Expression of PD1 Differs on T Cells from a Pathogenic Versus Nonpathogenic Primate Models of AIDS (43.50)

• Published in: The Journal of immunology (1950) Vol. 178; no. 1_Supplement; p. S46
• Main Authors: Rogers, Kenneth, Onlamoon, N, Hudson, K, Bryan, P, Mayne, A E, Mori, K, Pattanapanyasat, K, Villinger, F, Ansari, A A
• Format: Journal Article
• Language: English
• Published: 01.04.2007
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.178.Supp.43.50

Abstract In most chronic infections antigen specific memory T cells experience a progressive immune exhaustion. Recent reports of HIV infection demonstrate increased expression of PD1 on exhausted T cells correlating with viral loads, and in vitro restoration of function by blockade of PD1 interactions with its ligands. We characterized PD1 in a rhesus macaque model of SIV infection where AIDS develops versus an asymptomatic natural host, sooty mangabeys. Infected animals of both species showed an increase in frequency of total PD1+ CD4+ cells, but not CD8+, which correlated with viral loads in macaques, but not in mangabeys. Furthermore this increase was noted in naïve mangabey CD4+ cells, but central memory macaque CD4+ cells. In macaques, antigen specific CD8+ T cells had increased PD1 expression (MFI) that was reduced with antiviral therapy. While the blockade of PD1-PDL1 interactions in vitro enhanced overall SIV antigen specific responses, individual responses to specific peptides were found enhanced, unchanged or even diminished. These data support a potential for role PD1 in the phenomena of “immune exhaustion” and a rationale for its study using monkey models of AIDS.