Gammadelta+ T cells preferentially respond to live rather than killed malaria parasites.
We have compared the in vitro responses of peripheral blood T cells from malaria-unexposed donors to live Plasmodium falciparum schizonts, freeze-thawed schizont extracts (P. falciparum schizont extracts [PfSE]), and parasite culture supernatants. We show that the cells responding to PfSE and parasite culture supernatants are predominantly CD4+ TCR alphabeta+ while in the presence of live schizonts there is an additional activation of TCR gammadelta+ cells. Activation of TCR gammadelta+ cells in response to PfSE was seen only when irradiated autologous feeder cells or recombinant interleukin-2 (IL-2) was added to the cultures. Live schizonts but not PfSE induced significant IL-2 production in vitro in the first 5 days after stimulation, suggesting that induction of early IL-2 by live parasites may contribute to the marked activation of the TCR gammadelta+ population.
Waterfall
M
M
Institute of Cell, Animal and Population Biology, Ashworth Laboratories, University of Edinburgh, United Kingdom.
Black
A
A
Riley
E
E
D000818:Animals; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis / Q000494:pharmacology; D008213:Lymphocyte Activation; D017780:Malaria Vaccines / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology*
D007376:Interleukin-2; D017780:Malaria Vaccines; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta