Activated Tim-3/Galectin-9 participated in the development of multiple myeloma by negatively regulating CD4 T cells

The interaction between Tim-3 on T cells and its ligand Galectin-9 negatively regulates the cellular immune response. However, the regulation of Tim-3/Galectin-9 on CD4 T cell subsets in multiple myeloma (MM) remains unclear. The aim of this study was to investigate the relationship between the regulation of CD4 T cell subsets by the Tim-3/Galectin-9 pathway and clinical prognostic indicators in MM. Tim-3/Galectin-9 were detected by flow cytometry, PCR and ELISA in 60 MM patients and 40 healthy controls, and its correlation with clinical prognostic parameters was analyzed. The expressions of Tim-3 on CD4 T cells, Galectin-9 mRNA in PBMC and level of Galectin-9 protein in serum were significantly elevated in MM patients, especially those with poor prognostic indicators. In MM patients, Tim-3 was highly expressed on the surfaces of Th1, Th2, and Th17 cells, but lowly expressed on Treg. Moreover, level of cytokine IFN-γ in serum was negatively correlated with Tim-3+Th1 cell and Galectin-9mRNA, Galectin-9 protein level. In addition, cell culture experiments showed that the anti-tumor effect and the ability to secrete IFN-γ were restored by blocking the Tim-3/Galectin-9 pathway. In MM patients, Tim-3/Galectin-9 is elevated and associated with disease progression, by inhibiting the cytotoxic function of Th1, and also promoting Th2 and Th17 to be involved in immune escape of MM. Therefore, Tim-3/Galectin-9 may serve as a new immunotherapeutic target for MM patients.

The evaluation of PD-1 and Tim-3 expression besides their related miRNAs in PBMCs of women with recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a multifactorial disorder, associated with immunologic abnormalities. During pregnancy, the maternal immune system uses different tolerance mechanisms to deal with a semi-allogenic fetus. The expression of immune checkpoints and their related miRNAs in immune cells can ensure pregnancy at the feto-maternal interface by modulating immune responses. This study aims to evaluate the expression of the immune checkpoint molecules PD-1 and Tim-3 on circulating T cells by flow cytometry, that of mir-138 and mir-155 in PBMCs by Real-time PCR, and the concentrations of TGF-β and IP-10 in the sera of women suffering from RPL as well as of gestational age-matched healthy pregnant women by ELISA. The percentage of PD-1 or Tim-3 expressing CD8+ T cells was significantly lower in RPL patients compared to the controls, while there was no significant difference in Tim-3 expression of CD4+ T cells between the two groups. The mRNA of both the PD-1 and Tim-3 genes were downregulated in PBMCs of RPL patients compared to controls, however, the difference was not statistically significant for Tim-3. The concentration of TGF-β was significantly lower and that of IP-10 was significantly higher in the sera of RPL patients than in those of the controls. The relative expression of mir-138 and miR-155 were significantly lower, in PBMCs of RPL patients than in those of healthy pregnant women. These data confirm that by affecting cytokine production, immune checkpoints, and microRNAs play a role in establishing the appropriate local immune environment for successful pregnancy. The wider analysis of immune checkpoints may also yield new biomarkers for the diagnosis and prevention of RPL.

Evaluation of changes in exhausted T lymphocytes and miRNAs expression in the different trimesters of pregnancy in pregnant women

BACKGROUND

Throughout the three trimesters of a typical pregnancy, we looked at changes in the expression of miRNAs and exhausted T lymphocytes for this study.

METHODS AND RESULTS

Fifty healthy subjects were included in this study. The frequency of exhausted T lymphocytes was measured in isolated PBMCs using flow cytometry. PD-1, TIM-3, and related miRNAs gene expression were assessed using qRT-PCR. The analyses revealed a significant decline in PD-1 and Tim-3 expression in PBMCs from RPL women (p = 0.0003 and p = 0.001, respectively). In addition, PD-1 and TIM-3 expression increased significantly in the 2nd trimester compared with the 1st trimester of healthy pregnant women (p < 0.0001 and p = 0.0002, respectively). PD-1 and TIM-3 expression was down-regulated in the 3rd trimester compared with the 1st and 2nd trimesters. In the present study, we demonstrated that TIM-3+/CD4+, TIM-3+/CD8+, PD-1+/CD4+, and PD-1+/CD8 + exhausted T lymphocytes increased in the circulation of women in the 2nd trimester compared to the 1st and 3rd trimester. In the 3rd trimester, the expression of miR-16-5p increased significantly (p < 0.0001). miR-125a-3p expression was down and upregulated in 2nd (p < 0.0001) and 3rd (p = 0.0007) trimesters compared to 1st trimester, respectively. This study showed a significant elevation of miR-15a-5p in 3rd trimester compared to 1st trimester of pregnant women (p = 0.0002).

CONCLUSIONS

Expression pattern of PD-1 and TIM3 in exhausted T lymphocytes is different not only between normal pregnant and RPL women but also in different trimesters of pregnancy. So, our results showed the role of these markers in the modulation lymphocytes activity in different stages of pregnancy.

Germline HAVCR2/TIM-3 Checkpoint Inhibitor Receptor Deficiency in Recurrent Autoinflammatory Myocarditis

Myocarditis can be caused by viral infection, drug reaction or general inflammatory condition. To provide understanding on inflammatory myocarditis, we describe clinical, genetic, and immunological properties of a young male patient who suffered from recurrent myocarditis episodes since the age of four years. Electrocardiography, troponin I/T, echocardiography, myocardial magnetic resonance imaging and histological findings were consistent with recurrent myocarditis episodes. Homozygous c.245 A > G p.Tyr82Cys pathogenic variant in Hepatitis A Virus Cellular Receptor 2 (HAVCR2) gene encoding T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) receptor was found. Peripheral blood mononuclear cells were collected when the patient was asymptomatic; CD4+ and CD8+ T lymphoblasts, CD56+ natural killer cells and CD14+ monocytes were negative for surface TIM-3 expression. In vitro, TLR4 mediated interleukin-1β (IL-1β) response was high after LPS/ATP stimulation. Clinical symptoms responded to IL-1 receptor antagonist anakinra. TIM-3 p.Tyr82Cys CD4+ and CD8+ T cell proliferation in vitro was unrestrained. Findings on IL-2, interferon gamma, regulatory T cells, signal transducer and activator of transcription (STAT) 1, 3 and 4 phosphorylation, and PD-1 and LAG-3 checkpoint inhibitor receptor analyses were comparable to controls. We conclude that TIM-3 deficiency due to homozygous HAVCR2 c.245 A > G p.Tyr82Cys pathogenic variant in the patient described here is associated with autoinflammatory symptoms limited to early onset recurrent febrile myocarditis. Excessive IL-1β production and defective regulation of T cell proliferation may contribute to this clinical condition responsive to anakinra treatment.

TIM-3, LAG-3, or 2B4 gene disruptions increase the anti-tumor response of engineered T cells

Background

In adoptive T cell therapy, the long term therapeutic benefits in patients treated with engineered tumor specific T cells are limited by the lack of long term persistence of the infused cellular products and by the immunosuppressive mechanisms active in the tumor microenvironment. Exhausted T cells infiltrating the tumor are characterized by loss of effector functions triggered by multiple inhibitory receptors (IRs). In patients, IR blockade reverts T cell exhaustion but has low selectivity, potentially unleashing autoreactive clones and resulting in clinical autoimmune side effects. Furthermore, loss of long term protective immunity in cell therapy has been ascribed to the effector memory phenotype of the infused cells.

Methods

We simultaneously redirected T cell specificity towards the NY-ESO-1 antigen via TCR gene editing (TCRED) and permanently disrupted LAG3, TIM-3 or 2B4 genes (IRKO) via CRISPR/Cas9 in a protocol to expand early differentiated long-living memory stem T cells. The effector functions of the TCRED-IRKO and IR competent (TCRED-IRCOMP) cells were tested in short-term co-culture assays and under a chronic stimulation setting in vitro. Finally, the therapeutic efficacy of the developed cellular products were evaluated in multiple myeloma xenograft models.

Results

We show that upon chronic stimulation, TCRED-IRKO cells are superior to TCRED-IRCOMP cells in resisting functional exhaustion through different mechanisms and efficiently eliminate cancer cells upon tumor re-challenge in vivo. Our data indicate that TIM-3 and 2B4-disruption preserve T-cell degranulation capacity, while LAG-3 disruption prevents the upregulation of additional inhibitory receptors in T cells.

Conclusion

These results highlight that TIM-3, LAG-3, and 2B4 disruptions increase the therapeutic benefit of tumor specific cellular products and suggest distinct, non-redundant roles for IRs in anti-tumor responses.

Post-transplant Inflammatory Bowel Disease Associated with Donor-Derived TIM-3 Deficiency

Inflammatory bowel disease (IBD) occurring following allogeneic stem cell transplantation (aSCT) is a very rare condition. The underlying pathogenesis needs to be better defined. There is currently no systematic effort to exclude loss- or gain-of-function mutations in immune-related genes in stem cell donors. This is despite the fact that more than 100 inborn errors of immunity may cause or contribute to IBD. We have molecularly characterized a patient who developed fulminant inflammatory bowel disease following aSCT with stable 100% donor-derived hematopoiesis. A pathogenic c.A291G; p.I97M HAVCR2 mutation encoding the immune checkpoint protein TIM-3 was identified in the patient's blood-derived DNA, while being absent in DNA derived from the skin. TIM-3 expression was much decreased in the patient's serum, and in vitro-activated patient-derived T cells expressed reduced TIM-3 levels. In contrast, T cell-intrinsic CD25 expression and production of inflammatory cytokines were preserved. TIM-3 expression was barely detectable in the immune cells of the patient's intestinal mucosa, while being detected unambiguously in the inflamed and non-inflamed colon from unrelated individuals. In conclusion, we report the first case of acquired, "transplanted" insufficiency of the regulatory TIM-3 checkpoint linked to post-aSCT IBD.

Tim-3 deficiency aggravates cadmium nephrotoxicity via regulation of NF-κB signaling and mitochondrial damage

Kidney is the target organ of serious cadmium injury. Kidney damage caused by cadmium exposure is greatly influenced by the inflammatory response and mitochondrial damage. T cell immunoglobulin domain and mucin domain 3 (Tim-3) is an essential protein that functions as a negative immunological checkpoint to regulate inflammatory responses. Mice were given cadmium treatments at various dosages (0, 1.5, 3, 4.5 mg/kg) and times (0, 3, 5, 7 days) to assess the effects of cadmium on kidney damage. We found that the optimal way to induce kidney injury in mice was to inject 4.5 mg/kg of cadmium intraperitoneally for five days. It is interesting that giving mice 4.5 mg/kg of cadmium intravenously for seven days drastically lowered their survival rate. After cadmium exposure, Tim-3 knockout mice exhibited higher blood concentrations of urea nitrogen and creatinine compared to control mice. Tim-3 impacted the expression of oxidative stress-associated genes such as UDP glucuronosyltransferase family 1 member A9 (Ugt1a9), oxidative stress-induced growth inhibitor 2 (Osgin2), and S100 calcium binding protein A8 (S100a8), according to RNA-seq and real-time RT-PCR data. Tim-3 deficiency also resulted in activated nuclear factor-kappa B (NF-κB) signaling pathway. The NF-κB inhibitor 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) significantly alleviated cell apoptosis, oxidative stress response, and renal tubule inflammation in Tim-3 knockout mice exposed to cadmium. Furthermore, cadmium caused obvious B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) translocation from cytoplasm to mitochondria, which can be inhibited by TPCA-1. In conclusion, Tim-3 prevented mitochondrial damage and NF-κB signaling activation, hence providing protection against cadmium nephrotoxicity.

Tim-3 Is Not Required for Establishment of CD8+ T Cell Memory to Lymphocytic Choriomeningitis Virus

Tim-3 is a transmembrane protein that is best known for being highly expressed on terminally exhausted CD8+ T cells associated with chronic infection and tumors, although its expression is not limited to those settings. Tim-3 is also expressed by CD8+ T cells during acute infection and by multiple other immune cell types, including CD4+ Th1 and regulatory T cells, dendritic cells, and mast cells. In this study, we investigated the role of Tim-3 signaling on CD8+ T cell memory using a Tim-3 conditional knockout mouse model and mice lacking the signaling portion of the Tim-3 cytoplasmic domain. Together, our results indicate that Tim-3 has at most a modest effect on the formation and function of CD8+ memory T cells.

Retrospective Analyses of PD-L1, LAG-3, TIM-3, OX40L Expressions and MSI Status in Gastroenteropancreatic Neuroendocrine Neoplasms

We investigated expressions of PD-L1, LAG-3, TIM-3, and OX40L as immune checkpoint proteins, and MSI (repetitive short-DNA-sequences due to defective DNA-repair system) status were analyzed with immunohistochemistry from tissue blocks. Of 83 patients, PD-L1 expression was observed in 18.1% (n = 15) of the patients. None of the patients exhibited LAG-3 expression. TIM-3 expression was 4.9% (n = 4), OX40L was 22.9% (n = 19), and 8.4% (n = 7) of the patients had MSI tumor. A low-to-intermediate positive correlation was observed between PD-L1 and TIM-3 expressions (rho: 0.333, p < 0.01). Although PD-L1 expression was higher in grade 3 NET/NEC, MSI status was prominent in grade 1/2 NET.

TIM-3 regulates the proliferation by BDNF-mediated PI3K/AKT axis in the process of endometriosis

BACKGROUND

T cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) initially discovered on the surface of Th1 cells, negatively regulates immune responses and mediates apoptosis of Th1 cells. An increasing number of studies have since shown that TIM-3 is crucial in the genesis and development of immune diseases, cancers, and chronic infectious illnesses. However, the effect of TIM-3 on endometriosis is still unknown.

METHODS

Quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry were used to measure TIM-3 levels in endometriosis. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, colony-forming, Transwell® migration, Matrigel® invasion, and flow cytometry assays were used to explore the function of TIM-3 in vitro, and xenograft experiments in nude mice were used to assess its role in vivo. According to the RNA seq, brain-derived neurotrophic factor (BDNF) was screened. The involvement of specific proliferation-related signaling molecules was determined by transfecting a plasmid and adding an inhibitor in vivo and in vitro.

RESULTS

TIM-3 mRNA and protein expression levels were significantly higher in eutopic and ectopic endometrial tissues than in normal endometrial tissues. By examining the effects of TIM-3 overexpression and knockdown on cell proliferation, migration, and invasion in vitro, and lesions formation in vivo, we found that the expression of TIM-3 was positively correlated with cell proliferation and clone formation in vitro, as well as lesions growth in nude mice. By adding the phosphatidylinositol 3 kinase/protein kinase B(PI3K/AKT) pathway inhibitor LY294002 and knocking down PI3K, we further verified that TIM-3 promotes proliferation in vivo and in vitro via the PI3K pathway. By transfecting the plasmid into ESC cells and gave inhibitors to endometriotic rats models, we tested that TIM-3 regulates the proliferation by BDNF-mediated PI3K/AKT axis.

CONCLUSION

TIM-3 can promote the proliferation of endometriosis by BDNF-mediated PI3K/AKT axis in vivo and in vitro, which may provide a new therapeutic target for the treatment of endometriosis.

Itaconate promotes hepatocellular carcinoma progression by epigenetic induction of CD8+ T-cell exhaustion

Itaconate is a well-known immunomodulatory metabolite; however, its role in hepatocellular carcinoma (HCC) remains unclear. Here, we find that macrophage-derived itaconate promotes HCC by epigenetic induction of Eomesodermin (EOMES)-mediated CD8+ T-cell exhaustion. Our results show that the knockout of immune-responsive gene 1 (IRG1), responsible for itaconate production, suppresses HCC progression. Irg1 knockout leads to a decreased proportion of PD-1+ and TIM-3+ CD8+ T cells. Deletion or adoptive transfer of CD8+ T cells shows that IRG1-promoted tumorigenesis depends on CD8+ T-cell exhaustion. Mechanistically, itaconate upregulates PD-1 and TIM-3 expression levels by promoting succinate-dependent H3K4me3 of the Eomes promoter. Finally, ibuprofen is found to inhibit HCC progression by targeting IRG1/itaconate-dependent tumor immunoevasion, and high IRG1 expression in macrophages predicts poor prognosis in HCC patients. Taken together, our results uncover an epigenetic link between itaconate and HCC and suggest that targeting IRG1 or itaconate might be a promising strategy for HCC treatment.

Immune checkpoint status and exhaustion-related phenotypes of CD8+ T cells from the tumor-draining regional lymph nodes in breast cancer

BACKGROUND

Functional status of T cells determines the responsiveness of cancer patients to immunotherapeutic interventions. Even though T cell-mediated immunity is inaugurated in the tumor-adjacent lymph nodes, peripheral blood has been routinely sampled for testing the immunological assays. The purpose of this study is to determine the immune checkpoint molecule expression and the exhaustion-related phenotype of cytotoxic T cells in the regional lymph nodes from breast cancer patients.

PATIENTS AND METHODS

Multicolor immunophenotyping was used to determine the expression of PD-1, TIM-3, LAG3, CTLA-4, CCR7, CD45RO, CD127, CD25, CXCR5, and ICOS molecules on CD3+ CD4- CD56- CD8+ cytotoxic T cells freshly obtained from the lymph nodes and the peripheral blood samples of the breast cancer patients. The results were assessed together with the clinical data.

RESULTS

A population of cytotoxic T cells was noted with high PD-1 and CXCR5 expression in the lymph nodes of the breast cancer patients. Co-expression of PD-1, CXCR5, TIM-3, and ICOS indicated a follicular helper T cell (Tfh)-like, exhaustion-related immunophenotype in these cytotoxic T cells. Only a minor population with CTLA-4 and LAG3 expression was noted. The PD-1+ CXCR5+ cytotoxic T cells largely displayed CD45RO+ CCR7+ central memory markers. The amount of CXCR5-expressing PD-1- cytotoxic T cells was elevated in the lymph nodes of the patients.

CONCLUSION

The regional lymph nodes of breast cancer patients harbor Tfh-like exhausted cytotoxic T lymphocytes with high PD-1 and TIM-3 checkpoint molecule expression. The immunological conditions in the regional lymph nodes should be implicated for immune checkpoint immunotherapy (ICI) of cancer.

Case Report: HAVCR2 mutation-associated Hemophagocytic lymphohistiocytosis

Germline HAVCR2 mutation has been reported to be associated with subcutaneous panniculitis-like T-cell lymphoma (SPTCL) leading to Hemophagocytic lymphohistiocytosis (HLH). Several studies have indicated that HAVCR2 mutation can cause HLH even in the absence of lymphoma, though the exact mechanism remains unclear. In this article, we reported five cases of HAVCR2 mutation-associated HLH. Our analysis revealed an elevated level of IL-1RA in the serum of these patients. Furthermore, we investigated the potential mechanisms underlying HLH associated with HAVCR2 mutation based on changes in cytokine levels. Our findings suggest that HAVCR2 mutation may represent a distinct genetic defect underlying HLH, differing from traditional primary HLH.

The one-two punch: TIM-3 blockade targets immune and tumor cells to knock out pediatric brain tumors

Diffuse midline gliomas (DMGs) pose treatment challenges due to their location within the brainstem and invasive nature. Although classical immune checkpoint inhibitors have demonstrated limited success in clinical trials, Ausejo-Mauleon et al. demonstrate TIM-3 is an effective DMG strategy, targeting both immune and tumor cells for dual therapeutic benefit.

T Cell CEACAM1-TIM-3 Crosstalk Alleviates Liver Transplant Injury in Mice and Humans

BACKGROUND & AIMS

Carcinoembryonic antigen-related cell adhesion molecule 1 (CC1) acts through homophilic and heterophilic interactions with T cell immunoglobulin domain and mucin domain-containing protein 3 (TIM-3), which regulates innate immune activation in orthotopic liver transplantation (OLT). We investigated whether cluster of differentiation (CD) 4+ T cell-dependent CC1-TIM-3 crosstalk may affect OLT outcomes in mice and humans.

METHODS

Wild-type (WT) and CC1-deficient (CC1 knock-out [KO]) mouse livers were transplanted into WT, CC1KO, or T-cell TIM-3 transgenic (TIM-3Tg)/CC1KO double-mutant recipients. CD4+ T cells were adoptively transferred into T/B cell-deficient recombination activating gene 2 protein (Rag2) KO recipients, followed by OLT. The perioperative liver-associated CC1 increase was analyzed in 50 OLT patients.

RESULTS

OLT injury in WT livers deteriorated in CC1KO compared with CC1-proficient (WT) recipients. The frequency of TIM-3+CD4+ T cells was higher in WT than CC1KO hosts. Reconstitution of Rag2KO mice with CC1KO-T cells increased nuclear factor (NF)-κB phosphorylation and OLT damage compared with recipients repopulated with WT T cells. T-cell TIM-3 enhancement in CC1KO recipients (WT → TIM3Tg/CC1KO) suppressed NF-κB phosphorylation in Kupffer cells and mitigated OLT injury. However, TIM-3-mediated protection was lost by pharmacologic TIM-3 blockade or an absence of CC1 in the donor liver (CC1KO → TIM-3Tg/CC1KO). The perioperative CC1 increase in human OLT reduced hepatocellular injury, early allograft dysfunction, and the cumulative rejection rate.

CONCLUSIONS

This translational study identifies T cell-specific CC1 signaling as a therapeutic means to alleviate OLT injury by promoting T cell-intrinsic TIM-3, which in turn interacts with liver-associated CC1 to suppress NF-κB in Kupffer cells. By suppressing peritransplant liver damage, promoting T-cell homeostasis, and improving OLT outcomes, recipient CC1 signaling serves as a novel cytoprotective sentinel.

CD28/PD1 co-expression: dual impact on CD8+ T cells in peripheral blood and tumor tissue, and its significance in NSCLC patients' survival and ICB response

BACKGROUND

Immune checkpoint blockade (ICB) has significantly prolonged survival of non-small cell lung cancer (NSCLC) patients, although most patients develop mechanisms of resistance. Recently single-cell RNA-sequencing (scRNA-Seq) revealed a huge T-cell phenotypic and (dys)functional state variability. Accordingly, T-cell exhaustion is recognized as a functional adaptation, with a dynamic progression from a long-lived "pre-exhausted stem-like progenitor" to a "terminally exhausted" state. In this scenario it is crucial to understand the complex interplay between co-stimulatory and inhibitory molecules in CD8+ T-cell functionality.

METHODS

To gain a baseline landscape of the composition, functional states, and transcriptomic signatures predictive of prognosis, we analyzed CD8+ T-cell subsets characterized by the presence/absence of PD1 and CD28 from periphery, adjacent non-tumor tissue and tumor site of a cohort of treatment-naïve NSCLC patients, by integrated multiparametric flow cytometry, targeted multi-omic scRNA-seq analyses, and computational pipelines.

RESULTS

Despite the increased PD1 levels, an improved PD1+CD28+ T-cell polyfunctionality was observed with the transition from periphery to tumor site, associated with lack of TIGIT, TIM-3 and LAG-3, but not with Ag-experienced-marker CD11a. Differently from CD28+ T cells, the increased PD1 levels in the tumor were associated with reduced functionality in PD1+CD28- T cells. CD11ahigh, although expressed only in a small fraction of this subset, still sustained its functionality. Absence of TIGIT, TIM-3 and CTLA-4, alone or combined, was beneficial to CD28- T cells. Notably, we observed distinct TRM phenotypes in the different districts, with CD28+ T cells more capable of producing TGFβ in the periphery, potentially contributing to elevated CD103 levels. In contrast CD28- TRM mainly produced CXCL13 within the tumor. ScRNA-seq revealed 5 different clusters for each of the two subsets, with distinctive transcriptional profiles in the three districts. By interrogating the TCGA dataset of patients with lung adenocarcinoma (LUAD) and metastatic NSCLC treated with atezolizumab, we found signatures of heterogeneous TRM and "pre-exhausted" long-lived effector memory CD8+ T cells associated with improved response to ICB only in the presence of CD28.

CONCLUSIONS

Our findings identify signatures able to stratify survival of LUAD patients and predict ICB response in advanced NSCLC. CD28 is advocated as a key determinant in the signatures identified, in both periphery and tumor site, thus likely providing feasible biomarkers of ICB response.

Increased co-expression of PD1 and TIM3 is associated with poor prognosis and immune microenvironment heterogeneity in gallbladder cancer

BACKGROUND

The effectiveness of immune checkpoint inhibitors in treating gallbladder cancer (GBC) remains unsatisfactory. Recently, several new immune checkpoints have been identified. However, investigations exploring these immune checkpoints in GBC are limited. In this study, we aim to investigate the expression patterns and clinical implications of various immune checkpoints, and further characterize the spatial and quantitative heterogeneity of immune components in GBC.

METHODS

We employed single and multiplex immunohistochemistry to evaluate the expression of five immune checkpoint markers and four immune cell markers in the primary tumor core, hepatic invasion margin, and liver metastasis. Subsequently, we analyzed their interrelationships and their prognostic significance.

RESULTS

We observed a robust positive correlation between PD1/TIM3 expression in GBC (R = 0.614, P < 0.001). The co-expression of PD1/TIM3 exhibited a synergistic effect in predicting poor prognosis among postoperative GBC patients. Further analysis revealed that the prognostic significance of PD1/TIM3 was prominent in the subgroup with high infiltration of CD8 + T cells (P < 0.001). Multiplex immunohistochemistry reveals that PD1 + TIM3 + FOXP3 + cells constitute a significant proportion of FOXP3 + TILs in GBC tissue. Moreover, the co-high expression of PD1 and TIM3 is positively correlated with the accumulation of CD8 + TILs at the hepatic invasion margin. Lastly, our findings indicated reduced expression levels of immune checkpoints and diminished immune cell infiltration in liver metastases compared to primary tumors.

CONCLUSIONS

Increased co-expression of PD1/TIM3 is associated with poor prognosis in GBC patients and is related to the heterogeneity of immune microenvironment between GBC primary tumor and its hepatic invasion margin or liver metastases, which may be a potential target for future immunotherapy of GBC.

Lower PTEN may be associated with CD8+ T cell exhaustion in diffuse large B-cell lymphoma

Initially discovered in chronic viral infection and then extended to tumor, 'T-cell exhaustion' is a broad term describing the response of T cells to chronic antigen stimulation. By definition, whether T-cell exhaustion occurs in diffuse large B-cell lymphoma (DLBCL) remains largely unknown because little has been described. Here, the immune-suppressing checkpoint molecules involved in T-cell exhaustion, including PD-1, PD-L1, TIM-3 and TIGIT, whose expression levels were analyzed in DLBCL, were retrieved from the GEPIA database. Compared with the normal control, CD8A, TNFA, IFNG and GZMA were markedly elevated in DLBCL, indicating that infiltrated CD8+ T cells predominate in DLBCL. Meanwhile, inhibitory immune checkpoints, such as PD-1, PD-L1, TIGIT and TIM-3 were drastically higher in DLBCL. PTEN, WNT2 and DKK3 expression were also appraised. It was revealed that PTEN was lower in DLBCL, without being statistically significant. In contrast with PTEN, DKK3 and WNT2 were shown to be pronouncedly higher in DLBCL relative to the normal control. Prognostically, only TIGIT was found to be associated with overall survival in DLBCL. Collectively, all the data we curetted from the GEPIA and TIMER 2.0 databases explicitly indicate that CD8+ T cell exhaustion took place, which may be linked with lower PTEN in DLBCL. To the best of our knowledge, this is the first bioinformatic report explicitly proposing that CD8+ T cell exhaustion occurs in DLBCL, which may be associated with lower PTEN.

Germline HAVCR2 mutations and their relation to the clinical spectrum of subcutaneous panniculitis-like T-cell lymphoma and hemophagocytic lymphohistiocytosis: results from a multicenter study and meta-analysis

Germline HAVCR2 mutations are frequently detected in subcutaneous panniculitis-like T-cell lymphoma (SPTCL) patients with/without hemophagocytic lymphohistiocytosis (HLH) but factors associated with variable manifestations remain undetermined. To evaluate clinical variations and associated factors in SPTCL and/or HLH with/without HAVCR2 mutations, we performed direct sequencing of HAVCR2 exon 2 using DNA from patients with SPTCL or idiopathic HLH/HLH-like systemic illnesses, defined by HLH alone without secondary causes. The systematic review and individual patient data (IPD) level meta-analysis which included the present and previously published studies reporting HAVCR2 mutations in SPTCL with/without HLH populations was subsequently conducted using random-effects meta-analysis and multivariate logistic regression. Among 34 patients enrolled, ten of 28 SPTCL patients developed HLH/HLH-like systemic illnesses. Six cases with HAVCR2Y82C mutation manifested with HLH without panniculitis. Male sex (P=0.03) and age <18 years (P=0.04) were associated with HLH, corresponding to the inverse correlation between age and HLH-2004 score (r=-0.40; P=0.02). Homozygous HAVCR2Y82C mutation was more common in the presence of HLH compared with the absence (75.0% vs. 44.4%; P=0.02). Using IPD from the present and the other three eligible cohorts (N=127), male sex, heterozygous and homozygous/compound heterozygous HAVCR2 mutations were associated with HLH by the adjusted odds ratio of 2.93 (95% confidence interval [CI]: 1.22-7.06), 4.77 (95% CI: 1.05-21.63) and 8.48 (95% CI: 2.98-24.10), respectively. Patients with male sex and/or germline HAVCR2 mutations showed an increased risk of developing HLH. Younger patients tended to manifest with HLH, while older patients typically presented with SPTCL with less frequent HLH/HLH-like systemic illnesses.

