Mechanistic convergence of the TIGIT and PD-1 inhibitory pathways necessitates co-blockade to optimize anti-tumor CD8+ T cell responses

Changes in PD-1 expression on T lymphocyte subsets and related immune indicators before and after definitive chemoradiotherapy for esophageal squamous cell carcinoma

OBJECTIVE

This study aimed to observe the dynamic changes in the expression of T lymphocytes, natural killer (NK) cells, and PD-1 in patients with first-diagnosed esophageal squamous cell carcinoma (ESCC) before and after chemoradiotherapy (CRT) and evaluate the impact of PD-1 expression in peripheral blood on the short-term outcome of patients with ESCC.

PATIENTS AND METHODS

Seventy-three patients with ESCC who were treated with definitive CRT were enrolled. Before and after CRT, flow cytometry was used to detect thePD-1 expression in the peripheral blood and related immune indicators. Peripheral blood from 10 healthy individuals was used as control.

RESULTS

The percentages of CD3+ (p = 0.018), CD4+ (p < 0.001), and CD8+ T cells (p < 0.001); NK cells (p = 0.009); and the CD4+/CD8+ ratio (p < 0.001), as well as PD-1+CD3+ (p < 0.001), PD-1+CD4+ (p < 0.001), and PD-1+CD8+ (p < 0.001) T cells, before CRT significantly differed from those in the post-CRT group. The percentages of PD-1+CD8+ T cells differed significantly between the radiotherapy alone and CRT groups (p < 0.05). PD-1 expression in CD3+, CD4+, and CD8+ T cells significantly decreased in patients achieving overall response rate (all p < 0.05). Compared with those in the incomplete response group, PD-1+CD8+ T cells significantly decreased in the CR group (p < 0.05).

CONCLUSION

CRT aggravated immunosuppression and increased PD-1 expression in T lymphocyte subsets in patients with ESCC, possibly related to the radiation field. PD-1 expression in T lymphocyte subsets can predict short-term outcomes in patients and provide a theoretical basis for the sequential application of PD-1 immunosuppressants after radiotherapy and chemotherapy.

Optimization of Immunotherapy Strategies Based on Spatiotemporal Heterogeneity of Tumour-Associated Tissue-Resident Memory T Cells

Tissue-resident memory T cells (TRMs) reside in peripheral tissues and provide rapid immune defence against local infection and tumours. Tumour-associated TRMs share common tissue-resident features and formation mechanisms, representing some unique subsets of tumour-infiltrating lymphocytes (TILs). However, differences in the tumour microenvironment(TME) and tumour evolution stage result in TRMs exhibiting temporal and spatial heterogeneity of phenotype and function not only at different stages, before and after treatment, but also between tumours originating from different tissues, primary and metastatic cancer, and tumour and adjacent normal tissue. The infiltration of TRMs is often associated with immunotherapy response and favourable prognosis; however, due to different definitions, it has been shown that some subtypes of TRMs can also have a negative impact. Therefore, it is crucial to precisely characterise the TRM subpopulations that can influence the therapeutic efficacy and clinical prognosis of various solid tumours. Here, we review the spatiotemporal heterogeneity of tumour-associated TRMs, as well as the differences in their impact on clinical outcomes. We also explore the relationship between TRMs and immune checkpoint blockade (ICB) and TIL therapy, providing insights into potential new targets and strategies for immunotherapy.

[New therapeutic approaches in the neoadjuvant/adjuvant treatment of melanoma]

BACKGROUND

Although effective treatment options for malignant melanoma already exist, currently available adjuvant and neoadjuvant therapies are not always sufficient to prevent relapse or ensure a long-term treatment response. Many patients develop resistance or show inadequate responses to existing therapies. Therefore, there is an urgent need for new and more effective therapeutic approaches in the adjuvant and neoadjuvant settings to sustainably improve patient prognosis.

OBJECTIVE

This study provides an overview of current developments in melanoma treatment, with a particular focus on the adjuvant and neoadjuvant application of novel immunotherapies.

MATERIAL AND METHODS

A literature search and discussion of relevant recent studies was carried out.

RESULTS

Adjuvant mRNA-based adjuvant treatment combined with pembrolizumab demonstrated a significantly improved relapse-free survival compared to pembrolizumab monotherapy (79% vs. 62%). The value of adjuvant LAG‑3 antibodies in combination with PD‑1 blockers remains inconclusive. A neoadjuvant intralesional treatment with daromun after complete removal of tumor tissue reduced the risk of recurrence by 41% and led to a significant extension in relapse-free survival (16.7 months vs. 6.8 months). Tebentafusp improved overall survival in metastatic uveal melanoma and is currently being investigated in the adjuvant and neoadjuvant setting.

DISCUSSION

The mRNA-based treatment combined with checkpoint inhibitors have the potential to induce long-term immune responses. The efficacy of LAG-3 inhibitors in the adjuvant setting is currently under evaluation in clinical studies. The immunocytokine treatment with daromun shows promising results in the neoadjuvant setting by stimulating both local and systemic immune responses. Future studies should focus on identifying optimal combinations of treatment to improve the long-term prognosis of patients.

TIGIT antibody with PVR competitive ability enhances cancer immunotherapy and capable of eliciting anti-tumour immune memory

BACKGROUND

T-cell immunoreceptor with immunoglobulin (Ig) and ITIM domains (TIGIT) is a checkpoint receptor thought to be involved in mediating T-cell exhaustion and dysfunction of natural killer (NK) cells in tumours and is emerging as novel promising targets in immunotherapy, however, the ligand binding and the efficacy of its antibody still need to be further explored.

METHODS

Four different TIGIT antibodies in characteristics of antigen binding, in vitro effects on activated T cells, Fc region functions and tumour inhibition in animal models were compared. The antibody as monotherapy and combined with anti-PD-L1 antibody, effects on PBMC in ex vivo coculture with autologous human CRC organoids as well as PK profile were evaluated.

RESULTS

Studies demonstrated that TIGIT antibody with PVR-competitive ability as monotherapy resulted in inhibition of tumour growth, sustained anti-tumour immune memory in tumour re-challenge mice, enhanced anti-tumour therapy in combination with anti-PD-L1. Ex vivo coculture assay suggested that TIGIT antibody treatment activated immune cells and promoted infiltration and tumour killing ability of autologous PBMC in human CRC organoids.

CONCLUSIONS

Our study broadens the knowledge of TIGIT antibody in cancer immunotherapy and may benefit future development of next-generation checkpoint inhibitors with improved clinical outcomes.

Beyond Canonical Immune Checkpoints: Overexpression of TNFRSF Members 4-1BB and OX-40 Marks T Cells Exhibiting Phenotypic Features of Exhaustion in Cervical Carcinoma

T cells are pivotal in combating cancer; however, they can become exhausted during tumour progression, losing their cytotoxic capacity and upregulating inhibitory receptors including PD-1 and TIGIT. While checkpoint blockade has emerged as a potent treatment option for numerous cancers, patient selection, long-term efficacy, and adverse effects still remain an issue. For these reasons, it is important to investigate other pathways that might lead to selective reactivation of the immune system. Co-stimulatory TNFRSF receptors, including 4-1BB and OX-40, have emerged as promising targets for reactivating exhausted T cells. However, their expression on exhausted peripheral and tumour-infiltrating lymphocytes (TILs) is not well characterised, particularly in cervical cancer (CC), which remains the leading cause of gynaecological cancer mortality in low- and middle-income countries. To investigate the expression of these receptors, PBMCs were collected from CC patients and healthy donors, along with TILs from tumour biopsies, and analysed using multiparametric flow cytometry. Our findings revealed an increased population of phenotypically exhausted (PD-1+TIGIT+) CD4+ and CD8+ T cells in TILs, and, to a lesser extent, in peripheral blood and from CC patients. These exhausted T cell subsets exhibited selective overexpression of 4-1BB and OX-40 compared to phenotypically non-exhausted cells (PD-1-TIGIT-). In TILs, 4-1BB was overexpressed 12.7-fold in CD8 cells with the exhausted phenotype, OX-40 was overexpressed 3.3-fold; in CD4 cells with the exhausted phenotype, the overexpression was 7.8× and 3.8× for 4-1BB and OX-40, respectively. CD8 and CD4 T cells that were PD-1 + TIGIT+ 4-1BB+ were 7.3× and 16× more likely to be found in the tumour versus peripheral blood. Additionally, subpopulations of PD-1high T cells were significantly elevated in the tumour-infiltrating T cells and TIGIT expression was positively associated with PD-1 levels in peripheral patient CD8+ and CD4+ T cells, potentially indicating an advanced state of exhaustion. These findings suggest that TNFRSF members, especially 4-1BB, may serve as potential immunotherapeutic targets for reinvigorating exhausted T cells in CC.

