T Cells Research Articles

Near-Infrared Activatable Copper Nanoplatforms Synergize with the 5-Azacytidine Prodrug to Potentiate Cuproptosis.

Cuproptosis, a newly discovered cell death modality, is gaining recognition for its crucial role in antitumor therapy. Here, we demonstrated that Ferredoxin 1 (FDX1), a key gene involved in cuproptosis, is negatively correlated with malignancy and T-cell exhaustion in head and neck squamous cell carcinoma (HNSCC). Based on these findings, we developed near-infrared (NIR) light-controlled nanoparticles (NPs), CuD@PM, which can selectively deliver copper to HNSCC cells and induce cuproptosis in the presence of microneedles loaded with triacetylated azacitidine (TAc-AzaC) and 808 nm laser irradiation. Intravenous administration of these NPs significantly suppressed tumor growth in HNSCC animal models and enhanced the antitumor immune response. The NIR-controlled activation of cuproptosis offers great potential as a safe, targeted, and image-guided antitumor therapy for HNSCC.

Dynamic Changes in Lymphocyte Populations and Their Relationship with Disease Severity and Outcome in COVID-19

Studies suggest that the dynamic changes in cellular response might correlate with disease severity and outcomes in SARS-CoV-2 patients. The study aimed to investigate the dynamic changes of lymphocyte subsets in patients with COVID-19. In this regard, 53 patients with COVID-19 were prospectively included, classified as mild, moderate, and severe. The peripheral lymphocyte profiles (LyT, LyB, and NK cells), as well as CD4+/CD8+, CD3+/CD19+, CD3+/NK and CD19+/NK ratios, and their dynamic changes during hospitalization and correlation with disease severity and outcome were assessed. We found significant differences in CD3+ lymphocytes between severity groups (p < 0.0001), with significantly decreased CD3+CD4+ and CD3+CD8+ in patients with severe disease (p < 0.0001 and p = 0.048, respectively). Lower CD3+/CD19+ and CD3+/NK ratios among patients with severe disease (p = 0.019 and p = 0.010, respectively) were found. The dynamic changes of lymphocyte subsets showed a significant reduction in NK cells (%) and a significant increase in CD3+CD4+ and CD3+CD8+ cells in patients with moderate and severe disease. The ROC analysis on the relationship between CD3+ cells and fatal outcome yielded an AUC of 0.723 (95% CI 0.583–0.837; p = 0.007), while after addition of age and SpO2, ferritin and NLR, the AUC significantly improved to 0.927 (95%CI 0.811–0.983), p < 0.001 with a sensitivity of 90.9% (95% CI 58.7–99.8%) and specificity of 85.7% (95% CI 69.7–95.2%). The absolute number of CD3+ lymphocytes might independently predict fatal outcomes in COVID-19 patients and T-lymphocyte subset evaluation in high-risk patients might be useful in estimating disease progression.

Fine-mapping and molecular characterisation of primary sclerosing cholangitis genetic risk loci

Genome-wide association studies of primary sclerosing cholangitis have identified 23 susceptibility loci. The majority of these loci reside in non-coding regions of the genome and are thought to exert their effect by perturbing the regulation of nearby genes. Here, we aim to identify these genes to improve the biological understanding of primary sclerosing cholangitis, and nominate potential drug targets. We first build an eQTL map for six primary sclerosing cholangitis-relevant T-cell subsets obtained from the peripheral blood of primary sclerosing cholangitis and ulcerative colitis patients. These maps identify 10,459 unique eGenes, 87% of which are shared across all six primary sclerosing cholangitis T-cell types. We then search for colocalisations between primary sclerosing cholangitis loci and eQTLs and undertake Bayesian fine-mapping to identify disease-causing variants. In this work, colocalisation analyses nominate likely primary sclerosing cholangitis effector genes and biological mechanisms at five non-coding (UBASH3A, PRKD2, ETS2 and AP003774.1/CCDC88B) and one coding (SH2B3) primary sclerosing cholangitis loci. Through fine-mapping we identify likely causal variants for a third of all primary sclerosing cholangitis-associated loci, including two to single variant resolution.

γδ T17 Cells Regulate the Acute Antiviral Response of NK Cells in HSV-1-Infected Corneas.

To determine whether γδ T cells regulate natural killer (NK) cells in the herpes simplex virus 1 (HSV-1)-infected cornea. CD57Bl/6 (wild-type [WT]), TCRδ-/-, and IFN-γ-/- mice were infected intracorneally with HSV-1. TCR-/- mice were treated with IL-17A at 24 hours post-infection (PI), and the WT mice received treatments of fingolimod (FTY720) and anti-IL-17A. At 48hours PI, corneas were excised, and intracellular staining flow cytometry was performed, as well as multiplex analysis. Additionally, single-cell RNA sequencing (scRNAseq) was done to analyze the transcriptome of NK cells from WT and TCRδ-/- mice. In mice lacking γδ T cells, there were significantly fewer NK cells following ocular HSV-1 infection. This reduction of NK cells corresponded with lower levels of cytokines and chemokines associated with the antiviral response. Furthermore, NK cells from WT mice had enriched IL-17A signaling compared to those from TCRδ-/- mice. The NK cell response was partially rescued in TCRδ-/- mice by administration of IL-17A. Correspondingly, the NK cell response could be blunted in WT mice by administration of anti-IL-17A. Finally, IFN-γ-/- mice had significantly less IL-17A production compared to WT mice. γδ T17 cells promote NK cell accumulation in HSV-1-infected corneas. In turn, NK cells secrete IFN-γ, which negatively regulates further IL-17A production by γδ T cells.

Uncovering cell-type-specific immunomodulatory variants and molecular phenotypes in COVID-19 using structurally resolved protein networks

Immunomodulatory variants that lead to the loss or gain of specific protein interactions often manifest only as organismal phenotypes in infectious disease. Here, we propose a network-based approach to integrate genetic variation with a structurally resolved human protein interactome network to prioritize immunomodulatory variants in COVID-19. We find that, in addition to variants that pass genome-wide significance thresholds, variants at the interface of specific protein-protein interactions, even though they do not meet genome-wide thresholds, are equally immunomodulatory. The integration of these variants with single-cell epigenomic and transcriptomic data prioritizes myeloid and Tcell subsets as the most affected by these variants across both the peripheral blood and the lung compartments. Of particular interest is a common coding variant that disrupts the OAS1-PRMT6 interaction and affects downstream interferon signaling. Critically, our framework is generalizable across infectious disease contexts and can be used to implicate immunomodulatory variants that do not meet genome-wide significance thresholds.

Spatial context of immune checkpoints as predictors of overall survival in patients with resectable colorectal cancer independent of standard TNM stages.

While immune checkpoint blockade (ICB) therapy has shown promising results in a small subset of colorectal cancer patients with high microsatellite instability (MSI-H), the majority of patients with colorectal cancer do not respond to ICB therapy. The main obstacle to the success of immunotherapy in cancer treatment is the exhaustion of tumor-infiltrating lymphocytes (TILs). Elucidating the spatial organization of immune checkpoints within the tumor microenvironment could pave the way for the development of novel prognostic tools and therapeutic strategies to enhance antitumor immune responses. To clarify the spatial and functional diversity of tumor-infiltrating lymphocytes (TILs) in the colorectal tumor microenvironment (TME), we performed multiplexed IHC to examine the exhaustion of TILs in the TME (the expression of PD-1 and TIM-3 (T-cell immunoglobulin and mucin-domain-containing protein 3), which are major biomarkers of T-cell exhaustion) and Lasso-Cox analyses of the correlation between CRC prognosis and TME features. For proof of concept, the antitumor efficacy of TIM-3 and PD-1 dual blockade in CRC was further evaluated in a CT26 subcutaneous tumor model of human CRC. We found that the spatial context of PD-1 and TIM-3 successfully predicted the overall survival of CRC patients independent of TNM stage. Dual targeting of PD-1 and TIM-3 in mouse tumor models inhibited tumor progression and reduced T-cell exhaustion, indicating a potential strategy for improving the clinical treatment of CRC.

WWOX tuning of oleic acid signaling orchestrates immunosuppressive macrophage polarization and sensitizes hepatocellular carcinoma to immunotherapy

BackgroundImmune checkpoint inhibitors (ICIs) are therapeutically effective for hepatocellular carcinoma (HCC) but are individually selective. This study examined the role of specific common fragile sites (CFSs) related gene in HCC...

SARS-CoV-2 infection elucidates features of pregnancy-specific immunity

Pregnancy is a risk factor for increased severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory infections, but the mechanisms underlying this risk are poorly understood. To gain insight into the role of pregnancy in modulating immune responses at baseline and upon SARS-CoV-2 infection, we collected peripheral blood mononuclear cells and plasma from 226 women, including 152 pregnant individuals and 74 non-pregnant women. We find that SARS-CoV-2 infection is associated with altered Tcell responses in pregnant women, including a clonal expansion of CD4-expressing CD8+ Tcells, diminished interferon responses, and profound suppression of monocyte function. We also identify shifts in cytokine and chemokine levels in the sera of pregnant individuals, including a robust increase of interleukin-27, known to drive Tcell exhaustion. Our findings reveal nuanced pregnancy-associated immune responses, which may contribute to the increased susceptibility of pregnant individuals to viral respiratory infection.

Identification and analysis of microplastic aggregation in CAR-T cells

Microplastics (MPs) are increasingly recognized as contaminants present in various environments and are widely acknowledged as potential hazards to the mammalian immune system. In our study of chimeric antigen receptor T cell (CAR-T) therapy, we observed the presence of MP in CAR-T cell products for the first time. It is worth exploring whether MP could enter CAR-T cells and how they might affect CAR-T cells’ functionality. Therefore, we analyzed how MP affected CD19 and BCMA-CAR-T cells. Based on flow cytometry, ELISA, and cytotoxicity analysis of in vitro and in vivo experiments, MP suppressed the activity of CAR-T cells. Subsequent investigation revealed that the exposure of CAR-T cells to varying concentrations of MP resulted in a notable increase in apoptosis, ferroptosis, and exhaustion levels. Furthermore, the hyperactivation of the mTOR signaling pathway in MP-treated CAR-T cells was verified. The partial restoration of CAR-T cell function in MP was achieved by inhibiting the mTOR pathway. MP present a threat to CAR-T cell function due to their role in inducing CAR-T cell apoptosis, ferroptosis, and T-cell exhaustion through the hyperactivation of mTOR signaling pathways.

Antiviral immune response against HTLV-1 invalidates T-SPOT.TB® results in patients with HTLV-1-positive rheumatic diseases

BackgroundT-SPOT.TB®, one of the screening tests for latent tuberculosis infection (LTBI), yields invalid results in human T-cell leukemia virus type 1 (HTLV-1)-positive patients with rheumatoid arthritis. However, the detailed mechanisms behind this invalidation are unclear. Additionally, it remains unclear whether T-SPOT.TB® or QuantiFERON-TB (QFT) is more useful in HTLV-1-positive patients with rheumatic disease (RD).MethodAmong all of the HTLV-1-positive RD patients who visited our department between August 2012 and December 2022, 44 patients who were screened using T-SPOT.TB® were included in the analysis. QFT testing was performed in 33 of the 44 patients, and the results were compared with that of T-SPOT.TB®. Furthermore, we performed a culture experiment mimicking T-SPOT.TB® using peripheral blood mononuclear cells (PBMCs) obtained from HTLV-1-positive patients with RD. Additionally, T-cell subsets with autonomous product IFN-γ were analyzed using a flow cytometer.ResultsOf the included patients, 13 (29.5%) were invalid for T-SPOT.TB® because of the increased number of negative control spots. The median HTLV-1 proviral load in the invalid group was higher than that in the valid group (2.45 vs. 0.49 copies/100 PBMCs, respectively, p = 0.002). QFT was performed in all 33 patients, including 13 patients who were invalid in T-SPOT.TB®. The main source of IFN-γ production was CD8+ T-cells in the T-SPOT.TB® mimic experiment. Furthermore, Tax-expressing CD4+ T-cells and Tax-specific cytotoxic CD8+ T-cells were more frequently observed in patients with invalid results than in patients with valid results. CD4+ T-cell depletion in the T-SPOT.TB® mimic experiment reduced the population of IFN-γ producing CD8+ T cells.ConclusionT-SPOT.TB® may be invalidated by the interaction between Tax-expressing CD4+ T-cells and cytotoxic CD8+ T-cells. Moreover, HTLV-1-associated immune reactions due to contact between these cells may be unlikely to occur in QFT using whole blood. Therefore, our results reveal the superiority of QFT over T-SPOT.TB® as a screening test for LTBI in HTLV-1-positive patients with RD.

CAR T-cell Therapy for Central Nervous System Lymphoma.