[Effect of Echinococcus multilocularis infection on Tim3 expression in spleen natural killer cells of mice]

OBJECTIVE

To investigate the effect of Echinococcus multilocularis infection on Tim3 expression and its co-expression with immune checkpoint molecules 2B4 and LAG3 in spleen natural killer (NK) cells of mice.

METHODS

C57BL/6 mice, each weighing (20 ± 2) g, were randomly divided into a high-dose infection group (15 mice), a low-dose infection group (13 mice), and a control group (11 mice). Mice in the high- and low-dose infection groups were inoculated with 2 000 and 50 Echinococcus multilocularis protoscolices via the hepatic portal vein, while animals in the control group was injected with an equivalent amount of physiological saline via the hepatic portal vein. Mouse spleen cells were harvested 12 and 24 weeks post-infection, and Tim3 expression and its co-expression with 2B4 and LAG3 in NK cells were detected using flow cytometry.

RESULTS

There were significant differences in the proportions of Tim3 expression (F = 13.559, P < 0.001) and Tim3 and 2B4 co-expression (F = 12.465, P < 0.001) in mouse spleen NK cells among groups 12 weeks post-infection with E. multilocularis, and the proportion of Tim3 expression was significantly higher in mouse spleen NK cells in the low-dose infection group [(23.84 ± 2.28)%] than in the high-dose infection group [(15.72 ± 3.67)%] and the control group [(16.14 ± 3.83)%] (both P values < 0.01), while the proportion of Tim3 and 2B4 co-expression was significantly higher in mouse spleen NK cells in the low-dose infection group [(22.20 ± 2.13)%] than in the high-dose infection group [(14.17 ± 3.81)%] and the control group [(15.20 ± 3.77)%] (both P values < 0.01). There were significant differences in the proportions of Tim3 expression (F = 5.243, P < 0.05) and Tim3 and 2B4 co-expression (F = 4.659, P < 0.05) in mouse spleen NK cells among groups 24 weeks post-infection with E. multilocularis infection, and the proportions of Tim3 expression and Tim3 and 2B4 co-expression were significantly lower in mouse spleen NK cells in the high-dose infection group [(20.55 ± 7.04)% and (20.98 ± 7.12)%] than in the control group [(31.38 ± 3.19)% and (31.25 ± 3.06)%] (both P values < 0.05), and there were no significantly difference between the proportions of Tim3 expression and Tim3 and 2B4 co-expression in splenic NK cells in the low-dose infection group [(26.80 ± 6.47)% and (26.48 ± 6.48)%] and the control group (both P > 0.05). There were no significant differences in the proportions of Tim3 and LAG3 co-expression in mouse spleen NK cells among groups 12 (F = 2.283, P > 0.05) and 24 weeks post-infection (F = 0.375, P > 0.05). In the low-dose infection group, there were no significant differences in the proportions of Tim3 expression or Tim3 and 2B4 co-expression in mouse spleen NK cells 12 (t = -1.137, P > 0.05) or 24 weeks post-infection (t = -1.658, P > 0.05), and the proportion of Tim3 and LAG3 co-expression increased in mouse spleen NK cells 24 weeks post-infection relative to 12 weeks post-infection (t = -5.261, P < 0.01). In the highdose infection group, there was no significant difference in the proportion of Tim3 expression in mouse spleen NK cells 12 and 24 weeks post-infection (t = -1.546, P > 0.05); however, the proportions of Tim3 co-expression with 2B4 and LAG3 increased in mouse splenic NK cells 24 weeks post-infection relative to 12 weeks post-infection (t = -2.425 and -4.745, both P values < 0.05).

CONCLUSIONS

The Tim3 expression and Tim3 co-expression with LAG3 and 2B4 on spleen NK cells is affected by doses of E. multilocularis infection and disease stages, and present different phenotypes during the course of alveolar echinococcosis. NK cells tend to form an immunosuppressive phenotype with the progression of E. multilocularis infection, which facilitates immune escape and chronic parasitism of E. multilocularis.

Identification and validation of a prognostic risk-scoring model based on the level of TIM-3 expression in acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by an unfavorable prognosis due to the presence of self-renewing leukemic stem cells (LSCs). The presence of T-cell immunoglobulin mucin-3 (TIM-3) on the surface of LSCs has been observed in various types of human AML, exerting an impact on the prognostic outcome. Exploring the hub genes associated with varying levels of TIM-3 expression offers a valuable approach to enhance our understanding of the underlying mechanisms involving TIM-3 and to identify potential prognostic indicators in AML. Nevertheless, to date, no research studies have reported a prognostic model that relies on the level of TIM-3 expression. In our study, we screen the hub-genes based on different expression level of TIM-3 through WGCNA. The prognostic risk-scoring model was constructed based on hub-genes. The results show the risk prognostic model has extraordinary ability to predict prognosis in both the training and validation sets. The high-risk group present poor prognosis with mutation of NPM1, TP53 (Multiple Hit) and FLT3(multiple hit), while IDH2 (Missense Mutation), MUC16 (Multiple Hit/Missense Mutation) occur mutation in low-risk group presenting favorite prognosis than high-risk group. Leukocyte cell-cell adhesion, regulation of T cell activation and I-κB kinase/NF-κB signaling enriched in high-risk group, involving in HSCs or LSCs anchoring to BM, which implicated in LSCs survival and chemotherapy resistance. B7-H3 (CD276) and CD276 would be the potential immune targets in high-risk group. The risk score model may help in distinguishing immune and molecular characteristics, predicting patient outcomes.

Good prognosis of adult hemophagocytic lymphohistiocytosis associated with the germline HAVCR2 mutation

Hemophagocytic lymphohistiocytosis (HLH) in adults may be idiopathic or secondary to various conditions. Recent studies identified germline hepatitis A virus-cellular receptor 2 (HAVCR2) mutations in subcutaneous panniculitis-like T-cell lymphoma (SPTCL) with HLH. The roles of this mutation in HLH, especially in idiopathic group, have never been explored. Of the 65 HLH cases, we detected germline HAVCR2Y82C mutations in nine (13.8%) cases (five SPTCL and four idiopathic HLH). Other causes of HLH were hematologic malignancies excluding SPTCL (32.3%), idiopathic HLH without HAVCR2 mutation (29.2%), infections (15.3%), and autoimmune diseases (9.2%). Germline HAVCR2 mutation was significantly associated with less anemia and better survival. This defines a distinct subgroup of HLH.

Role of Tim-3 in COVID-19: a potential biomarker and therapeutic target

T cell immunoglobulin and mucin domain containing protein 3 (Tim-3), an immune checkpoint, is important for maintaining immune tolerance. There is increasing evidence that Tim-3 is aberrantly expressed in patients with COVID-19, indicating that it may play an important role in COVID-19. In this review, we discuss the altered expression and potential role of Tim-3 in COVID-19. The expression of Tim-3 and its soluble form (sTim-3) has been found to be upregulated in COVID-19 patients. The levels of Tim-3 on T cells and circulating sTim-3 have been shown to be associated with the severity of COVID-19, suggesting that this protein could be a potential biomarker of COVID-19. Moreover, this review also highlights the potential of Tim-3 as a therapeutic target of COVID-19.

TIM-3 increases the abundance of type-2 dendritic cells during Leishmania donovani infection by enhancing IL-10 production via STAT3

The outcome of the disease visceral leishmaniasis (VL), caused by Leishmania donovani (LD), largely relies on the relative dominance of host-protective type-1 T helper (Th1) cell response versus disease-promoting type-2 T helper (Th2) cell response. The Th1 and Th2 responses, in turn, are believed to be elicited by type-1 conventional dendritic cells (cDC1) and type-2 conventional DCs (cDC2), respectively. However, it is still unknown which DC subtype (cDC1 or cDC2) predominates during chronic LD infection and the molecular mechanism governing such occurrence. Here we report that in chronically infected mice, the splenic cDC1-cDC2 balance shifted toward the cDC2 subtype and that the receptor T cell immunoglobulin and mucin protein-3 (TIM-3) expressed by DCs played a key role in mediating this effect. Transfer of TIM-3-silenced DCs in fact prevented the predominance of the cDC2 subtype in mice with chronic LD infection. We also found that LD actually upregulated TIM-3 expression on DCs by triggering a TIM-3-mediated signaling pathway STAT3 (signal transducer and activator of transcription 3)→interleukin (IL)-10→c-Src→transcription factors Ets1, Ets2, USF1, and USF2. Notably, TIM-3 promoted STAT3 activation via a non-receptor tyrosine kinase Btk. Adoptive transfer experiments further demonstrated a critical role for STAT3-driven TIM-3 upregulation on DCs in increasing cDC2 abundance in chronically infected mice, which ultimately aided disease pathogenesis by augmenting Th2 responses. These findings document a new immunoregulatory mechanism contributing to disease pathology during LD infection and define TIM-3 as a key mediator of this process.

