Blocking intrahepatic deletion of activated CD8+ T cells by an altered peptide ligand

Background ted CD8+ T cells are retained by the healthy liver where the majority undergo apoptosis. The intrahepatic apoptosis of activated CD8+ T cells is enhanced by the presence of SIINFEKL peptide. It is of great interest to identify strategies for maintaining intrahepatic T cell number and function in the presence of SIINFEKL peptides. m was to test if low affinity peptides can block SIINFEKL peptide induced T cell deletion. s d an in vivo model of intrahepatic CD8+ T cell deletion with peptides of different affinities. s and discussion w that the intrahepatic deletion of CD8+ T cells by SIINFEKL peptide results in loss of in vivo cytotoxic T lymphocyte function. In contrast we show that a low affinity peptide (G4) does not result in intrahepatic deletion of CD8+ T cells. High concentrations G4 peptide can however block intrahepatic deletion of activated CD8+ T cells, and prevent loss of in vivo cytotoxicity due to SIINFEKL peptide. This is the first demonstration of blocking of SIINFEKL peptide induced CD8+ T cell deletion in the liver, with enhancement of in vivo cytotoxicity.