TIGIT deficiency promotes autoreactive CD4+ T-cell responses through a metabolic‒epigenetic mechanism in autoimmune myositis

Polymyositis (PM) is a systemic autoimmune disease characterized by muscular inflammatory infiltrates and degeneration. T-cell immunoreceptor with Ig and ITIM domains (TIGIT) contributes to immune tolerance by inhibiting T cell-mediated autoimmunity. Here, we show that a reduced expression of TIGIT in CD4+ T cells from patients with PM promotes these cells' differentiation into Th1 and Th17 cells, which could be rescued by TIGIT overexpression. Knockout of TIGIT enhances muscle inflammation in a mouse model of experimental autoimmune myositis. Mechanistically, we find that TIGIT deficiency enhances CD28-mediated PI3K/AKT/mTOR co-stimulatory pathway, which promotes glucose oxidation, citrate production, and increased cytosolic acetyl-CoA levels, ultimately inducing epigenetic reprogramming via histone acetylation. Importantly, pharmacological inhibition of histone acetylation suppresses the differentiation of Th1 and Th17 cells, alleviating muscle inflammation. Thus, our findings reveal a mechanism by which TIGIT directly affects the differentiation of Th1 and Th17 T cells through metabolic‒epigenetic reprogramming, with important implications for treating systemic autoimmune diseases.

NKG2D triggering hampers DNAM-1-mediated signaling in human NK cells

Introduction

Natural Killer (NK) cells are cytotoxic innate lymphocytes able to detect transformed cells through the balanced action of inhibitory and activating receptors. NKG2D is one of the main activating receptors involved in tumor surveillance thanks to its ability to recognize stress-induced ligands. Of note, the prolonged exposure to NKG2D ligands promotes receptor down-modulation that results in defective activation of NKG2D and other unrelated activating receptors, including DNAM-1 that is also involved in tumor clearance. However, further investigations are necessary to characterize how the NKG2D/DNAM-1 interplay affects NK cell anti-tumor function.

Methods

Primary cultured human NK cells were stimulated with the natural ligand MICA or an anti-NKG2D agonist antibody. The expression of activating and inhibitory receptors as well as DNAM-1-triggered signaling events and cytotoxicity were evaluated by flow cytometry. DNAM-1-mediated granule polarization was evaluated by confocal microscopy.

Results

We showed that NKG2D crosslinking mediated by the natural ligand MICA or an agonist antibody had different consequences on primary cultured human NK cells. Indeed, MICA stimulation increases the expression of the checkpoint receptor TIGIT that is able to counteract DNAM-1 activation. Stimulation with the agonist antibody, without altering TIGIT expression, directly inhibits DNAM-1-mediated signal transduction and cytotoxic function with a mechanism that required NKG2D endocytosis.

Discussion

Our findings contribute to shed light on the functional consequences of NKG2D engagement, demonstrating that a direct impact on DNAM-1-mediated signal transduction occurs independently from the modality of NKG2D crosslinking. Understanding the molecular mechanisms responsible for suppression of NK cell activation may help the development of therapeutic anti-cancer strategies aimed to prevent NK cell dysfunction or to reinvigorate an impaired cytotoxic activity.

TIGIT blockade increases efficacy of PD-1 blockade combined with radiation therapy in triple-negative breast cancer model

BACKGROUND AND PURPOSE

T-cell immunoreceptor with Ig and ITIM domains (TIGIT) suppresses functions of CD8+ T cells, and radiation therapy (RT) induces stimulation of regulatory T cells (Tregs), thereby limiting antitumor efficacy. This study aims to investigate the role of TIGIT in the immunosuppressive tumor environment and evaluate the potential of TIGIT blockade (αTIGIT) to enhance antitumor immune responses.

METHODS

We analyzed public transcriptomic data to identify the expression patterns of TIGIT on T cells in breast cancer and its prognostic impact. In addition, a murine TNBC model was utilized to evaluate the effects of αPD-1, local RT, and αTIGIT. T cells in tumors, tumor-draining lymph nodes (TdLNs), and the spleen were analyzed to assess the antitumor immune responses upon the treatments.

RESULTS

The analysis revealed that TIGIT is predominantly expressed on T cells within breast cancer, and the expression of TIGIT was associated with poor outcomes in TNBC patients. In the murine model, the combination of αPD-1 and RT increased TIGIT+CD226+CD8+ TILs, which are crucial for the efficacy of αTIGIT. Adding αTIGIT to αPD-1 and RT (αPD-1/RT) resulted in a synergistic antitumor effect, which was accompanied by increased infiltration of CD8+ TILs in both irradiated and nonirradiated tumors by the triple combination therapy compared to αPD-1/RT. The triple combination therapy also resulted in a less exhausted phenotype among CD8+ TILs and increased the proliferation of splenic CD8+ T cells. Moreover, αTIGIT significantly reduced Tregs in tumors, TdLNs, and the spleen when combined with αPD-1/RT.

CONCLUSION

αTIGIT exhibits synergistic effects when added to αPD-1/RT by increasing the infiltration and activation of CD8+ TILs while reducing Tregs. The study suggests that αTIGIT could be an effective strategy to enhance the antitumor efficacy of αPD-1 and RT in TNBC.

Identification and verification of a combined ferroptosis- and pyroptosis-related signature for a prognostic classifier and immunosuppressive targets in colorectal cancer

BACKGROUND AND STUDY AIMS

Ferroptosis and pyroptosis, two forms of cell death, are increasingly reported for their pivotal roles in cancer biology. However, the understanding of the combined ferroptosis-pyroptosis (FPtosis)-related gene signature in colorectal cancer (CRC) remains limited.

MATERIAL AND METHODS

We conducted a comprehensive investigation of the FPtosis-related signature in CRC. Data integration from both the training and validation cohorts was performed. The FPtosis-related signature was established. We evaluated the prognostic significance of the signature through Kaplan-Meier analysis, as well as univariate and multivariate Cox regression models. Functional analyses were conducted to explore the underlying biological mechanisms. Additionally, we analyzed the correlations between the FPtosis-related signature, immune infiltration, and immune checkpoint blockade (ICB) immunotherapy.

RESULTS

The FPtosis-related signature demonstrated significant prognostic potential and can serve as an independent biomarker for predicting outcomes. The signature showed correlations with advanced tumor stage, invasion depth, lymph node metastasis, and distant metastasis. Subgroup analyses revealed the valuable predictive role of the FPtosis-related signature in predicting survival across different clinical subgroups, including age, gender, tumor stage, invasion depth, lymph node metastasis status, and distant metastasis status. Moreover, the signature exhibited positive associations with inflammation and the infiltration of diverse immune cells, such as neutrophils, M0 and M2 macrophages, and regulatory T cells (Tregs). In microsatellite instable (MSI) CRC, the expression of most ICB genes was higher in the high-FPtosis group compared to the low-FPtosis group.

CONCLUSION

The FPtosis signature can effectively predict the prognosis of CRC and had the potential to improve the development of innovative therapeutic strategies.

Integration of single-cell and bulk RNA sequencing identifies and validates T cell-related prognostic model in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a lethal malignancy, and predicting patient prognosis remains a significant challenge in clinical treatment. T cells play a crucial role in the tumor microenvironment, influencing tumorigenesis and progression. In this study, we constructed a T cell-related prognostic model for HCC. Using single-cell RNA sequencing (scRNA-seq) data from the Gene Expression Omnibus (GEO) database, we identified 6,281 T cells from 10 HCC patients and subsequently identified 855 T cell-related genes. Comprehensive analyses were conducted on T cells and their associated genes, including enrichment analysis, cell-cell communication, trajectory analysis, and transcription factor analysis. By integrating scRNA-seq and bulk RNA-seq data with prognostic information from The Cancer Genome Atlas (TCGA), we identified T cell-related prognostic genes and constructed a model using LASSO regression. The model, incorporating PTTG1, LMNB1, SLC38A1, and BATF, was externally validated using the International Cancer Genome Consortium (ICGC) database. It effectively stratified patients into high- and low-risk groups based on risk scores, revealing significant differences in immune cell infiltration between these groups. Differential expression levels of PTTG1 and BATF between HCC and adjacent non-tumor tissues were further validated by immunohistochemistry (IHC) in 25 patient tissue samples. Moreover, a Cox regression analysis was performed to integrate risk scores with clinical features, resulting in a nomogram capable of predicting patient survival probabilities. This study introduces a novel prognostic risk model for HCC patients, aimed at stratifying patients by risk, enhancing personalized treatment strategies, and offering new insights into the role of T cell-related genes in HCC progression.