The Variations' in Genes Encoding TIM-3 and Its Ligand, Galectin-9, Influence on ccRCC Risk and Prognosis

Renal cell cancer is the most common type of kidney cancer in adults, and clear cell renal cell carcinoma (ccRCC) is the most diagnosed type. T cell immunoglobulin and mucin-domain-containing-3 (TIM-3) belongs to immunological checkpoints that are key regulators of the immune response. One of the known TIM-3 ligands is galectin-9 (LGALS9). A limited number of studies have shown an association between TIM-3 polymorphisms and cancer risk in the Asian population; however, there is no study on the role of LGALS9 polymorphisms in cancer. The present study aimed to analyze the influence of TIM-3 and LGALS9 polymorphisms on susceptibility to ccRCC and patient overall survival (OS), with over ten years of observations. Using TaqMan probes, ARMS-PCR, and RFPL-PCR, we genotyped two TIM-3 single-nucleotide polymorphisms (SNPs): rs1036199 and rs10057302, and four LGALS9 SNPs: rs361497, rs3751093, rs4239242, and rs4794976. We found that the presence of the rs10057302 A allele (AC + AA genotypes) as well as the rs4794976 T allele (GT + TT genotypes) decreased susceptibility to ccRCC by two-fold compared to corresponding homozygotes. A subgroup analysis showed the association of some SNPs with clinical features. Moreover, TIM-3 rs1036199 significantly influenced OS. Our results indicate that variations within TIM-3 and LGALS9 genes are associated with ccRCC risk and OS.

mTOR regulates T cell exhaustion and PD-1-targeted immunotherapy response during chronic viral infection

T cell exhaustion is a state of T cell dysfunction associated with expression of programmed death 1 (PD-1). Exhausted CD8+ T cells are maintained by self-renewing stem-like T cells that provide differentiated TIM3+ cells, a part of which possesses effector-like properties. PD-1-targeted therapies enhance T cell response by promoting differentiation of stem-like T cells toward TIM3+ cells, but the role of mTOR during T cell exhaustion remains elusive. Here, we showed that mTOR inhibition has distinct outcomes during the beginning of and after the establishment of chronic viral infection. Blocking mTOR during the T cell expansion phase enhanced the T cell response by causing accumulation of stem-like T cells, leading to improved efficacy of PD-1 immunotherapy; whereas, after exhaustion progressed, mTOR inhibition caused immunosuppression, characterized by decreased TIM3+ cells and increased viral load with minimal changes in stem-like T cells. Mechanistically, a cell-intrinsic mTOR signal was vital for differentiation of stem-like T cells into the TIM3+ state in the early and late phases of chronic infection as well as during PD-1 immunotherapy. Thus, PD-1 blockade worked after cessation of mTOR inhibition, but simultaneous treatment failed to induce functional TIM3+ cells, reducing efficacy of PD-1 immunotherapy. Our data demonstrate that mTOR regulates T cell exhaustion and have important implications for combination cancer therapies with PD-1 blockade.

Tim-3 Coordinates Macrophage-Trophoblast Crosstalk via Angiogenic Growth Factors to Promote Pregnancy Maintenance

T-cell immunoglobulin mucin-3 (Tim-3) is an important checkpoint that induces maternal-fetal tolerance in pregnancy. Macrophages (Mφs) play essential roles in maintaining maternal-fetal tolerance, remodeling spiral arteries, and regulating trophoblast biological behaviors. In the present study, the formation of the labyrinth zone showed striking defects in pregnant mice treated with Tim-3 neutralizing antibodies. The adoptive transfer of Tim-3⁺Mφs, rather than Tim-3^-Mφs, reversed the murine placental dysplasia resulting from Mφ depletion. With the higher production of angiogenic growth factors (AGFs, including PDGF-AA, TGF-α, and VEGF), Tim-3⁺dMφs were more beneficial in promoting the invasion and tube formation ability of trophoblasts. The blockade of AGFs in Tim-3⁺Mφs led to the narrowing of the labyrinthine layer of the placenta, compromising maternal-fetal tolerance, and increasing the risk of fetal loss. Meanwhile, the AGFs-treated Tim-3^-Mφs could resolve the placental dysplasia and fetal loss resulting from Mφ depletion. These findings emphasized the vital roles of Tim-3 in coordinating Mφs-extravillous trophoblasts interaction via AGFs to promote pregnancy maintenance and in extending the role of checkpoint signaling in placental development. The results obtained in our study also firmly demonstrated that careful consideration of reproductive safety should be taken when selecting immune checkpoint and AGF blockade therapies in real-world clinical care.

BLIMP1 and NR4A3 transcription factors reciprocally regulate antitumor CAR T cell stemness and exhaustion

Chimeric antigen receptor (CAR) T cells have not induced meaningful clinical responses in solid tumors. Loss of T cell stemness, poor expansion capacity, and exhaustion during prolonged tumor antigen exposure are major causes of CAR T cell therapeutic resistance. Single-cell RNA-sequencing analysis of CAR T cells from a first-in-human trial in metastatic prostate cancer identified two independently validated cell states associated with antitumor potency or lack of efficacy. Low expression of PRDM1, encoding the BLIMP1 transcription factor, defined highly potent TCF7 [encoding T cell factor 1 (TCF1)]-expressing CD8⁺ CAR T cells, whereas enrichment of HAVCR2 [encoding T cell immunoglobulin and mucin-domain containing-3 (TIM-3)]-expressing CD8⁺ T cells with elevated PRDM1 was associated with poor outcomes. PRDM1 knockout promoted TCF7-dependent CAR T cell stemness and proliferation, resulting in marginally enhanced leukemia control in mice. However, in the setting of PRDM1 deficiency, a negative epigenetic feedback program of nuclear factor of activated T cells (NFAT)-driven T cell dysfunction was identified. This program was characterized by compensatory up-regulation of NR4A3 and other genes encoding exhaustion-related transcription factors that hampered T cell effector function in solid tumors. Dual knockout of PRDM1 and NR4A3 skewed CAR T cell phenotypes away from TIM-3⁺CD8⁺ and toward TCF1⁺CD8⁺ to counter exhaustion of tumor-infiltrating CAR T cells and improve antitumor responses, effects that were not achieved with PRDM1 and NR4A3 single knockout alone. These data underscore dual targeting of PRDM1 and NR4A3 as a promising approach to advance adoptive cell immuno-oncotherapy.

Cutting edges and therapeutic opportunities on tumor-associated macrophages in lung cancer

Lung cancer is a disease with remarkable heterogeneity. A deep understanding of the tumor microenvironment (TME) offers potential therapeutic strategies against this malignant disease. More and more attention has been paid to the roles of macrophages in the TME. This article briefly summarizes the origin of macrophages, the mutual regulation between anti-tumoral immunity and pro-tumoral statuses derived from macrophage polarization, and the therapeutic opportunities targeting alternately activated macrophages (AAM)-type macrophage polarization. Among them, cellular components including T cells, as well as acellular components represented by IL-4 and IL-13 are key regulators driving the polarization of AAM macrophages. Novel treatments targeting macrophage-associated mechanisms are mainly divided into small molecule inhibitors, monoclonal antibodies, and other therapies to re-acclimate AMM macrophages. Finally, we paid special attention to an immunosuppressive subgroup of macrophages with T cell immunoglobulin and mucin domain-3 (TIM-3) expression. Based on cellular interactions with cancer cells, TIM3+ macrophages facilitate the proliferation and progression of cancer cells, yet this process exposes targets blocking the ligand-receptor recognition. To sum up, this is a systematic review on the mechanism of tumor-associated macrophages (TAM) polarization, therapeutic strategies and the biological functions of Tim-3 positive macrophages that aims to provide new insights into the pathogenesis and treatment of lung cancer.

Characteristics of the immune microenvironment and their clinical significance in non-small cell lung cancer patients with ALK-rearranged mutation

Background

Although immune checkpoint inhibitors (ICIs) are one of the most important treatments for advanced-stage non-small-cell lung cancer (NSCLC), NSCLC patients with ALK-rearranged usually don’t obtain a clinical benefit. The reason may be related to the unique tumor microenvironment (TME). We evaluated the characteristics of immune biomarkers of the TME and their prognostic value in ALK-rearranged NSCLC.

Methods

Tumor samples from patients with ALK-rearranged (N = 39) and EGFR- (N = 40)/KRAS- (N = 30) mutated NSCLC were collected. Immunohistochemistry (IHC) was used to assess the expression of 9 tumor immune markers as well as 6 immune markers of tumor-infiltrating cells. To research the TME of ALK-rearranged NSCLC, EGFR/KRAS-positive patients were used as controls. Furthermore, the correlation between the efficacy and prognosis of patients with advanced-stage (IIIC-IV) ALK rearrangements treated with targeted drugs was analyzed in terms of the TME.

Results

The proportion of PD-L1+ tumors was lower in ALK-positive NSCLC than in KRAS-positive NSCLC. Besides, the proportion of T cells expressing TIM-3-CD8+ (15.38%), CTLA4-CD8+ (12.82%), LAG3-CD8+ (33.33%) and PD-1-CD8+ (2.56%) in ALK-positive NSCLC was lower than that in EGFR/KRAS-positive NSCLC. The expression of CD3, CD8 T cells and CD20 B cells was lower in ALK-positive NSCLC than in KRAS-positive NSCLC (p < 0.0001, < 0.005, and < 0.001, respectively). Nevertheless, the level of CD4 helper T cells was higher in ALK-positive NSCLC than in EGFR/KRAS-positive NSCLC (p < 0.0001 and p < 0.05, respectively). The repression of TIM3 was higher in ALK-positive NSCLC than in KRAS-positive NSCLC (p < 0.001). In addition, our data showed that high expression of PD-L1 (HR = 0.177, 95% CI 0.038–0.852, p = 0.027) and CTLA4 (HR = 0.196, 95% CI 0.041–0.947, p = 0.043) was related to lower OS in advanced-stage ALK- rearranged NSCLC patients treated with ALK tyrosine kinase inhibitors (TKIs).

Conclusions

Immunosuppressive status was characteristic of the TME in patients with ALK-positive NSCLC compared with EGFR/KRAS-positive NSCLC. High expression of PD-L1 and CTLA4 was an adverse prognostic factor in advanced-stage ALK-rearranged NSCLC patients treated with ALK-TKIs. Immunotherapy for ALK-rearranged patients requires further exploration and validation by clinical trials.

