Expression of Fc_γ receptors on splenic T cells of mice infected with Plasmodium chabaudi adami

Abstract

In previous studies, it was shown that mice infected with Plasmodium chabaudi adami have a deficiency in their production of IgG1 immunoglobulin, suggesting isotype-specific immunoregulation. In order to examine this phenomenon in further detail the expression of Fc gamma receptors (Fc gamma R) on T cells obtained from mice infected with P. chabaudi was studied by flow cytometry. There was an increase in the number of splenic T cells which expressed Fc gamma R during infection. At the peak of the acute stage of infection (10-15 days) up to 40% of T cells were positive for Fc gamma R expression. These Fc gamma R were present on about 40% of both Lyt-2+ and L3T4+T cells. The isotype preference of these receptors on control Thy-1+ T cells is IgG1 greater than IgG2b greater than IgG2a as determined by an inhibition assay and fluorescence-activated cell sorter (FACS) analysis. However, 2 to 3 weeks after infection this pattern was altered such that IgG2b and IgG2a represented the major isotypes binding to the Fc gamma R of the L3T4+ T cell. At this stage of infection Fc gamma R on L3T4+ cells fail to bind IgG1. In the Lyt-2% T cells IgG1 and IgG2b remained the best inhibitors. These data suggest that there may be changes in Fc gamma R expression on T cells during infection reflected particularly in a decreased ability of IgG1 to bind to the Fc gamma R of L3T4+ cells.

Altered Immune Responses in Mice with ConcomitantSchistosoma mansoniandPlasmodium chabaudiInfections

“…The rapid decrease in anti-SEA IgG antibodies during the early inflammatory response could be due to a malaria-induced increase in Fc-␥ receptor expression, involved in the elimination of the antibodies from the circulation. Increased Fc-␥ receptor expression has been found in mice with bacterial, viral, and parasitic infections (41), in humans with P. falciparum malaria (17,42), and in mice with P. chabaudi adami infection (26). An alternative explanation could be a defect at the T-cell level.…”

CD4+ T cells and B cells are necessary for the transfer of protective immunity to Plasmodium chabaudi chabaudi

“…[23]). Staining of lymphocytes was carried out as described previously [24] and FCM analyses were performed on a FACScan (Becton Dickinson) using the FACScan software.…”

Roles of CD4- and CD8-bearing T lymphocytes in the immune response to the erythrocytic stages of Plasmodium chabaudi

“…FC analyses. FC analyses of lymph node and splenic cells of infected mice from each group were carried out essentially as described previously (28). Briefly, for single-parameter analyses, lymph node or splenic lymphocytes were incubated with fluorescein-labeled anti-Lyt-2, anti-Thy-1.2 (Becton Dickinson GmbH, Heidelberg, Federal Republic of Germany), or fluorescein-labeled goat anti-mouse immunoglobulin (a gift of B. J. Fowlkes, National Institutes of Health, Bethesda, Md.)…”