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

The KEYVIBE program: vibostolimab and pembrolizumab for the treatment of advanced malignancies

Vibostolimab, a humanized IgG1 monoclonal antibody, blocks the interaction between TIGIT and its ligands, preventing the immunosuppressive effects of TIGIT. The addition of vibostolimab to the PD-1 inhibitor pembrolizumab has shown promising antitumor activity, warranting further exploration of vibostolimab as a potential therapeutic option. The KEYVIBE program consists of nine trials that will evaluate the safety and efficacy of vibostolimab monotherapy and vibostolimab-based combination therapy in advanced solid tumors and hematological malignancies. These studies will also evaluate coformulated immunotherapy addressing issues that occur with the sequential administration of immunotherapy. The KEYVIBE program will provide further insight into the clinical utility of vibostolimab-based therapy across multiple indications and various stages of disease.

Mechanistic Insights into the Successful Development of Combination Therapy of Enfortumab Vedotin and Pembrolizumab for the Treatment of Locally Advanced or Metastatic Urothelial Cancer

Antibody-drug conjugates (ADCs) consist of an antibody backbone that recognizes and binds to a target antigen expressed on tumor cells and a small molecule chemotherapy payload that is conjugated to the antibody via a linker. ADCs are one of the most promising therapeutic modalities for the treatment of various cancers. However, many patients have developed resistance to this form of therapy. Extensive efforts have been dedicated to identifying an effective combination of ADCs with other types of anticancer therapies to potentially overcome this resistance. A recent clinical study demonstrated that a combination of the ADC enfortumab vedotin (EV) with the immune checkpoint inhibitor (ICI) pembrolizumab can achieve remarkable clinical efficacy as the first-line therapy for the treatment of locally advanced or metastatic urothelial carcinoma (la/mUC)-leading to the first approval of a combination therapy of an ADC with an ICI for the treatment of cancer patients. In this review, we highlight knowledge and understanding gained from the successful development of EV and the combination therapy of EV with ICI for the treatment of la/mUC. Using urothelial carcinoma as an example, we will focus on dissecting the underlying mechanisms necessary for the development of this type of combination therapy for a variety of cancers.

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.

A novel enzyme-linked immunosorbent assay tool to evaluate plasma soluble CD226 in primary Sjögren's syndrome

CD226 is an important receptor constitutively expressed on most immune cells, performing vital functions in immune responses. However, the levels of soluble CD226 (sCD226) and its roles in primary Sjögren syndrome (pSS) remain unclear. In this study, we developed two novel mouse anti-human CD226 monoclonal antibodies (mAbs) and established a novel sandwich enzyme-linked immunosorbent assay (ELISA) system, which proved to be highly effective in detecting human sCD226. We then analyzed the expression of sCD226 in the plasma of pSS patients. Our results showed that the levels of sCD226 were significantly lower in patients with pSS compared to healthy controls. The significant decline was also observed in active group and the patients with high levels of IgG or positive anti-SSB. Additionally, reduced sCD226 was found to be negatively correlated with the disease activity of pSS and several clinical manifestations, including arthralgia, fatigue, decayed tooth and interstitial lung disease (ILD). Furthermore, receiver operator characteristics (ROC) curve analysis showed that sCD226 displayed outstanding capacity in discriminating pSS and predicting the disease activity. Altogether, plasma sCD226 emerges as a promising candidate for diagnostic markers in the context of pSS.

The current status of immunotherapy and future horizon in the treatment of metastatic and locally advanced gastroesophageal adenocarcinoma

INTRODUCTION

Immunochemotherapy with PD-1 blockade has been established as the current standard first-line therapy for patients with mGEA. Reviewing the history of clinical trials offers valuable insight into the evolution of immune oncology in mGEA, paving the way for future advancements in this field.

AREAS COVERED

This review summarizes the findings of previous clinical trials related to immunotherapy for patients with GEA in the metastatic and locally advanced setting. We also introduce ongoing clinical trials to address the current challenging issues in clinical practice.

EXPERT OPINION

In general, GEA exhibits intermediate immunogenic characteristics with heterogeneous expressions, and responders to anti-PD-(L)1 therapy are mostly enriched to patients with specific genomic profiles such as MSI-H, high PD-L1 expression, high TMB, and EBV-associated type. Co-administration with anti-angiogenic agents or simultaneous blockade of immune checkpoint molecules is being explored to offer benefit of immunotherapy for more patients. We hope that CLDN18.2 and upcoming targets like FGFR2b will complement the treatment niche of immunotherapy in the field of mGEA. Bispecific antibodies, antibody drug conjugates, CAR-T, and vaccine are anticipated to enhance efficacy and expand the scope of immunotherapy.

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.

Mutual exclusivity and co-occurrence patterns of immune checkpoints indicate NKG2A relates to anti-PD-1 resistance in gastric cancer

BACKGROUND

An increasing number of clinical studies have begun to explore combination strategies with immune checkpoint inhibitors, aiming to present new opportunities for overcoming anti-PD-1 treatment resistance in gastric cancer. Unfortunately, the exploration of certain immune checkpoint inhibitor combination strategies has yielded suboptimal results. Therefore, it is necessary to comprehensively analyze the expression patterns of immune checkpoints and identify optimal combination regimens of anti-PD-1 inhibitors with other immune checkpoint inhibitors.

METHODS

Leveraging single-cell RNA sequencing (scRNA-seq) and multivariate linear regression interaction models, we dissected the immune checkpoint expression characteristics of CD8+ T cells in gastric cancer and the immune checkpoint expression pattern (ICEP) mediating anti-PD-1 treatment resistance. Furthermore, we employed transcription factor analysis and CellOracle to explore the transcriptional regulatory mechanisms governing CD8+ T cell differentiation fates. Finally, we utilized Nichenet and spatial transcriptomic analysis to investigate the spatial expression patterns of immune checkpoints.

RESULTS

Interaction analysis indicated that, among the known immune checkpoints, co-expression of NKG2A and PD-1 might exert a more profound inhibitory effect on the proliferative capacity of CD8+ T cells. The co-expression analysis revealed differential co-expression pattern of PD-1 and NKG2A, defined as ICEP1 (CD8+ T cells co-expressing PD-1, CTLA-4, TIGIT, LAG-3 or CD38) and ICEP2 (CD8+ T cells solely expressing NKG2A or co-expressing with other immune checkpoints), reflecting the co-occurrence pattern of PD-1 and the mutual exclusivity of NKG2A. Further, these two ICEP CD8+ T cell subsets represented distinct CD8+ T cell differentiation fates governed by MSC and RUNX3. Notably, ICEP2 CD8+ T cells were associated with anti-PD-1 therapy resistance in gastric cancer. This phenomenon may be attributed to the recruitment of LGMN+ macrophages mediated by the CXCL16-CXCR6 signaling pathway.

CONCLUSION

This study unveiled two distinct ICEPs and the mutually exclusivity and co-occurrence characteristics of CD8+ T cells in gastric cancer. The ICEP2 CD8+ T cell subset, highly expressed in gastric cancer patients resistant to anti-PD-1 therapy, may be recruited by LGMN+ macrophages through CXCL16-CXCR6 axis. These findings provide evidence for NKG2A as a novel immunotherapeutic target in gastric cancer and offer new insights into combination strategies for immune checkpoint inhibitors in gastric cancer.

Inhibition of CD226 Co-Stimulation Suppresses Diabetes Development in the NOD Mouse by Augmenting Tregs 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. A growing number of T cell-directed therapeutics have demonstrated partial therapeutic efficacy, with anti-CD3 (α-CD3) representing the only regulatory agency-approved drug capable of slowing disease progression through a mechanism involving the induction of partial T cell exhaustion. There is an outstanding need to augment the durability and effectiveness of T cell targeting by directly restraining proinflammatory T helper type 1 (Th1) and type 1 cytotoxic CD8 + T cell (Tc1) subsets, while simultaneously augmenting regulatory T cell (Treg) activity. Here, we present a novel strategy for reducing 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 between 7-8 weeks of age and then monitored for diabetes incidence and therapeutic mechanism of action.

Results

Compared to isotype-treated controls, anti-CD226 treated NOD mice showed reduced insulitis severity at 12 weeks and decreased disease incidence at 30 weeks. Flow cytometric analysis performed five weeks post-treatment demonstrated reduced proliferation of CD4 + and CD8 + effector memory T cells in spleens of anti-CD226 treated mice. Phenotyping of pancreatic Tregs revealed increased CD25 expression and STAT5 phosphorylation following anti-CD226, with splenic Tregs displaying augmented suppression of CD4 + T cell responders 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 and single-cell T cell receptor sequencing (scTCR-seq) approaches. 51 Cr-release assays demonstrated reduced cell-mediated lysis of beta-cells 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.

