Vista

VISTA is the acronym for "V-domain Ig suppressor of T cell activation". VISTA is a 50kDa transmembrane protein that is biologically active as an immune checkpoint inhibitor. It is encoded by the C10orf54 gene.

VISTA belongs to the family of anti-inflammatory immune checkpoints (ICs). Anti-inflammatory immune checkpoints inhibit the immunoreactivity of T lymphocytes, in contrast to pro-inflammatory ICs, which increase the immunoreactivity of T lymphocytes. The immune checkpoints are activated by precisely fitting cytokines (ligands) that are presented and released by other cells.

VISTA has an IgV domain and is expressed by lymphocytes and monocytes. There is evidence that VISTA acts both as a ligand and as a receptor on T-cells, thus controlling T-cell effector functions and thus significantly influencing the homeostasis of biological tolerance.

For example, VISTA is produced in high concentrations by tumour-infiltrating lymphocytes. In animal experiments, VISTA blockade leads to reduced tumor growth of squamous cell carcinomas and malignant melanomas. Monocytes of HIV-infected patients also produce significantly increased VISTA levels.