CTLA4 , PD-1 , PD-L1 , PD-L2 , TIM-3 , TIGIT , and LAG3 DNA Methylation Is Associated With BAP1 -Aberrancy, Transcriptional Activity, and Overall Survival in Uveal Melanoma

Uveal melanoma (UM) is an aggressive disease with poor response to oncological treatment, including immunotherapy. Loss of the epigenetic modifier BRCA1-associated protein 1 (BAP1) function drives UM oncogenesis and is associated with an immune-suppressive tumor microenvironment, poor prognosis, and a distinct DNA methylation and gene expression profile. Our study aimed to analyze comprehensively the DNA methylation status of the immune checkpoint genes PD-1 , PD-L1 , PD-L2 , CTLA4, TIM-3 ( HAVCR2 ), TIGIT , and LAG3 and its association with mRNA expression, BAP1 -aberrancy, and patients' survival. We analyzed the DNA methylation landscape of immune checkpoint genes at single CpG resolution in N=80 UM samples provided by The Cancer Genome Atlas. We analyzed CpG methylation levels of the immune checkpoints with regard to their transcriptional signatures and patient outcomes.Methylation of specific CpG sites within the immune checkpoint genes PD-1 , PD-L1 , PD-L2 , CTLA4 , TIM-3 , TIGIT , and LAG3 correlated strongly with mRNA expression levels, indicating a strong regulation of gene expression through DNA methylation. Moreover, immune checkpoint gene methylation was strongly associated with BAP1 -mutation status and associated with overall survival in UM. Our data indicate an epigenetic regulation of immune checkpoints through DNA methylation in UM. Further, our data highlight the prognostic significance of DNA methylation of immune checkpoint genes in UM thereby providing a rationale for methylation testing as predictive biomarkers for immunotherapy response.

Increased Expression of Multiple Co-Inhibitory Molecules on Malaria-Induced CD8+ T Cells Are Associated With Increased Function Instead of Exhaustion

Activated cytotoxic CD8+ T cells can selectively kill target cells in an antigen-specific manner. However, their prolonged activation often has detrimental effects on tissue homeostasis and function. Indeed, overwhelming cytotoxic activity of CD8+ T cells can drive immunopathology, and therefore, the extent and duration of CD8+ T cell effector function needs to be tightly regulated. One way to regulate CD8+ T cell function is their suppression through engagement of co-inhibitory molecules to their cognate ligands (e.g., LAG-3, PD-1, TIM-3, TIGIT and CTLA-4). During chronic antigen exposure, the expression of co-inhibitory molecules is associated with a loss of T cell function, termed T cell exhaustion and blockade of co-inhibitory pathways often restores T cell function. We addressed the effect of co-inhibitory molecule expression on CD8+ T cell function during acute antigen exposure using experimental malaria. To this end, we infected OT-I mice with a transgenic P. berghei ANKA strain that expresses ovalbumin (PbTG), which enables the characterization of antigen-specific CD8+ T cell responses. We then compared antigen-specific CD8+ T cell populations expressing different levels of the co-inhibitory molecules. High expression of LAG-3 correlated with high expression of PD-1, TIGIT, TIM-3 and CTLA-4. Contrary to what has been described during chronic antigen exposure, antigen-specific CD8+ T cells with the highest expression of LAG-3 appeared to be fully functional during acute malaria. We evaluated this by measuring IFN-γ, Granzyme B and Perforin production and confirmed the results by employing a newly developed T cell cytotoxicity assay. We found that LAG-3high CD8+ T cells are more cytotoxic than LAG-3low or activated but LAG-3neg CD8+ T cells. In conclusion, our data imply that expression of co-inhibitory molecules in acute malaria is not necessarily associated with functional exhaustion but may be associated with an overwhelming T cell activation. Taken together, our findings shed new light on the induction of co-inhibitory molecules during acute T cell activation with ramifications for immunomodulatory therapies targeting these molecules in acute infectious diseases.

Tim-3 mediates T cell trogocytosis to limit antitumor immunity

T cell immunoglobulin mucin domain-containing protein 3 (Tim-3) negatively regulates innate and adaptive immunity in cancer. To identify the mechanisms of Tim-3 in cancer immunity, we evaluated the effects of Tim-3 blockade in human and mouse melanoma. Here, we show that human programmed cell death 1-positive (PD-1+) Tim-3+CD8+ tumor-infiltrating lymphocytes (TILs) upregulate phosphatidylserine (PS), a receptor for Tim-3, and acquire cell surface myeloid markers from antigen-presenting cells (APCs) through transfer of membrane fragments called trogocytosis. Tim-3 blockade acted on Tim-3+ APCs in a PS-dependent fashion to disrupt the trogocytosis of activated tumor antigen-specific CD8+ T cells and PD-1+Tim-3+ CD8+ TILs isolated from patients with melanoma. Tim-3 and PD-1 blockades cooperated to disrupt trogocytosis of CD8+ TILs in 2 melanoma mouse models, decreasing tumor burden and prolonging survival. Deleting Tim-3 in dendritic cells but not in CD8+ T cells impeded the trogocytosis of CD8+ TILs in vivo. Trogocytosed CD8+ T cells presented tumor peptide-major histocompatibility complexes and became the target of fratricide T cell killing, which was reversed by Tim-3 blockade. Our findings have uncovered a mechanism Tim-3 uses to limit antitumor immunity.

Differential expression of Tim3 protein in colorectal cancer associated with MSI and Braf mutation

Tim3 is a negative immune checkpoint molecule and plays a crucial part in tumor-induced immune suppression. Tim3 is a cell surface molecule expressed on T cells marking dysfunctional CD8+ cells in various kinds of cancers. Tim3 expression was mainly reported in tumor-infiltrating lymphocytes (TILs). There are few studies focusing on the expression of Tim3 in tumor cells. Immunohistochemistry was performed to determine Tim3 expression level. The relationships between Tim3 expression in colorectal cancer cells and in tumor-infiltrating lymphocytes and cilicopathological parameters were statistically analyzed. Tim3 was differentially detected in TILs and in colorectal cancer cells. Positive expression of Tim3 in colorectal cancer cells was associated with tumor location (P=0.001), depth of tumor invasion (P<0.001), lymph node metastasis (P=0.001), TNM stage (P=0.001), MSI (P=0.008), and Braf V600E mutation (P=0.001). On the other hand, positive expression of Tim3 in TILs was only related to depth of tumor invasion (P<0.001). Positive expression of Tim3 in both colorectal cancer cells and TILs was associated with depth of tumor invasion (P<0.001), lymph node metastasis (P=0.002), TNM stage (P=0.002), MSI (P=0.039), and Braf V600E mutation (P=0.009). Kaplan-Meier survival analysis showed that Tim3 expression in colorectal cancer and in TILs was significantly associated with patient overall survival (OS) rate (P=0.039, and 0.001). Tim3 may be a potential prognostic marker and a therapy target for colorectal cancer.

Simultaneous Genetic Ablation of PD-1, LAG-3, and TIM-3 in CD8 T Cells Delays Tumor Growth and Improves Survival Outcome

Immune checkpoint inhibitors (ICI) represented a step forward in improving the outcome of patients with various refractory solid tumors and several therapeutic regimens incorporating ICI have already been approved for a variety of tumor entities. However, besides remarkable long-term responses, checkpoint inhibition can trigger severe immune-related adverse events in some patients. In order to improve safety of ICI as well as T cell therapy, we tested the feasibility of combining T cell-based immunotherapy with genetic disruption of checkpoint molecule expression. Therefore, we generated H-Y and ovalbumin antigen-specific CD8⁺ T cells with abolished PD-1, LAG-3, and TIM-3 expression through CRISPR/Cas9 technology. CD8⁺ T cells, subjected to PD-1, LAG-3, and TIM-3 genetic editing, showed a strong reduction in immune checkpoint molecule expression after in vitro activation, while no relevant reduction in responsiveness to in vitro stimulation was observed. At the same time, in B16-OVA tumor model, transferred genetically edited OT-1 CD8⁺ T cells promoted longer survival compared to control T cells and showed enhanced expansion without associated toxicity. Our study supports the notion that antigen-specific adoptive T cell therapy with concomitant genetic disruption of multiple checkpoint inhibitory receptors could represent an effective antitumor immunotherapy approach with improved tolerability profile.

[TIM-3 gene is highly expressed in ephithelial ovarian cancer to promote proliferation and migration of ovarian cancer cells]

OBJECTIVE

To analyze the expression of immunoglobulin mucin molecule 3 (TIM-3) in epithelial ovarian cancer (EOC) and the effects of TIM-3 knockdown and overexpression on proliferation and migration of ovarian cancer cells.

METHODS

We analyzed TIM-3 expression in EOC and normal ovarian tissues using GEPIA database. We also detected TIM-3 expression levels in 82 surgical specimens of EOC and 18 specimens of normal ovarian tissues using immunohistochemistry, and analyzed the correlation of TIM-3 expression with clinicopathological parameters and survival outcomes of the patients. The expression of TIM-3 and Wnt1 mRNA in the tissues were detected using qRT-PCR. We constructed SKOV3 cell models of TIM-3 knockdown and overexpression and examined the changes in proliferation, apoptosis, migration and invasion of the cells using MTT assay, Annexin V-FITC/PI staining, scratch test and Transwell assay. The activity of Wnt/β-catenin pathway in the transfected was detected using dual luciferase reporter assay, and the mRNA levels of TCF-7, TCCFL-2 and CD44 were detected using qPCR. The protein expressions of MMP-9, CD44, Wnt1, β-catenin and E-cad in the transfected cells were detected with Western blotting.

RESULTS

The positive expression rate of TIM-3 was significantly higher in EOC tissues than in normal ovarian tissues (P < 0.05). The expression of TIM-3 was significantly correlated with FIGO stage, histological differentiation and lymph node metastasis, and was positively correlated with Wnt1 level (P < 0.05). In SKOV3 cells, TIM-3 knockdown significantly lowered the activity of Wnt/ β-catenin pathway, inhibited cell proliferation, migration and invasion, and promoted cell apoptosis. TIM-3 knockdown significantly down-regulated the mRNA levels of TCF-7, TCFL-2 and CD44 and the protein levels of MMP-9, CD44, Wnt1 and β-catenin, and significantly up-regulated the expression level of E-cad (P < 0.05). Overexpression of TIM-3 caused opposite effects in SKOV3 cells.

CONCLUSION

TIM-3 is highly expressed in EOC tissue to promote malignant behaviors of the tumor cells possibly by activating the Wnt/β-catenin signal pathway.

