Levels Of CTLA-4 Research Articles

Radiotherapy plus camrelizumab affects peripheral CD8 T-cell differentiation subsets expressing PD-1, TIGIT, and CTLA-4 in esophageal squamous cell carcinoma.

Our previous phase Ib trial (NCT03222440) showed that radiotherapy plus the anti-PD-1 antibody camrelizumab is a safe and feasible first-line therapy for locally advanced esophageal squamous cell carcinoma. In this study, we divided peripheral CD8 T-cell differentiation subsets into 4 subpopulations (naive T cells, central memory T cells, effector memory T cells, and CD45RA+ effector memory T cells). We then investigated the influence of radiotherapy plus camrelizumab therapy on the proportions of the 4 subsets and their PD-1, TIGIT, and CTLA-4 expression as well as their proliferative activity and compared the effects with those of concurrent chemoradiotherapy. Nineteen and 15 patients with esophageal squamous cell carcinoma who received radiotherapy plus camrelizumab therapy and concurrent chemoradiotherapy, respectively, were enrolled in this study. We isolated peripheral blood mononuclear cells from these patients before treatment and longitudinally after the delivery of 40 Gy radiotherapy. Flow cytometry was conducted to detect peripheral CD8 T-cell subsets and PD-1, TIGIT, CTLA-4, and Ki67 expression levels in patients with esophageal squamous cell carcinoma. We found that radiotherapy plus camrelizumab therapy did not change the proportions of the 4 subsets or the expression of CTLA-4, but this therapy decreased PD-1 expression by the 4 subsets and TIGIT expression by effector memory T cells, as well as significantly enhanced the proliferative activity of CD8 T cells, whereas concurrent chemoradiotherapy produced different effects. In addition, we further identified peripheral biomarkers that potentially predict the outcome of radiotherapy plus camrelizumab therapy.

EXPERIMENTAL GESTATIONAL DIABETES DISRUPTS THE FORMATION OF IMMUNE TOLERANCE IN OFFSPRING.

The aim: To analyze the mRNA gene expression level of Aire, Deaf1, Foxp3, Ctla4, Il10, Nlrp3 and distribution of NLRP3+-cells in mesenteric lymph nodes (MLNs) of the offspring of rats with GD, both untreated and treated with glibenclamide and in conditions of insulin oral tolerance formation. Materials and methods: The study involves 160 male rats, one- or six-month-old. The mRNA genes expression was studied by real time quantitative poly¬merase chain reaction. Structure of Nlrp3+ -cells population was studied by histological sections of MLNs. Results: We observed AIRE gene repression, reduced mRNA levels of Deaf1 and the transcription factor Foxp3 in offspring of rats with GD. This was accompanied by inhibition of IL-10 gene expression and negative costimulatory molecules Ctla4. The development of the experimental GD was accompanied by transcrip¬tional induction of the Nlrp3 gene in MLNs of descendants. The administration of glibenclamide to pregnant female rats with GD inhibited the transcription of the Nlrp3 gene only in one-month-old offspring (5.3-fold) and did not change it in six-month-old animals. In offspring of rats with GD, the density of the NLRP3+-lymphocyte population in the MLNs increased, more pronounced in one-month-old animals. The administration of glibenclamide to pregnant rats with GD reduced the number of NLRP3+ -lymphocytes only in one-month-old offspring (by 33.0 %), whereas this index in six month-old offspring even increased. Conclusions: Experimental prenatal hyperglycemia leads to increased proinflammatory signaling and violation of peripheral immunological tolerance formation more pronounced at one month of life.

Epigenetic Regulation of the Expression of T Cell Stimulatory and Inhibitory Factors by Histone H3 Lysine Modification Enzymes and Its Prognostic Roles in Glioblastoma.

This study aimed to identify the specific T cell co-stimulatory and co-inhibitory factors that play prognostic roles in patients with glioblastoma. Additionally, the unique histone H3 modification enzymes that regulate the expression levels of these specific co-stimulatory and co-inhibitory factors were investigated. The medical records of 84 patients newly diagnosed with glioblastoma at our institution from January 2006 to December 2020 were retrospectively reviewed. Immunohistochemical (IHC) staining for T cell co-stimulatory factors (CD27, CD28, CD137, OX40, and ICOS), T cell co-inhibitory factors (CTLA4, PD1, PD-L1, TIM3, and CD200R), and histone H3 lysine modification enzymes (MLL4, RIZ, EZH1, NSD2, KDM5c, JMJD1a, UTX, and JMJD5) was performed on archived paraffin-embedded tissues obtained by biopsy or resection. Quantitative real time-polymerase chain reaction (qRT-PCR) was performed for specific factors, which demonstrated causal relationships, in order to validate the findings of the IHC examinations. The mean follow-up duration was 27.5 months (range, 4.1-43.5 months). During this period, 76 patients (90.5%) died, and the mean OS was 19.4 months (95% confidence interval, 16.3-20.9 months). Linear positive correlations were observed between the expression levels of CD28 and JMJD1a (R2 linear = 0.982) and those of CD137 and UTX (R2 linear = 1.528). Alternatively, significant negative correlations were observed between the expression levels of CTLA4 and RIZ (R2 linear = -1.746) and those of PD-L1 and EZH1 (R2 linear = -2.118); these relationships were confirmed by qRT-PCR. In the multivariate analysis, increased expression levels of CD28 (P = 0.042), and CD137 (P = 0.009), and decreased expression levels of CTLA4 (P = 0.003), PD-L1 (P = 0.020), and EZH1 (P = 0.040) were significantly associated with longer survival. These findings suggest that the expression of certain T cell co-stimulatory factors, such as CD28 and CD 137, and co-inhibitory factors, such as CTLA4 and PD-L1 are associated with prognosis of glioblastoma patients.

