=51), 53-77: A2 (n=361), >77: A3 (n=75)). With age, mutational frequencies in CTNNB1 (A1=13.04%, A2=33.43%, A3=38.24%) and TERT (A1=25%, A2=68.84%, A3=76.92%) increased, while ATM (A1=6.52%, A2=0.93%, A3=1.49%) decreased (p<0.05, q>0.05). There were fold increases in median TMB (A2/A1=1.33, A3/A1=1.33, p<0.01), LAG3 (A2/A1=1.75, A3/A1=1.93 p<0.01), CTLA4 (A2/A1=2.05, A3/A1=2.15, p<0.05) expression; median cell fractions of CD8+ T cells (A2/A1=1.37, A3/A1=1.50, p<0.05) & B cells (A3/A1=3.01 p<0.05) increased while cancer associated fibroblasts (A1/A2=0.62, A1/A3=0.69, p<0.01) decreased with age. PD-L1 was not statistically significant. While there was no change in OS, reduced TOT with sorafenib was observed in patients aged>65 (p=0.013). Conclusions: Increased alterations in oncogenic drivers and estimates of CD8+ T cells and B cells were observed in the elderly population with HCC. The enhanced presence of co-inhibitory molecules suggests potential immune evasion. While we observed reduced TOT with sorafenib, additional studies are needed to elucidate the impact of molecular alterations on outcomes with sorafenib and newer therapies (i.e. immunotherapy) in older adults.

Ablation of T cell-associated PD-1H enhances functionality and promotes adoptive immunotherapy.

Programmed death-1 homolog (PD-1H) is a coinhibitory molecule that negatively regulates T cell–mediated immune responses. In this study, we determined whether ablation of T cell–associated PD-1H could enhance adoptive T cell therapy in experimental tumor models. The expression of PD-1H is upregulated in activated and tumor-infiltrating CD8+ T cells. Activated CD8+ T cells from PD-1H–deficient (PD-1H–KO) mice exhibited increased cell proliferation, cytokine production, and antitumor activity in vitro. Adoptive transfer of PD-1H–KO CD8+ T cells resulted in the regression of established syngeneic mouse tumors. Similar results were obtained when PD-1H was ablated in T cells by CRISPR/Cas9-mediated gene silencing. Furthermore, ablation of PD-1H in CAR-T cells significantly improved their antitumor activity against human xenografts in vivo. Our results indicate that T cell–associated PD-1H could suppress immunity in the tumor microenvironment and that targeting PD-1H may improve T cell adoptive immunotherapy.

A negative association of CTLA-4 genetic variant (rs11571317) with breast cancer risk in Moroccan population

Background/aimsCytotoxic T-lymphocyte antigen-4 (CTLA-4) is a co-inhibitory molecule expressed on activated T cells. CTLA-4 polymorphisms have been associated with various cancers including breast cancer. We performed a case-control study to evaluate the influence of three CTLA-4 gene polymorphisms (658T/C (rs11571317), 1661G/A (rs4553808) and +49G/A (rs231775)), on breast cancer risk in Moroccan women. MethodsWe genotyped CTLA-4 polymorphisms in 400 subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We also investigated association of these three polymorphisms with clinicopathological characteristics in breast cancer cases. The data was analyzed through suitable statistics. ResultsAccording to cases clinicopathological characteristics, breast cancer was most frequent in pre-menopausal cases with a predominance of invasive ductal breast cancer and grade II SBR. Concerning CTLA-4 polymorphisms association with breast cancer, data analysis showed a significant association of rs11571317 (658C/T) polymorphism with breast cancer risk. TT genotype was associated with decreased breast cancer risk (OR = 0.12, 95% CI (0.01-0.96)). None of the studied SNPs was directly associated with tumor characteristics, while a significant association was observed between AGC haplotype (−1661A/G, +49 A/G, −658 C/T) and increased breast cancer susceptibility. ConclusionAccording to our results, rs11571317 (−658 C/T) polymorphism have a protective effect on breast cancer risk in the studied population.

Immunotherapeutic Strategies in Cancer and Atherosclerosis-Two Sides of the Same Coin.

The development and clinical approval of immunotherapies has revolutionized cancer therapy. Although the role of adaptive immunity in atherogenesis is now well-established and several immunomodulatory strategies have proven beneficial in preclinical studies, anti-atherosclerotic immunotherapies available for clinical application are not available. Considering that adaptive immune responses are critically involved in both carcinogenesis and atherogenesis, immunotherapeutic approaches for the treatment of cancer and atherosclerosis may exert undesirable but also desirable side effects on the other condition, respectively. For example, the high antineoplastic efficacy of immune checkpoint inhibitors, which enhance effector immune responses against tumor cells by blocking co-inhibitory molecules, was recently shown to be constrained by substantial proatherogenic properties. In this review, we outline the specific role of immune responses in the development of cancer and atherosclerosis. Furthermore, we delineate how current cancer immunotherapies affect atherogenesis and discuss whether anti-atherosclerotic immunotherapies may similarly have an impact on carcinogenesis.

The Immunomodulating Effects of Thalidomide and Dexamethasone in a Murine Cardiac Allograft Transplantation Model.

PurposeThe immunomodulatory effects of thalidomide (TM) and dexamethasone (DX) on immune cells and their co-stimulatory, co-inhibitory molecules in vitro and in vivo have been previously reported. The current study investigated the effects of TM and the combinatorial treatment with DX on immune cells using a murine cardiac allograft transplantation model.Materials and MethodsIntraabdominal transplant of cardiac allografts from BALB/c (H-2d) donors to C57BL/6 (H-2b) recipients was performed. After transplantation, mice were injected daily with TM or DX or a combination of both TM and DX (TM/DX) by intraperitoneal route until the time of graft loss. CD4+ T cell subsets and CD11c+ cells in the peripheral blood mononuclear cells and spleen were examined and quantified with flow cytometry. Serum IL-6 levels were measured by enzyme-linked immunosorbent assay on day 7.ResultsThe mean graft survivals were 6.86 days in the untreated group, and 10.0 days in the TM/DX group (p<0.001). The TM/DX treatment affected the CD4+ T cell subsets without suppressing the total CD4+ T cell population. The CD4+FOXP3+/CD4+CD44hi T cell ratio increased. Increase in cell counts and median fluorescence intensity on CD11c+CD85k+ with TM/DX were observed. The inhibition of pro-inflammatory cytokine interleukin-6 was also observed.ConclusionThese outcomes suggest the immunomodulating effect of the TM/DX combinatorial treatment. In conclusion, TM/DX combination may be a promising immunomodulatory approach for preventing allograft rejection and improving graft survival by inducing tolerance in transplantation.

Co-Stimulatory Molecules during Immune Control of Epstein Barr Virus Infection

The Epstein Barr virus (EBV) is one of the prominent human tumor viruses, and it is efficiently immune-controlled in most virus carriers. Cytotoxic lymphocytes strongly expand during symptomatic primary EBV infection and in preclinical in vivo models of this tumor virus infection. In these models and patients with primary immunodeficiencies, antibody blockade or deficiencies in certain molecular pathways lead to EBV-associated pathologies. In addition to T, NK, and NKT cell development, as well as their cytotoxic machinery, a set of co-stimulatory and co-inhibitory molecules was found to be required for EBV-specific immune control. The role of CD27/CD70, 4-1BB, SLAMs, NKG2D, CD16A/CD2, CTLA-4, and PD-1 will be discussed in this review. Some of these have just been recently identified as crucial for EBV-specific immune control, and for others, their important functions during protection were characterized in in vivo models of EBV infection and its immune control. These insights into the phenotype of cytotoxic lymphocytes that mediate the near-perfect immune control of EBV-associated malignancies might also guide immunotherapies against other tumors in the future.

Temporal single-cell tracing reveals clonal revival and expansion of precursor exhausted T cells during anti-PD-1 therapy in lung cancer

Anti-PD-1 treatment has shown unprecedented clinical success in the treatment of non-small-cell lung cancer (NSCLC), but the underlying mechanisms remain incompletely understood. Here, we performed temporal single-cell RNA and paired T-cell receptor sequencing on 47 tumor biopsies from 36 patients with NSCLC following PD-1-based therapies. We observed increased levels of precursor exhausted T (Texp) cells in responsive tumors after treatment, characterized by low expression of coinhibitory molecules and high expression of GZMK. By contrast, nonresponsive tumors failed to accumulate Texp cells. Our data suggested that Texp cells were unlikely to be derived from the reinvigoration of terminally exhausted cells; instead, they were accumulated by (1) local expansion and (2) replenishment by peripheral T cells with both new and pre-existing clonotypes, a phenomenon we named clonal revival. Our study provides insights into mechanisms underlying PD-1-based therapies, implicating clonal revival and expansion of Texp cells as steps to improve NSCLC treatment.

128P Ex-vivo co-blockade of CD-155/TIGIT and PD-1/PD-L1 using CCAT-1, H19 and MALAT-1 LncRNAs in hepatocellular carcinoma

128P Ex-vivo co-blockade of CD-155/TIGIT and PD-1/PD-L1 using CCAT-1, H19 and MALAT-1 LncRNAs in hepatocellular carcinoma

MiR-155-overexpressing monocytes resemble HLAhighISG15+ synovial tissue macrophages from patients with rheumatoid arthritis and induce polyfunctional CD4+ T-cell activation.

MicroRNAs (miRs) are known to regulate pro-inflammatory effector functions of myeloid cells, and miR dysregulation is implicated in rheumatoid arthritis (RA), a condition characterized by inflammation and destruction of the joints. We showed previously that miR-155 is increased in myeloid cells in RA and induces pro-inflammatory activation of monocytes and macrophages; however, its role at the interface between innate and adaptive immunity was not defined. Here, RNA-sequencing revealed that overexpression of miR-155 in healthy donor monocytes conferred a specific gene profile which bears similarities to that of RA synovial fluid-derived CD14+ cells and HLAhighISG15+ synovial tissue macrophages, both of which are characterized by antigen-presenting pathways. In line with this, monocytes in which miR-155 was overexpressed, displayed increased expression of HLA-DR and both co-stimulatory and co-inhibitory molecules, and induced activation of polyfunctional T cells. Together, these data underpin the notion that miR-155-driven myeloid cell activation in the synovium contributes not only to inflammation but may also influence the adaptive immune response.