Abnormal intracellular IL-2 and interferon-gamma (IFN-gamma) production as HIV-1-assocated markers of immune dysfunction.
We used three-colour cytometry to analyse intracellular cytokine production in activated whole blood cultures derived from patients with HIV-1 infection. We assessed mitogen-induced IL-2, IL-4 and IFN-gamma production from T cells as possible markers of immune dysfunction. The percentages of T cells staining for IL-2 were significantly reduced in stimulated cultures from HIV+ individuals relative to normal controls (P<0.0001); this reduction was observed in both the CD4+ and the CD8+ subsets. IL-2 production was significantly reduced in CD4+ T cells from HIV+ individuals clinically classified as symptomatics compared with HIV+ asymptomatics (P<0.001); in addition, production of IL-2 inversely correlated with viral load (r2=0.832). On the other hand, HIV+ individuals showed significantly more T cells staining positive for IFN-gamma (P<0.0001); subset analysis identified these T cells as CD8+. Increased IFN-gamma production in the CD8+ T cell subset of HIV+ individuals correlated neither with clinical status nor with plasma viral load. IL-4 staining in activated T cells was low (<5%) and no differences were observed between HIV+ and control groups. Three-colour FACS analysis of whole blood provides a sensitive, rapid and relatively easy means to detect cytokine profiles within T cell subpopulations. Only small volumes of blood are required (0.5 ml), since there is no need for cell isolation, making it more practical than ELISA or reverse transcriptase-polymerase chain reaction (RT-PCR) for the analysis of immune function in HIV+ individuals. This technique could therefore play a role in mapping the dynamics and extent of immune recovery in AIDS patients undergoing triple combination therapy.
Westby
M
M
Division of Oncology, St George's Hospital Medical School, London, UK.
Marriott
J B
JB
Guckian
M
M
Cookson
S
S
Hay
P
P
Dalgleish
A G
AG
D000328:Adult; D015415:Biomarkers / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000097:blood* / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000097:blood; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000097:blood; D007424:Intracellular Fluid / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D013268:Stimulation, Chemical; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism / Q000821:virology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015415:Biomarkers; D007376:Interleukin-2; D012367:RNA, Viral; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate