Human T clones reactive to the sexual stages of plasmodium falciparum malaria. high frequency of gamete-reactive T cells in peripheral blood from nonexposed donors

Good, M.F.; Quakyi, I.A.; Saul, A.; Berzofsky, J.A.; Carter, R.; Miller, L.H.

Human T clones reactive to the sexual stages of plasmodium falciparum malaria. high frequency of gamete-reactive T cells in peripheral blood from nonexposed donors

Date

1987

Authors

Publisher

Journal of Immunology

Abstract

Malarial gametocytes, which are taken up by mosquitoes during a blood meal, develop in the gut of the mosquito into gametes. Gametes and gametocytes contain the target antigens of transmission-blocking immunity. Here, we show that the peripheral blood of nonexposed donors contains Plasmodium falciparum gamete-reactive T cells at frequencies ranging from 1/300 to 1/4000. Studies on long-term clones demonstrated that these cells often recognized antigens shared between gametes and asexual stage parasites or even between heterologous gametes, although it has been possible to derive a P. falciparum gamete-specific T clone. The T clones examined were T3+, T4+, T8-, and either HLA-DR- or HLA-DQ-restricted. They responded to gametes by both proliferation and the secretion of γ-interferon. The gamete-specific clone and other asexual cross-reactive clones examined could be stimulated in vitro by a preparation of mature gametocytes within RBC, but not by RBC alone, suggesting that gametocytes are immunogenic or can become immunogenic for T cells in vivo. The significance of these observations to mosquito transmission of malaria and development and application of a gamete vaccine are discussed.

Keywords

EMTREE drug terms: gamma interferon; monoclonal antibody; parasite antigen; vaccine, EMTREE medical terms: animal cell; blood and hemopoietic system; chicken; gamete; gametocyte; human; lymphocyte proliferation; malaria; mosquito; normal human; plasmodium falciparum; plasmodium gallinaceum; priority journal; protozoon; t lymphocyte, MeSH: Adult; Animals; Antigen-Presenting Cells; Antigens, Differentiation, T-Lymphocyte; Antigens, Protozoan; Antigens, Surface; Clone Cells; Epitopes; Germ Cells; HLA Antigens; Humans; Lymphocyte Activation; Lymphokines; Plasmodium falciparum; T-Lymphocytes

Citation

Good, M. F., Quakyi, I. A., Saul, A., Berzofsky, J. A., Carter, R., & Miller, L. H. (1987). Human T clones reactive to the sexual stages of plasmodium falciparum malaria. high frequency of gamete-reactive T cells in peripheral blood from nonexposed donors. Journal of Immunology, 138(1), 306-311