Inducible T-Cell Co Stimulator Ligand (ICOSLG)

ICOSLG has also been designated as CD275 (cluster of differentiation 275).BIAcore analysis by Yoshinaga et al. (2000) indicated that B7RP1 binds preferentially to ICOS and does not bind to CTLA4. Flow cytometric analysis demonstrated that tumor necrosis factor-alpha  enhances B7RP1 expression on B cells and monocytes, but decreases its expression on dendritic cells.

B7RP1 fusion protein or cells expressing B7RP1 enhanced T-cell proliferation and interleukin-2 (IL2; 147680)-dependent cytokine production (gamma-interferon and IL10 but not IL2) in response to anti-CD3 stimulation. This enhancement could be blocked by soluble ICOS.