TIGIT and PD-1 expression atlas predicts response to adjuvant chemotherapy and PD-L1 blockade in muscle-invasive bladder cancer

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.

Exploring the role of TIGIT in patients with Small Cell Lung Cancer as a novel predictor of prognosis and immunotherapy response

BACKGROUND

T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) is a novel immune checkpoint playing a crucial role in immunosuppression and immune evasion. This study aims to elucidate the expression patterns, characteristics, and possible mechanisms of TIGIT in small cell lung cancer (SCLC).

METHODS

TIGIT expression was analyzed across various cancers and normal tissues using The Cancer Genome Atlas (TCGA). Transcriptomic data from SCLC patients, sourced from the Gene Expression Omnibus (GEO) and literature, were analyzed to assess TIGIT-related characteristics. Immunohistochemistry (IHC) was used to verify TIGIT expression in post-surgical and advanced SCLC samples, focusing on expression characteristics, prognostic value, and treatment response.

RESULTS

TIGIT was significantly overexpressed in various tumors, including SCLC (p < 0.05). Higher expression was associated with better overall survival (OS) (p < 0.05). Notably, a significant positive correlation was observed between TIGIT expression and immune-related metagenes, such as HCK, interferon, and LCK (p < 0.05). Immune infiltration analysis revealed a strong positive correlation between TIGIT expression and immune score in multiple cohorts. Additionally, TIGIT expression correlated positively with immune cells, including CD8 T cells, cytotoxic lymphocytes, and B cells (p < 0.05), and multiple immune checkpoints like BTLA, ICOS, and LAG3 (p < 0.05), while it had a significant negative correlation with the TIDE score (p < 0.05). In the validation section, patients with high TIGIT expression showed significantly prolonged disease-free survival (DFS) and OS (p < 0.05), and demonstrated a better response to adjuvant chemotherapy (ACT) and immunotherapy.

CONCLUSION

TIGIT serves as a biomarker in SCLC, with its high expression indicating favorable prognosis and treatment response. These effects may be due to TIGIT's unique immune landscape and its association with other immune checkpoints.

Exploring the Immunoresponse in Bladder Cancer Immunotherapy

Bladder cancer (BC) represents a wide spectrum of diseases, ranging from recurrent non-invasive tumors to advanced stages that require intensive treatments. BC accounts for an estimated 500,000 new cases and 200,000 deaths worldwide every year. Understanding the biology of BC has changed how this disease is diagnosed and treated. Bladder cancer is highly immunogenic, involving innate and adaptive components of the immune system. Although little is still known of how immune cells respond to BC, immunotherapy with bacillus Calmette-Guérin (BCG) remains the gold standard in high-risk non-muscle invasive BC. For muscle-invasive BC and metastatic stages, immune checkpoint inhibitors targeting CTLA-4, PD-1, and PD-L1 have emerged as potent therapies, enhancing immune surveillance and tumor cell elimination. This review aims to unravel the immune responses involving innate and adaptive immune cells in BC that will contribute to establishing new and promising therapeutic options, while reviewing the immunotherapies currently in use in bladder cancer.

Bladder cancer immune-related markers: diagnosis, surveillance, and prognosis

As an immune-related tumor type, bladder cancer has been attracting much attention in the study of its markers. In recent years, researchers have made rapid progress in the study of immune-related markers for bladder cancer. Studies have shown that immune-related markers play an important role in the diagnosis, prognosis assessment and treatment of bladder cancer. In addition, the detection of immune-related markers can also be used to evaluate the efficacy of immunotherapy and predict the treatment response of patients. Therefore, in depth study of the expression of immune-related markers in bladder cancer and their application in the clinic is of great significance and is expected to provide new breakthroughs for individualized treatment of bladder cancer. Future studies will focus more on how to detect immune-related markers with low cost and high accuracy, as well as develop new immunotherapeutic strategies to bring better therapeutic outcomes to bladder cancer patients.

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.

Targeting TIGIT for cancer immunotherapy: recent advances and future directions

As a newly identified checkpoint, T cell immunoreceptor with immunoglobulin and tyrosine-based inhibitory motif (ITIM) domain (TIGIT) is highly expressed on CD4+ T cells, CD8+ T cells, natural killer (NK) cells, regulatory T cells (Tregs), and tumor-infiltrating lymphocytes (TILs). TIGIT has been associated with NK cell exhaustion in vivo and in individuals with various cancers. It not only modulates NK cell survival but also mediates T cell exhaustion. As the primary ligand of TIGIT in humans, CD155 may be the main target for immunotherapy due to its interaction with TIGIT. It has been found that the anti-programmed cell death protein 1 (PD-1) treatment response in cancer immunotherapy is correlated with CD155 but not TIGIT. Anti-TIGIT alone and in combination with anti-PD-1 agents have been tested for cancer immunotherapy. Although two clinical studies on advanced lung cancer had positive results, the TIGIT-targeted antibody, tiragolumab, recently failed in two new trials. In this review, we highlight the current developments on TIGIT for cancer immunotherapy and discuss the characteristics and functions of TIGIT.

The spatial coexistence of TIGIT/CD155 defines poorer survival and resistance to adjuvant chemotherapy in pancreatic ductal adenocarcinoma

Background: Targeting emerging T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT)/CD155 axis shows promise for restoring anti-tumor immunity, but its immune phenotypes and prognostic significance in a large cohort of pancreatic ductal adenocarcinoma (PDAC) are limited. Methods: Three seven-color multispectral panels were rationally designed to investigate the protein expression, immune-microenvironmental feature, prognostic value, and the response to adjuvant chemotherapy of TIGIT/CD155 in 272 PDAC specimens using multiplex immunohistochemistry. Results: We revealed low immunogenicity and high heterogeneity of the PDAC immune microenvironment featured by abundant CD3+ T cells and CD68+ macrophages and low infiltration of activated cytotoxic T lymphocytes. TIGIT and CD155 were highly expressed in PDAC tissues compared to paracancerous tissues. Tumor-infiltrating lymphocytes expressing TIGIT were correlated with high densities of CD45RO+ T cells; TIGTI+CD8+ T cells were associated with high infiltration of CD3+CD45RO+FOXP3+. CD155+CK+ were significantly related to high densities of CD3+ and CD3+CD8+CD45RO+ T cells. High positive rates for TIGIT in TCs, CD8+ T cells, and CD155 in macrophages were correlated with poor progression-free and disease-specific survival, respectively, and their clinical significance was correlated with PD-L1 status. Notably, spatial co-existence of TIGIT+CK+ or TIGIT+CD8+ and CD155+CD68+ indicated poor survival and resistance to adjuvant chemotherapy response in patients with PDAC. Conclusion: Our findings suggest that targeting TIGIT/CD155 immunosuppressive axis may guide patient stratification and improve the clinical outcome of PDAC.

Co-inhibition of TIGIT and PD-1/PD-L1 in Cancer Immunotherapy: Mechanisms and Clinical Trials

Over the past decade, immune checkpoint inhibitors (ICIs) have emerged as a revolutionary cancer treatment modality, offering long-lasting responses and survival benefits for a substantial number of cancer patients. However, the response rates to ICIs vary significantly among individuals and cancer types, with a notable proportion of patients exhibiting resistance or showing no response. Therefore, dual ICI combination therapy has been proposed as a potential strategy to address these challenges. One of the targets is TIGIT, an inhibitory receptor associated with T-cell exhaustion. TIGIT has diverse immunosuppressive effects on the cancer immunity cycle, including the inhibition of natural killer cell effector function, suppression of dendritic cell maturation, promotion of macrophage polarization to the M2 phenotype, and differentiation of T cells to regulatory T cells. Furthermore, TIGIT is linked with PD-1 expression, and it can synergize with PD-1/PD-L1 blockade to enhance tumor rejection. Preclinical studies have demonstrated the potential benefits of co-inhibition of TIGIT and PD-1/PD-L1 in enhancing anti-tumor immunity and improving treatment outcomes in several cancer types. Several clinical trials are underway to evaluate the safety and efficacy of TIGIT and PD-1/PD-L1 co-inhibition in various cancer types, and the results are awaited. This review provides an overview of the mechanisms of TIGIT and PD-1/PD-L1 co-inhibition in anti-tumor treatment, summarizes the latest clinical trials investigating this combination therapy, and discusses its prospects. Overall, co-inhibition of TIGIT and PD-1/PD-L1 represents a promising therapeutic approach for cancer treatment that has the potential to improve the outcomes of cancer patients treated with ICIs.

TIGIT in Lung Cancer: Potential Theranostic Implications

TIGIT (T cell immunoreceptor with Ig and ITIM domains) is a co-inhibitory receptor expressed on various immune cells, including T cells, NK cells, and dendritic cells. TIGIT interacts with different ligands, such as CD155 and CD112, which are highly expressed on cancer cells, leading to the suppression of immune responses. Recent studies have highlighted the importance of TIGIT in regulating immune cell function in the tumor microenvironment and its role as a potential therapeutic target, especially in the field of lung cancer. However, the role of TIGIT in cancer development and progression remains controversial, particularly regarding the relevance of its expression both in the tumor microenvironment and on tumor cells, with prognostic and predictive implications that remain to date essentially undisclosed. Here, we provide a review of the recent advances in TIGIT-blockade in lung cancer, and also insights on TIGIT relevance as an immunohistochemical biomarker and its possible theranostic implications.

Clinical significance of immune checkpoint proteins in HPV-infected cervical cancer

OBJECTIVE

To investigate T cell immunoreceptor with Ig and ITIM domain (TIGIT), V-domain Ig suppressor of T cell activation (VISTA), and lymphocyte-activation gene-3 (LAG-3) expression in pathological tissue of human papillomavirus (HPV)-infected cervical cancer (CC) patients and their relationship with patient prognosis.

