Inhibition of T-cell responsiveness during experimental infections with Trypanosoma brucei: active involvement of endogenous gamma interferon.
Lymph node cells (LNC) from mice infected with Trypanosoma brucei contain macrophage-like cells that inhibit interleukin-2 receptor (IL-2R) expression (M. Sileghem, A. Darji, R. Hamers, M. Van De Winkel, and P. De Baetselier, Eur. J. Immunol. 19:829-835, 1989). Evidence that gamma interferon (IFN-gamma) is actively involved in (i) the inhibition of IL-2R expression and (ii) the generation of suppressive cells during infections with T. brucei is presented. First, despite an impaired T-cell mitogenic response, LNC from infected mice are hyperresponsive for IFN-gamma production. Second, addition of neutralizing anti-IFN-gamma antibodies to cocultures of normal LNC and suppressive LNC populations reduces the level of suppression and restores the level of IL-2R expression. Third, administration of anti-IFN-gamma to T. brucei-infected animals increases the blastogenic response and reduces the suppressive activity of LNC.
Laboratory of Cellular Immunology, University of Brussels, Belgium.
A
A
Darji
M
M
Sileghem
H
H
Heremans
L
L
Brys
P
P
De Baetselier
D000818:Animals; D007108:Immune Tolerance; D007371:Interferon-gamma / Q000502:physiology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D051381:Rats; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*; D014346:Trypanosoma brucei brucei; D014353:Trypanosomiasis, African / Q000276:immunology*
D015375:Receptors, Interleukin-2; D007371:Interferon-gamma