ScRNA-seq profiling of neonatal and adult thymus-derived CD4+ T cells by a T cell origin-time tracing model.

It is well documented that the neonatal thymus-derived (neonatal-TD) regulatory T cells (Treg) are essential to prevent lethal autoimmune diseases and allergies, and neonatal and adult thymus possesses distinct output potentials for naïve T cells, including Treg. However, the molecular features and detailed functional differences between neonatal-TD and adult thymus-derived (adult-TD) T cells in terms of their ability to maintain immune homeostasis during long-term environmental influences are still largely unknown, partially due to the lack of appropriate animal models to precisely trace these cells at specific time points. In this study, neonatal-TD and adult-TD CD4+ T cells from the spleen and Peyer's patches were traced for 9 weeks by a T cell origin-time tracing mouse model and analysed by single-cell RNA sequencing. More Treg but fewer naïve T cells were found in neonatal-TD CD4+ T cells from both tissues than those from adult-TD counterparts. Interestingly, the neonatal-TD Treg in both the spleen and Peyer's patches exhibited augmented expression of Foxp3, Gata3, Ctla4, Icos, Il2ra, Tgfb1, and Nrp1, as well as enriched Gene Ontology terms like T cell activation and tolerance induction, indicating an enhanced immunosuppressive function. These results were further confirmed by flow cytometry analysis and in vitro immune suppression assays. Flow cytometry also revealed a significantly higher proportion of neonatal-TD Treg in total Treg than that of adult-TD counterparts, suggesting the longer lifespan of neonatal-TD Treg. To investigate the intrinsic features of neonatal-TD and adult-TD CD4+ T cells, a shortened tracing time was performed. Surprisingly, the neonatal-TD and adult-TD CD4+ T cells had similar proportions of Treg and did not exhibit significant differences in Foxp3, Gata3, Ctla4, Icos, Il2ra, and Tgfb1 expression levels after tracing for 12 days. On the other hand, neonatal-TD Treg present an increased Nrp1 expression level compared with adult-TD counterparts, indicating the enhanced stability. Together, our work reveals that the neonatal-TD Treg are more immunosuppressive, which is likely shaped primarily by environmental factors.

Factors affecting HBV DNA suppression in chronic hepatitis B patients treated with tenofovir disoproxil fumarate

Background: This study aims to determine the factors affecting HBV DNA suppression in chronic hepatitis B patients with tenofovir disoproxil fumarate (TDF). Methods: A case-control was carried out from October 2021 to August 2022 on 182 chronic hepatitis B patients who had TDF therapy regularly for 24 weeks at H. Adam Malik and USU Hospitals in Medan, Indonesia. The history of the samples was obtained, followed by physical examination, and blood collection. CTLA-4 polymorphism examination was carried out using real-time PCR, while the serum CTLA-4 levels were assessed with ELISA. Results: The results showed that CTLA-4, HBV DNA, ALT, and CTLA-4 -1661G>A polymorphisms have a relationship with HBV DNA suppression in chronic hepatitis B patients with TDF. Conclusions: The levels of CTLA-4, HBV DNA, ALT, and CTLA-4 -1661G>A polymorphism have a potential relationship with the suppression of HBV DNA in chronic hepatitis B patients with TDF.

An autophagy-related long non-coding RNA prognostic model and related immune research for female breast cancer.

Breast cancer (BRCA) is the most common malignancy among women worldwide. It was widely accepted that autophagy and the tumor immune microenvironment play an important role in the biological process of BRCA. Long non-coding RNAs (lncRNAs), as vital regulatory molecules, are involved in the occurrence and development of BRCA. The aim of this study was to assess the prognosis of BRCA by constructing an autophagy-related lncRNA (ARlncRNA) prognostic model and to provide individualized guidance for the treatment of BRCA. The clinical data and transcriptome data of patients with BRCA were acquired from the Cancer Genome Atlas database (TCGA), and autophagy-related genes were obtained from the human autophagy database (HADb). ARlncRNAs were identified by conducting co‑expression analysis. Univariate and multivariate Cox regression analysis were performed to construct an ARlncRNA prognostic model. The prognostic model was evaluated by Kaplan-Meier survival analysis, plotting risk curve, Independent prognostic analysis, clinical correlation analysis and plotting ROC curves. Finally, the tumor immune microenvironment of the prognostic model was studied. 10 ARlncRNAs(AC090912.1, LINC01871, AL358472.3, AL122010.1, SEMA3B-AS1, BAIAP2-DT, MAPT-AS1, DNAH10OS, AC015819.1, AC090198.1) were included in the model. Kaplan-Meier survival analysis of the prognostic model showed that the overall survival(OS) of the low-risk group was significantly better than that of the high-risk group (p< 0.001). Multivariate Cox regression analyses suggested that the prognostic model was an independent prognostic factor for BRCA (HR = 1.788, CI = 1.534-2.084, p < 0.001). ROCs of 1-, 3- and 5-year survival revealed that the AUC values of the prognostic model were all > 0.7, with values of 0.779, 0.746, and 0.731, respectively. In addition, Gene Set Enrichment Analysis (GSEA) suggested that several tumor-related pathways were enriched in the high-risk group, while several immune‑related pathways were enriched in the low-risk group. Patients in the low-risk group had higher immune scores and their immune cells and immune pathways were more active. Patients in the low-risk group had higher PD-1 and CTLA-4 levels and received more benefits from immune checkpoint inhibitors (ICIs) therapy. The ARlncRNA prognostic model showed good performance in predicting the prognosis of patients with BRCA and is of great significance to guide the individualized treatment of these patients.

Identification of a novel gene signature of lung adenocarcinoma based on epidermal growth factor receptor-tyrosine kinase inhibitor resistance.

Tyrosine kinase inhibitors (TKIs) that target epidermal growth factor receptor (EGFR) mutations are commonly administered to EGFR-positive lung cancer patients. However, resistance to EGFR-TKIs (mostly gefitinib and erlotinib) is presently a significant problem. Limited studies have focused on an EGFR-TKI resistance-related gene signature (ERS) in lung adenocarcinoma (LUAD). Gefitinib and erlotinib resistance-related genes were obtained through the differential analyses of three Gene Expression Omnibus datasets. These genes were investigated further in LUAD patients from The Cancer Genome Atlas (TCGA). Patients in the TCGA-LUAD cohort were split into two groups: one for training and one for testing. The training cohort was used to build the ERS, and the testing cohort was used to test it. GO and KEGG analyses were explored for the enriched pathways between the high-risk and low-risk groups. Various software, mainly CIBERSORT and ssGSEA, were used for immune infiltration profiles. Somatic mutation and drug sensitivity analyses were also explored. An ERS based on five genes (FGD3, PCDH7, DEPDC1B, SATB2, and S100P) was constructed and validated using the TCGA-LUAD cohort, resulting in the significant stratification of LUAD patients into high-risk and low-risk groups. Multivariable Cox analyses confirmed that ERS had an independent prognostic value in LUAD. The pathway enrichment analyses showed that most of the genes that were different between the two risk groups were related to the immune system. Further immune infiltration results revealed that a lower immune infiltration score was observed in high-risk patients, and that various leukocytes were significantly related to the ERS. Importantly, samples from the high-risk group showed lower levels of PD-1, PD-L1, and CTLA-4, which are important biomarkers for immunotherapy responses. Patients in the high-risk group also had more gene mutation changes and were more sensitive to chemotherapy drugs like docetaxel and sorafenib. The ERS was also validated in the GSE30219, GSE11969 and GSE72094, and showed a favorable prognostic value for LUAD patients. The ERS established during this study was able to predict a poor prognosis for LUAD patients and had great potential for predicting drug responses.

Regulatory T cells in psoriatic arthritis: an IL-17A-producing, Foxp3intCD161 + RORγt + ICOS + phenotype, that associates with the presence of ADAMTSL5 autoantibodies

In psoriatic arthritis (PsA), predisposing class I HLA alleles, the presence of synovial clonally proliferated CD8 + T cells and autoantibodies all point towards the loss of immune tolerance. However, the key mechanisms that lead to immune dysregulation are not fully understood. In other types of inflammatory arthritis, T regulatory cell (Treg) dysfunction and plasticity at sites of inflammation were suggested to negatively affect peripheral tolerance. We here addressed if Treg variances associate with psoriatic disease. We collected clinical data, sera and peripheral blood mononuclear cells from 13 healthy controls, 21 psoriasis and 21 PsA patients. In addition, we obtained synovial fluid mononuclear cells from 6 PsA patients. We studied characteristics of CD4 + CD25 + CD127loFoxp3 + Tregs by flow cytometry and used ELISA to quantify antibodies against ADAMTSL5, a recently discovered autoantigen in psoriatic disease. In comparison with their circulating counterparts, Tregs from inflamed joints express increased levels of ICOS, CTLA-4 and TIGIT. Furthermore, synovial fluid-derived Tregs have a distinct phenotype, characterized by IL-17A production and upregulation of CD161 and RORγt. We identified a subset of Tregs with intermediate Foxp3 expression as the major cytokine producer. Furthermore, ICOS + Tregs associate with PsA disease activity as measured by PASDAS. Lastly, we observed that presence of the Foxp3int Tregs associates with an increased abundance of anti-ADAMTSL5 autoantibodies. Tregs derived from the inflammatory environment of inflamed PsA joints exhibit a distinct phenotype, which associates with loss of peripheral immune tolerance in psoriatic disease.

Regulatory T Cell Depletion during Stem Cell Mobilization Enhances Anti-Myeloma Immunity after Experimental Autologous Stem Cell Transplantation

