The effects of interleukin-15 on human gammadelta T cell responses to Plasmodium falciparum in vitro.
We observed that the gammadelta T cell subset expands when human peripheral blood mononuclear cells (PBMC) from malaria-naive donors are cultured with Plasmodium falciparum lysate in the presence of IL-2 or IL-15, cytokines that utilize two common IL-2 receptor subunits. IL-15 induced the expansion of the gammadelta T cell subset at all levels tested, whereas IL-2 was not stimulatory at high levels. Flow cytometric analysis of apoptosis using the TUNEL assay indicated that the percentage and absolute number of gammadelta T cells undergoing apoptosis were greater in cultures stimulated with antigen and IL-2 than in cultures stimulated with either antigen and IL-15 or control erythrocyte lysate and IL-2. The ability of IL-15 to enhance gammadelta T cell function was also assessed; the results suggest that IL-15 can function with IL-2 to enhance the capacity of gammadelta T cells to inhibit parasite replication. Together these data indicate that IL-2 and IL-15, which both bind to IL-2Rbeta and IL-2R(gamma)c, enhance gammadelta T cell function, but they appear to have different effects on proliferation and survival.
Elloso
M M
MM
Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison 53706, USA.
Wallace
M
M
Manning
D D
DD
Weidanz
W P
WP
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D017209:Apoptosis; D002478:Cells, Cultured; D004912:Erythrocytes / Q000469:parasitology; D005434:Flow Cytometry; D006801:Humans; D020287:In Situ Nick-End Labeling; D019409:Interleukin-15 / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D010963:Plasmodium falciparum / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000502:physiology
D000953:Antigens, Protozoan; D019409:Interleukin-15; D007376:Interleukin-2; D016692:Receptors, Antigen, T-Cell, gamma-delta