While anti-CD19 CAR T-cell therapy represents a major advance in systemic diffuse large B-cell lymphomas, central nervous system (CNS) lymphomas have been excluded from pivotal trials because of the fear of neurotoxicity. The purpose of this review was to assess the efficacy and tolerance of CAR T-cells in CNS lymphomas based on recently published studies. All the studies on CAR T-cell therapy for both primary and secondary CNS lymphomas reported high response rates (complete response rates ranging from 32 to 67%) in highly pre-treated patients. One-year PFS reached 40 to 60% in several studies. Neurotoxicity occurred in 36 to 68% of patients, including grade 3-4 neurotoxicity in 4.5 to 29% of patients. CAR T-cell therapy appears to be a very promising treatment in CNS lymphomas, with efficacy results close to those observed in systemic lymphomas. The toxicity profile, notably regarding neurotoxicity, is reassuring and should not prevent the development of CAR T-cells in the disease.

Bispecific antibody (ABL602 2 + 1) induced bistable acute myeloid leukemia kinetics

ABL602 2 + 1, a bispecific antibody with two distinct domains binding to CLL-1 on leukemias and CD3 on T cells, exhibits superior T cell activation and tumour lysing activity. Treatment outcomes of bispecific antibody rely on acute myeloid leukemia cell replication and antibody induced tumour lysing, but their quantitative relationship was unknown. Mathematical models are employed to quantitatively investigate HL-60 cell kinetics determined by bispecific antibody and tumour burden. First, we analysed cytotoxicity assay data testing HL-60 cell against bispecific antibody and T cells, and found efficiency of bispecific antibody induced tumour lysing increases but saturates with increase of HL-60 cell, T cell and bispecific antibody concentration. As a result, their interaction leads to bistable HL-60 cell kinetics; namely, at a given bispecific antibody and T cell concentration interval, HL-60 cell kinetics with small tumour burdens are inhibited but refractory to large tumour burdens. T cell concentration is strong negatively correlated with HL-60 cell concentration. With bispecific antibody clearance, observed bistable HL-60 cell kinetics still exists. Our finding explains observed phenomenon that bispecific antibody was less efficacious at high tumour burden even with enough activated cytotoxic CD8 + T cells. Maintaining high antibody concentration and preventing T-cell exhaustion are equivalently important to sustain long-term control.

Chimeric antigen receptor T-cell therapy in patients with malignant glioma-From neuroimmunology to clinical trial design considerations.

Clinical trials evaluating chimeric antigen receptor (CAR) T-cell therapy in patients with malignant gliomas have shown some early promise in pediatric and adult patients. However, the long-term benefits and safety for patients remain to be established. The ultimate success of CAR T-cell therapy for malignant glioma will require the integration of an in-depth understanding of the immunology of the central nervous system (CNS) parenchyma with strategies to overcome the paucity and heterogeneous expression of glioma-specific antigens. We also need to address the cold (immunosuppressive) microenvironment, exhaustion of the CAR T-cells, as well as local and systemic immunosuppression. Here, we discuss the basics and scientific considerations for CAR T-cell therapies and highlight recent clinical trials. To help identify optimal CAR T-cell administration routes, we summarize our current understanding of CNS immunology and T-cell homing to the CNS. We also discuss challenges and opportunities related to clinical trial design and patient safety/monitoring. Finally, we provide our perspective on future prospects in CAR T-cell therapy for malignant gliomas by discussing combinations and novel engineering strategies to overcome immuno-regulatory mechanisms. We hope this review will serve as a basis for advancing the field in a multiple discipline-based and collaborative manner.

Antibody blockade of the PSGL-1 immune checkpoint enhances T-cell responses to B-cell lymphoma.

Despite advancements in cancer immunotherapy, most lymphomas remain unresponsive to checkpoint inhibitors. P-selectin glycoprotein ligand-1 (PSGL-1), recently identified as a promoter of T-cell exhaustion in murine melanoma models, has emerged as a novel immune checkpoint protein and promising immunotherapeutic target. In this study, we investigated the potential of PSGL-1 antibody targeting in B-cell lymphoma. Using allogeneic co-culture systems, we demonstrated that targeted antibody interventions against human PSGL-1 enhanced T-cell activation and effector cytokine production in response to lymphoma cells. Moreover, in vitro treatment of primary lymphoma cell suspensions with PSGL-1 antibody resulted in increased activation of autologous lymphoma-infiltrating T cells. Using the A20 syngeneic B-cell lymphoma mouse model, we found that PSGL-1 antibody treatment significantly slowed tumor development and reduced the endpoint tumor burden. This antitumoral effect was accompanied by augmented tumor infiltration of CD4+ and CD8+ T cells and reduced infiltration of regulatory T cells. Finally, anti-PSGL-1 administration enhanced the expansion of CAR T cells previously transferred to mice bearing the aggressive Eμ-Myc lymphoma cells and improved disease control. These results demonstrate that PSGL-1 antibody blockade bolsters T-cell activity against B-cell lymphoma, suggesting a potential novel immunotherapeutic approach for treating these malignancies.