Postmortem high-dimensional immune profiling of severe COVID-19 patients reveals distinct patterns of immunosuppression and immunoactivation

A complete diagnostic autopsy is the gold-standard to gain insight into Coronavirus disease 2019 (COVID-19) pathogenesis. To delineate the in situ immune responses to SARS-CoV-2 viral infection, here we perform comprehensive high-dimensional transcriptional and spatial immune profiling in 22 COVID-19 decedents from Wuhan, China. We find TIM-3-mediated and PD-1-mediated immunosuppression as a hallmark of severe COVID-19, particularly in men, with PD-1+ cells being proximal rather than distal to TIM-3+ cells. Concurrently, lymphocytes are distal, while activated myeloid cells are proximal, to SARS-CoV-2 viral antigens, consistent with prevalent SARS-CoV-2 infection of myeloid cells in multiple organs. Finally, viral load positively correlates with specific immunosuppression and dendritic cell markers. In summary, our data show that SARS-CoV-2 viral infection induces lymphocyte suppression yet myeloid activation in severe COVID-19, so these two cell types likely have distinct functions in severe COVID-19 disease progression, and should be targeted differently for therapy.

In Acute Dengue Infection, High TIM-3 Expression May Contribute to the Impairment of IFNγ Production by Circulating Vδ2 T Cells

γδ T cells are innate cells able to quickly eliminate pathogens or infected/tumoral cells by their antiviral and adjuvancy activities. The role of γδ T cells during Dengue Viral Infection (DENV) infection is not fully elucidated. Nevertheless, human primary γδ T cells have been shown to kill in vitro DENV-infected cells, thus highlighting their possible antiviral function. The aim of this work was to characterize the phenotype and function of Vδ2 T cells in DENV patients. Fifteen DENV patients were enrolled for this study and peripheral blood mononuclear cells (PBMC) were used to analyze Vδ2-T-cell frequency, differentiation profile, activation/exhaustion status, and functionality by multiparametric flow cytometry. Our data demonstrated that DENV infection was able to significantly reduce Vδ2-T-cell frequency and to increase their activation (CD38 and HLA-DR) and exhaustion markers (PD-1 and TIM-3). Furthermore, Vδ2 T cells showed a reduced capability to produce IFN-γ after phosphoantigenic stimulation that can be associated to TIM-3 expression. Several studies are needed to depict the possible clinical impact of γδ-T-cell impairment on disease severity and to define the antiviral and immunoregulatory activities of γδ T cells in the first phases of infection.

[The Minor T Allele of the Single Nucleotide Polymorphism rs 13360222 Decreases the Activity of the HAVCR2 Gene Enhancer in a Cell Model of Human Macrophages]

The TIM-3 receptor, encoded by the Hepatitis A Virus Cellular Receptor 2 (HAVCR2) gene, is an immune checkpoint and plays an important role in preventing the development of autoimmune reactions. This receptor is expressed on the surface of various immunocytes and its functions in myeloid cells remain poorly understood, compared to the role of T cell specific TIM-3 that is actively studied in the context of the search for promising therapeutic targets in cancer immunotherapy. During this study, we performed deletion analysis of the promoter region of the HAVCR2 gene, as well as functional characterization of its enhancer, and studied the effect of a number of single nucleotide polymorphisms (SNPs) on the activity of these regulatory elements in the relevant model of human macrophage-like cells-U937 activated monocytes. We have shown that the SNPs rs10515746(A) and rs4704853(A) located in the HAVCR2 gene promoter and associated with the development of a number of pathologies, do not affect the activity of the promoter in activated monocytes. However, a minor T variant of SNP rs13360222 located in the enhancer in the third intron of the gene, significantly reduces the ability of the enhancer to activate the HAVCR2 promoter, presumably due to weakening of the binding of nuclear receptor ESR2 to the respective region.

Altered expression of Tim family molecules and an imbalanced ratio of Tim-3 to Tim-1 expression in patients with type 1 diabetes

BACKGROUND

T-cell immunoglobulin and mucin domain (Tim) proteins are immunomodulatory molecules that play key roles in the regulation of T-cell activation. Published studies have reported that Tim molecules are involved in the pathogenesis of certain autoimmune diseases. Type 1 diabetes (T1D) is an autoimmune disease in which T cells mediate the destruction of islet β cells. However, the expression of Tim molecules in T1D remains unclear. In this study, we measured the expression of Tim family molecules as well as T-cell subset-specific transcription factors in T1D patients, and we explored the possible involvement of Tim molecules in the pathogenesis of T1D.

METHODS

Ninety T1D patients, Thirty-six type 2 diabetes (T2D) patients and forty healthy controls (HCs) were recruited for this study. Peripheral blood mononuclear cells (PBMCs) were isolated, RNA was extracted from the PBMCs and reverse transcribed into cDNA, and gene expression patterns were analysed by RT-qPCR. The expression of Tim molecules in different T-cell subsets was analysed by flow cytometry.

RESULTS

Compared with that in HCs, the mRNA expression of Tim-1 and RORC was increased in T1D patients (P=0.0355 and P=0.0423, respectively), while the expression of Tim-3 was decreased (P=0.0013). In addition, compared with HCs, the ratio of Tim-3 to Tim-1 expression in diabetic patients was decreased (P<0.0001 for T1D and P=0.0387 for T2D). The ratios of T-Bet to GATA3 expression and RORC to FOXP3 expression were higher in T1D patients than in HCs (P=0.0042 and P=0.0066, respectively). Furthermore, the T1D patients with defective islet function had more significant imbalances in the Tim-3/Tim-1 and RORC/FOXP3 ratios (P<0.0001, and P=0.001, respectively). Moreover, Both Tim-3 expression in CD4⁺ T cells and the Tim-3 to Tim-1 ratio were elevated in T1D in the remission phase compared to T1D.

CONCLUSION

Our study revealed altered expression of Tim molecules in T1D patients. The imbalanced ratios of Tim-3/Tim-1 expression were more pronounced in T1D patients with defective islet function. However, alterations in Tim molecule expression are mitigated in T1D in the remission phase. All these findings suggest that Tim family molecules may be involved in the pathogenesis of T1D.

TIM-3 restrains anti-tumour immunity by regulating inflammasome activation

T cell immunoglobulin and mucin-containing molecule 3 (TIM-3), first identified as a molecule expressed on interferon-γ producing T cells1, is emerging as an important immune-checkpoint molecule, with therapeutic blockade of TIM-3 being investigated in multiple human malignancies. Expression of TIM-3 on CD8+ T cells in the tumour microenvironment is considered a cardinal sign of T cell dysfunction; however, TIM-3 is also expressed on several other types of immune cell, confounding interpretation of results following blockade using anti-TIM-3 monoclonal antibodies. Here, using conditional knockouts of TIM-3 together with single-cell RNA sequencing, we demonstrate the singular importance of TIM-3 on dendritic cells (DCs), whereby loss of TIM-3 on DCs-but not on CD4+ or CD8+ T cells-promotes strong anti-tumour immunity. Loss of TIM-3 prevented DCs from expressing a regulatory program and facilitated the maintenance of CD8+ effector and stem-like T cells. Conditional deletion of TIM-3 in DCs led to increased accumulation of reactive oxygen species resulting in NLRP3 inflammasome activation. Inhibition of inflammasome activation, or downstream effector cytokines interleukin-1β (IL-1β) and IL-18, completely abrogated the protective anti-tumour immunity observed with TIM-3 deletion in DCs. Together, our findings reveal an important role for TIM-3 in regulating DC function and underscore the potential of TIM-3 blockade in promoting anti-tumour immunity by regulating inflammasome activation.

TIM-3 polymorphism is involved in the progression of esophageal squamous cell carcinoma by regulating gene expression

The T-cell immunoglobulin and mucin domain containing molecule 3 (TIM-3), a crucial immune regulatory molecule, is an emerging immune checkpoint target for cancer therapy. Our study aimed to investigate the association between TIM-3 polymorphisms (rs10053538 C > A, rs10515746 C > A, and rs1036199 A > C) and the susceptibility and prognosis of esophageal squamous cell carcinoma (ESCC). We further detect the effects of polymorphisms on TIM-3 expression. Two independent case-control sets (population-based and hospital-based sets) were performed in total 994 ESCC patients and 998 controls. TIM-3 polymorphisms were genotyped by polymerase chain reaction-ligase detection reaction (PCR). Survival data were available for 198 patients who received platinum-based chemotherapy after surgery. The regulation on TIM-3 expression by the polymorphisms was investigated in 35 patients using real-time quantitative PCR. The association between mRNA level of TIM-3 and survival was detected by using Kaplan-Meier plotter database. We found that for rs10053538 C > A polymorphisms, A allele was associated with significant increased risk of ESCC (odds ratios [OR] = 1.34, 95%CI = 1.05-1.72), and CA/AA genotypes enhanced susceptibility to ESCC for smokers (adjusted OR = 1.61, 95%CI = 1.00-2.59). The patients with AA genotypes had significantly poor prognosis (adjusted HR = 4.98, 95%CI = 1.14-21.71). The patients carrying CA/AA genotypes had significantly higher mRNA levels of TIM-3 than those carrying the CC genotype. Furthermore, high mRNA level of TIM-3 had a shorter overall survival in patients (HR = 2.56, 95%CI = 1.04-6.28). For rs10515746 C > A and rs1036199 A > C polymorphisms, there were no statistical correlation with the progression of ESCC. These data demonstrate that rs10053538 C > A polymorphisms may be associated with the susceptibility and prognosis of ESCC patients through regulating expression of TIM-3.