Polyfunctional CD8+CD226+RUNX2hi effector T cells are diminished in advanced stages of chronic lymphocytic leukemia

CD8+ T cells, a subset of T cells identified by the surface glycoprotein CD8, particularly those expressing the co-stimulatory molecule CD226, play a crucial role in the immune response to malignancies. However, their role in chronic lymphocytic leukemia (CLL), an immunosuppressive disease, has not yet been explored. We studied 64 CLL patients and 25 age- and sex-matched healthy controls (HCs). We analyzed the proportion of CD226-expressing cells among different CD8+ T cell subsets (including naïve, central memory, effector memory, and effectors) in CLL patients, stratified by Rai stage and immunoglobulin heavy-chain variable region gene (IgHV) mutation status. Additionally, we compared the effector functions of CD8+CD226+ cells and their CD226- counterparts. We also quantified cytokine and chemokine levels in the plasma of CLL and HCs. Furthermore, we reanalyzed the publicly available bulk RNA-seq on CD226+ and CD226-CD8+ T cells. Finally, we evaluated the impact of elevated cytokines/chemokines on CD226 expression. Our results showed that CD226-expressing cells were significantly decreased within the effector memory and effector CD8+ T cell subsets in CLL patients with advanced Rai stages and unmutated IgHV, a marker of poor prognosis. These cells displayed robust effector functions, including cytokine production, cytolytic activity, degranulation, proliferation, and migration capacity. In contrast, CD8+CD226- T cells displayed an exhausted phenotype with reduced Runt-related transcription factor 2 (RUNX2) expression. Elevated levels of interleukin-6 (IL-6) and macrophage inflammatory protein-1 beta (MIP-1β) were inversely correlated with the frequency of CD8+CD226+ T cells and may contribute to the downregulation of CD226, possibly leading to T cell dysfunction in CLL. Our findings highlight the critical role of CD8+CD226+RUNX2hi T cells in CLL and suggest that their reduction is associated with disease progression and poor clinical outcomes. This study also underscores the potential of targeting IL-6 and MIP-1β to preserve polyfunctional CD8+CD226+ T cells as a promising immunotherapy strategy.

Curcumin enhances anti-tumor immunity in anaplastic thyroid carcinoma by elevating CD8+ T cell function and downregulating the AKT/mTORC1/STAT3/PD-L1 axis

Curcumin, a compound isolated from turmeric, has been found to have promising anti-tumor effects in various cancers, including anaplastic thyroid carcinoma (ATC). However, the molecular mechanism of curcumin in ATC remains largely unclear. CD8 +T cells could eliminate rapidly proliferating malignant cells, whereas interaction between programmed death-1 (PD-1) and programmed cell death ligand 1 (PD-L1) could inhibit the activation and functions of CD8 + T cells. Thus, we aimed to explore whether curcumin could inhibit ATC progression via regulating CD8 + T cells and PD-L1 expression. The protein expression of PD-L1 in ATC cells was detected by western blot assay. Additionally, a syngeneic mouse model was used to assess the effect of curcumin or/and anti-PD-1 treatment on tumorigenesis in vivo. The effect of curcumin on CD8 +T cell function was investigated by flow cytometry in vitro and in vivo. The results indicated curcumin notably suppressed ATC cell proliferation, migration and invasion and induced cell apoptosis. Additionally, curcumin could reduce PD-L1 level in ATC cells through inactivating AKT/mTORC1/STAT3 signaling. Meanwhile, curcumin obviously elevated CD8 + T cell function by elevating the number of IFN-γ producing CD8 + T cells. Furthermore, curcumin or anti-PD-L1 treatment could enhance anti-tumor immunity by increasing infiltration of CD8 + T cells in tumor tissues in vivo. As expected, compared to the single treatment, combination curcumin and anti-PD-1 treatment further elevated CD8 + T cell function in vivo, thereby potentiating anti-tumor immunity in ATC. Collectively, curcumin could enhance anti-tumor immunity in ATC by elevating CD8 + T cell function and inactivating the AKT/mTORC1/STAT3/PD-L1 axis. Our findings demonstrated a novel mechanism of the anti-tumor effects of curcumin in ATC.

T-cell immunoglobulin and ITIM domain as a target in combo anti-PD-(L)1 cancer therapy

Immunoregulatory roles of T-cell immunoglobulin and ITIM domain (TIGIT) in solid tumors, and its interactions with other checkpoints is a focus of research in cancer immunotherapy. The increased activity of TIGIT/CD155 promotes dendritic cell (DC) tolerance and CD8+ T cell exclusion/energy/exhaustion. Increased TIGIT activity also hampers natural killer (NK) cell function and increases immunosuppressive activity of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), with the latter serving as a key cell type to pursue TIGIT regulatory effects in tumor immune ecosystem. Frequent co-expression of TIGIT with programmed death-1 (PD-1) on CD8+ T cells along with the increased TIGIT expression in Tregs after anti-PD-1 therapy, the stimulatory effect of TIGIT+ Tregs on T-cell immunoglobulin and mucin-domain containing-3 (TIM-3), and the inducible effect of anti-programmed death-ligand 1 (PD-L1) on CD155 are all rationalizing a possibility for application of anti-TIGIT as a desired combinatory with anti-PD-(L)1 drugs in cancer immunotherapy. TIGIT can also be a target for development of bispecific antibodies to simultaneously target activities within the TIGIT/CD155 and PD-1/PD-L1 axes or for dual targeting of two inhibitory receptors, such as TIGIT/anti-poliovirus receptor-related immunoglobulin domain-containing protein (PVRIG), with the latter also acting to hamper activation of other inhibitory receptors occurring secondary to the anti-TIGIT therapy.

Immunotherapy for Renal Cell Carcinoma-What More is to Come?

The treatment of renal cell carcinoma (RCC), a malignancy that is typically chemoresistant, has drastically evolved with the introduction of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR TKIs) and immune checkpoint inhibitors (ICIs). The introduction of ICI-based regimens has significantly improved outcomes for patients with metastatic RCC. Currently, first-line therapy for patients with metastatic RCC involves multiple ICI-based regimens, either dual ICIs (with anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA- 4) and anti-programmed cell death- 1 (PD- 1) therapies) or anti-PD- 1 therapy in combination with VEGFR TKIs. Despite improving patient outcomes with ICI-based regimens, durable responses remain uncommon, highlighting the need for innovative treatment strategies. In this review, we highlight the current standard of care ICI-based regimens followed by ongoing clinical trials with novel combinations of existing FDA-approved agents and targets. We also discuss novel immunotherapies currently in clinical trials, which aim to improve antitumor T cell immunity either by improving T cell activation or T cell navigation to the tumor microenvironment. The incorporation of these novel therapies offers the potential to improve RCC patient outcomes, particularly by enhancing the durability of treatment responses.

Dual modulation of cytotoxic and checkpoint receptors tunes the efficacy of adoptive Delta One T cell therapy against colorectal cancer

Colorectal cancer (CRC) remains a challenge for current immunotherapies. Vδ1+ γδ T cells offer a promising alternative because of their HLA-I-independent cytotoxicity and natural tissue tropism. We developed Delta One T (DOT) cells, a Vδ1+ γδ T cell-based adoptive cell therapy clinically explored for hematological malignancies but not yet for solid tumors. Here we demonstrate the capacity of DOT cells to target CRC cell lines and patient-derived specimens and organoids in vitro and to control tumor growth in an orthotopic xenograft model of CRC. Notwithstanding, we found tumor-infiltrating DOT cells to exhibit a dysregulated balance of cytotoxic and inhibitory receptors that paralleled that of endogenous Vδ1+ tumor-infiltrating lymphocytes and limited their cytotoxicity. To maximize efficacy, we unveil two strategies, increasing targeting through upregulation of NKG2D ligands upon butyrate administration and blocking the checkpoints TIGIT and PD1, which synergistically unleashed DOT cell cytotoxicity. These findings support DOT cell-based combinatorial approaches for CRC treatment.

Targeting the poliovirus receptor to activate T cells and induce myeloid-derived suppressor cells to differentiate to pro-inflammatory macrophages via the IFN-γ-p-STAT1-IRF8 axis in cancer therapy

T cell immunoglobulin and ITIM domain (TIGIT) is one of the most important immune checkpoints expressed on lymphocytes, and poliovirus receptor (PVR, also CD155) serves as the most crucial ligand for TIGIT, harboring an important function in cancer cells and influencing the tumor microenvironment (TME). While it's well-established that TIGIT blockade could reverse immunosuppression, the question of whether direct inhibition of PVR yields comparable results remains to be fully elucidated. This study investigated the role of PVR within the TME on the LLC, CT26 and MC38 tumor models and found that direct blockade of PVR on tumor cells could trigger T cell activation, enhance the production of immunostimulatory cytokine IFN-γ, and drive the differentiation of intratumoral myeloid-derived suppressor cells (MDSCs) into pro-inflammatory macrophages through the IFN-γ-p-STAT1-IRF8 axis. Furthermore, this study found that the anti-PVR nanobody monotherapy reduced tumor volume in the CT26 and MC38 tumor models. Combination of anti-PVR nanobody and anti-PD-1 antibody was effective in the LLC, CT26 and MC38 tumor models and had acceptable toxicity. These findings collectively suggest that PVR exhibits considerable promise as a therapeutic target in the development of immunotherapies aimed at augmenting the anti-tumor immune response.