Research in Context

What is already known about this subject?: The co-stimulatory receptor CD226 is upregulated upon activation and is highly expressed on NK cell subsets, myeloid cells, and effector T cells. A single nucleotide polymorphism in CD226 ( rs763361 ; C>T) results in a Gly307Ser missense mutation linked to genetic susceptibility for type 1 diabetes. Global knockout of Cd226 and conditional Cd226 knockout in FoxP3 + Tregs reduced insulitis severity and diabetes incidence in NOD mice, indicating a crucial role for CD226 in disease pathogenesis. What is the key question?: Can CD226 blockade reduce T cell cytotoxicity and improve Treg function to diminish diabetes incidence in NOD mice?What are the new findings?: Anti-CD226 treatment reduced insulitis, decreased disease incidence, and inhibited splenic CD4 + and CD8 + effector memory T cell proliferation. Pancreatic Tregs from anti-CD226 treated mice exhibited increased CD25 expression; splenic Tregs displayed augmented STAT5 phosphorylation and suppressive capacity in vitro . Anti-CD226 treatment reduced IGRP-specific pancreatic CD8 + T cell frequencies, and reduced autoreactive CD8 + T cell-mediated lysis of beta-cells in vitro . How might this impact on clinical practice in the foreseeable future?: CD226 blockade could reduce autoreactive T cell cytotoxicity, enhance Treg function, and slow disease progression in high-risk or recent-onset type 1 diabetes cases.

Lipid-based nanosystems: the next generation of cancer immune therapy

Immunotherapy has become an important part of the oncotherapy arsenal. Its applicability in various cancer types is impressive, as well as its use of endogenous mechanisms to achieve desired ends. However, off-target or on-target-off-tumor toxicity, limited activity, lack of control in combination treatments and, especially for solid tumors, low local accumulation, have collectively limited clinical use thereof. These limitations are partially alleviated by delivery systems. Lipid-based nanoparticles (NPs) have emerged as revolutionary carriers due to favorable physicochemical characteristics, with specific applications and strengths particularly useful in immunotherapeutic agent delivery. The aim of this review is to highlight the challenges faced by immunotherapy and how lipid-based NPs have been, and may be further utilized to address such challenges. We discuss recent fundamental and clinical applications of NPs in a range of areas and provide a detailed discussion of the main obstacles in immune checkpoint inhibition therapies, adoptive cellular therapies, and cytokine therapies. We highlight how lipid-based nanosystems could address these through either delivery, direct modulation of the immune system, or targeting of the immunosuppressive tumor microenvironment. We explore advanced and emerging liposomal and lipid nanoparticle (LNP) systems for nucleic acid delivery, intrinsic and extrinsic stimulus-responsive formulations, and biomimetic lipid-based nanosystems in immunotherapy. Finally, we discuss the key challenges relating to the clinical use of lipid-based NP immunotherapies, suggesting future research directions for the near term to realize the potential of these innovative lipid-based nanosystems, as they become the crucial steppingstone towards the necessary enhancement of the efficacy of immunotherapy.

Association of CD8+TILs co-expressing granzyme A and interferon-γ with colon cancer cells in the tumor microenvironment

CD8+T cells secreting granzyme A (GZMA) can induce pyroptosis in tumor cells by effectively cleaving gasdermin B (GSDMB), which is stimulated by interferon-γ (IFN-γ). However, the interaction between GZMA-expressing CD8+T cells and GSDMB-expressing tumor cells in colon cancer remains poorly understood. Our research employed multi-color immunohistochemistry (mIHC) staining and integrated clinical data to explore the spatial distribution and clinical relevance of GZMA- and IFN-γ-expressing CD8+ tumor-infiltrating lymphocytes (TILs), as well as GSDMB-expressing CK+ cells, within the tumor microenvironment (TME) of human colon cancer samples. Additionally, we utilizing single-cell RNA sequencing (scRNA-seq) data to examine the functional dynamics and interactions among these cell populations. scRNA-seq analysis of colorectal cancer (CRC) tissues revealed that CD8+TILs co-expressed GZMA and IFN-γ, but not other cell types. Our mIHC staining results indicated that a significant reduction in the infiltration of GZMA+IFN-γ+CD8+TILs in colon cancer patients (P < 0.01). Functional analysis results indicated that GZMA+IFN-γ+CD8+TILs demonstrated enhanced activation and effector functions compared to other CD8+TIL subsets. Furthermore, GSDMB-expressing CK+ cells exhibited augmented immunogenicity. Correlation analysis highlighted a positive association between GSDMB+CK+ cells and GZMA+IFN-γ+CD8+TILs (r = 0.221, P = 0.033). Analysis of cell-cell interactions further showed that these interactions were mediated by IFN-γ and transforming growth factor-β (TGF-β), the co-stimulatory molecule ICOS, and immune checkpoint molecules TIGIT and TIM-3. These findings suggested that GZMA+IFN-γ+CD8+TILs modulating GSDMB-expressing tumor cells, significantly impacted the immune microenvironment and patients' prognosis in colon cancer. By elucidating these mechanisms, our present study aims to provide novel insights for the advancement of immunotherapeutic strategies in colon cancer.

Neoadjuvant immunochemotherapy improves clinical outcomes of patients with esophageal cancer by mediating anti-tumor immunity of CD8+ T (Tc1) and CD16+ NK cells

Background

Esophageal cancer (ESCA) is one of the most common tumors in the world, and treatment using neoadjuvant therapy (NT) based on radiotherapy and/or chemotherapy has still unsatisfactory results. Neoadjuvant immunochemotherapy (NICT) has also become an effective treatment strategy nowadays. However, its impact on the tumor microenvironment (TME) and regulatory mechanisms on T cells and NK cells needs to be further elucidated.

Methods

A total of 279 cases of ESCA who underwent surgery alone [non-neoadjuvant therapy (NONE)], neoadjuvant chemotherapy (NCT), and NICT were collected, and their therapeutic effect and survival period were compared. Further, RNA sequencing combined with biological information was used to analyze the expression of immune-related genes. Immunohistochemistry, immunofluorescence, and quantitative real-time PCR (qRT-PCR) were used to verify the activation and infiltration status of CD8+ T and CD16+ NK cells, as well as the function and regulatory pathway of killing tumor cells.

Results

Patients with ESCA in the NICT group showed better clinical response, median survival, and 2-year survival rates (p < 0.05) compared with the NCT group. Our RNA sequencing data revealed that NICT could promote the expression of immune-related genes. The infiltration and activation of immune cells centered with CD8+ T cells were significantly enhanced. CD8+ T cells activated by PD-1 inhibitors secreted more IFN-γ and cytotoxic effector factor cells through the transcription factor of EOMES and TBX21. At the same time, activated CD8+ T cells mediated the CD16+ NK cell activation and secreted more IFN-γ to kill ESCA cells. In addition, the immunofluorescence co-staining results showed that more CD276+ tumor cells and CD16+ NK cells were existed in pre-NCT and pre-NICT group. However, CD276+ tumor cells were reduced significantly in the post-NICT group, while they still appeared in the post-NCT group, which means that CD16+ NK cells can recognize and kill CD276+ tumor cells after immune checkpoint blocker (ICB) treatment.

Conclusion

NICT can improve the therapeutic effect and survival period of resectable ESCA patients. NICT could promote the expression of immune-related genes and activate CD8+ T and CD16+ NK cells to secrete more IFN-γ to kill ESCA cells. It provides a theoretical basis and clinical evidence for its potential as an NT strategy in ESCA.

Structural basis for the immune recognition and selectivity of the immune receptor PVRIG for ligand Nectin-2

Nectin and nectin-like (Necl) co-receptor axis, comprised of receptors DNAM-1, TIGIT, CD96, PVRIG, and nectin/Necl ligands, is gaining prominence in immuno-oncology. Within this axis, the inhibitory receptor PVRIG recognizes Nectin-2 with high affinity, but the underlying molecular basis remains unknown. By determining the crystal structure of PVRIG in complex with Nectin-2, we identified a unique CC' loop in PVRIG, which complements the double-lock-and-key binding mode and contributes to its high affinity for Nectin-2. The association of the corresponding charged residues in the F-strands explains the ligand selectivity of PVRIG toward Nectin-2 but not for Necl-5. Moreover, comprehensive comparisons of the binding capacities between co-receptors and ligands provide innovative insights into the intra-axis immunoregulatory mechanism. Taken together, these findings broaden our understanding of immune recognition and regulation mediated by nectin/Necl co-receptors and provide a rationale for the development of immunotherapeutic strategies targeting the nectin/Necl axis.

Differential impact of genetic deletion of TIGIT or PD-1 on melanoma-specific T-lymphocytes

Immune checkpoint (IC) blockade and adoptive transfer of tumor-specific T-cells (ACT) are two major strategies to treat metastatic melanoma. Their combination can potentiate T-cell activation in the suppressive tumor microenvironment, but the autoimmune adverse effects associated with systemic injection of IC blockers persist with this strategy. ACT of tumor-reactive T-cells defective for IC expression would overcome this issue. For this purpose, PD-1 and TIGIT appear to be relevant candidates, because their co-expression on highly tumor-reactive lymphocytes limits their therapeutic efficacy within the tumor microenvironme,nt. Our study compares the consequences of PDCD1 or TIGIT genetic deletion on anti-tumor properties and T-cell fitness of melanoma-specific T lymphocytes. Transcriptomic analyses revealed down-regulation of cell cycle-related genes in PD-1KO T-cells, consistent with biological observations, whereas proliferative pathways were preserved in TIGITKO T-cells. Functional analyses showed that PD-1KO and TIGITKO T-cells displayed superior antitumor reactivity than their wild-type counterpart in vitro and in a preclinical melanoma model using immunodeficient mice. Interestingly, it appears that TIGITKO T-cells were more effective at inhibiting tumor cell proliferation in vivo, and persist longer within tumors than PD-1KO T-cells, consistent with the absence of impact of TIGIT deletion on T-cell fitness. Taken together, these results suggest that TIGIT deletion, over PD-1 deletion, in melanoma-specific T-cells is a compelling option for future immunotherapeutic strategies.

Radiation and systemic immunotherapy for metastatic uveal melanoma: a clinical retrospective review

Introduction

Metastatic uveal melanoma (mUM) is a difficult to treat disease. The liver is the primary site of metastasis in most patients, though uveal melanoma spreads widely in advanced disease. The only FDA approved immunotherapy medication for metastatic uveal melanoma is the HLA-A02:01 restricted bispecific T cell engager drug, Tebentafusp. Checkpoint inhibitor strategies and combination approaches have been tried with some limited success. We describe our experience treating patients at the University of Minnesota.

Methods

Patients were included if they had biopsy-confirmed mUM. Twenty-five (25) patients meeting the criteria were identified. Medical records were reviewed and data extracted for patient baseline characteristics and response to treatments.

Results

Median time to metastasis from the time of local therapy to the eye was 14.2 months (IQR; 9.3-22.0), and first site of metastasis was liver in 92% of patients. Two patients (8%) did not receive systemic therapy or radiation therapy for metastatic disease. Twenty-three (92%) patients received systemic therapy, 13 patients (52%) received ipilimumab-nivolumab as the first-line, while 4 patients (16%) received pembrolizumab. Landmark survival analysis by receipt of systemic therapy and radiation therapy treatments within 6 months of biopsy confirmed diagnosis is shown. Twenty patients (80%) received systemic therapy within 6 months of mUM diagnosis. Thirteen patients (52%) received liver directed radiation therapy within 6 months of mUM diagnosis.

Discussion

Within our cohort, there was no overall survival benefit for patients receiving treatment of metastatic disease within 6 months of mUM diagnosis, versus those electing later or no treatment at all. There was remarkable clinical activity of ipilimumab and nivolumab in a subset of patients with mUM, in agreement with prior studies, and metastatic PD-L1 positive tumors were associated with a prolonged survival.

Second-generation checkpoint inhibitors and Treg depletion synergize with a mouse cancer vaccine in accordance with tumor microenvironment characterization

BACKGROUND

Despite advances in checkpoint inhibitor (CPI) therapy for cancer treatment, many cancers remain resistant. Tumors deemed "cold" based on lack of T cell infiltration show reduced potential for CPI therapy. Cancer vaccines may overcome the inadequacy of existing T cells by inducing the needed antitumor T cell response to synergize with CPIs and overcome resistance.

METHODS

CT26 and TC1 tumor cells were injected subcutaneously into mice. Mice were treated with combinations of CPIs alone or a cancer vaccine specific to the tumor antigen E7 present in TC1 cells. CPIs for the TC1 model were selected because of immunophenotyping TC1 tumors. Antitumor and protumor immunity, tumor size and survival, sequence and timing of vaccine and CPI administration, and efficacy of treatment in young and aged mice were probed.

RESULTS

While "hot" CT26 tumors are treatable with combinations of second-generation CPIs alone or with anti-TGFβ, "cold" TC1 tumor reduction requires the synergy of a tumor-antigen-specific vaccine in combination with two CPIs, anti-TIGIT and anti-PD-L1, predicted by tumor microenvironment (TME) characterization. The synergistic triple combination delays tumor growth better than any pairwise combination and improves survival in a CD8+T cell-dependent manner. Depletion of CD4+T cells improved the treatment response, and depleting regulatory T cells (Treg) revealed Tregs to be inhibiting the response as also predicted from TME analysis. We found the sequence of CPI and vaccine administration dictates the success of the treatment, and the triple combination administered concurrently induces the highest E7-specific T cell response. Contrary to young mice, in aged mice, the cancer vaccine alone is ineffective, requiring the CPIs to delay tumor growth.

CONCLUSIONS

These findings show how pre-existing or vaccine-mediated de novo T cell responses can both be amplified by and facilitate synergistic CPIs and Treg depletion that together lead to greater survival, and how analysis of the TME can help rationally design combination therapies and precision medicine to enhance clinical response to CPI and cancer vaccine therapy.

Tilianin enhances the antitumor effect of sufentanil on non-small cell lung cancer

Non-small cell cancer (NSCLC) is the most common cancer in the world, but its effective therapeutic methods are limited. Tilianin and sufentanil alleviate various human tumors. This research aimed to clarify the functions and mechanisms of Tilianin and sufentanil in NSCLC. The functions of Tilianin and sufentanil on NSCLC cell viability, apoptosis, mitochondrial dysfunction, and immunity in vitro were examined using Cell Counting Kit-8 assay, flow cytometry, reactive oxygen species level analysis, CD8+ T cell percentage analysis, Western blot, and enzyme-linked immunosorbent assay, respectively. The molecular mechanism regulated by Tilianin and sufentanil in NSCLC was assessed using Western blot, and immunofluorescence assays. Meanwhile, the roles of Tilianin and sufentanil in NSCLC tumor growth, apoptosis, and immunity in vivo were determined by establishing a tumor xenograft mouse model, immunohistochemistry, and Western blot assays. When sufentanil concentration was proximity 2 nM, the inhibition rate of NSCLC cell viability was 50%. The IC50 for A549 cells was 2.36 nM, and the IC50 for H1299 cells was 2.18 nM. The IC50 of Tilianin for A549 cells was 38.7 μM, and the IC50 of Tilianin for H1299 cells was 44.6 μM. Functionally, 0.5 nM sufentanil and 10 μM Tilianin reduced NSCLC cell (A549 and H1299) viability in a dose-dependent manner. Also, 0.5 nM sufentanil and 10 μM Tilianin enhanced NSCLC cell apoptosis, yet this impact was strengthened after a combination of Tilianin and Sufentanil. Furthermore, 0.5 nM sufentanil and 10 μM Tilianin repressed NSCLC cell mitochondrial dysfunction and immunity, and these impacts were enhanced after a combination of Tilianin and Sufentanil. Mechanistically, 0.5 nM sufentanil and 10 μM Tilianin repressed the NF-κB pathway in NSCLC cells, while this repression was strengthened after a combination of Tilianin and Sufentanil. In vivo experimental data further clarified that 1 µg/kg sufentanil and 10 mg/kg Tilianin reduced NSCLC growth, immunity, and NF-κB pathway-related protein levels, yet these trends were enhanced after a combination of Tilianin and Sufentanil. Tilianin strengthened the antitumor effect of sufentanil in NSCLC.