Unraveling subcutaneous panniculitis-like T-cell lymphoma: An association between subcutaneous panniculitis-like T-cell lymphoma, autoimmune lymphoproliferative syndrome, and familial hemophagocytic lymphohistiocytosis

Germline HAVCR2 mutations, recently identified in a large subset of patients with subcutaneous panniculitis-like T-cell lymphoma (SPTCL), are associated with an increased risk of hemophagocytic lymphohistiocytosis (HLH). Discovery of this heritable HLH/SPTCL diathesis has expanded our understanding of a rare and molecularly heterogeneous lymphoma. Furthermore, patients with SPTCL have excellent survival unless they develop HLH. Therefore, through compiling data on SPTCL-related conditions that predispose patients to HLH, we are better able to predict which patients with SPTCL have the greatest risk of mortality. We present the first case of SPTCL with concomitant HLH and autoimmune lymphoproliferative syndrome (ALPS) in a patient who was subsequently diagnosed with familial HLH (F-HLH) attributable to a germline STXBP2 splice-site mutation. She had wild-type HAVCR2. Reports including ours show how SPTCL can evolve in the setting of an exaggerated host inflammatory response attributable to a variety of unusual underlying etiologies.

CRISPR-Cas9-Mediated TIM3 Knockout in Human Natural Killer Cells Enhances Growth Inhibitory Effects on Human Glioma Cells

Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor in adults. Natural Killer (NK) cells are potent cytotoxic effector cells against tumor cells inducing GBM cells; therefore, NK cell based- immunotherapy might be a promising target in GBM. T cell immunoglobulin mucin family member 3 (TIM3), a receptor expressed on NK cells, has been suggested as a marker of dysfunctional NK cells. We established TIM3 knockout in NK cells, using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9). Electroporating of TIM3 exon 2- or exon 5-targeting guide RNA- Cas9 protein complexes (RNPs) inhibited TIM3 expression on NK cells with varying efficacy. T7 endonuclease I mutation detection assays showed that both RNPs disrupted the intended genome sites. The expression of other checkpoint receptors, i.e., programmed cell death 1 (PD1), Lymphocyte-activation gene 3 (LAG3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), and TACTILE (CD96) were unchanged on the TIM3 knockout NK cells. Real time cell growth assays revealed that TIM3 knockout enhanced NK cell-mediated growth inhibition of GBM cells. These results demonstrated that TIM3 knockout enhanced human NK cell mediated cytotoxicity on GBM cells. Future, CRISPR-Cas9 mediated TIM3 knockout in NK cells may prove to be a promising immunotherapeutic alternative in patient with GBM.

Designed improvement to T-cell immunotherapy by multidimensional single cell profiling

BACKGROUND

Adoptive cell therapy based on the infusion of chimeric antigen receptor (CAR) T cells has shown remarkable efficacy for the treatment of hematologic malignancies. The primary mechanism of action of these infused T cells is the direct killing of tumor cells expressing the cognate antigen. However, understanding why only some T cells are capable of killing, and identifying mechanisms that can improve killing has remained elusive.

METHODS

To identify molecular and cellular mechanisms that can improve T-cell killing, we utilized integrated high-throughput single-cell functional profiling by microscopy, followed by robotic retrieval and transcriptional profiling.

RESULTS

With the aid of mathematical modeling we demonstrate that non-killer CAR T cells comprise a heterogeneous population that arise from failure in each of the discrete steps leading to the killing. Differential transcriptional single-cell profiling of killers and non-killers identified CD137 as an inducible costimulatory molecule upregulated on killer T cells. Our single-cell profiling results directly demonstrate that inducible CD137 is feature of killer (and serial killer) T cells and this marks a different subset compared with the CD107apos (degranulating) subset of CAR T cells. Ligation of the induced CD137 with CD137 ligand (CD137L) leads to younger CD19 CAR T cells with sustained killing and lower exhaustion. We genetically modified CAR T cells to co-express CD137L, in trans, and this lead to a profound improvement in anti-tumor efficacy in leukemia and refractory ovarian cancer models in mice.

CONCLUSIONS

Broadly, our results illustrate that while non-killer T cells are reflective of population heterogeneity, integrated single-cell profiling can enable identification of mechanisms that can enhance the function/proliferation of killer T cells leading to direct anti-tumor benefit.

Galectin-9 interacts with PD-1 and TIM-3 to regulate T cell death and is a target for cancer immunotherapy

The two T cell inhibitory receptors PD-1 and TIM-3 are co-expressed during exhausted T cell differentiation, and recent evidence suggests that their crosstalk regulates T cell exhaustion and immunotherapy efficacy; however, the molecular mechanism is unclear. Here we show that PD-1 contributes to the persistence of PD-1+TIM-3+ T cells by binding to the TIM-3 ligand galectin-9 (Gal-9) and attenuates Gal-9/TIM-3-induced cell death. Anti-Gal-9 therapy selectively expands intratumoral TIM-3+ cytotoxic CD8 T cells and immunosuppressive regulatory T cells (Treg cells). The combination of anti-Gal-9 and an agonistic antibody to the co-stimulatory receptor GITR (glucocorticoid-induced tumor necrosis factor receptor-related protein) that depletes Treg cells induces synergistic antitumor activity. Gal-9 expression and secretion are promoted by interferon β and γ, and high Gal-9 expression correlates with poor prognosis in multiple human cancers. Our work uncovers a function for PD-1 in exhausted T cell survival and suggests Gal-9 as a promising target for immunotherapy.

Tim-3 Promotes Listeria monocytogenes Immune Evasion by Suppressing Major Histocompatibility Complex Class I

BACKGROUND

T-cell immunoglobulin and mucin protein 3 (Tim-3) is an immune checkpoint inhibitor that has therapeutic implications for many tumors and infectious diseases. However, the mechanisms by which Tim-3 promotes immune evasion remain unclear.

METHODS

In this study, we demonstrated that Tim-3 inhibits the expression of major histocompatibility complex class I (MHC-I) in macrophages at both the messenger ribonucleic acid and protein levels by inhibiting the STAT1-NLRC5 signaling pathway.

RESULTS

As a result, MHC-I-restricted antigen presentation by macrophages was inhibited by Tim-3 both in vitro and in a Listeria monocytogenes infection model in vivo. Systemic overexpression of Tim-3 or specific knockout of Tim-3 in macrophages significantly attenuated or enhanced CD8+ T-cell activation and infection damage in L monocytogenes-infected mice, respectively.

CONCLUSIONS

Thus, we identified a new mechanism by which Tim-3 promotes L monocytogenes immune evasion. Further studies on this pathway might shed new light on the physio-pathological roles of Tim-3 and suggest new approaches for intervention.

Relationship between TIM-3 gene polymorphisms and steroid-resistant primary nephrotic syndrome in children

Nephrotic syndrome, also known as nephrosis, is a collection of symptoms in medicine and urology caused by damage to the basement membrane of the kidney glomeruli and the kidneys excrete a large amount of protein. This experiment was carried out to investigate the association of three single nucleotide polymorphisms (SNPs) of T-cell immunoglobulin and mucin-domain-containing-3 (Tim-3) with childhood primary nephrotic syndrome (PNS) steroid response in Han Chinese. For this purpose, a total of 218 children with steroid-resistant PNS and 189 children with steroid-responsive PNS were enrolled in this case-control study. Three single nucleotide polymorphisms (SNPs) of the TIM-3 gene promoter region (rs4704853, rs1051746, and rs10053538) were analyzed by polymerase chain reaction (PCR) and restriction enzyme digestion.  Results showed that there were 124 males and 94 females in the steroid-resistant PNS group and 114 males and 75 females in the steroid-responsive PNS group. The mean ages of the two groups were 7.9 years and 7.7 years, respectively. The distribution of alleles of Rs1051746 and Rs10053538 were significantly different between the steroid-resistant PNS group and the steroid-responsive PNS group (P-value = 0.047 and 0.012, respectively). The distribution of their genotypes was also significantly different between the steroid-resistant PNS group and the steroid-responsive PNS group (P-value = 0.044 and 0.010, respectively). Haplotype G-C-G was less frequent among steroid-resistant PNS children than the steroid-responsive PNS children (P = 0.015). There was no significant difference between the three SNPs of TIM-3 and the clinical features of these PNS children (P&gt;0.05). It concluded that this study provided evidence showing that the polymorphisms of Rs1051746 and Rs10053538 at the TIM-3 gene were related to childhood PNS steroid response. This result provided fundamental support for future studies on the role of TIM-3 in pathogenesis and therapy of childhood PNS.

Genetic variants and expression of the TIM-3 gene are associated with clinical prognosis in patients with epithelial ovarian cancer

OBJECTIVE

Polymorphisms of T cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) were reported to be associated with cancer risk and patients' survival. This study aims to investigate the correlation of TIM-3 polymorphisms with susceptibility to epithelial ovarian cancer (EOC) and patients' outcomes.

METHODS

A total of 700 EOC patients and 710 healthy controls from North China were included. The polymorphisms (rs10053538, rs10515746 and rs1036199) were genotyped using the polymerase chain reaction/ligase detection reaction (PCR-LDR) method. Survival data were available for 339 patients after cytoreductive surgery. The expression level of TIM-3 was detected by real-time quantitative PCR (RT-qPCR). The prognostic value of TIM3 in EOC patients was assessed using the Kaplan-Meier plotter database.

RESULTS

The results showed that none of the TIM3 polymorphisms were associated with the risk of developing EOC. Patients with the rs10053538 CA + AA genotype had worse PFS and OS than those with the CC genotype (HR = 1.49, 95% CI = 1.05-2.09, P = 0.024 and HR = 1.57, 95%CI = 1.09-2.26, P = 0.017, respectively). The RT-qPCR results showed that the expression levels of TIM-3 mRNA in EOC tissues with the rs10053538CA + AA genotypes were significantly higher than those with the CC genotype (P = 0.006). Analysis using the Kaplan-Meier plotter database showed that high expression of TIM-3 mRNA was significantly associated with shorter PFS and OS in EOC patients (HR = 1.57, 95%CI = 1.29-1.91, P < 0.001 and HR = 1.31, 95% CI = 1.06-1.63, P = 0.013, respectively).

CONCLUSIONS

TIM-3 polymorphisms were not associated with risk of developing EOC. Both rs10053538 and the expression level of TIM-3 mRNA may be associated with its clinical outcome in EOC patients.