Identification and Characterization of T Cell-Stimulating Antigens from Leishmania by CD4 T Cell Expression Cloning

• Published in: The Journal of immunology (1950) Vol. 166; no. 1; pp. 498 - 505
• Main Authors: Probst, Peter, Stromberg, Erika, Ghalib, Hashim W, Mozel, Michelle, Badaro, Roberto, Reed, Steven G, Webb, John R
• Format: Journal Article
• Language: English
• Published: United States Am Assoc Immnol 01.01.2001
• Subjects: Animals; Antigens, Protozoan - chemistry; Antigens, Protozoan - genetics; Antigens, Protozoan - immunology; Antigens, Protozoan - isolation & purification; Bacteriophage lambda - genetics; Bacteriophage lambda - immunology; CD4 antigen; CD4-Positive T-Lymphocytes - cytology; CD4-Positive T-Lymphocytes - immunology; CD4-Positive T-Lymphocytes - metabolism; CD4-Positive T-Lymphocytes - parasitology; Cell Line; Clone Cells; Cloning, Molecular - methods; Dendritic Cells - immunology; Dendritic Cells - parasitology; Epitopes, T-Lymphocyte - immunology; Gene Library; Histones - immunology; Histones - metabolism; Humans; Leishmania; Leishmania major - genetics; Leishmania major - growth & development; Leishmania major - immunology; Leishmania tropica - genetics; Leishmania tropica - growth & development; Leishmania tropica - immunology; Leishmaniasis, Cutaneous - immunology; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - parasitology; Lymphocyte Activation - genetics; Macrophages - immunology; Macrophages - parasitology; Malate Dehydrogenase - immunology; Malate Dehydrogenase - metabolism; Male; Molecular Sequence Data; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - immunology; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - parasitology; Tubulin - immunology; Tubulin - metabolism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.166.1.498

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.