Fc-Silent Anti-TIGIT Antibodies Potentiate Antitumor Immunity without Depleting Regulatory T Cells

T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) is an inhibitory receptor on immune cells that outcompetes an activating receptor, CD226, for shared ligands. Tumor-infiltrating lymphocytes express TIGIT and CD226 on regulatory T cells (Treg) and on CD8+ T cells with tumor-reactive or exhausted phenotypes, supporting the potential of therapeutically targeting TIGIT to enhance antitumor immunity. To optimize the efficacy of therapeutic antibodies against TIGIT, it is necessary to understand IgG Fc (Fcγ) receptor binding for therapeutic benefit. In this study, we showed that combining Fc-enabled (Fce) or Fc-silent (Fcs) anti-TIGIT with antiprogrammed cell death protein 1 in mice resulted in enhanced control of tumors by differential mechanisms: Fce anti-TIGIT promoted the depletion of intratumoral Treg, whereas Fcs anti-TIGIT did not. Despite leaving Treg numbers intact, Fcs anti-TIGIT potentiated the activation of tumor-specific exhausted CD8+ populations in a lymph node-dependent manner. Fce anti-TIGIT induced antibody-dependent cell-mediated cytotoxicity against human Treg in vitro, and significant decreases in Treg were measured in the peripheral blood of patients with phase I solid tumor cancer treated with Fce anti-TIGIT. In contrast, Fcs anti-TIGIT did not deplete human Treg in vitro and was associated with anecdotal objective clinical responses in two patients with phase I solid tumor cancer whose peripheral Treg frequencies remained stable on treatment. Collectively, these data provide evidence for pharmacologic activity and antitumor efficacy of anti-TIGIT antibodies lacking the ability to engage Fcγ receptor.

SIGNIFICANCE

Fcs-silent anti-TIGIT antibodies enhance the activation of tumor-specific pre-exhausted T cells and promote antitumor efficacy without depleting T regulatory cells.

Current and future immunotherapeutic approaches in pancreatic cancer treatment

Pancreatic cancer is a major cause of cancer-related death, but despondently, the outlook and prognosis for this resistant type of tumor have remained grim for a long time. Currently, it is extremely challenging to prevent or detect it early enough for effective treatment because patients rarely exhibit symptoms and there are no reliable indicators for detection. Most patients have advanced or spreading cancer that is difficult to treat, and treatments like chemotherapy and radiotherapy can only slightly prolong their life by a few months. Immunotherapy has revolutionized the treatment of pancreatic cancer, yet its effectiveness is limited by the tumor's immunosuppressive and hard-to-reach microenvironment. First, this article explains the immunosuppressive microenvironment of pancreatic cancer and highlights a wide range of immunotherapy options, including therapies involving oncolytic viruses, modified T cells (T-cell receptor [TCR]-engineered and chimeric antigen receptor [CAR] T-cell therapy), CAR natural killer cell therapy, cytokine-induced killer cells, immune checkpoint inhibitors, immunomodulators, cancer vaccines, and strategies targeting myeloid cells in the context of contemporary knowledge and future trends. Lastly, it discusses the main challenges ahead of pancreatic cancer immunotherapy.

Beyond the Barrier: Unraveling the Mechanisms of Immunotherapy Resistance

Immune checkpoint blockade (ICB) induces a remarkable and durable response in a subset of cancer patients. However, most patients exhibit either primary or acquired resistance to ICB. This resistance arises from a complex interplay of diverse dynamic mechanisms within the tumor microenvironment (TME). These mechanisms include genetic, epigenetic, and metabolic alterations that prevent T cell trafficking to the tumor site, induce immune cell dysfunction, interfere with antigen presentation, drive heightened expression of coinhibitory molecules, and promote tumor survival after immune attack. The TME worsens ICB resistance through the formation of immunosuppressive networks via immune inhibition, regulatory metabolites, and abnormal resource consumption. Finally, patient lifestyle factors, including obesity and microbiome composition, influence ICB resistance. Understanding the heterogeneity of cellular, molecular, and environmental factors contributing to ICB resistance is crucial to develop targeted therapeutic interventions that enhance the clinical response. This comprehensive overview highlights key mechanisms of ICB resistance that may be clinically translatable.

Advances in Immunotherapy in Esophagogastric Cancer

Immune checkpoint inhibitors are rapidly transforming the care of patients with esophagogastric cancer. Particularly, anti-PD-1 therapy has demonstrated promising efficacy in metastatic and resectable disease. In this review, the authors discuss landmark clinical trials, highlight challenges and opportunities in this field, and propose potential directions for future work.

State-of-the-Art Advancements in Gastroesophageal Cancer Treatment: Harnessing Biomarkers for Precision Care

Gastroesophageal cancers (GECs) represent a significant clinical challenge. For early resectable GEC, the integration of immune checkpoint inhibitors into the perioperative chemotherapy and chemoradiation treatment paradigms are being explored and showing promising results. Frontline management of metastatic GEC is exploring the role of targeted therapies beyond PD-1 inhibitors, including anti-human epidermal growth factor receptor 2 agents, Claudin 18.2 inhibitors, and FGFR2 inhibitors, which have shown considerable efficacy in recent trials. Looking ahead, ongoing trials and emerging technologies such as bispecific antibodies, antibody-drug conjugates, and adoptive cell therapies like chimeric antigen receptor T cells are expected to define the future of GEC management. These advancements signify a paradigm shift toward personalized and immunotherapy-based approaches, offering the potential for improved outcomes and reduced toxicity for patients with GEC.

PD-1: A critical player and target for immune normalization

Immune system imbalances contribute to the pathogenesis of several different diseases, and immunotherapy shows great therapeutic efficacy against tumours and infectious diseases with immune-mediated derivations. In recent years, molecules targeting the programmed cell death protein 1 (PD-1) immune checkpoint have attracted much attention, and related signalling pathways have been studied clearly. At present, several inhibitors and antibodies targeting PD-1 have been utilized as anti-tumour therapies. However, increasing evidence indicates that PD-1 blockade also has different degrees of adverse side effects, and these new explorations into the therapeutic safety of PD-1 inhibitors contribute to the emerging concept that immune normalization, rather than immune enhancement, is the ultimate goal of disease treatment. In this review, we summarize recent advancements in PD-1 research with regard to immune normalization and targeted therapy.

Single cell analyses reveal the PD-1 blockade response-related immune features in hepatocellular carcinoma

Background: Immunotherapy has demonstrated its potential to improve the prognosis of patients with hepatocellular carcinoma (HCC); however, patients' responses to immunotherapy vary a lot. A comparative analysis of the tumor microenvironment (TME) in responders and non-responders is expected to unveil the mechanisms responsible for the immunotherapy resistance and provide potential treatment targets. Methods: We performed sequencing analyses using 10x Genomics technology on six HCC patients who responded to anti-PD-1 therapy and one HCC patient who did not respond. Additionally, we obtained single cell data from untreated, responsive, and nonresponsive HCC patients from public databases, and used part of the datasets as a validation cohort. These data were integrated using algorithms such as Harmony. An independent validation cohort was established. Furthermore, we performed spatial transcriptomic sequencing on the tumor adjacent tissues of three HCC responsive patients using 10x Genomics spatial transcriptomic technology. Additionally, we analyzed data about three HCC patients obtained from public databases. Finally, we validated our conclusions using immunofluorescence, flow cytometry, and in vivo experiments. Results: Our findings confirmed the presence of "immune barrier" partially accounting for the limited efficacy of immunotherapy. Our analysis revealed a significant increase in TREM2+ Macrophages among non-responsive patients expressing multiple immunosuppressive signals. anti-Csf1r monoclonal antibodies effectively eliminated these macrophages and augmented the therapeutic effects of anti-PD-1 therapy. TCR+ Macrophages possessed direct tumor-killing capabilities. IL1B+ cDC2 was the primary functional subtype of cDC2 cells. Absence of THEMIShi CD8+ T subtypes might diminish immunotherapeutic effects. Furthermore, CD8+ T cells entered a state of stress after anti-PD-1 treatment, which might be associated with CD8+ T cell exhaustion and senescence. Conclusions: The profiles of immune TMEs showed differences in HCC patients responsive, non-responsive and untreated. These differences might explain the discounted efficacy of immunotherapy in some HCC patients. The cells and molecules, which we found to carry unique capabilities, may be targeted to enhance immunotherapeutic outcomes in patients with HCC.