Comparison οf Immune Responses Through Multiparametric T-Cell Cytokine Expression Profile Between Children with Convalescent COVID-19 or Multisystem Inflammatory Syndrome

Background/objectives: The immunological pathways that cause Multisystem Inflammatory Syndrome after SARS-CoV-2 infection in children (MIS-C) remain under investigation. Methods: The aim of this study was to prospectively compare the T-cell cytokine expression profile in unvaccinated children with acute MIS-C (MISC_A) before immunosuppression, convalescent MIS-C (one month after syndrome onset, MISC_C), convalescent COVID-19 (one month after hospitalization), and in healthy, unvaccinated controls. The intracellular expression of IL-4, IL-2, IL-17, IFNγ, TNF-α and Granzyme B, and the post SARS-CoV-2-Spike antigenic mix stimulation of T-cell subsets was analyzed by 13-color flow cytometry. Results: Twenty children with a median age (IQR) of 11.5 (7.25–14) years were included in the study. From the comparison of the flow cytometry analysis of the 14 markers of MISC_A with the other three groups (MISC_C, post-COVID-19 and controls), significant differences were identified as follows: 1. CD4+IL-17+/million CD3+: 293.0(256.4–870.9) vs. 50.7(8.4–140.5); p-value: 0.03, vs. 96.7(89.2–135.4); p-value: 0.03 and vs. 8.7(0.0–82.4); p-value: 0.03, respectively; 2. CD8+IL-17+/million CD3+: 335.2(225.8–429.9) vs. 78.0(31.9–128.9) vs. 84.1(0.0–204.6) vs. 33.2(0.0–114.6); p-value: 0.05, respectively; 3. CD8+IFNγ+/million CD3+: 162.2(91.6–273.4) vs. 41.5(0.0–77.4); p-value: 0.03 vs. 30.3(0.0–92.8); p-value: 0.08, respectively. Conclusions: In children presenting with MIS-C one month after COVID-19 infection, T cells were found to be polarized towards IL-17 and IFNγ production compared to those with uncomplicated convalescent COVID-19, a finding that could provide possible immunological biomarkers for MIS-C detection.

Characterization of HPV6/11-reactive T-cell subsets in papillomas of patients with juvenile-onset recurrent respiratory papillomatosis and identification of HPV11 E7-specific candidate TCR clonotypes.

Juvenile-onset recurrent respiratory papillomatosis (JORRP) is caused by persistent infection of epithelial cells by low-risk human papillomavirus (HPV) types 6 and 11. While multiple infiltrated immune cells have been reported to mediate disease progress, knowledge of HPV-reactive T-cell subsets in papillomas remains elusive. Through single-cell RNA sequencing and RNA microarray, we found that CD8+ tissue-resident memory T (CD8+ TRM) cells with strong interferon-gamma (IFN-γ) production expanded, and were negatively correlated to the disease severity in the frequency of surgery. These IFN-γ+ CD8+ memory T cells were readily activated and expanded in vitro by autologous dendritic cells loaded with HPV11 E7 peptide pool. Moreover, T cell receptor (TCR) clonal expansion was observed in JORRP papilloma tissues, indicating a biased TCR repertoire toward HPV-specific recognition. Finally, we identified and characterized HPV11 E7-specific candidate TCR clonotypes from IFN-γ+ CD8+ memory T cells, suggesting their potential application in TCR-engineered T cells (TCR-T) therapy for HPV11-related diseases. Our findings provided insights into the specific local immune response to HPV6/11 infection and highlighted the importance of IFN-γ+ CD8+ TRM cells in anti-HPV6/11 T-cell immunity.IMPORTANCEThe persistent recurrence of human papillomavirus (HPV) 6/11 infection in papillomas underscores the failure of local immune responses in patients with juvenile-onset recurrent respiratory papillomatosis (JORRP). Our previous study demonstrated that T cells constitute the predominant immune cell population in JORRP papilloma tissues. Understanding the T-cell-mediated immune responses within JORRP papilloma tissues is crucial for disease control. In the present study, we characterized CD8+ tissue-resident memory T (CD8+ TRM) cells as the primary T-cell subset responsible for local anti-HPV6/11 immunity. Moreover, we identified two HPV11 E7-specific candidate T cell receptor (TCR) clonotypes out of IFN-γ+ CD8+ memory T cells. Overall, our findings provided insights into the local immune responses to HPV6/11 infection and offered information for developing more effective immunotherapeutic strategies against JORRP.