Expression Patterns of Immune Checkpoint Molecules and Their Clinical Values in Gastric Neuroendocrine Neoplasms

INTRODUCTION

Gastric neuroendocrine neoplasms (g-NENs) are a rare type of stomach tumor. However, limited data exist about the expression and clinical significance of B7 family ligands/receptors in patients with g-NENs. Thus, we conducted this study to address this issue in a cohort of 112 patients with g-NENs.

METHODS

Using immunohistochemistry, we mapped and quantified the expression of the B7 family ligands/receptors in 112 g-NEN samples: programmed cell death ligand 1 and 2 (PD-L1 and PD-L2), B7-H3, B7-H4, recombinant human galectin-9 (LGALS9), and CD155. Associations between the marker levels, clinicopathological variables, and survival were evaluated.

RESULTS

The percentages of high expression of PD-L1, PD-L2, B7-H3, B7-H4, LGALS9, and CD155 in the cohort of 112 g-NEN cases were 37.5%, 55.4%, 46.4%, 37.5%, 46.4%, and 51.8%, respectively. Elevated expression of PD-L1, PD-L2, B7-H3, B7-H4, LGALS9, and CD155 was significantly associated with several clinicopathological characteristics. K-M analysis indicated that high expression levels of CD155, B7-H3, PD-L2, and LGALS9 were correlated with poor overall survival (OS) ( P < 0.0001, P = 0.0002, P = 0.0319 and P = 0.0120, respectively). Multivariate Cox regression analysis indicated that high CD155 expression, vasculature invasion, and worse World Health Organization pathological grade were independent prognostic factors for OS ( P = 0.007, P = 0.030, and P = 0.019, respectively).

DISCUSSION

We detected variable expression of the PD-L1, PD-L2, B7-H3, B7-H4, LGALS9, and CD155 proteins in g-NENs. These results suggest that the expression level of CD155 may be a vital indicator of OS in patients with g-NENs. B7 family ligands/receptors could be potential immunotherapeutic targets for g-NENs.

Exploring novel immunotherapy in advanced esophageal squamous cell carcinoma: Is targeting TIGIT an answer?

Esophageal squamous cell carcinoma (ESCC) is a prevalent and highly lethal malignancy in Asia. Recent advancements in immune checkpoint inhibitors (ICIs) have markedly transformed the systemic therapy landscape for ESCC. Anti-PD-1-based combination with chemotherapy or with ipilimumab, an anti-CTLA-4 antibody, have been established as the new standard first-line treatments for patients with advanced ESCC. Moreover, anti-PD-1 monotherapy has demonstrated improved efficacy and survival compared with second-line chemotherapy in previously treated patients with ESCC. Novel ICIs targeting other immune checkpoints also show potential for enhancing anticancer therapy in advanced ESCC.The TIGIT/PVR pathway represents a new immune checkpoint. Preclinical studies have indicated that the dual blockade of TIGIT and PD-1 can enhance antitumor immune responses. Clinical trials have reported that combining anti-TIGIT with anti-PD-1/PD-L1 antibodies elicited clinical responses in patients with advanced ESCC. In the first-line systemic therapy setting, combinations of dual ICIs targeting TIGIT and PD-1/PD-L1 plus platinum-based chemotherapy have demonstrated acceptable toxicity profiles and promising antitumor activity in several phase II trials and one phase III study. However, the role of adding an anti-TIGIT antibody to the current standard of anti-PD-1/PD-L1 plus platinum-based chemotherapy in first-line therapy for advanced ESCC remains to be fully determined, necessitating further clinical trials. Ongoing studies are also investigating the role of anti-TIGIT, with or without anti-PD-1/PD-L1, in locoregional ESCC. Additional research is essential to optimize the potential of anti-TIGIT therapy in ESCC and other malignancies by identifying predictive biomarkers, determining optimal antibody types, and gaining key mechanistic insights.

Lidocaine Modulates Cytokine Production and Reprograms the Tumor Immune Microenvironment to Enhance Anti-Tumor Immune Responses in Gastric Cancer

Lidocaine, a local anesthetic, has been shown to modulate immune responses. This study examines its effects on cytokine production in peripheral blood mononuclear cells (PBMCs) from healthy donors and tumor-infiltrating immune cells (TIICs) from gastric cancer patients. PBMCs from healthy donors and TIICs from gastric cancer patients were treated with lidocaine. Cytokine production was assessed using flow cytometry and cytokine assays, with a focus on IFN-γ, IL-12, IL-10, TGF-β, and IL-35 levels. Cytotoxicity against primary gastric cancer cells (PGCCs) was also evaluated. Lidocaine inhibited IFN-γ production in CD8+ PBMCs and IL-12 in CD14+ PBMCs while increasing anti-inflammatory cytokines (IL-10, TGF-β, IL-35) in CD4+CD25+ and CD14+ cells. In TIICs, lidocaine enhanced IFN-γ and IL-12 production in CD8+ and CD14+ cells while reducing IL-10, TGF-β, and IL-35 levels, promoting an M1-like phenotype in macrophages. Mechanistically, lidocaine enhanced IFN-γ production in sorted CD8+ TIICs through G-protein-coupled receptor (GPCR) signaling and increased IL-12 production in sorted CD14+ TIICs via the toll-like receptor 4 (TLR4) signaling pathway. Lidocaine also increased IFN-γ production and cytotoxicity in CD8+ TIICs via NF-κB activation. Importantly, lidocaine did not affect the viability of PBMCs, TIICs, or PGCCs at concentrations up to 1.5 mM. Lidocaine reprogrammed the tumor immune microenvironment, enhancing anti-tumor immune responses, suggesting its potential to modulate immune functions in gastric cancer.

Pan-cancer analysis of co-inhibitory molecules revealing their potential prognostic and clinical values in immunotherapy

Background

The widespread use of immune checkpoint inhibitors (anti-CTLA4 or PD-1) has opened a new chapter in tumor immunotherapy by providing long-term remission for patients. Unfortunately, however, these agents are not universally available and only a minority of patients respond to them. Therefore, there is an urgent need to develop novel therapeutic strategies targeting other co-inhibitory molecules. However, comprehensive information on the expression and prognostic value of co-inhibitory molecules, including co-inhibitory receptors and their ligands, in different cancers is not yet available.

Methods

We investigated the expression, correlation, and prognostic value of co-inhibitory molecules in different cancer types based on TCGA, UCSC Xena, TIMER, CellMiner datasets. We also examined the associations between the expression of these molecules and the extent of immune cell infiltration. Besides, we conducted a more in-depth study of VISTA.

Result

The results of differential expression analysis, correlation analysis, and drug sensitivity analysis suggest that CTLA4, PD-1, TIGIT, LAG3, TIM3, NRP1, VISTA, CD80, CD86, PD-L1, PD-L2, PVR, PVRL2, FGL1, LGALS9, HMGB1, SEMA4A, and VEGFA are associated with tumor prognosis and immune cell infiltration. Therefore, we believe that they are hopefully to serve as prognostic biomarkers for certain cancers. In addition, our analysis indicates that VISTA plays a complex role and its expression is related to TMB, MSI, cancer cell stemness, DNA/RNA methylation, and drug sensitivity.

Conclusions

These co-inhibitory molecules have the potential to serve as prognostic biomarkers and therapeutic targets for a broad spectrum of cancers, given their strong associations with key clinical metrics. Furthermore, the analysis results indicate that VISTA may represent a promising target for cancer therapy.

Multiple mechanisms and applications of tertiary lymphoid structures and immune checkpoint blockade

BACKGROUND

Immune checkpoint blockade (ICB) inhibits tumor immune escape and has significantly advanced tumor therapy. However, ICB benefits only a minority of patients treated and may lead to many immune-related adverse events. Therefore, identifying factors that can predict treatment outcomes, enhance synergy with ICB, and mitigate immune-related adverse events is urgently needed.

MAIN TEXT

Tertiary lymphoid structures (TLS) are ectopic lymphoid tissues that arise from the tumor periphery. They have been found to be associated with better prognosis and improved clinical outcomes after ICB therapy. TLS may help address the problems associated with ICB. The multiple mechanisms of action between TLS and ICB remain unknown. This paper described potential mechanisms of interaction between the two and explored their potential applications.