Immune checkpoint inhibitors: breakthroughs in cancer treatment

Over the past two decades, immunotherapies have increasingly been considered as first-line treatments for most cancers. One such treatment is immune checkpoint blockade (ICB), which has demonstrated promising results against various solid tumors in clinical trials. Monoclonal antibodies (mAbs) are currently available as immune checkpoint inhibitors (ICIs). These ICIs target specific immune checkpoints, including cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1). Clinical trial results strongly support the feasibility of this immunotherapeutic approach. However, a substantial proportion of patients with cancer develop resistance or tolerance to treatment, owing to tumor immune evasion mechanisms that counteract the host immune response. Consequently, substantial research focus has been aimed at identifying additional ICIs or synergistic inhibitory receptors to enhance the effectiveness of anti-PD-1, anti-programmed cell death ligand 1 (anti-PD-L1), and anti-CTLA-4 treatments. Recently, several immune checkpoint molecular targets have been identified, such as T cell immunoreceptor with Ig and ITIM domains (TIGIT), mucin domain containing-3 (TIM-3), lymphocyte activation gene-3 (LAG-3), V-domain immunoglobulin suppressor of T cell activation (VISTA), B and T lymphocyte attenuator (BTLA), and signal-regulatory protein α (SIRPα). Functional mAbs targeting these molecules are under development. CTLA-4, PD-1/PD-L1, and other recently discovered immune checkpoint proteins with distinct structures are at the forefront of research. This review discusses these structures, as well as clinical progress in mAbs targeting these immune checkpoint molecules and their potential applications.

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.

Development of pharmacological immunoregulatory anti-cancer therapeutics: current mechanistic studies and clinical opportunities

Immunotherapy represented by anti-PD-(L)1 and anti-CTLA-4 inhibitors has revolutionized cancer treatment, but challenges related to resistance and toxicity still remain. Due to the advancement of immuno-oncology, an increasing number of novel immunoregulatory targets and mechanisms are being revealed, with relevant therapies promising to improve clinical immunotherapy in the foreseeable future. Therefore, comprehending the larger picture is important. In this review, we analyze and summarize the current landscape of preclinical and translational mechanistic research, drug development, and clinical trials that brought about next-generation pharmacological immunoregulatory anti-cancer agents and drug candidates beyond classical immune checkpoint inhibitors. Along with further clarification of cancer immunobiology and advances in antibody engineering, agents targeting additional inhibitory immune checkpoints, including LAG-3, TIM-3, TIGIT, CD47, and B7 family members are becoming an important part of cancer immunotherapy research and discovery, as are structurally and functionally optimized novel anti-PD-(L)1 and anti-CTLA-4 agents and agonists of co-stimulatory molecules of T cells. Exemplified by bispecific T cell engagers, newly emerging bi-specific and multi-specific antibodies targeting immunoregulatory molecules can provide considerable clinical benefits. Next-generation agents also include immune epigenetic drugs and cytokine-based therapeutics. Cell therapies, cancer vaccines, and oncolytic viruses are not covered in this review. This comprehensive review might aid in further development and the fastest possible clinical adoption of effective immuno-oncology modalities for the benefit of patients.

The diversity of inhibitory receptor co-expression patterns of exhausted CD8+ T cells in oropharyngeal carcinoma

Exhausted CD8+ T cells (Texs) are characterized by the expression of various inhibitory receptors (IRs), whereas the functional attributes of these co-expressed IRs remain limited. Here, we systematically characterized the diversity of IR co-expression patterns in Texs from both human oropharyngeal squamous cell carcinoma (OPSCC) tissues and syngeneic OPSCC model. Nearly 60% of the Texs population co-expressed two or more IRs, and the number of co-expressed IRs was positively associated with superior exhaustion and cytotoxicity phenotypes. In OPSCC patients, programmed cell death-1 (PD-1) blockade significantly enhanced PDCD1-based co-expression with other IR genes, whereas dual blockades of PD-1 and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) significantly upregulated CTLA4-based co-expression with other IR genes. Collectively, our findings demonstrate that highly diverse IR co-expression is a leading feature of Texs and represents their functional states, which might provide essential clues for the rational selection of immune checkpoint inhibitors in treating OPSCC.

Tumor derived exosomal ENTPD2 impair CD8+ T cell function in colon cancer through ATP-adenosine metabolism reprogramming

BACKGROUND

Extracellular ATP-AMP-adenosine metabolism plays a pivotal role in modulating tumor immune responses. Previous studies have shown that the conversion of ATP to AMP is primarily catalysed by Ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1/CD39), a widely studied ATPase, which is expressed in tumor-associated immune cells. However, the function of ATPases derived from tumor cells themselves remains poorly understood. The purpose of this study was to investigate the role of colon cancer cell-derived ATPases in the development and progression of colon cancer.

METHODS

Bioinformatic and tissue microarray analyses were performed to investigate the expression of ATPase family members in colon cancer. An ATP hydrolysis assay, high-performance liquid chromatography (HPLC), and CCK8 and colony formation assays were used to determine the effects of ENTPD2 on the biological functions of colon cancer cells. Flow cytometric and RNA-seq analyses were used to explore the function of CD8+ T cells. Immunoelectron microscopy and western blotting were used to evaluate the expression of ENTPD2 in exosomes. Double-labelling immunofluorescence and western blotting were used to examine the expression of ENTPD2 in serum exosomes and colon cancer tissues.

RESULTS

We found that ENTPD2, rather than the well-known ATPase CD39, is highly expressed in cancer cells and is significantly positively associated with poor patient prognosis in patients with colon cancer. The overexpression of ENTPD2 in cancer cells augmented tumor progression in immunocompetent mice by inhibiting the function of CD8+ T cells. Moreover, ENTPD2 is localized primarily within exosomes. On the one hand, exosomal ENTPD2 reduces extracellular ATP levels, thereby inhibiting P2X7R-mediated NFATc1 nuclear transcription; on the other hand, it facilitates the increased conversion of ATP to adenosine, hence promoting adenosine-A2AR pathway activity. In patients with colon cancer, the serum level of exosomal ENTPD2 is positively associated with advanced TNM stage and high tumor invasion depth. Moreover, the level of ENTPD2 in the serum exosomes of colon cancer patients is positively correlated with the ENTPD2 expression level in paired colon cancer tissues, and the ENTPD2 level in both serum exosomes and tissues is significantly negatively correlated with the ENTPD2 expression level in tumor-infiltrating CD8+ T cells.

CONCLUSION

Our study suggests that exosomal ENTPD2, originated from colon cancer cells, contributes to the immunosuppressive microenvironment by promoting ATP-adenosine metabolism. These findings highlight the importance of exosome-derived hydrolytic enzymes as independent entities in shaping the tumor immune microenvironment.

Deciphering the potential role of PGRN in regulating CD8+ T cell antitumor immunity

A key factor contributing to resistance in immune checkpoint blockade (ICB) therapies is CD8+ T-cell tolerance in the tumor microenvironment (TME), partly resulting from upregulating coinhibitory receptors. Here, we describe the role of PGRN as a coinhibitory molecule that modulates the antitumor response of CD8+ T cells, thus presenting a novel immunosuppressive target for lung cancer. The in vivo subcutaneous transplanted lung cancer model showed that PGRN expression was elevated on CD8+ T cells that infiltrated transplanted lung cancers. Furthermore, PGRN deficiency was found to specifically encourage the infiltration of CD8+ T cells, enhance their proliferation, migration, and activation, and resist apoptosis, ultimately inhibiting tumor growth. This was achieved by PGRN knockout, increasing the production of T cell chemokine CCL3, which boosts the antitumor immune response induced by CD8+ T cells. Critically, the PD-L1 inhibitor exhibited a synergistic effect in enhancing the antitumor response in PGRN-/- mice. In summary, our findings highlight the significance of PGRN as a novel target for boosting CD8+ T cells antitumor immunity and its potential to overcome the resistance in ICB therapy.

An On-Treatment Decreased Trend of Serum IL-6 and IL-8 as Predictive Markers Quickly Reflects Short-Term Efficacy of PD-1 Blockade Immunochemotherapy in Patients with Advanced Gastric Cancer

Objective

Immunotherapy has proven effective in treating advanced gastric cancer (AGC), yet its benefits are limited to a subset of patients. Our aim is to swiftly identify prognostic biomarkers using cytokines to improve the precision of clinical guidance and decision-making for PD-1 inhibitor-based cancer immunotherapy in AGC.

Materials and Methods

The retrospective study compared 36 patients with AGC who received combined anti-PD-1 immunotherapy and chemotherapy (immunochemotherapy) with a control group of 20 patients who received chemotherapy alone. The concentrations of TNF-α, IL-1β, IL-2R, IL-6, IL-8, IL-10, and IL-17 in the serum were assessed using chemiluminescence immunoassay at three distinct time intervals following the commencement of immunochemotherapy.

Results

When compared to controls, patients undergoing immunochemotherapy demonstrated a generalized rise in cytokine levels after the start of treatment. However, patients who benefited from immunochemotherapy showed a decrease in IL-6 or IL-8 concentrations throughout treatment (with varied trends observed for IL-1β, IL-2R, IL-10, IL-17, and TNF-α) was evident in patients benefiting from immunochemotherapy but not in those who did not benefit. Among these markers, the combination of IL-6, IL-8, and CEA showed optimal predictive performance for short-term efficacy of immunochemotherapy in AGC patients.

Conclusion

Reductions in IL-6/IL-8 levels observed during immunochemotherapy correlated with increased responsiveness to treatment effectiveness. These easily accessible blood-based biomarkers are predictive and rapid and may play a crucial role in identifying individuals likely to derive benefits from PD-1 blockade immunotherapy.

Persistent T cell unresponsiveness associated with chronic visceral leishmaniasis in HIV-coinfected patients

A large proportion of HIV-coinfected visceral leishmaniasis (VL-HIV) patients exhibit chronic disease with frequent VL recurrence. However, knowledge on immunological determinants underlying the disease course is scarce. We longitudinally profiled the circulatory cellular immunity of an Ethiopian HIV cohort that included VL developers. We show that chronic VL-HIV patients exhibit high and persistent levels of TIGIT and PD-1 on CD8+/CD8- T cells, in addition to a lower frequency of IFN-γ+ TIGIT- CD8+/CD8- T cells, suggestive of impaired T cell functionality. At single T cell transcriptome and clonal resolution, the patients show CD4+ T cell anergy, characterised by a lack of T cell activation and lymphoproliferative response. These findings suggest that PD-1 and TIGIT play a pivotal role in VL-HIV chronicity, and may be further explored for patient risk stratification. Our findings provide a strong rationale for adjunctive immunotherapy for the treatment of chronic VL-HIV patients to break the recurrent disease cycle.

HPK1 citron homology domain regulates phosphorylation of SLP76 and modulates kinase domain interaction dynamics

Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of T-cell receptor signaling and as such is an attractive target for cancer immunotherapy. Although the role of the HPK1 kinase domain (KD) has been extensively characterized, the function of its citron homology domain (CHD) remains elusive. Through a combination of structural, biochemical, and mechanistic studies, we characterize the structure-function of CHD in relationship to KD. Crystallography and hydrogen-deuterium exchange mass spectrometry reveal that CHD adopts a seven-bladed β-propellor fold that binds to KD. Mutagenesis associated with binding and functional studies show a direct correlation between domain-domain interaction and negative regulation of kinase activity. We further demonstrate that the CHD provides stability to HPK1 protein in cells as well as contributes to the docking of its substrate SLP76. Altogether, this study highlights the importance of the CHD in the direct and indirect regulation of HPK1 function.

STAR-121: A Phase III Randomized Study of Domvanalimab and Zimberelimab in Combination With Chemotherapy Versus Pembrolizumab With Chemotherapy in Untreated Metastatic Non-Small Cell Lung Cancer With No Actionable Gene Alterations

INTRODUCTION

Dual inhibition with a T-cell immunoreceptor with immunoglobulin and ITIM domains plus programmed death (ligand)-1 (PD[L]-1) inhibitors, with or without chemotherapy, is an emerging therapeutic strategy in metastatic non-small cell lung cancer (mNSCLC). The STAR-121 (NCT05502237) phase III, global, randomized, open-label study will investigate first-line domvanalimab (anti-TIGIT) and zimberelimab (anti-PD-1) plus chemotherapy versus pembrolizumab plus chemotherapy in mNSCLC with no actionable gene alterations.

PARTICIPANTS AND METHODS

Approximately 720 participants (≥18 years old) with untreated mNSCLC and no EGFR and ALK mutations will be randomized into 3 groups (A, B, or C) in a 4:4:1 ratio and stratified by baseline PD-L1 expression (tumor cells <50% vs. ≥50%), histology (squamous vs. nonsquamous), and geographic region (East Asia vs. non-East Asia). Group A will receive domvanalimab 1200 mg plus zimberelimab 360 mg plus platinum-doublet chemotherapy (PT), group B will receive pembrolizumab 200 mg plus PT, and group C will receive zimberelimab 360 mg plus PT, every 3 weeks. Treatment will be administered until disease progression or intolerable toxicity. Dual primary endpoints are progression-free survival (by blinded independent central review [BICR]) and overall survival for group A versus B. Key secondary endpoints comprise overall response rate (by BICR), safety, and quality of life. Exploratory endpoints include efficacy and safety between groups A and C, pharmacokinetics, patient-reported outcomes, and biomarkers.

CONCLUSION

Enrollment in the STAR-121 study commenced on October 12, 2022, and is currently ongoing with completion planned by September 2024. The study completion is expected by December 2027.

Dual targeting of TIGIT and PD-1 with a novel small molecule for cancer immunotherapy

Immune checkpoint inhibitors have unveiled promising clinical prospects in cancer treatment. Nonetheless, their effectiveness remains restricted, marked by consistently low response rates and affecting only a subset of patients. The co-blockade of TIGIT with PD-1 has exhibited substantial anti-tumor effects. Notably, there is a dearth of reports on small-molecule inhibitors concurrently targeting both TIGIT and PD-1. In this study, we employed Microscale Thermophoresis (MST) to screen our laboratory's existing repository of small molecules. Our findings illuminated Gln(TrT) 's affinity for both TIGIT and PD-1, affirming its potential to effectively inhibit TIGIT/PVR and PD-1/PD-L1 pathways. In vitro co-culture experiments substantiated Gln(TrT)'s proficiency in restoring Jurkat T-cell functionality by blocking both TIGIT/PVR and PD-1/PD-L1 interactions. In the MC38 murine tumor model, Gln(TrT) emerges as a pivotal modulator, promoting the intratumoral infiltration and functional competence of CD8+ T cells. Furthermore, whether used as a monotherapy or in conjunction with radiotherapy, Gln(TrT) substantially impedes MC38 tumor progression, significantly extending the survival of murine subjects.

Hemin blocks TIGIT/PVR interaction and induces ferroptosis to elicit synergistic effects of cancer immunotherapy

The immune checkpoint TIGIT/PVR blockade exhibits significant antitumor effects through activation of NK and CD8+ T cell-mediated cytotoxicity. Immune checkpoint blockade (ICB) could induce tumor ferroptosis through IFN-γ released by immune cells, indicating the synergetic effects of ICB with ferroptosis in inhibiting tumor growth. However, the development of TIGIT/PVR inhibitors with ferroptosis-inducing effects has not been explored yet. In this study, the small molecule Hemin that could bind with TIGIT to block TIGIT/PVR interaction was screened by virtual molecular docking and cell-based blocking assay. Hemin could effectively restore the IL-2 secretion from Jurkat-hTIGIT cells. Hemin reinvigorated the function of CD8+ T cells to secrete IFN-γ and the elevated IFN-γ could synergize with Hemin to induce ferroptosis in tumor cells. Hemin inhibited tumor growth by boosting CD8+ T cell immune response and inducing ferroptosis in CT26 tumor model. More importantly, Hemin in combination with PD-1/PD-L1 blockade exhibited more effective antitumor efficacy in anti-PD-1 resistant B16 tumor model. In summary, our finding indicated that Hemin blocked TIGIT/PVR interaction and induced tumor cell ferroptosis, which provided a new therapeutic strategy to combine immunotherapy and ferroptosis for cancer treatment.

Self-supervised learning of T cell receptor sequences exposes core properties for T cell membership

The T cell receptor (TCR) repertoire is an extraordinarily diverse collection of TCRs essential for maintaining the body's homeostasis and response to threats. In this study, we compiled an extensive dataset of more than 4200 bulk TCR repertoire samples, encompassing 221,176,713 sequences, alongside 6,159,652 single-cell TCR sequences from over 400 samples. From this dataset, we then selected a representative subset of 5 million bulk sequences and 4.2 million single-cell sequences to train two specialized Transformer-based language models for bulk (CVC) and single-cell (scCVC) TCR repertoires, respectively. We show that these models successfully capture TCR core qualities, such as sharing, gene composition, and single-cell properties. These qualities are emergent in the encoded TCR latent space and enable classification into TCR-based qualities such as public sequences. These models demonstrate the potential of Transformer-based language models in TCR downstream applications.

ITPRIPL1 binds CD3ε to impede T cell activation and enable tumor immune evasion

Cancer immunotherapy has transformed treatment possibilities, but its effectiveness differs significantly among patients, indicating the presence of alternative pathways for immune evasion. Here, we show that ITPRIPL1 functions as an inhibitory ligand of CD3ε, and its expression inhibits T cells in the tumor microenvironment. The binding of ITPRIPL1 extracellular domain to CD3ε on T cells significantly decreased calcium influx and ZAP70 phosphorylation, impeding initial T cell activation. Treatment with a neutralizing antibody against ITPRIPL1 restrained tumor growth and promoted T cell infiltration in mouse models across various solid tumor types. The antibody targeting canine ITPRIPL1 exhibited notable therapeutic efficacy against naturally occurring tumors in pet clinics. These findings highlight the role of ITPRIPL1 (or CD3L1, CD3ε ligand 1) in impeding T cell activation during the critical "signal one" phase. This discovery positions ITPRIPL1 as a promising therapeutic target against multiple tumor types.