No more LAGging behind PD-1: uncovering the unique role of LAG-3 in T-cell exhaustion.

No more LAGging behind PD-1: uncovering the unique role of LAG-3 in T-cell exhaustion.

Role of T Lymphocytes in Glioma Immune Microenvironment: Two Sides of a Coin.

Glioma is known for its immunosuppressive microenvironment, which makes it challenging to target through immunotherapies. Immune cells like macrophages, microglia, myeloid-derived suppressor cells, and T lymphocytes are known to infiltrate the glioma tumor microenvironment and regulate immune response distinctively. Among the variety of immune cells, T lymphocytes have highly complex and multifaceted roles in the glioma immune landscape. T lymphocytes, which include CD4+ helper and CD8+ cytotoxic T cells, are known for their pivotal roles in anti-tumor responses. However, these cells may behave differently in the highly dynamic glioma microenvironment, for example, via an immune invasion mechanism enforced by tumor cells. Therefore, T lymphocytes play dual roles in glioma immunity, firstly by their anti-tumor responses, and secondly by exploiting gliomas to promote immune invasion. As an immunosuppression strategy, glioma induces T-cell exhaustion and suppression of effector T cells by regulatory T cells (Tregs) or by altering their signaling pathways. Further, the expression of immune checkpoint inhibitors on the glioma cell surface leads to T cell anergy and dysfunction. Overall, this dynamic interplay between T lymphocytes and glioma is crucial for designing more effective immunotherapies. The current review provides detailed knowledge on the roles of T lymphocytes in the glioma immune microenvironment and helps to explore novel therapeutic approaches to reinvigorate T lymphocytes.

Targeted Drug Screening Leveraging Senescence-Induced T-Cell Exhaustion Signatures in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most prevalent cancer and a leading cause of cancer-related mortality globally, with most patients diagnosed at advanced stages and facing limited early treatment options. This study aimed to identify characteristic genes associated with T-cell exhaustion due to senescence in hepatocellular carcinoma patients, elucidating the interplay between senescence and T-cell exhaustion. We constructed prognostic models based on five signature genes (ENO1, STMN1, PRDX1, RAN, and RANBP1) linked to T-cell exhaustion, utilizing elastic net regression. The findings indicate that increased expression of ENO1 in T cells may contribute to T-cell exhaustion and Treg infiltration in hepatocellular carcinoma. Furthermore, molecular docking was employed to screen small molecule compounds that target the anti-tumor effects of these exhaustion-related genes. This study provides crucial insights into the diagnosis and treatment of hepatocellular carcinoma, establishing a strong foundation for the development of predictive biomarkers and therapeutic targets for affected patients.

PD-1 and CTLA-4 serve as major gatekeepers for effector and cytotoxic T-cell potentiation by limiting a CXCL9/10-CXCR3-IFNγ positive feedback loop.

CXCR3 is a chemokine receptor with three ligands: CXCL9, CXCL10 and CXCL11. We report that in addition to attracting CXCR3+ T cells to tumor sites a key role of CXCL9 and CXCL10 is in inducing a self-feeding feedback loop that accelerates effector/cytotoxic activities of both CD4+ and CD8+ T cells while downregulating immunoregulatory protein TIM3. CXCR3KO mice displayed a markedly reduced response to anti-PD-1 and anti-CTLA-4 therapy. Results from a panel of in vivo and ex vivo 3D tumor models imply that, beyond driving CD8+ T cells into T-cell exhaustion, a major role of PD-1 and CTLA-4 is in limiting the CXCR3-based self-feeding mechanism of T cell potentiation. This may explain why patients that are CXCL9/CXCL10high tend to respond well to anti-PD-1 therapy, as opposed to patients that are CXCL9/CXCL10low. It also suggests a therapeutic role for CXCL9-Fc or CXCL10-Fc therapy; herein we demonstrate significant anti-tumor activity in multiple murine tumor models with such agents.