Utilizing network pharmacology and experimental validation to explore the mechanisms of the Qijiafuzheng formula promoting CD8+ T-cell infiltration in the microenvironment of lung adenocarcinoma through STAT1/CXCL10

Qijiafuzheng formula (QJFZF), a Traditional Chinese Medicine used to treat lung cancer and mitigate chemotherapy side effects, was studied to clarify its impact on the tumor immune microenvironment (TIME). Using network pharmacology and experimental validation, 39 overlapping targets were identified from 579 QJFZF-related and 752 lung adenocarcinoma (LUAD)-TIME targets. Key genes (CCL3, IL10, CXCL10, FOXP3, CD86) correlated negatively with tumor purity and positively with CD8+ T-cell infiltration. CXCL10 emerged as the core target, with experiments showing QJFZF activates the STAT1/CXCL10 pathway to enhance CD8+ T-cell recruitment in LUAD-TIME. This study elucidates QJFZF's immunomodulatory mechanisms, supporting its clinical application.

Dynamic Peripheral T-Cell Analysis Identifies On-Treatment Prognostic Biomarkers of Atezolizumab plus Bevacizumab in Hepatocellular Carcinoma

Introduction

Variability in response to atezolizumab plus bevacizumab (AB) treatment of hepatocellular carcinoma (HCC) underscores the critical need for the development of effective biomarkers. We sought to identify peripheral blood biomarkers reflecting response to AB treatment.

Methods

We analyzed dynamic changes in peripheral blood mononuclear cells from a prospective, multicenter cohort of 65 patients with HCC, using flow cytometry to evaluate the T-cell population before and 3 weeks after the first AB treatment.

Results

We found a unique response of the CD8+ T cells in terms of both frequency and phenotype, in contrast to CD4+ T cells and regulatory T cells. Notably, CD8+ T cells showed significant changes in expression of Ki-67 and T-cell immunoreceptors with Ig and ITIM domains (TIGIT). These distinct responses were observed particularly in the programmed cell death receptor-1 (PD-1)+ subpopulation of CD8+ T cells. Interestingly, the baseline differentiation status of PD-1+CD8+ T cells, particularly the central memory T-cell subset, correlated positively with greater proliferation (higher Ki-67 expression) of PD-1+CD8+ T cells after treatment. Moreover, effector memory cells expressing CD45RA correlated negatively with the increase in TIGIT+/PD-1+CD8+ T cells. The increase in TIGIT+/CD8+ T cells was associated with the development of immune-related adverse events, whereas increase in Ki-67+/PD-1+CD8+ T cells was associated with the better objective response rate. Importantly, dynamic shifts of Ki-67+/PD-1+CD8+ T cells and TIGIT+/CD8+ T cells significantly predicted progression-free survival and overall survival, as confirmed by multivariate analysis.

Conclusion

These findings highlight the potential of dynamic changes in CD8+ T cells as an on-treatment prognostic biomarker. Our study underscores the value of peripheral blood profiling as a noninvasive and practical method for predicting the clinical outcomes of AB treatment in patients with HCC.

Tumor infiltration of inactive CD8 + T cells was associated with poor prognosis in Gastric Cancer

BACKGROUND

Gastric cancer (GC) shows limited response to immune checkpoint inhibitors due to its complex tumor immune microenvironment (TIME). This study explores the functions of various immune cells in the complex TIME in GC.

METHODS

We assessed CD8 + T-cell infiltration of GC tissues by immunohistochemistry, and performed single-cell RNA sequencing (scRNA-seq) of tumor and normal tissues from 34 patients with GC.

RESULTS

We categorized 157 GC patients into LOW, MID, and HIGH groups based on their CD8 + T-cell infiltration. Overall survival was notably lower for the HIGH and LOW groups compared with the MID group. Our scRNA-seq data analysis showed that CD8 + T-cell activity markers in the HIGH group were expressed at lower levels than in normal tissue, but the T-cell-attracting chemokine CCL5 was expressed at a higher level. Notably, CD8 + T-cells in the HIGH group displayed lower PD1 expression and higher CTLA4 expression. TCR repertoire analysis using only Epstein-Barr virus-negative cases showed that CD8 + T-cell receptor clonality was lower in the HIGH group than in the MID group. Furthermore, in the HIGH group, the antigen-presenting capacity of type 1 conventional dendritic cells was lower, the immunosuppressive capacity of myeloid-derived suppressor cells was higher, and the expression of CTLA4 in regulatory T-cells was higher.

CONCLUSION

The present data suggest that the infiltration of inactive CD8 + T-cells with low clonality is induced by chemotaxis in the HIGH group, possibly leading to a poor prognosis for patients with GC.

Immune Imbalance in Primary Membranous Nephropathy at Single-cell Resolution

BACKGROUND

Primary membranous nephropathy (pMN) often progresses to end-stage renal disease (ESRD) in the absence of immunosuppressive therapy. The immunological mechanisms driving pMN progression remain insufficiently understood.

METHODS

We developed a single-cell transcriptomic profile of peripheral blood mononuclear cells (PBMCs) from 11 newly-diagnosed pMN patients and 5 healthy donors. Through correlation analysis, we identified potential biomarkers for disease stratification and poor prognosis.

RESULTS

Expression levels of several proinflammatory factors were significantly increased in patients compared to healthy donors, such as interleukins (IL1B, IL8, and IL15) and interferon G (IFNG). Multiple pattern recognition receptors involved in proinflammatory signaling were also upregulated in patients, including NOD-like receptors (NLRs) (NLRP1, NLRP3, and NLRC5), RNA helicases (DDX58, IFIH1, DHX9, and DHX36), cGAS (cyclic GMP-AMP synthase) and IFI16 (interferon gamma inducible protein 16). Additionally, human leukocyte antigen molecules HLA-DQA1 and HLA-DRB1 enriched in memory B cells were upregulated in patients. More importantly, we found that the genes for antiviral defense response were significantly elevated in high-risk patients relative to the low-risk group. More than twenty genes were negatively correlated with estimated glomerular filtration rate (eGFR), such as BST2 (bone marrow stromal cell antigen 2) and SLC35F1 (solute carrier family 35 member F1). Their predicted values were confirmed in a larger population with nephrotic syndrome or other chronic kidney diseases from a public database. Furthermore, we developed a series of scoring systems for distinguishing high-risk patients from low- and moderate-risk individuals.

CONCLUSIONS

Our study provides insight into the immunological mechanism of pMN and identifies numerous biomarkers and signaling pathways as potential therapeutic targets for managing the progression of high-risk pMN.

Evolving Field of Immunotherapy: Pioneering New Paths in Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive form of lung cancer that displays rapid proliferation and early metastatic potential. It accounts for approximately 15% of lung cancers and is strongly associated with tobacco carcinogens. Despite patients' initial response to systemic therapy, the majority develop early resistance and relapse. The outcomes of patients with metastatic SCLC are poor, prompting the need for new therapies. Over the past decade, the treatment landscape for NSCLC (non-small cell lung cancer) has significantly changed with the immergence of novel targeted therapies and immunotherapies. However, inroads of these therapies into SCLC have posed significant challenges due to its molecular and genomic heterogeneity. Despite the challenges of this disease, promising new first-in-class immunomodulatory agents have emerged and are currently undergoing extensive research. Herein, we review the current treatment paradigm of immunotherapy in SCLC and discuss future directions of this evolving field.

TIGIT Regulates T Cell Inflammation in Airway Inflammatory Diseases

TIGIT, a co-inhibitory receptor found on T cells and NK cells, transmits inhibitory signals upon binding to its ligand. This interaction suppresses the activation of various signaling pathways, leading to functional exhaustion of cells, ultimately dampening excessive inflammatory responses or facilitating immune evasion in tumors. Dysregulated TIGIT expression has been noted in T cells across different inflammatory conditions, exhibiting varying effects based on T cell subsets. TIGIT predominantly restrains the effector function of pro-inflammatory T cells, upholds the suppressive function of regulatory T cells, and influences Tfh maturation. Mechanistically, the IL27-induced transcription factors c-Maf and Blimp-1 are believed to be key regulators of TIGIT expression in T cells. Notably, TIGIT expression in T cells is implicated in lung diseases, particularly airway inflammatory conditions such as lung cancer, obstructive pulmonary disease, interstitial lung disease, sarcoidosis, and COVID-19. This review emphasizes the significance of TIGIT in the context of T cell immunity and airway inflammatory diseases.

Inhibition of CD226 co-stimulation suppresses diabetes development in the NOD mouse by augmenting regulatory T cells and diminishing effector T cell function

AIMS/HYPOTHESIS

Immunotherapeutics targeting T cells are crucial for inhibiting autoimmune disease progression proximal to disease onset in type 1 diabetes. There is an outstanding need to augment the durability and effectiveness of T cell targeting therapies by directly restraining proinflammatory T cell subsets, while simultaneously augmenting regulatory T cell (Treg) activity. Here, we present a novel strategy for preventing diabetes incidence in the NOD mouse model using a blocking monoclonal antibody targeting the type 1 diabetes risk-associated T cell co-stimulatory receptor, CD226.