Autologous stem cell transplantation (ASCT) with G-CSF/plerixafor mobilized peripheral blood stem cells (PBSC) remains the standard of care for newly diagnosed eligible multiple myeloma (MM) patients and prolongs progression-free survival. However, most patients eventually progress and require additional therapy. We have previously demonstrated that experimental ASCT can enhance myeloma-specific immunity and limits disease progression characterized by immunological escape. Here we explored the ability of stem cell mobilization (SCM) to mobilize putative myeloma-specific T cells from the bone marrow (BM) and concurrent effects of regulatory T cell depletion (Treg), hypothesizing that this may represent an opportunity to optimize myeloma-specific immunity prior to ASCT. In myeloma patients we noted increased proportions of subsets of effector memory CD8 T cells, including a CX3CR1/granzyme B (GzmB)+ subset in PBSC grafts relative to BM (P<0.01). TIGIT+ Treg were also significantly expanded in PBSC (P <0.01). To study the relevance of these effects, we transferred congenically marked BM T cells into syngeneic mice. We noted that BM-derived effector (CD44+) CD8 cells preferentially homed back to BM (vs. spleen/blood), consistent with T cell residency at this site. SCM subsequently promoted the migration of these resident effector CD8 T cells from BM (4-fold reduction, P <0.001) to blood (5-fold expansion, P <0.001), confirming that PBSC contain BM resident T cells. BM Foxp3+ Treg were also reduced in BM and increased in blood after SCM. Mobilized Treg were characterized by an immunosuppressive phenotype with high levels of CD73, Nrp-1, CTLA4 and TIGIT, and this represents a possible suppressive pathway invoked by SCM. We thus examined the role of BM Treg in limiting myeloma-specific immunity during SCM with Foxp3-GFP-DTR mice. Depletion of Treg with diphtheria toxin (DT) during SCM promoted the expansion of antigen experienced CD8 T cells that secreted IFNg, TNF and GzmB. We next hypothesized that expansion of these polyfunctional cells would enhance myeloma-specific immunity after ASCT. To test this, we treated Vk*MYC bearing Foxp3-GFP-DTR donor mice with DT (vs. saline) 1 week after tumor injection followed by SCM. CD8 T cells from mobilized grafts were transplanted with BM and CD4 T cells from naïve B6 into lethally irradiated Vk*MYC bearing recipients (Figure 1A). Recipients transplanted with CD8 T cells from Treg depleted donors had dramatically improved tumor control (Figure 1B) after ASCT compared to recipients of cells from Treg intact donors (survival 100 days post-ASCT; 100% for DT group vs 13% for saline group, P <0.0001). Rechallenge of mice surviving over 100 days after ASCT confirmed MM clone-specific immunity with complete elimination of the MM seen at initial ASCT, but not an unrelated clone. We next studied clinically relevant approaches to mimic this scenario. Administration of TIGIT, CTLA4, CD25 or LAG3 antibodies resulted in inadequate Treg depletion in BM to recapitulate this effect. In contrast, a synthetic IL-2/IL-15 mimetic NL-201 that selectively binds the beta and gamma chains of IL-2 receptor but not the high affinity IL-2Ra (CD25) reduced BM Treg (45.9% vs 18.6%, P <0.05) and expanded polyfunctional effector cells expressing IFNg+TNF+GzmB+ in SCM grafts. MM-bearing mice transplanted with NL-201 mobilized CD8 T cells were also protected against relapse after ASCT (survival 100 days post-ASCT; 87.5% for NL-201 group vs 25% for saline group, P <0.05). This protection was characterized by expansion of antigen experienced (CD38+) and cytokine secreting (TNF, IFNg) memory (CD44+) CD8 T cells in the BM 3 weeks after ASCT. BM CD8 T cells and Treg are efficiently mobilized after G-CSF/plerixafor. Depletion of Treg in donors during SCM dramatically increases myeloma specific T cells in stem cell grafts and enhances myeloma-specific immunity after ASCT. Stem cell mobilization in the presence of the synthetic IL-2/15 mimetic NL-201 is a promising clinically tractable approach to recapitulate these effects. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Peripheral Blood Cytotoxic T Cells from Myelofibrosis Patients Show Early Exhausted Features Targetable By CTLA-4 Inhibition

Introduction: Myelofibrosis (MF), either primary or secondary, belongs to Philadelphia-negative myeloproliferative neoplasms (MPN) and is characterized by bone marrow fibrosis, hematopoietic stem cell mobilization and extramedullary hematopoiesis. Compelling evidence are suggesting that persistent antigen stimulation in the tumor microenvironment can differentiate T effector cells into terminally exhausted T cells, a functional state characterized by decrease in proliferation, cytotoxicity, and cytokine production. Innovative therapies aim at reversing the exhausted state through immune checkpoint inhibition to recover the immune response against the tumor. Even in myeloid neoplasms such as MPNs, T cells are showing dysfunctional features; thus we investigated T cell exhaustion in MF to assess the possibility of immune checkpoint inhibition as a new effective therapy. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from 44 MF patients and 22 healthy donors (HD). CD3+CD8+ T cells were characterized by multicolor flowcytometry to assess surface expression of the following inhibitory receptors (IRs): PD-1, CD244, CD160, TIM-3, LAG-3, CTLA-4. Results were correlated with clinical features such as Dynamic International Prognostic Scoring System (DIPSS) classification, splenomegaly, high-molecular risk (HMR) mutation number and other negative prognostic factors. We performed intracellular flowcytometry staining to assess residual cytokine production in PBMCs stimulated overnight with anti-CD3, anti-CD28 and Brefeldin A. Total cellular RNA was isolated from granulocytes of 141 primary and secondary MF patients and 28 HDs, and we performed Gene expression profiling (GEPs) by microarray platform to evaluate IRs-ligands expression. To test the possible inhibitory effect of the neoplastic clone we cultured T cells either alone or in co-culture with the myeloid cells for 4 days in the presence of anti-CD3/CD28 stimulatory beads, SCF, TPO, FLT3l, IL6, IL7 and IL15 and then we tested the activation marker OX40 expression level. The co-culture system was also used to test the effect of CTLA-4 inhibition. Results: We observed increased expressions of PD-1, CD244, CTLA-4 and CD160 on cytotoxic T cells from MF patients together with the expansion of PD-1+CD57- cytotoxic T cell populations (Panel A), which also showed increased expression of all the IRs assessed, with CD160 and CTLA-4 being the more significantly upregulated. Higher levels of PD-1, CD244, CD160, CTLA-4, LAG-3 or TIM-3 on cytotoxic T cells correlate with detrimental features like splenomegaly, low hemoglobin levels, HMR mutation number and more severe DIPSS classification. Moreover, we observed decreased secretion of IFNɣ and TNFɑ by total CD3+CD8+ T cells and PD1+ subpopulation from MF patients (Panel B). A significant reduction of Granzyme B production was observed mainly in patients with expansion of PD1+CD57- exhausted T cells. GEPs analysis highlighted increased expression of IR-ligands like CD274, CEACAM1, CD48, CD80 on granulocytes from MF patients compared to HDs. While cytotoxic T cells from HDs were effectively activated either alone or in co-culture with myeloid cells, the activation of cytotoxic T cells from MF patients was damped in presence of myeloid cells and restored when T cells were cultured alone. Treatment with anti-CTLA-4 was able to partially restore the MF T cells activation potential in the presence of myeloid cells. Conclusions: Our data evidenced in MF patients the presence of an impaired population of peripheral blood cytotoxic T cells expressing multiple IRs and with reduced cytokine production after in vitro activation. Clinical correlations suggest a more severe disease in patients with higher IRs expression on cytotoxic T cells. Moreover, granulocytes from MF patients display higher level of IR-ligands transcripts suggesting an immunosuppressive interplay between the myeloid neoplastic clone and T cells. This was also suggested by reduced activation level of T cells in co-culture with myeloid cells that was restored by removing of myeloid cells or with anti-CTLA-4 treatment. Taken together this data highlights an exhausted state likely implicated in immune escape that could be targeted and potentially reverted by immune checkpoint inhibitions. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Costimulatory Domains Direct Distinct Fates of CAR T Cell Dysfunction

