VISTA expressed in tumour cells regulates T cell function.

Area of Science:

• Immunology
• Oncology
• Cancer Research

Background:

• V-domain Ig suppressor of T cell activation (VISTA) is an inhibitory immune-checkpoint protein.
• VISTA expression and regulatory mechanisms in tumor cells are not well understood.
• This study investigates VISTA expression and function in tumor cells.

Purpose of the Study:

• To investigate VISTA expression and function in tumor cells.
• To evaluate the mechanism and activity of VISTA in the tumor microenvironment.
• To assess VISTA as a potential target for cancer immunotherapy.

Main Methods:

• Tissue microarray analysis, immunohistochemistry, and western blot were used to assess VISTA expression.
• In vitro assays were performed to determine the function of tumor-expressed VISTA.
• In vivo efficacy was evaluated in syngeneic tumor models.

Main Results:

• VISTA was highly expressed in human ovarian and endometrial cancers.
• Tumor-expressed VISTA suppressed T cell proliferation and cytokine production in vitro.
• VISTA expression in tumors reduced CD8+ T cell infiltration in vivo, and anti-VISTA antibody treatment prolonged survival in mice.

Conclusions:

• VISTA is highly expressed in ovarian and endometrial cancer cells, acting as an immunosuppressive factor.
• Anti-VISTA antibody treatment significantly prolongs survival in mice with VISTA-expressing tumors.
• VISTA represents a novel therapeutic target for cancer immunotherapy.