Activation of CD4+ and CD8+ parasite -specific T-cells by macrophages infected with live T. cruzi amastigotes.
T. cruzi-infected macrophages are potential candidates for the presentation of parasite antigens to T. cruzi-specific T lymphocytes. To assess this question, we examine the ability of peritoneal exudate macrophages to process exogenous live or dead parasites and to activate defined populations of T. cruzi-specific immune T-cells. Macrophages infected with live amastigotes activated both lymph node CD4+ and spleen CD8 + T-primed cells that proliferated and secreted cytokines. Lymph node CD4+ T-cells produced IFN-gamma and IL-10 while CD8 + T-cells produced IFN-gamma. In contrast, macrophages pulsed with dead parasites activated only lymph node CD4+ T-cells, which proliferated and secreted IFN-gamma. Interestingly, the immunization with heat-killed parasites primed mice for CD8+ T-cells which were expanded in vitro by recognition of infected macrophages. Taken together, these results demonstrated that amastigote infected macrophages present parasite peptides associated with MHC I and II molecules, activating both CD4 + and CD8+ T-cells. Furthermore, the development of T. cruzi-specific CD8+ T-cells in vivo using the immunization protocol with non-living parasites as described in this report could be explored for further studies on the role of CTL in the outcome of infection.
Caulada-Benedetti
Z
Z
Departamento de Immunologia, Instituto de Ciências Biomédicas, Edifico Biomédicas IV, Cidade Universitária, Universidade de São Paulo, SP, Brazil. caulada@ibm.net
Vecchio
L C
LC
Pardi
C C
CC
Massironi
S M
SM
D'Império Lima
M R
MR
Abrahamsohn
I A
IA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017951:Antigen Presentation / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000469:parasitology; D000953:Antigens, Protozoan / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D016827:CD8 Antigens / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology*; D007371:Interferon-gamma / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000469:parasitology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D012680:Sensitivity and Specificity; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan; D015704:CD4 Antigens; D016827:CD8 Antigens; D007378:Interleukins; D007371:Interferon-gamma