While CAR T cell therapy can be curative for some, clinical data suggest that T cell dysfunction after infusion is a central cause of the therapeutic failure that occurs for most patients. Recent studies have demonstrated that chronic CAR activation, either from antigen-independent signaling (Long AH, Nature Medicine 2015; Lynn R, Nature 2019) or persistent exposure to antigen (Singh N, Cancer Discovery 2020; Good CR, Cell 2021) can lead to T cell dysfunction. Whether all CAR-driven T cell dysfunction results from the same cellular mechanisms remains unknown. We sought to directly interrogate the contribution of costimulatory domains, the primary structures differentiating approved CAR T cell products, to CAR-driven dysfunction. To undertake this, we established an in vitro model that recreates prolonged anti-CD19 CAR stimulation and performed integrated functional and genomic profiling of CD28 or 41BB-based (19/28 or 19/BB) CAR T cells over time. Both cell types were initially able to control high quantities of tumor but became dysfunctional after ~10-12 days of chronic stimulation. This dysfunction manifested as an inability to kill target cells, secrete cytokines, expand and persist, mirroring defects in function seen in patients who do not have responses. RNA sequencing revealed that 19/28 and 19/BB had very similar transcriptional profiles at rest and during activation but diverge as they lost function. Dysfunctional 19/28 cells bore the hallmarks of classical T cell exhaustion, expressing high levels of PDCD1, CTLA4, TOX and NR4A. In contrast, dysfunctional 19/BB cells preferentially expressed class II MHC genes as well as genes associated with T cell memory, such as LEF1, TCF7 and IL7R (Figure 1a). Evaluation of chromatin accessibility using ATAC sequencing revealed a similar trend, with opening of loci associated with exhaustion only in 19/28 cells. To further clarify the transcriptional identity of dysfunctional 19/BB cells we performed single cell RNA sequencing of both cell types at rest, during activation and after onset of dysfunction. These data revealed that dysfunctional 19/BB cells were a heterogenous population, wherein some cells expressed class II MHC genes but the majority (70%) belonged to a unique cluster defined by expression of GNLY, CCL5, KLRK1, GZMA and ID2. Single cell RNA sequencing of CAR+ T cells from a patient with diffuse large B cell lymphoma who received Kymriah, a 19/BB-based CAR T cell product, demonstrated consistent transcriptional evolution. This patient had a partial response one month after treatment with disease progression at three months. We evaluated circulating CAR+ T cells at days 14 and 100 after treatment and observed that day 100 cells were also defined by high expression of GNLY, CCL5, KLRK1 and GZMA. We next sought to identify the transcriptional regulators that led to 19/BB dysfunction. Using our ATACseq data we performed motif analysis to identify which transcription factor binding sites were opening as each cell type progressed from rest to dysfunction. As has been previously shown (Lynn R, Nature 2019), 19/28 cells demonstrated opening of sites for AP-1 factors Jun and Fos. 19/BB cells, instead, had increased accessibility at binding sites for forkhead box-O (FOXO) proteins. Consistent with these data, our single cell RNAseq demonstrated increased expression of FOXO3 target genes in dysfunctional 19/BB cells, confirming not only increased accessibility but also increased FOXO3 activity in these cells. To determine if FOXO3 was responsible for failure of 19/BB cells we disrupted the FOXO3 locus in T cells expressing either 19/28 or 19/BB and subjected these cells to our chronic stimulation cultures. Intriguingly, disruption of FOXO3 consistently delayed the onset of dysfunction in 19/BB but not 19/28 cells (Figure 1b). Collectively, these data suggest that costimulatory domains play a central role in CAR-driven T cell dysfunction that leads to therapeutic failure. While CD28-based CARs promote classical exhaustion programs, 41BB-based CARs drive a dysfunctional trajectory driven by re-activation of FOXO proteins. Development of strategies that can bypass both forms of failure will be critical to improving the efficacy of this platform. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Deficiency of C-reactive protein or human C-reactive protein transgenic treatment aggravates influenza A infection in mice.