METHODS

Female NOD mice were treated with anti-CD226 at 7-8 weeks of age and then monitored for diabetes incidence and therapeutic mechanism of action.

RESULTS

Compared with isotype-treated controls, anti-CD226-treated NOD mice showed reduced insulitis severity (0.84-fold, p=0.0002) at 12 weeks and decreased disease incidence (HR 0.41, p=0.015) at 30 weeks. Flow cytometric analysis performed 5 weeks post treatment demonstrated reduced proliferation of conventional CD4+ T cells (0.87-fold, p=0.030) and CD8+ (0.78-fold, p=0.0018) effector memory T cells in spleens of anti-CD226-treated mice. Phenotyping of pancreatic Tregs revealed increased CD25 expression (2.05-fold, p=0.0073) and signal transducer and activator of transcription 5 (STAT5) phosphorylation (1.39-fold, p=0.0007) following anti-CD226, with splenic Tregs displaying augmented suppression of CD4+ responder T cells (Tresps) (1.49-fold, p=0.0008, 1:2 Treg:Tresp) in vitro. Anti-CD226-treated mice exhibited reduced frequencies of islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-reactive CD8+ T cells in the pancreas, using both ex vivo tetramer staining (0.50-fold, p=0.0317) and single-cell T cell receptor sequencing (0.61-fold, p=0.022) approaches. 51Cr-release assays demonstrated reduced cell-mediated lysis of beta cells (0.61-fold, p<0.0001, 1:1 effector:target) by anti-CD226-treated autoreactive cytotoxic T lymphocytes.

CONCLUSIONS/INTERPRETATION

CD226 blockade reduces T cell cytotoxicity and improves Treg function, representing a targeted and rational approach for restoring immune regulation in type 1 diabetes.

Overcoming CD226-related immune evasion in acute myeloid leukemia with CD38 CAR-engineered NK cells

CD226 plays a vital role in natural killer (NK) cell cytotoxicity, interacting with its ligands CD112 and CD155 to initiate immune synapse formation, primarily through leukocyte function-associated-1 (LFA-1). Our study examined the role of CD226 in NK cell surveillance of acute myeloid leukemia (AML). NK cells in patients with AML had lower expression of CD226. CRISPR-Cas9 deletion of CD226 led to reduced LFA-1 recruitment, poor synapse formation, and decreased NK cell anti-leukemic activity. Engineering NK cells to express a chimeric antigen receptor targeting the AML antigen CD38 (CAR38) could overcome the need for CD226 to establish strong immune synapses. LFA-1 blockade reduced CAR38 NK cell activity, and this depended on the CD38 expression levels of AML cells. This suggests parallel but potentially cooperative roles for LFA-1 and CAR38 in synapse formation. Our findings suggest that CAR38 NK cells could be an effective therapeutic strategy to overcome CD226-mediated immune evasion in AML.

CD226 identifies effector CD8+ T cells during tuberculosis and costimulates recognition of Mycobacterium tuberculosis-infected macrophages

CD8+ T cells defend against Mycobacterium tuberculosis (Mtb) infection but variably recognize Mtb-infected macrophages. To define how the diversity of lung parenchymal CD8+ T cells changes during chronic infection, cells from C57BL/6J mice infected for 6- and 41-weeks were analyzed by scRNA-seq. We identified an effector lineage, including a cluster that expresses high levels of cytotoxic effectors and cytokines, and dysfunctional lineage that transcriptionally resembles exhausted T cells. The most significant differentially expressed gene between two distinct CD8+ T cell lineages is CD226. Mtb-infected IFNγ-eYFP reporter mice revealed IFNγ production is enriched in CD226+CD8+ T cells, confirming these as functional T cells in vivo. Purified CD226+ but not CD226- CD8+ T cells recognize Mtb-infected macrophages, and CD226 blockade inhibits IFNγ and granzyme B production. Thus, CD226 costimulation is required for efficient CD8+ T cell recognition of Mtb-infected macrophages, and its expression identifies CD8+ T cells that recognize Mtb-infected macrophages.

Coordinated immune networks in leukemia bone marrow microenvironments distinguish response to cellular therapy

Understanding how intratumoral immune populations coordinate antitumor responses after therapy can guide treatment prioritization. We systematically analyzed an established immunotherapy, donor lymphocyte infusion (DLI), by assessing 348,905 single-cell transcriptomes from 74 longitudinal bone marrow samples of 25 patients with relapsed leukemia; a subset was evaluated by both protein- and transcriptome-based spatial analysis. In acute myeloid leukemia (AML) DLI responders, we identified clonally expanded ZNF683+ CD8+ cytotoxic T lymphocytes with in vitro specificity for patient-matched AML. These cells originated primarily from the DLI product and appeared to coordinate antitumor immune responses through interaction with diverse immune cell types within the marrow microenvironment. Nonresponders lacked this cross-talk and had cytotoxic T lymphocytes with elevated TIGIT expression. Our study identifies recipient bone marrow microenvironment differences as a determinant of an effective antileukemia response and opens opportunities to modulate cellular therapy.

Unraveling the Role of Fusobacterium nucleatum in Colorectal Cancer: Molecular Mechanisms and Pathogenic Insights

Fusobacterium nucleatum, a gram-negative anaerobic bacterium, has emerged as a significant player in colorectal cancer (CRC) pathogenesis. The bacterium causes a persistent inflammatory reaction in the colorectal mucosa by stimulating the release of pro-inflammatory cytokines like IL-1β, IL-6, and TNF-α, creating an environment conducive to cancer progression. F. nucleatum binds to and penetrates epithelial cells through adhesins such as FadA, impairing cell junctions and encouraging epithelial-to-mesenchymal transition (EMT), which is associated with cancer advancement. Additionally, the bacterium modulates the host immune system, suppressing immune cell activity and creating conditions favorable for tumor growth. Its interactions with the gut microbiome contribute to dysbiosis, further influencing carcinogenic pathways. Evidence indicates that F. nucleatum can inflict DNA damage either directly via reactive oxygen species or indirectly by creating a pro-inflammatory environment. Additionally, it triggers oncogenic pathways, especially the Wnt/β-catenin signaling pathway, which promotes tumor cell growth and longevity. Moreover, F. nucleatum alters the tumor microenvironment, impacting cancer cell behavior, metastasis, and therapeutic responses. The purpose of this review is to elucidate the molecular mechanisms by which F. nucleatum contributes to CRC. Understanding these mechanisms is crucial for the development of targeted therapies and diagnostic strategies for CRC associated with F. nucleatum.

Revolutionizing ESCC prognosis: the efficiency of tumor-infiltrating immune cells (TIIC) signature score

BACKGROUND

Patients suffer from esophageal squamous cell carcinoma (ESCC), which is the ninth highly aggressive malignancy. Tumor-infiltrating immune cells (TIIC) exert as major component of the tumor microenvironment (TME), showing possible prognostic value in ESCC.

METHODS

Transcriptome data and scRNA-seq data of ESCC samples were extracted from the GEO and TCGA databases. Tissue Specific Index (TSI) was defined to identify potential TIIC-RNAs from the TME. Twenty machine learning algorithms were further applied to evaluate the prognostic efficacy of TIIC signature score. Gene colocalization analysis was performed. Differences in CNV on chromosomes and SNP sites of prognostic model genes were calculated.

RESULTS

The most reliable model of TIIC signature score was developed based on three prognostic TIIC-RNAs. It showed a higher C-index than any other reported prognostic models. ESCC patients with high TIIC signature score showed poorer survival outcomes than low TIIC signature score. The activity of most immune cells decreased with the increase of TIIC score. TIIC signature score showed difference in the expression levels and methylation levels of DEGs. There was also significant different correlation with the degree of CNV amplification and CNV deletion of the immune checkpoint genes. Gene colocalization analysis showed two prognostic model genes (ATP6V0E1 and BIRC2). MR analysis found that rs148710154 and rs75146099 SNP sites of TIIC-RNA gene had a significant correlation between them gastro-oesophageal reflux and ESCC.

CONCLUSION

TIIC signature score was the first time developed which provided a novel strategy and guidance for the prognosis and immunotherapy of ESCC. It also gave the evidence in the important role of immune cells from the TME in the treatment of cancers.

New insight in immunotherapy and combine therapy in colorectal cancer

The advent of immune checkpoint inhibitors (ICIs) in colorectal cancer (CRC) treatment marks a major breakthrough. These therapies have proven safer and more effective than traditional radiotherapy and targeted treatments. Immunotherapies like pembrolizumab, nivolumab, and ipilimumab have pioneered new treatment avenues, potentially improving patient outcomes and quality of life. Additionally, advances in immunotherapy have prompted detailed research into CRC therapies, especially those integrating ICIs with conventional treatments, providing new hope for patients and shaping future research and practice. This review delves into the mechanisms of various ICIs and evaluates their therapeutic potential when combined with radiotherapy, chemotherapy, and targeted therapies in clinical settings. It also sheds light on the current application and research involving ICIs in CRC treatment.

