Identification and characterization of T cell-stimulating antigens from Leishmania by CD4 T cell expression cloning.
Persistent immunity against Leishmania: infections in humans is mediated predominantly by CD4(+) T cells of the Th1 phenotype. Herein we report the expression cloning of eight Leishmania: Ags using parasite-specific T cell lines derived from an immune donor. The Ags identified by this technique include the flagellar proteins alpha- and beta-tubulin, histone H2b, ribosomal protein S4, malate dehydrogenase, and elongation factor 2, as well as two novel parasite proteins. None of these proteins have been previously reported as T cell-stimulating Ags from Leishmania: beta-tubulin-specific T cell clones generated against Leishmania: major amastigotes responded to Leishmania:-infected macrophages and dendritic cells. IFN-gamma enzyme-linked immunospot analysis demonstrated the presence of T cells specific for several of these Ags in PBMC from self-healing cutaneous leishmaniasis patients infected with either Leishmania: tropica or L. major. The responses elicited by Leishmania: histone H2b were particularly striking in terms of frequency of histone-specific T cells in PBMC (1 T cell of 6000 PBMC) as well as the percentage of responding donors (86%, 6 of 7). Ags identified by T cells from immune donors might constitute potential vaccine candidates for leishmaniasis.
Probst
P
P
Corixa Corporation, Seattle, WA 98104, USA. jwebb@uottawa.ca
Stromberg
E
E
Ghalib
H W
HW
Mozel
M
M
Badaro
R
R
Reed
S G
SG
Webb
J R
JR
D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D010582:Bacteriophage lambda / Q000235:genetics / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism* / Q000469:parasitology; D002460:Cell Line; D002999:Clone Cells; D003001:Cloning, Molecular / Q000379:methods*; D003713:Dendritic Cells / Q000276:immunology / Q000469:parasitology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015723:Gene Library; D006657:Histones / Q000276:immunology / Q000378:metabolism; D006801:Humans; D018320:Leishmania major / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D007895:Leishmania tropica / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000469:parasitology; D008213:Lymphocyte Activation / Q000235:genetics; D008264:Macrophages / Q000276:immunology / Q000469:parasitology; D008291:Malate Dehydrogenase / Q000276:immunology / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000469:parasitology; D014404:Tubulin / Q000276:immunology / Q000378:metabolism
D000953:Antigens, Protozoan; D018984:Epitopes, T-Lymphocyte; D006657:Histones; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D008291:Malate Dehydrogenase