C-reactive protein (CRP) has been shown to be a potential candidate target in the immunotherapy of severe influenza A infection. However, it is unclear on the pathogenesis associated with CRP in influenza infections. Here, we used influenza A H1N1 CA04 to infect human CRP transgenic mice (KI), CRP knockout mice (KO), and wild-type mice (WT), respectively, and compared the viral pathogenicity and associated immune response in those mice. The results showed that CA04 infection resulted in 100%, 80%, and 60% death in KO, KI, and WT mice, respectively. Compared to WT mice, CA04 infection resulted in higher TCID50 in lungs on day 3 after infection but lowered HI antibody titers in sera of survivors on day 21 after infection in KI mice. ELISA assay showed that IFN-γ concentration was significantly increased in sera of WT, KI, or KO mice on day 7 after infection, and IL-17 was remarkably increased in sera of WT mice but decreased in sera of KI mice while no significant change in sera of KO mice on day 3 or 7 after infection. Quantitative RT-PCR showed that the relative expression levels of immune checkpoint CTLA-4, LAIR-1, GITR, BTLA, TIM-3, or PD-1 mRNA in the lung presented decreased levels on day 3 or 7 after infection in KI or KO mice. The correlation analysis showed that mRNA expression levels of the 6 molecules positively correlated with viral TICD50 in WT mice but negatively correlated with viral TCID50 in KI or KO mice. However, only LAIR-1 presented a significant correlation in each lung tissue of WT, KI, or KO mice with CA07 infection statistically. IHC results showed that LAIR-1 positive cells could be found in WT, KO, or KI mice lung tissues with CA04 infection, and the positive cells were mainly distributed in an inflammatory dense area. Our results suggested that deficiency of CRP or human CRP transgenic treatment aggravates influenza A virus infection in mice. CRP is a double sword in immune regulation of influenza infection in which IL-17 and immune checkpoint may be involved.

The proportion and phenotypic changes of CD4+CD25−Foxp3+ T cells in patients with untreated rheumatoid arthritis

ObjectiveCD4+CD25+Foxp3+ regulatory T (Treg) cell-mediated immunosuppression is an essential mechanism of rheumatoid arthritis (RA). However, little is known regarding the specific role of CD4+CD25−Foxp3+ Treg cells in RA. This study aimed to investigate the frequency of circulating CD4+CD25−Foxp3+ Treg cells and their role in RA.MethodsSixty-one untreated RA patients and 40 healthy controls (HCs) were enrolled in this study. The proportion of CD4+CD25−Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs; the levels of CTLA4, GITR, Helios, and ICOS; and the production of IL-17A, IFN-γ, and IL-10 were assessed by flow cytometry. The correlation of CD4+CD25–Foxp3+ T cells and CD4+CD25+Foxp3+ Tregs with the clinical indicators was conducted by Spearman correlation analysis.ResultsThe proportion of CD4+CD25–Foxp3+ T cells was elevated in RA and positively correlated with disease activity. CD4+CD25–Foxp3+ T cells expressed less Helios and produced more IFN-γ than conventional Tregs in RA. Additionally, the proportion of CD4+CD25–Foxp3+ T cells was positively correlated with DAS28 score, IgG titer, and anti-CCP titer.ConclusionsThese data indicate that CD4+CD25−Foxp3+ T cells in RA exhibit several different functional properties from conventional Tregs and are correlated with RA disease activity.

Stemness analysis in hepatocellular carcinoma identifies an extracellular matrix gene-related signature associated with prognosis and therapy response.

Background: Tumor stemness is the stem-like phenotype of cancer cells, as a hallmark for multiple processes in the development of hepatocellular carcinoma (HCC). However, comprehensive functions of the regulators of tumor cell’s stemness in HCC remain unclear. Methods: Gene expression data and clinical information of HCC samples were downloaded from The Cancer Genome Atlas (TCGA) dataset as the training set, and three validation datasets were derived from Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC). Patients were dichotomized according to median mRNA expression–based stemness index (mRNAsi) scores, and differentially expressed genes were further screened out. Functional enrichment analysis of these DEGs was performed to identify candidate extracellular matrix (ECM)–related genes in key pathways. A prognostic signature was constructed by applying least absolute shrinkage and selection operator (LASSO) to the candidate ECM genes. The Kaplan–Meier curve and receiver operating characteristic (ROC) curve were used to evaluate the prognostic value of the signature. Correlations between signatures and genomic profiles, tumor immune microenvironment, and treatment response were also explored using multiple bioinformatic methods. Results: A prognostic prediction signature was established based on 10 ECM genes, including TRAPPC4, RSU1, ILK, LAMA1, LAMB1, FLNC, ITGAV, AGRN, ARHGEF6, and LIMS2, which could effectively distinguish patients with different outcomes in the training and validation sets, showing a good prognostic prediction ability. Across different clinicopathological parameter stratifications, the ECMs signature still retains its robust efficacy in discriminating patient with different outcomes. Based on the risk score, vascular invasion, α-fetoprotein (AFP), T stage, and N stage, we further constructed a nomogram (C-index = 0.70; AUCs at 1-, 3-, and 5-year survival = 0.71, 0.75, and 0.78), which is more practical for clinical prognostic risk stratification. The infiltration abundance of macrophages M0, mast cells, and Treg cells was significantly higher in the high-risk group, which also had upregulated levels of immune checkpoints PD-1 and CTLA-4. More importantly, the ECMs signature was able to distinguish patients with superior responses to immunotherapy, transarterial chemoembolization, and sorafenib. Conclusion: In this study, we constructed an ECM signature, which is an independent prognostic biomarker for HCC patients and has a potential guiding role in treatment selection.

Lactate score predicts survival, immune cell infiltration and response to immunotherapy in breast cancer.