CD155 as an emerging target in tumor immunotherapy

CD155 is an immunoglobulin-like protein overexpressed in almost all the tumor cells, which not only promotes proliferation, adhesion, invasion, and migration of tumor cells, but also regulates immune responses by interacting with TIGIT, CD226 or CD96 receptors expressed on several immune cells, thereby modulating the functionality of these cellular subsets. As a novel immune checkpoint, the inhibition of CD155/TIGIT, either as a standalone treatment or in conjunction with other immune checkpoint inhibitors, has demonstrated efficacy in managing advanced solid malignancies. In this review, we summarize the intricate relationship between on tumor surface CD155 and its receptors, with further discussion on how they regulate the occurrence of tumor immune escape. In addition, novel therapeutic strategies and clinical trials targeting CD155 and its receptors are summarized, providing a strong rationale and way forward for the development of next-generation immunotherapies.

Chemotherapy induces myeloid-driven spatial T-cell exhaustion in ovarian cancer

To uncover the intricate, chemotherapy-induced spatiotemporal remodeling of the tumor microenvironment, we conducted integrative spatial and molecular characterization of 97 high-grade serous ovarian cancer (HGSC) samples collected before and after chemotherapy. Using single-cell and spatial analyses, we identify increasingly versatile immune cell states, which form spatiotemporally dynamic microcommunities at the tumor-stroma interface. We demonstrate that chemotherapy triggers spatial redistribution and exhaustion of CD8+ T cells due to prolonged antigen presentation by macrophages, both within interconnected myeloid networks termed "Myelonets" and at the tumor stroma interface. Single-cell and spatial transcriptomics identifies prominent TIGIT-NECTIN2 ligand-receptor interactions induced by chemotherapy. Using a functional patient-derived immuno-oncology platform, we show that CD8+T-cell activity can be boosted by combining immune checkpoint blockade with chemotherapy. Our discovery of chemotherapy-induced myeloid-driven spatial T-cell exhaustion paves the way for novel immunotherapeutic strategies to unleash CD8+ T-cell-mediated anti-tumor immunity in HGSC.

Dual immunotherapy in advanced or metastatic non-small cell lung cancer: A network meta-analysis

Objectives

Recently, there has been extensive research on dual immunotherapy for advanced or metastatic non-small cell lung cancer (NSCLC), yet a comprehensive evaluation is lacking. This study aimed to rank the available treatment options and assess the efficacy and safety of dual immunotherapy regimens through the implementation of a Bayesian network meta-analysis (NMA).

Materials and methods

A thorough search was conducted to recognize eligible randomized controlled trials (RCTs) on March 20, 2023. Overall survival (OS), progression-free survival (PFS), treatment-related adverse events (TRAEs) and grade ≥3 TRAEs were evaluated to identify the efficacy and safety of dual immunotherapy regimens. The surface under the cumulative ranking curve (SUCRA) and P score were employed to rank the treatments.

Results

Eleven clinical trials involving six different regimens were included in this study. The combination of anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) antibodies with anti-T-cell immunoglobulin and ITIM domain (TIGIT) antibodies emerged as the most promising regimen for improving OS and PFS, followed by anti-PD-1/PD-L1 + anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) + chemotherapy treatment and anti-PD-1/PD-L1 + anti-CTLA-4 treatment. The forest plots demonstrated that these three regimens were all superior to chemotherapy. The above results were observed in both unselected treatment line and first-line settings. The least likely to be associated with TRAEs and grade ≥3 TRAEs were respectively anti-CTLA-4 treatment and anti-PD-1/PD-L1 + anti-TIGIT treatment, with anti-PD-1/PD-L1 + anti-CTLA-4 + chemotherapy treatment to be the worst.

Conclusions

This NMA validated the promising efficacy and safety of dual immunotherapy in advanced or metastatic NSCLC. Among them, anti-PD-1/PD-L1 + anti-TIGIT regimen emerges as a highly potential therapeutic approach. Ongoing research efforts should focus on improving treatment regimens, identifying biomarkers, and managing TRAEs to optimize the patient benefits of dual immunotherapy.

TIGIT acts as an immune checkpoint upon inhibition of PD1 signaling in autoimmune diabetes

Introduction

Chronic activation of self-reactive T cells with beta cell antigens results in the upregulation of immune checkpoint molecules that keep self-reactive T cells under control and delay beta cell destruction in autoimmune diabetes. Inhibiting PD1/PD-L1 signaling results in autoimmune diabetes in mice and humans with pre-existing autoimmunity against beta cells. However, it is not known if other immune checkpoint molecules, such as TIGIT, can also negatively regulate self-reactive T cells. TIGIT negatively regulates the CD226 costimulatory pathway, T-cell receptor (TCR) signaling, and hence T-cell function.

Methods

The phenotype and function of TIGIT expressing islet infiltrating T cells was studied in non-obese diabetic (NOD) mice using flow cytometry and single cell RNA sequencing. To determine if TIGIT restrains self-reactive T cells, we used a TIGIT blocking antibody alone or in combination with anti-PDL1 antibody.

Results

We show that TIGIT is highly expressed on activated islet infiltrating T cells in NOD mice. We identified a subset of stem-like memory CD8+ T cells expressing multiple immune checkpoints including TIGIT, PD1 and the transcription factor EOMES, which is linked to dysfunctional CD8+ T cells. A known ligand for TIGIT, CD155 was expressed on beta cells and islet infiltrating dendritic cells. However, despite TIGIT and its ligand being expressed, islet infiltrating PD1+TIGIT+CD8+ T cells were functional. Inhibiting TIGIT in NOD mice did not result in exacerbated autoimmune diabetes while inhibiting PD1-PDL1 resulted in rapid autoimmune diabetes, indicating that TIGIT does not restrain islet infiltrating T cells in autoimmune diabetes to the same degree as PD1. Partial inhibition of PD1-PDL1 in combination with TIGIT inhibition resulted in rapid diabetes in NOD mice.

Discussion

These results suggest that TIGIT and PD1 act in synergy as immune checkpoints when PD1 signaling is partially impaired. Beta cell specific stem-like memory T cells retain their functionality despite expressing multiple immune checkpoints and TIGIT is below PD1 in the hierarchy of immune checkpoints in autoimmune diabetes.

Rejuvenated iPSC-derived GD2-directed CART Cells Harbor Robust Cytotoxicity Against Small Cell Lung Cancer

Small cell lung cancer (SCLC) is exceptionally aggressive, with limited treatment options. Disialoganglioside (GD2) is highly expressed on SCLC and is considered a good target for chimeric antigen receptor (CAR) T cells (CART). Although GD2-directed CARTs (GD2-CART) exhibit cytotoxicity against various GD2-expressing tumors, they lack significant cytotoxicity against SCLC. To enhance cytotoxicity of GD2-CARTs against SCLC, we introduced GD2-CAR into induced pluripotent stem cells (iPSC)-derived rejuvenated cytotoxic T lymphocytes (GD2-CARrejT). GD2-CARrejTs acted much more strongly against SCLC cells than did GD2-CARTs both in vitro and in vivo. Single-cell RNA sequencing elucidated that levels of expression of TIGIT were significantly lower and levels of expression of genes associated with cytotoxicity were significantly higher in GD2-CARrejTs than those in GD2-CARTs. Dual blockade of TIGIT and programmed death-1 (PD-1) increased the cytotoxicity of GD2-CARTs to some extent, suggesting that low TIGIT and PD-1 expression by GD2-CARrejTs is a major factor required for robust cytotoxicity against SCLC. Not only for robust cytotoxicity but also for availability as "off-the-shelf" T-cell therapy, iPSC-derived GD2-CARrejTs are a promising novel treatment for SCLC.

SIGNIFICANCE

This research introduces iPSC-derived rejuvenated GD2-CARTs (GD2-CARrejT) as a novel approach to combat SCLC. Compared with conventional GD2-CARTs, GD2-CARrejTs with reduced TIGIT and PD-1 expression demonstrate robust cytotoxicity against SCLC and would be a promising therapy for SCLC.

