Chemotherapy induces immune checkpoint VISTA expression in tumor cells via HIF-2alpha.

Tumor cells can evade the innate and adaptive immune systems, which play important roles in tumor recurrence and metastasis. Malignant tumors that recur after chemotherapy are more aggressiveciscis, suggesting an increased ability of the surviving tumor cells to evade innate and adaptive immunity. Therefore, in order to reduce patient mortality, it is important to discover the mechanisms by which tumor cells develop resistance to chemotherapeutics. In the present study we focused on the tumor cells that survived chemotherapy. We found that chemotherapy could promote the expression of VISTA in tumor cells, and that this change was mediated by HIF-2α. In addition, VISTA overexpression on melanoma cells promoted immune evasion, and the application of the VISTA-blocking antibody 13F3 enhanced the therapeutic effect of carboplatin. These results offer an insight into the immune evasion of chemotherapy-resistant tumors, and provide a theoretical basis for the combined application of chemotherapy drugs and VISTA inhibitors to treat tumors.

Adverse and unconventional reactions related to immune checkpoint inhibitor therapy for cancer.

Immunotherapy is an emerging method for the treatment of cancer. Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that block immune checkpoint pathways and release the body's anti-tumor immunity. They consist mainly of antibodies against cytotoxic T lymphocyte associated antigen-4 (CTLA-4), programmed death receptor 1 (PD-1), and programmed death ligand 1 (PD-L1). Although ICI therapy has been shown to be effective at treating cancer, it can also destroy immune tolerance and lead to organ toxicity. These unwanted side effects are known as immune related adverse events (irAEs). ICI treatment can also cause unconventional reactions such as pseudoprogression and hyperprogression. Pseudoprogression looks like an increase in the tumor parenchyma but is actually a temporary inflammation in the tumor; hyperprogression refers to the acceleration of tumor growth after the start of immunotherapy. Understanding the mechanisms of these two phenomena and distinguishing their differences are necessary for the effective prevention and treatment of unconventional reactions.

Biomarkers related to immune checkpoint inhibitors therapy.

Immune checkpoint inhibitors (ICIs) therapy is an emerging cancer treatment. During treatment it is necessary to monitor the patient at all times and respond to any adverse reactions that may occur, such as immune-related adverse events and unconventional reactions. Biomarkers, the biochemical indicators that mark changes in the structure or function of systems, organs, tissues, and cells, may be used to predict and design treatment for such reactions. Anti-tumor immunotherapy biomarkers can be derived from the tumors themselves (e.g. negative regulatory molecules and dynamic changes in genome sequence) or from the immune system (e.g. peripheral blood cell population counts, various cytokines, tumor-infiltrating lymphocytes, and intestinal microbes). The development of biomarkers is important for monitoring the effect of treatment, assessing the patient's response to ICIs, determining adverse reactions, and predicting the direction of disease development. In addition, organ toxicity and systemic events also have an impact on the therapeutic effect of ICIs.

The expression and immunoregulation of immune checkpoint molecule VISTA in autoimmune diseases and cancers.

Immune checkpoint inhibitors (ICIs) and immunotherapy have proven to be a transformative therapy for many forms of cancer treatment. While many antibodies targeting the PD-1, PD-L1, and CTLA-4 pathways have been approved for clinical use by the FDA, it is clear that a single ICI is not sufficient to eradicate disease. ICI combination strategies are being extensively investigated to advance cancer treatment to next curative stage. Among the immune checkpoint inhibitors being actively investigated, the potential of VISTA (V-domain Ig suppressor of T cell activation), a unique B7 family member that functions as both ligand and receptor, is being actively pursued. This article summarizes the expression and immunomodulatory effects of VISTA in autoimmune diseases and cancer, and assesses its potential as an additional component of immune checkpoint cancer therapy.