Background: Tumor-derived lactate can modulate the function of infiltrating immune cells to establish an immunosuppressive microenvironment that favors tumor progression. However, possible effects of lactate-related genes (LRGs) on the tumor microenvironment (TME) of breast cancer (BRCA) are still unknown. Methods: LRGs were comprehensively screened from lactate metabolism-related pathways. We correlated the expression of these LRGs with immune cell infiltrating characteristics in the TME and clinicopathological features of patients. We also established a lactate score for quantifying lactate metabolism patterns of cancers and to predict of recurrence-free survival (RFS). Results: We successfully constructed a lactate score that was an independent prognostic factor in BRCA. A low lactate score, which was associated with immune activation with increased CD8+ T cells infiltration levels, indicated an inflamed TME. Consistently, higher expression levels of inhibitory immune checkpoints, including PD-L1, LAG3, CTLA4, and TIM3, as observed from high lactate score subgroup, suggested an immune-desert phenotype as well as poor prognosis. Moreover, a low lactate score predicted the increased chemotherapeutic drug sensitivity and enhanced anti-PD-1 immunotherapy responses. Conclusion: The present study analyzed the potential roles of LRGs in the TME diversity and prognosis. These results will help to improve our understanding of the characteristics of TME immune cell infiltration and guide the development of more effective immunotherapy strategies.

A novel defined m7G regulator signature to investigate the association between molecular characterization and clinical significance in lung adenocarcinoma.

BackgroundAbout170 chemical modifications to RNAs have been identified, which significantly affect gene expression. Dysregulation of RNA modifications induced by abnormal expression or mutations in RNA modifiers might result in cancer. The most frequent RNA modifications are N6-methyladenosine (m6A), 5-methylcytosine (m5C), and N7-methylguanosine (m7G). Lung cancer is the leading cause of cancer-related deaths globally. The present study aimed to investigate whether the expression of the m7G-related genes is linked to lung cancer cases with lung adenocarcinoma (LUAD), which accounts for about 40% of lung cancer cases.MethodsA total of 12 m7G-related differentially expressed genes (DEGs) were identified in LUAD patients by The Cancer Genome Atlas (TCGA). The least absolute shrinkage and selection operator (LASSO) Cox regression method was used to build a four-gene risk model. Then, LUAD patients in the TCGA cohort were divided into low- and high-risk groups based on their risk scores for subsequent molecular and clinical research.ResultsCompared to the low-risk group, the high-risk group had a decreased overall survival (OS) (P=0.047). The risk score and stage were independent factors for predicting the OS of LUAD (P=0.0004 and P<0.0001, respectively). Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses based on the two groups showed that the DEGs were metabolically and hormonally related. The high-risk group showed a higher mutation rate and lesser immune cell infiltration, especially in TP53, KRAS, and MET. The expression level of PD-L1 and CTLA4 was high in the high-risk group (P<0.05). The high-risk group is more sensitive to anti-cancer therapy with lower IC50 and higher immunophenoscore (IPS).ConclusionsIn this study, we developed a novel LUAD stratification model based on m7G-related genes that successfully predicts the prognosis of LUAD patients and serves as a guide for clinically personalized treatment.

Expression level of immune checkpoint inhibitory factors in preeclampsia

Preeclampsia (PE) is a severe complication in pregnancy, and its symptoms (proteinuria and hypertension) manifest after 20 weeks of gestation, affecting up to 8 % of pregnancies. The pregnant women's immune system uses different tolerance mechanisms to deal with a semi-allogeneic fetus. The T-cell subsets including CD8+, CD4+, and Treg play a critical role in maintaining pregnancies. The expression of immune checkpoint molecules in T-cells can ensure pregnancy at the feto-maternal interface by controlling immune responses. This research aims to evaluate the expression level of immune checkpoint factors, including PD-1, LAG-3, CTLA-4, and TIM-3 in normal pregnant women and PE patients. Decidual tissue was collected from 50 participants (25 PE and 25 control). For evaluating the genes expression, real-time PCR was employed. The western blot was used to assess the proteins level. The results of real-time PCR indicated significantly decreased expression level of these immune checkpoints in PE patients. In parallel to gene expression results, the protein level of PD-1, LAG-3, CTLA-4, and TIM-3 in the PE group was also reduced. We revealed that the profile of proteins and genes expression of immune checkpoints in the decidua of PE mothers are different from normal pregnancy and these results indicate aberrant expression of immune checkpoints such as PD-1, LAG-3, CTLA-4, and TIM-3 may cause maladaptation immune response which results in PE manifestation.

An immune-related gene prognostic risk index for pancreatic adenocarcinoma.

ObjectiveOur goal is to construct an immune-related gene prognostic risk index (IRGPRI) for pancreatic adenocarcinoma (PAAD), and to clarify the immune and molecular features in IRGPRI-defined PAAD subgroups and the benefit of immune checkpoint inhibitors (ICIs) therapy.MethodThrough differential gene expression analysis, weighted gene co-expression network analysis (WGCNA), and univariate Cox regression analysis, 16 immune-related hub genes were identified using the Cancer Genome Atlas (TCGA) PAAD dataset (n = 182) and immune gene set. From these genes, we constructed an IRGPRI with the Cox regression method and the IRGPRI was verified based on the Gene Expression Omnibus (GEO) dataset (n = 45). Then, we analyzed the immune and molecular features and the benefit of ICI therapy in IRGPRI-defined subgroups.ResultsFive genes, including S100A16, CD40, VCAM1, TNFRSF4 and TRAF1 were used to construct IRGPRI. As with the results of the GEO cohort, the overall survival (OS) was more favorable in low IRGPRI patients versus high IRGPRI patients. The composite results pointed out that low IRGPRI was associated with immune response-related pathways, high level of CTLA4, low KRAS and TP53 mutation rate, more infiltration of activated memory CD4+ T cells, CD8+ T cells, and more benefits from ICIs therapy. In comparison, high IRGPRI was associated with cancer-related pathways, low expression of CTLA4, high KRAS and TP53 mutation rate, more infiltration of M2 macrophages, and less benefit from ICIs therapies.ConclusionThis IRGPRI is an encouraging biomarker to define the prognosis, immune and molecular features, and benefits from ICIs treatments in PAAD.

S138: MICROENVIRONMENT-REGULATED TRANSCRIPTIONS FACTORS AHR AND HIF-1Α EXPRESSION IN TREGS PROMOTE CLL PROGRESSION BY IMPAIRING CD8+ T-CELL MEDIATED ANTI-TUMOR IMMUNITY

Background: Chronic Lymphocytic Leukemia (CLL) progression is highly dependent on complex interactions between tumor cells and the tumor microenvironment (TME). Indeed, CLL cells can modify stromal cells and immune cells to promote the survival of the leukemic clone and to escape from the immune system surveillance. Within the TME, regulatory T cells (Tregs) represent a subtype of CD4+ T cells with immunosuppressive abilities, causing the evasion of cancer cells from the immune system. We previously characterized extensively the immune microenvironment of pre-clinical CLL mouse models using mass cytometry, and we described a significant increase in the Tregs subsets with an enhanced immunosuppressive and activated phenotype compared to non-leukemic animals (Wierz et al., Blood, 2018). Interestingly, TIGIT+ Tregs are more immunosuppressive than their TIGIT- Treg counterparts and express higher levels of several transcription factors, including Ahr and Hif1α (Joller et al., Immunity, 2014), both involved in the cellular response to microenvironment-mediated stimuli. Aims: The aim of the present study is to investigate the role of AHR and HIF-1α in the suppressive ability of Tregs during CLL development. Methods: We generated conditional knock out mice (cKO) lacking Ahr or Hif1a genes exclusively in Tregs (Foxp3YFP-CreAhrfx/fx and Foxp3YFP-CreHif1afx/fx mice). We then performed adoptive transfer (AT) of CLL cells obtained from diseased Eµ-TCL1 mice into cKO and control mice. In order to decipher the mechanism by which AHR and HIF-1α pathways in Tregs affect CLL progression, we analyzed the splenic TME of recipient mice and evaluated immune checkpoint expression and cytokine production. Finally, we evaluated the suppression ability of the regulatory T cells with ex vivo suppression assays. Results: Generated cKO mice showed no sign of abnormalities or autoimmune phenotypes, and immune cells phenotyping revealed no major differences. However, we showed that CLL growth in cKO mice was drastically delayed compared to the control mice (A). Interestingly, this decrease was mitigated when CD8+ T cells were depleted. The analysis of the splenic TME in recipient cKO mice revealed an increase in IL-17 and TNF-α production, two major T-cell cytokines, in CD4+ T cells as compared to their WT counterparts. We also measured the expression of immune checkpoints and activation markers in the different T cell subpopulations and observed that Tregs lacking AHR or HIF-1α show decreased levels of the immune checkpoints CTLA-4 and TIGIT, two key proteins for the suppressive functions of Tregs. Ex vivo suppression assays demonstrated an increased proliferation of CD8+ T cells in the presence cKO Tregs (B-C). This result confirmed the decreased suppressive ability of Tregs in absence of the two transcription factors, explaining the observed delay in CLL progression in cKO mice. Image:Summary/Conclusion: Altogether, these results indicate that the TME-regulated transcription factors AHR and HIF-1α in Tregs are crucial for CLL development by promoting escape to anti-tumor immune response, and therefore represent potential therapeutic targets during CLL progression.

Tumour-draining lymph nodes in head and neck cancer are characterized by accumulation of CTLA-4 and PD-1 expressing Treg cells

IntroductionHigh Tregs infiltration within the tumour microenvironment (TME) of various cancers shows a positive correlation with poor prognosis. Despite the fact that tumour draining lymph nodes (TDLNs) are recognized as key organs playing a crucial role in response to immunotherapy and modulating anti-cancer immunity, the distribution of Tregs and their role in TDLNs remain uncertain thus far. The purpose of this project is to investigate the density of Tregs in TDLNs and non-TDLNs and their expression of immune checkpoint molecules – PD-1 and CTLA-4. MethodsSamples including TDLNs, non-TDLNs and metastatic lymph nodes (LNs) from 23 patients with oral squamous cell carcinoma (OSCC) were analyzed by multicolour flow cytometry with a focus on Tregs population and expression of CTLA-4 and PD-1. ResultsTDLNs and metastatic LNs were characterized by a significantly higher infiltration of Tregs defined as CD4+FoxP3+CD25highCD127low cells and significantly higher expression of CTLA-4 and PD-1 on Tregs compared with non-TDLNs. Tregs in TDLNs and metastatic LNs co-expressed CTLA-4 and PD-1 abundantly. High expression of these immune check-point molecules correlated with positive N-stage but not with T-stage. ConclusionTDLNs and metastatic LNs are characterized by a high accumulation of Tregs expressing high levels of CTLA-4 and PD-1. High infiltration of Tregs can be a potential driver of an immunosuppressive milieu in TDLNs that can, in turn, favour cancer progression. High accumulation of Tregs expressing CTLA-4 and PD-1 in TDLNs is associated with lymph node involvement, but not with the size of the primary tumour.