These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Plasmodium yoelii in mice: antigen reactivity of CD4- and CD8-bearing T cells.
    Author: Lucas B, Engel A, Camus D, Haque A.
    Journal: Cell Immunol; 1993 Aug; 150(1):59-71. PubMed ID: 8102089.
    Abstract:
    Mice infected with Plasmodium yoelii (265 BY, a nonlethal strain) after recovering from parasitemia become resistant to reinfection. In the present study, we have attempted to define the role of T cell subsets in primary vs secondary P. yoelii infection. We have evaluated the in vivo effects of selective depletion of each subset of T cells on the course of infection and also investigated the in vitro expansion of each subset in response to homologous antigen. Depletion of CD4- or CD8-bearing T cells did not result in reappearance of parasitemia in animals cured from primary infection. However, 25% of reinfected animals treated with anti-CD4 mAb, but not with anti-CD8 mAb, displayed a low level (2 to 3%) of parasitemia late in the secondary infection. The splenocyte response to P. yoelii antigen or to T-cell mitogens was impaired during patient infection, even in the 25% of CD4-depleted animals with low parasitemia. A markedly high lymphocyte reactivity to antigen was observed in mice recovered from primary infection, and this was enhanced in animals exposed to a challenge infection. In the case of animals cured from primary infection, a marked decrease in antigen-induced in vitro lymphocyte proliferation occurred in CD8-depleted but not in CD4-depleted animals when total splenic cell populations were assayed. Although less dramatic, a significant diminution in antigen reactivity was observed also with T-rich populations in CD8-depleted animals. In contrast, there was no such decrease in CD4-depleted mice. Treatment of resistant animals which were challenged with a second infection, with anti-CD4 or anti-CD8 mAbs, resulted in a significant decrease in the proliferative response to antigen by both T-rich and total cell populations. In the secondary infection, the T-rich cell populations from CD8-depleted mice responded better to P. yoelii antigen than the total cell populations, indicating an inhibitory role on the expansion of CD4+ T cells of B cells or their product(s) which were removed during T cell enrichment. The results of our study suggest that CD8-bearing T cells were more reactive in the primary infection. In the secondary infection, although both CD8+ and CD4+ T cells were antigen reactive, the latter T cell subset appeared to play a superior role in controlling the parasitemia.
    [Abstract] [Full Text] [Related] [New Search]