METHODS

Clinical data of 175 patients with HPV-infected CC were collected retrospectively. Tumor tissue sections were stained immunohistochemically for TIGIT, VISTA, and LAG-3. The Kaplan-Meier method calculated patient survival. Univariate and multivariate Cox proportional hazards models analyzed all potential risk factors for survival.

RESULTS

When combined positive score (CPS)= 1 was used as the cut-off value, the Kaplan-Meier survival curve showed that the progression-free survival (PFS) and overall survival (OS) of patients with positive expression of TIGIT and VISTA are shorter (both p < 0.05). Univariate COX regression analysis showed that the positive expression of TIGIT and VISTA are related to patient PFS and OS (both HR>1.0 and p < 0.05). Multivariate COX regression analysis showed that TIGIT-positive patients had shorter OS and VISTA-positive patients had shorter PFS (both HR>1.0 and p < 0.05). There is no significant correlation between LAG-3 expression and PFS or OS. When CPS= 10 was used as the cut-off value, Kaplan-Meier survival curve showed that TIGIT-positive patients had shorter OS (p = 0.019). Univariate COX regression analysis showed that TIGIT-positive expression was associated with the OS of patients (HR=2.209, CI: 1.118-4.365, p = 0.023). However, multivariate COX regression analysis showed that TIGIT expression was not associated significantly with OS. There was no significant correlation between VISTA and LAG-3 expression and PFS or OS.

CONCLUSION

TIGIT and VISTA are associated closely with HPV-infected CC prognosis and are effective biomarkers.

Pembrolizumab and cabozantinib in recurrent metastatic head and neck squamous cell carcinoma: a phase 2 trial

Anti-programmed cell death protein 1 (PD-1) therapy is a standard of care in recurrent metastatic head and neck squamous cell carcinoma (RMHNSCC). Vascular endothelial growth factor inhibitors, including tyrosine kinase inhibitors, have immunomodulatory properties and have offered promising results when combined with anti-PD-1 agents. We conducted a phase 2, multicenter, single-arm trial of pembrolizumab and cabozantinib in patients with RMHNSCC who had Response Evaluation Criteria in Solid Tumors v.1.1 measurable disease and no contraindications to either agent. We assessed the primary end points of tolerability and overall response rate to the combination with secondary end points of progression-free survival and overall survival and performed correlative studies with PDL-1 and combined positive score, CD8+ T cell infiltration and tumor mutational burden. A total of 50 patients were screened and 36 were enrolled with 33 evaluable for response. The primary end point was met, with 17 out of 33 patients having a partial response (52%) and 13 (39%) stable disease with an overall clinical benefit rate of 91%. Median and 1-year overall survival were 22.3 months (95% confidence interval (CI) = 11.7-32.9) and 68.4% (95% CI = 45.1%-83.5%), respectively. Median and 1-year progression-free survival were 14.6 months (95% CI = 8.2-19.6) and 54% (95% CI = 31.5%-72%), respectively. Grade 3 or higher treatment-related adverse events included increased aspartate aminotransferase (n = 2, 5.6%). In 16 patients (44.4%), the dose of cabozantinib was reduced to 20 mg daily. The overall response rate correlated positively with baseline CD8+ T cell infiltration. There was no observed correlation between tumor mutational burden and clinical outcome. Pembrolizumab and cabozantinib were well tolerated and showed promising clinical activity in patients with RMHNSCC. Further investigation of similar combinations are needed in RMHNSCC. The trial is registered at ClinicalTrials.gov under registration no. NCT03468218 .

Update in TIGIT Immune-Checkpoint Role in Cancer

The in-depth characterization of cross-talk between tumor cells and T cells in solid and hematological malignancies will have to be considered to develop new therapeutical strategies concerning the reactivation and maintenance of patient-specific antitumor responses within the patient tumor microenvironment. Activation of immune cells depends on a delicate balance between activating and inhibitory signals mediated by different receptors. T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) is an inhibitory receptor expressed by regulatory T cells (Tregs), activated T cells, and natural killer (NK) cells. TIGIT pathway regulates T cell-mediated tumor recognition in vivo and in vitro and represents an exciting target for checkpoint blockade immunotherapy. TIGIT blockade as monotherapy or in combination with other inhibitor receptors or drugs is emerging in clinical trials in patients with cancer. The purpose of this review is to update the role of TIGIT in cancer progression, looking at TIGIT pathways that are often upregulated in immune cells and at possible therapeutic strategies to avoid tumor aggressiveness, drug resistance, and treatment side effects. However, in the first part, we overviewed the role of immune checkpoints in immunoediting, the TIGIT structure and ligands, and summarized the key immune cells that express TIGIT.