Cytokine profile and immunomodulation in asymptomatic human T-lymphotropic virus type 1-infected blood donors.
The modulation of the immune response has been used as therapy for clinical disorders associated with human T-lymphotropic virus type 1 (HTLV-1) infection. In this study, the cytokine profile was evaluated in 26 asymptomatic HTLV-1 blood donors. Additionally, both the cell responsible for producing interferon-gamma (IFN-gamma) and the role of exogenous interleukin (IL)-10 in downregulating IFN-gamma production were studied. Cytokine levels were determined in supernatants of unstimulated lymphocyte cultures by enzyme-linked immunosorbent assay. The levels of IFN-gamma, tumor necrosis factor-alpha, IL-5, and IL-10 were higher in supernatants of the lymphocyte cultures taken from HTLV-1-infected donors than in those taken from healthy subjects. Although depletion of CD8+ T cells and natural killer cells did not affect IFN-gamma production, depletion of CD4+ T cells significantly decreased IFN-gamma production. Furthermore, at a concentration of 2 ng/ml, IL-10 had only a minimum effect on IFN-gamma production, although at high concentrations (100 ng/ml), IL-10 decreased IFN-gamma production by 50% in HTLV-1-infected individuals. These data indicate that both T helper 1 and T helper 2 cytokines are elevated in HTLV-1 infection and that IL-10 in high concentrations modulates IFN-gamma production in these patients.
Carvalho
E M
EM
Serviço de Imunologia, Hospital Universitário Prof. Edgard Santos, Universidade Federal da Bahia, Salvador, Bahia, Brazil. immuno@ufba.br
Bacellar
O
O
Porto
A F
AF
Braga
S
S
Galvão-Castro
B
B
Neva
F
F
D000328:Adult; D001782:Blood Donors; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D015481:HTLV-I Antibodies / Q000097:blood; D015490:HTLV-I Infections / Q000276:immunology*; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D008875:Middle Aged
D016207:Cytokines; D015481:HTLV-I Antibodies; D007371:Interferon-gamma