Interferon-gamma and tumour necrosis factor-alpha production by CD4+ T and CD8+ T lymphocytes in AIDS patients with tuberculosis.
Tuberculosis (TB) is usually more severe in HIV-infected patients, and the immune derangement found in co-infected patients may differ from that in each isolated disease. Following mitogen stimulation of peripheral blood mononuclear cells (PBMC), interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha production was evaluated in T cells by flow cytometry, and in culture supernatants by enzyme-linked immunosorbent assay (ELISA) in 33 individuals: 11 AIDS patients with tuberculosis, six asymptomatic HIV-1-infected patients, eight patients with tuberculosis and eight healthy controls. The proportion of CD4+ T lymphocytes expressing IFN-gamma did not differ between the groups, whereas a trend towards increased proportions of TNF-alpha-expression in CD4+ T cells was observed in the TB compared to the HIV group, while intermediate values were observed in co-infected patients. Detection of IFN-gamma and TNF-alpha in CD8+ T lymphocytes was higher in TB than in HIV individuals. Co-infected patients presented intermediate values for IFN-gamma, while TNF-alpha detection was similar to that in HIV mono-infection. In conclusion, the proportion of T cells expressing IFN-gamma was relatively preserved in co-infected patients compared to TB patients, while the percentage of T cells expressing TNF-alpha was decreased, mainly in CD8+ T lymphocytes. However, the marked reduction in T lymphocyte numbers in co-infected patients led to a striking reduction of both cytokines in PBMC supernatants, a finding that is consistent with the impaired response to Mycobacterium tuberculosis.
de Castro Cunha
R M
RM
Division of Infectious Diseases, Universidade Federal de Sao Paulo--UNIFESP, Sao Paulo, Brazil.
Kallas
E G
EG
Rodrigues
D S
DS
Nascimento Burattini
M
M
Salomao
R
R
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology; D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D018655:Lymphocyte Count / Q000379:methods; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000276:immunology
D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma