Circulating CD8 T cells show increased interferon-gamma mRNA expression in HIV infection.
IFN-gamma mRNA levels were measured in unstimulated PBMC and purified cell subpopulations, utilizing branched DNA assays, to characterize the cell type(s) that contribute to the in vivo increase in IFN-gamma gene expression seen in HIV infection. PBMC and CD8 T cells from HIV-seropositive subjects (HIV+) showed 2.5-fold increases in mean IFN-gamma mRNA levels compared to HIV-uninfected subjects (HIV-). Within individuals, CD8 T cells showed the highest IFN-gamma expression regardless of HIV status, which suggests that HIV infection enhances the IFN-gamma gene expression in CD8 T cells rather than inducing a shift to and/or increasing expression of IFN-gamma mRNA in other cell types. HIV+ subjects with increased PBMC IFN-gamma mRNA had elevated plasma levels of HIV RNA, neopterin, and beta 2-microglobulin. No differences in IFN-gamma mRNA levels were seen among HIV+ stratified by CD4 T cell number. Increased IFN-gamma may result from or be a contributing factor to increased viral load.
Breen
E C
EC
Department of Microbiology and Immunology, University of California, Los Angeles 90095-1747, USA. ebreen@ucla.edu
Salazar-Gonzalez
J F
JF
Shen
L P
LP
Kolberg
J A
JA
Urdea
M S
MS
Martinéz-Maza
O
O
Fahey
J L
JL
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D015658:HIV Infections / Q000097:blood / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics
D012333:RNA, Messenger; D007371:Interferon-gamma