Blockade of PD-1 and CTLA-4: A potent immunotherapeutic approach for hepatocellular carcinoma

Immune checkpoints (ICPs) can promote tumor growth and prevent immunity-induced cancer cell apoptosis. Fortunately, targeting ICPs, such as programmed cell death 1 (PD-1) or cytotoxic T lymphocyte associated protein 4 (CTLA-4), has achieved great success in the past few years and has gradually become an effective treatment for cancers, including hepatocellular carcinoma (HCC). However, many patients do not respond to ICP therapy due to acquired resistance and recurrence. Therefore, clarifying the specific mechanisms of ICP in the development of HCC is very important for enhancing the efficacy of anti-PD-1 and anti-CTLA-4 therapy. In particular, antigen presentation and interferon-γ (IFN-γ) signaling were reported to be involved in the development of resistance. In this review, we have explained the role and regulatory mechanisms of ICP therapy in HCC pathology. Moreover, we have also elaborated on combinations of ICP inhibitors and other treatments to enhance the antitumor effect. Collectively, recent advances in the pharmacological targeting of ICPs provide insights for the development of a novel alternative treatment for HCC.

Anti-TIGIT antibody improves PD-L1 blockade through myeloid and Treg cells

Tiragolumab, an anti-TIGIT antibody with an active IgG1κ Fc, demonstrated improved outcomes in the phase 2 CITYSCAPE trial (ClinicalTrials.gov: NCT03563716 ) when combined with atezolizumab (anti-PD-L1) versus atezolizumab alone1. However, there remains little consensus on the mechanism(s) of response with this combination2. Here we find that a high baseline of intratumoural macrophages and regulatory T cells is associated with better outcomes in patients treated with atezolizumab plus tiragolumab but not with atezolizumab alone. Serum sample analysis revealed that macrophage activation is associated with a clinical benefit in patients who received the combination treatment. In mouse tumour models, tiragolumab surrogate antibodies inflamed tumour-associated macrophages, monocytes and dendritic cells through Fcγ receptors (FcγR), in turn driving anti-tumour CD8+ T cells from an exhausted effector-like state to a more memory-like state. These results reveal a mechanism of action through which TIGIT checkpoint inhibitors can remodel immunosuppressive tumour microenvironments, and suggest that FcγR engagement is an important consideration in anti-TIGIT antibody development.

Tissue biomarkers of immune checkpoint inhibitor therapy

Cancer immunotherapy has been rejuvenated by the growing understanding of the immune system's role in tumor activity over the past two decades. During cancer initiation and progression, tumor cells employ various mechanisms that resemble peripheral immune tolerance to evade the antitumor responses of the immune system. Immune checkpoint molecules are the major mechanism of immune resistance that are exploited by tumor cells to inhibit T-cell activation and suppress immune responses. The targeting of immune checkpoint pathways has led to substantial improvements in survival rates in a number of solid cancers. However, a lack of understanding of the heterogeneity of the tumor microenvironment (TME) has resulted in inefficient therapy responses. A greater understanding of the TME is needed to identify patients likely to respond, and those that will have resistance to immune checkpoint inhibitors (ICIs). Advancement in spatial single-cell technologies has allowed deeper insight into the phenotypic and functional diversities of cells in the TME. In this review, we provide an overview of ICI biomarkers and highlight how high-dimensional spatially resolved, single-cell approaches provide deep molecular insights into the TME and allow for the discovery of biomarkers of clinical benefit.

TIGIT: A potential immunotherapy target for gynecological cancers

Gynecological cancer represents a significant global health challenge, and conventional treatment modalities have demonstrated limited efficacy. However, recent investigations into immune checkpoint pathways have unveiled promising opportunities for enhancing the prognosis of patients with cancer. Among these pathways, TIGIT has surfaced as a compelling candidate owing to its capacity to augment the immune function of NK and T cells through blockade, thereby yielding improved anti-tumor effects and prolonged patient survival. Global clinical trials exploring TIGIT blockade therapy have yielded promising preliminary findings. Nevertheless, further research is imperative to comprehensively grasp the potential of TIGIT-based immunotherapy in optimizing therapeutic outcomes for gynecological cancers. This review primarily delineates the regulatory network and immunosuppressive mechanism of TIGIT, expounds upon its expression and therapeutic potential in three major gynecological cancers, and synthesizes the clinical trials of TIGIT-based cancer immunotherapy. Such insights aim to furnish novel perspectives and serve as reference points for subsequent research and clinical application targeting TIGIT in gynecological cancers.

Delineating immune variation between adult and children COVID-19 cases and associations with disease severity

The SARS-CoV-2 pandemic has emphasized the need to explore how variations in the immune system relate to the severity of the disease. This study aimed to explore inter-individual variation in response to SARS-CoV-2 infection by comparing T cell, B cell, and innate cell immune subsets among primary infected children and adults (i.e., those who had never experienced SARS-CoV-2 infection nor received vaccination previously), with varying disease severity after infection. We also examined immune subset kinetics in convalescent individuals compared to those with persistent infection to identify possible markers of immune dysfunction. Distinct immune subset differences were observed between infected adults and children, as well as among adult cases with mild, moderate, and severe disease. IgM memory B cells were absent in moderate and severe cases whereas frequencies of B cells with a lack of surface immunoglobulin expression were significantly higher in severe cases. Interestingly, these immune subsets remained stable during recovery implying that these subsets could be associated with underlying baseline immune variation. Our results offer insights into the potential immune markers associated with severe COVID-19 and provide a foundation for future research in this area.

Molecular basis, potential biomarkers, and future prospects of OSCC and PD-1/PD-L1 related immunotherapy methods

Oral squamous cell carcinoma (OSCC) affects a large number of individuals worldwide. Despite advancements in surgery, radiation, and chemotherapy, satisfactory outcomes have not been achieved. In recent years, the success of drugs targeting programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) has led to breakthroughs in cancer treatment, but systematic summaries on their effectiveness against OSCC are lacking. This article reviews the latest research on the PD-1/PD-L1 pathway and the potential of combination therapy based on this pathway in OSCC. Further, it explores the mechanisms involved in the interaction of this pathway with exosomes and protein-protein interactions, and concludes with potential future OSCC therapeutic strategies.

Research Progress of Nanomaterials Acting on NK Cells in Tumor Immunotherapy and Imaging

The prognosis for cancer patients has declined dramatically in recent years due to the challenges in treating malignant tumors. Tumor immunotherapy, which includes immune target inhibition and chimeric antigen receptor cell treatment, is currently evolving quickly. Among them, natural killer (NK) cells are gradually becoming another preferred cell immunotherapy after T cell immunotherapy due to their unique killing effects in innate and adaptive immunity. NK cell therapy has shown encouraging outcomes in clinical studies; however, there are still some problems, including limited efficacy in solid tumors, inadequate NK cell penetration, and expensive treatment expenses. Noteworthy benefits of nanomaterials include their chemical specificity, biocompatibility, and ease of manufacturing; these make them promising instruments for enhancing NK cell anti-tumor immune responses. Nanomaterials can promote NK cell homing and infiltration, participate in NK cell modification and non-invasive cell tracking and imaging modes, and greatly increase the effectiveness of NK cell immunotherapy. The introduction of NK cell-based immunotherapy research and a more detailed discussion of nanomaterial research in NK cell-based immunotherapy and molecular imaging will be the main topics of this review.

Revolutionizing cancer treatment: enhancing CAR-T cell therapy with CRISPR/Cas9 gene editing technology

CAR-T cell therapy, a novel immunotherapy, has made significant breakthroughs in clinical practice, particularly in treating B-cell-associated leukemia and lymphoma. However, it still faces challenges such as poor persistence, limited proliferation capacity, high manufacturing costs, and suboptimal efficacy. CRISPR/Cas system, an efficient and simple method for precise gene editing, offers new possibilities for optimizing CAR-T cells. It can increase the function of CAR-T cells and reduce manufacturing costs. The combination of CRISPR/Cas9 technology and CAR-T cell therapy may promote the development of this therapy and provide more effective and personalized treatment for cancer patients. Meanwhile, the safety issues surrounding the application of this technology in CAR-T cells require further research and evaluation. Future research should focus on improving the accuracy and safety of CRISPR/Cas9 technology to facilitate the better development and application of CAR-T cell therapy. This review focuses on the application of CRISPR/Cas9 technology in CAR-T cell therapy, including eliminating the inhibitory effect of immune checkpoints, enhancing the ability of CAR-T cells to resist exhaustion, assisting in the construction of universal CAR-T cells, reducing the manufacturing costs of CAR-T cells, and the security problems faced. The objective is to show the revolutionary role of CRISPR/Cas9 technology in CAR-T cell therapy for researchers.