PVR exposure influences the activation, adhesion, and protein expression of human CD8+ T cells, including the CD96-mediated transfer of PVR

Poliovirus receptor (PVR) ligands have gained attention as immunotherapy targets, yet their regulation remains unclear. Here, we examine the impact of PVR exposure on primary human CD8+ T cells. We used flow cytometry and Western blot analysis to quantify expression of PVR and its ligands in naïve and effector T cells and used adhesion assays and enzyme-linked immunosorbent assay (ELISA) to assess the impact of PVR on T cell adhesion and cytokine production. Stimulation with phytohemagglutinin P strongly increased DNAM-1 expression and caused a less robust and more variable increase in TIGIT expression. Exposure to PVR-Fc enhanced the CD8+ T cell adhesion to ICAM-1-coated plates in a dose-dependent manner, while exposure to PVR-expressing K32 cells mildly decreased CD8+ T cell interferon γ release. However, PVR exposure strongly decreased the expression of DNAM-1, TIGIT, and CD96. The reduction of DNAM-1, TIGIT, and CD96 induced by PVR was dominant to the increase caused by T cell receptor signaling. The impact of PVR on their expression was completely abolished by the Q63R and F128R point mutations of PVR, while DNAM-1 was partially rescued by inhibitors of Src and protein kinase C. Additionally, PVR exposure along with T cell receptor signaling promoted the transfer of surface proteins including PVR from K32 cells to CD8+ T cells. This PVR transfer was mediated by the IgV domain of PVR and CD96 on CD8+ T cells and required cellular contact. Our findings collectively demonstrate that PVR engagement has a mild antagonistic effect on interferon γ production but strongly impacts CD8+ T cell adhesion and protein expression.

Neoadjuvant anti-PD-1 alone or in combination with anti-TIGIT or an oncolytic virus in resectable stage IIIB-D melanoma: a phase 1/2 trial

Neoadjuvant immunotherapies have shown antitumor activity in melanoma. Substudy 02C of the global, rolling-arm, phase 1/2, adaptive-design KEYMAKER-U02 trial is evaluating neoadjuvant pembrolizumab (anti-PD-1) alone or in combination, followed by adjuvant pembrolizumab, for stage IIIB-D melanoma. Here we report results from the first three arms: pembrolizumab plus vibostolimab (anti-TIGIT), pembrolizumab plus gebasaxturev (coxsackievirus A21) and pembrolizumab monotherapy. Pathologic complete responses occurred in 10 of 26 patients (38%) with pembrolizumab plus vibostolimab, 7 of 25 (28%) with pembrolizumab plus gebasaxturev and 6 of 15 (40%) with pembrolizumab monotherapy. Major pathologic responses occurred in 13 (50%), 10 (40%) and 7 (47%) patients, respectively. Safety was manageable. Treatment-related adverse events occurred in 24 of 26 patients (92%) with pembrolizumab plus vibostolimab, 21 of 25 (84%) with pembrolizumab plus gebasaxturev and 12 of 15 (80%) with pembrolizumab monotherapy; grade 3 or 4 treatment-related adverse events occurred in 2 (8%), 7 (28%) and 1 (7%) patient in each arm, respectively. No deaths due to adverse events occurred. Exploratory objective responses per RECIST v1.1 were observed in 13 (50%), 8 (32%) and 4 (27%) patients, in each arm, respectively. In a post hoc analysis, scores for tumor mutational burden and an 18-gene T cell-inflamed gene expression profile were generally higher in patients with major pathologic response. Longer follow-up will provide insight into the incremental benefit of combining neoadjuvant pembrolizumab with other therapies in stage IIIB-D melanoma. ClinicalTrials.gov registration: NCT04303169 .

Progress of Immune Checkpoint Inhibitors Therapy for pMMR/MSS Metastatic Colorectal Cancer

Immunotherapy is one of the research hotspots in colorectal cancer field in recent years. The colorectal cancer patients with mismatch repair-deficient (dMMR) or high microsatellite instability (MSI-H) are the primary beneficiaries of immunotherapy. However, the vast majority of colorectal cancers are mismatch repair proficient (pMMR) or microsatellite stability (MSS), and their immune microenvironment is characterized by "cold tumors" that are generally insensitive to single immunotherapy based on immune checkpoint inhibitors (ICIs). Studies have shown that some pMMR/MSS colorectal cancer patients regulate the immune microenvironment by combining other treatments, such as multi-target tyrosine kinase inhibitors, anti-vascular endothelial growth factor (VEGF) monoclonal antibodies, chemotherapy, radiotherapy, anti-epithelial growth factor receptor (EGFR) monoclonal antibodies, and mitogen-activated protein kinase (MAPK) signaling pathway inhibitors and oncolytic viruses, etc. to transform "cold tumor" into "hot tumor", thereby improving the response to immunotherapy. In addition, screening for potential prognostic biomarkers can also enrich the population benefiting from immunotherapy for microsatellite stable colorectal cancer. Therefore, in pMMR or MSS metastatic colorectal cancer (mCRC), the optimization of immunotherapy regimens and the search for effective efficacy prediction biomarkers are currently important research directions. In this paper, we review the progress of efficacy of immunotherapy (mainly ICIs) in pMMR /MSS mCRC, challenges and potential markers, in order to provide research ideas for the development of immunotherapy for mCRC.

Analysis of the implication of steroid 5 alpha-reductase 3 on prognosis and immune microenvironment in Liver Hepatocellular Carcinoma

INTRODUCTION

This study combined the bioinformatics and in vitro experiment-related technologies to analyze the impact of steroid 5 alpha-reductase 3 (SRD5A3) on the prognosis and immune microenvironment of Liver Hepatocellular Carcinoma (LIHC).

METHOD

Gene expression and clinical data were obtained from public databases. The prognosis was evaluated using survival, multifactor Cox, enrichment, and mutation analyses. This was then verified through in vitro experiments.

RESULTS

The expression level of SRD5A3 in LIHC tissues was significantly higher than that in the adjacent tissues. Kaplan-Meier survival analysis showed that high SRD5A3 expression was associated with poor overall survival (OS) and short progression-free survival in patients with LIHC. Multivariate Cox regression analysis revealed that positive SRD5A3 expression was an independent risk factor for OS in patients with LIHC. Expression of SRD5A3 was negatively correlated with immune cell infiltration of CD4+ T, CD8+ T, and B cells. GO and KEGG enrichment analyses showed that SRD5A3 was significantly enriched in signaling- and tumor metastasis-related pathways. Nomogram and calibration curve showed that the predicted performance of the model was consistent with the actual results. In vitro results confirmed that SRD5A3 knockdown inhibited the migration, invasion, and proliferation of LIHC cells.

CONCLUSIONS

SRD5A3 is actively expressed in LIHC, and positive expression of SRD5A3 is an independent risk factor for different prognoses in patients with LIHC. SRD5A3 can promote the proliferation, migration, and invasion of liver cancer cells and is related to short immune infiltration in patients with LIHC.

TIGIT: Will it be the next star therapeutic target like PD-1 in hematological malignancies?

Research on the mechanism and application of checkpoint inhibitory receptors in hematologic diseases has progressed rapidly. However, in the treatment of relapserefractory (R/R) hematologic malignancies and anti-programmed cell death protein 1 (PD-1), patients who are resistant to anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) are in urgent need of alternative therapeutic targets. T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT) has a broad prospect as an inhibitory receptor like PD-1, but its more specific mechanism of action and application in hematologic diseases still need to be further studied. In this review, we discuss the mechanism of TIGIT pathway, combined effects with other immune checkpoints, immune-related therapy, the impact of TIGIT on hematopoietic stem cell transplantation (HSCT) and the tumor microenvironment (TME) provides a potential therapeutic target for hematologic malignancies.

Immune Checkpoints in B Cells: Unlocking New Potentials in Cancer Treatment

B cells are crucial component of humoral immunity, and their role in the tumor immune microenvironment (TME) has garnered significant attention in recent years. These cells hold great potential and application prospects in the field of tumor immunotherapy. Research has demonstrated that the TME can remodel various B cell functions, including proliferation, differentiation, antigen presentation, and antibody production, thereby invalidating the anti-tumor effects of B cells. Concurrently, numerous immune checkpoints (ICs) on the surface of B cells are upregulated. Aberrant B-cell IC signals not only impair the function of B cells themselves, but also modulate the tumor-killing effects of other immune cells, ultimately fostering an immunosuppressive TME and facilitating tumor immune escape. Blocking ICs on B cells is beneficial for reversing the immunosuppressive TME and restoring anti-tumor immune responses. In this paper, the intricate connection between B-cell ICs and the TME is delved into, emphasizing the critical role of targeting B-cell ICs in anti-tumor immunity, which may provide valuable insights for the future development of tumor immunotherapy based on B cells.

Neoadjuvant immunotherapy for dMMR and pMMR colorectal cancers: therapeutic strategies and putative biomarkers of response

Approximately 15% of locally advanced colorectal cancers (CRC) have DNA mismatch repair deficiency (dMMR), resulting in high microsatellite instability and a high tumour mutational burden. These cancers are frequently sensitive to therapy with immune-checkpoint inhibitors (ICIs) in the metastatic setting. This sensitivity seems to be even more pronounced in locally advanced disease, and organ preservation has become a realistic aim in ongoing clinical trials involving patients with dMMR rectal cancer. By contrast, metastatic CRCs with proficient DNA mismatch repair (pMMR) are generally resistant to ICIs, although a proportion of locally advanced pMMR tumours seem to have a high degree of sensitivity to ICIs. In this Review, we describe the current and emerging clinical evidence supporting the use of neoadjuvant ICIs in patients with dMMR and pMMR CRC, and the potential advantages (based on a biological rationale) of such an approach. We discuss how neoadjuvant 'window-of-opportunity' trials are being leveraged to progress biomarker discovery and we provide an overview of potential predictive biomarkers of response to ICIs, exploring the challenges faced when evaluating such biomarkers in biopsy-derived samples. Lastly, we describe how these discoveries might be used to drive a rational approach to trialling novel immunotherapeutic strategies in patients with pMMR CRC, with the ultimate aim of disease eradication and the generation of long-term immunosurveillance.

Clinical significance and potential mechanism of AEBP1 in glioblastoma

Glioblastomas (GBM), the most common primary brain tumor, lack accurate prognostic markers and have a poor prognosis. Our study was designed to identify effective biomarkers for GBM prognosis analysis and development of precise treatments. Differentially expressed genes (DEGs) between GBM patients and controls were analyzed from the Xena database and GEPIA. Based on the screened DEGs, univariate COX and LASSO regression analysis were performed to identify the most relevant genes associated with GBM prognosis. Genes highly expressed in GBM patients were selected to construct receiver operating characteristic analysis and enrichment analysis was constructed on groups of high and low expression of adipocyte enhancer-binding protein 1 (AEBP1). CIBERSORT, ssGSEA and ESTIMATE were used to perform immune infiltration analysis. About 3297 DEGs were identified using data from Xena database; 8 prognostic genes were identified. AEBP1, which plays a role in neuronal differentiation and development, was positively correlated in GBMs with immune infiltration; its high expression in cancer patients is associated with short overall survival and advanced tumor staging. This study suggests that AEBP1 could serve as a prognostic marker for GBMs and that patients with high expression may have a better response to immunotherapy.

CAR T-cells for pediatric solid tumors: where to go from here?

Despite the great success that chimeric antigen receptor (CAR) T-cells have had in patients with B-cell malignancies and multiple myeloma, they continue to have limited efficacy against most solid tumors. Especially in the pediatric population, pre- and post-treatment biopsies are rarely performed due to ethical reasons, and thus, our understanding is still very limited regarding the mechanisms in the tumor microenvironment by which tumor cells exclude effectors and attract immune-suppressive cells. Nevertheless, based on the principles that are known, current T-cell engineering has leveraged some of these processes and created more potent CAR T-cells. The recent discovery of new oncofetal antigens and progress made in CAR design have expanded the potential pool of candidate antigens for therapeutic development. The most promising approaches to enhance CAR T-cells are novel CAR gating strategies, creative ways of cytokine delivery to the TME without enhancing systemic toxicity, and hijacking the chemokine axis of tumors for migratory purposes. With these new modifications, the next step in the era of CAR T-cell development will be the clinical validation of these promising preclinical findings.

TIGIT and PD-L1 co-blockade promotes clonal expansion of multipotent, non-exhausted antitumor T cells by facilitating co-stimulation

Blockade of immune checkpoints PD-1 and TIGIT has demonstrated activity in mouse tumor models and human patients with cancer. Although these coinhibitory receptors can restrict signaling in CD8+ T cells by regulating their associated co-stimulatory receptors CD28 and CD226, the functional consequences of combining PD-1 and TIGIT blockade remain poorly characterized. In mouse tumor models, we show that combination blockade elicited CD226-driven clonal expansion of tumor antigen-specific CD8+ T cells. The expanded clones emerged from a population of stem-like cells in draining lymph nodes, entering the blood as a previously unidentified single-phenotype, multiclonal population. Upon reaching the tumor, these transiting cells expanded further and differentiated into effector or exhausted T cells, with combination blockade restricting entry into the exhaustion pathway by favoring co-stimulation. Thus, PD-1 and TIGIT inhibition helps shape the repertoire of tumor-reactive CD8+ T cells in draining lymph nodes and determines their immunological fate in the tumor to enhance therapeutic benefit. Analysis of clinical trial samples suggests a similar mechanism may also occur in patients with cancer.

T cell receptor-centric perspective to multimodal single-cell data analysis

The T cell receptor (TCR), despite its importance, is underutilized in single-cell analysis, with gene expression features solely driving current strategies. Here, we argue for a TCR-first approach, more suited toward T cell repertoires. To this end, we curated a large T cell atlas from 12 prominent human studies, containing in total 500,000 T cells spanning multiple diseases, including melanoma, head and neck cancer, blood cancer, and lung transplantation. Here, we identified severe limitations in cell-type annotation using unsupervised approaches and propose a more robust standard using a semi-supervised method or the TCR arrangement. We showcase the utility of a TCR-first approach through application of the STEGO.R tool for the identification of treatment-related dynamics and previously unknown public T cell clusters with potential antigen-specific properties. Thus, the paradigm shift to a TCR-first can highlight overlooked key T cell features that have the potential for improvements in immunotherapy and diagnostics.

Tumor Microenvironment Drives the Cross-Talk Between Co-Stimulatory and Inhibitory Molecules in Tumor-Infiltrating Lymphocytes: Implications for Optimizing Immunotherapy Outcomes

This review explores some of the complex mechanisms underlying antitumor T-cell response, with a specific focus on the balance and cross-talk between selected co-stimulatory and inhibitory pathways. The tumor microenvironment (TME) fosters both T-cell activation and exhaustion, a dual role influenced by the local presence of inhibitory immune checkpoints (ICs), which are exploited by cancer cells to evade immune surveillance. Recent advancements in IC blockade (ICB) therapies have transformed cancer treatment. However, only a fraction of patients respond favorably, highlighting the need for predictive biomarkers and combination therapies to overcome ICB resistance. A crucial aspect is represented by the complexity of the TME, which encompasses diverse cell types that either enhance or suppress immune responses. This review underscores the importance of identifying the most critical cross-talk between inhibitory and co-stimulatory molecules for developing approaches tailored to patient-specific molecular and immune profiles to maximize the therapeutic efficacy of IC inhibitors and enhance clinical outcomes.

Turning Cancer Immunotherapy to the Emerging Immune Checkpoint TIGIT: Will This Break Through the Limitations of the Legacy Approach?

The discovery of immune checkpoints (ICs) has pushed cancer treatment into the next era. As an emerging immune checkpoint, the TIGIT/CD155 axis inhibits the cytotoxicity of T and NK cells through multiple pathways. Immune checkpoint inhibitors (ICIs) targeting TIGIT are hopefully expected to address the issue of unresponsiveness to anti-PD-(L)1 monoclonal antibodies (mAbs) by combination therapy. This paper presents insights on the expression, structure and mechanism of action of TIGIT, as well as the principles and methods of designing mAbs targeting TIGIT and their clinical data. The advantages and disadvantages of targeting TIGIT using mAbs, bispecific and tri-specific antibodies (bsAbs and tsAbs), peptides, and compounds, in addition to potential combination therapies of anti-TIGIT with anti-PD-1 or cancer vaccines, are addressed. Finally, perspectives on current immunotherapies targeting TIGIT are discussed.

Targeting mitochondria: restoring the antitumor efficacy of exhausted T cells

Immune checkpoint blockade therapy has revolutionized cancer treatment, but resistance remains prevalent, often due to dysfunctional tumor-infiltrating lymphocytes. A key contributor to this dysfunction is mitochondrial dysfunction, characterized by defective oxidative phosphorylation, impaired adaptation, and depolarization, which promotes T cell exhaustion and severely compromises antitumor efficacy. This review summarizes recent advances in restoring the function of exhausted T cells through mitochondria-targeted strategies, such as metabolic remodeling, enhanced biogenesis, and regulation of antioxidant and reactive oxygen species, with the aim of reversing the state of T cell exhaustion and improving the response to immunotherapy. A deeper understanding of the role of mitochondria in T cell exhaustion lays the foundation for the development of novel mitochondria-targeted therapies and opens a new chapter in cancer immunotherapy.