Expression of VISTA on T cells in patients with cancer colon.

Colorectal cancer (CRC) is one of the most common tumors in the world. A recent area of study for the treatment of patients with solid tumors is anti-tumor immunity. PD-1/PD-L1 inhibitors were beneficial for cancer patients with multiple tumor types. However, their efficacy for CRC is low. Thus, there is an urgent need to explore additional co-inhibitory tools such as VISTA for CRC treatment.ObjectiveThe current study aimed to evaluate expression of VISTA on T cell subsets in patients with CRC and its correlation with other prognostic markers.Patients and methodsThe study included 31 patients with CRC and 25 healthy controls. All participants were subjected to full history taking, clinical examination, routine laboratory investigations, and flow cytometric detection of VISTA expression on T cell subsets on peripheral blood (PB). In addition to detection of VISTA expression on T cell subsets on tissue samples of both malignant CRC and normal colon tissue of the CRC patients.ResultsIn the peripheral blood, the expression of VISTA on CD4 T helper and CD8 T cytotoxic cells was significantly higher in CRC patients than the normal controls. There was no significant difference in VISTA expression on double positive T cells (CD4CD8) between the CRC patients and normal controls. In tissue samples, expression of VISTA on CD4 + T helper, CD8 + T cytotoxic, and double positive T (CD4 + CD8 +) cells in the malignant tissue of CRC patients was significantly higher than that in normal colonic tissue. Also, in CRC patients, the expression of VISTA on CD4 T helper, CD8 T cytotoxic, and double positive T cells in both malignant CRC tissue and normal colonic tissue was significantly higher than its expression PB.ConclusionThe higher expression of VISTA in CRC patients than the healthy controls and its higher levels in malignant CRC tissue and normal colonic tissue than PB of CRC patients suggest the role VISTA in the pathogenesis of CRC.