Heat shock cognate protein 71-associated peptides function as an epitope for Toxoplasma gondii-specific CD4+ CTL.
HLA-DR-restricted CD4+ cytotoxic T-lymphocyte (CTL) lines specific for Toxoplasma gondii (T. gondii)-infected melanoma cells have been established from peripheral blood lymphocytes (PBLs) of a patient with chronic toxoplasmosis. The role of heat shock cognate protein (HSC) 71 in antigen (Ag) processing and presentation of T. gondii-infected melanoma cells to these CD4+ CTL lines was investigated. A human melanoma cell line (P36) pulsed with T. gondii-infected P36 cell-derived HSC71 was lysed by a T. gondii-specific CD4+ CTL line (Tx-HSC-1). The Tx-HSC-1 also killed T. gondii-infected P36 cells. The lytic activity of Tx-HSC-1 against P36 cells pulsed with T. gondii-infected P36 cell-derived HSC71 was inhibited by monoclonal antibodies (mAbs) against HSC71. Anti-human leukocyte antigen (HLA)-DR mAb also partially blocked the lytic activity, whereas anti-HLA-A,B,C mAb did not block the lytic activity. In addition, a flow cytometric analysis with these specific mAbs against HSC71 showed HSC71 to be expressed on the cell surface of T. gondii-infected P36 cells as well as uninfected P36 cells. These data indicate that HSC71 molecules are expressed on human melanoma cell line P36, and that HSC71 may play a potential role in Ag presentation and processing of T. gondii-infected P36 cells to CD4+ CTL.
Yang
T H
TH
Department of Parasitology, Chiba University School of Medicine, Chiba, Japan.
Aosai
F
F
Norose
K
K
Mun
H S
HS
Yano
A
A
D000818:Animals; D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000913:Antibodies, Protozoan / Q000276:immunology; D017951:Antigen Presentation; D015704:CD4 Antigens / Q000276:immunology*; D003001:Cloning, Molecular; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology*; D005434:Flow Cytometry; D015870:Gene Expression; D006680:HLA Antigens / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000276:immunology; D011995:Recombination, Genetic; D013601:T-Lymphocytes / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology*; D014407:Tumor Cells, Cultured
D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D015704:CD4 Antigens; D000939:Epitopes; D006680:HLA Antigens; D018840:HSP70 Heat-Shock Proteins; D011994:Recombinant Proteins