Isolation of naturally processed peptides from a Toxoplasma gondii-infected human B lymphoma cell line that are recognized by cytotoxic T lymphocytes.
Naturally processed peptides derived from Toxoplasma gondii (T. gondii) were acid extracted from T. gondii-infected cells and detected by cytotoxic T lymphocytes (CTL) derived from peripheral blood lymphocytes of a patient with chronic toxoplasmosis. The CTL lines were obtained by weekly in vitro stimulation with a T. gondii-infected human B cell lymphoma line, ARH, which shares HLA-A2 and -Cw4 determinants with the patient. The lytic activity of these CTL lines against T. gondii-infected ARH and ARH pulsed with fraction 29 of a reversed-phase high-performance liquid chromatography (HPLC) extract from T. gondii-infected ARH was inhibited by an anti-HLA-A, B, C monoclonal antibody (mAb) and an anti-HLA-A2 mAb. Anti-HLA-DR mAb failed to block the lytic activity. Thus, the presentation of peptides by T. gondii-infected cells for CTL is mediated by HLA-A2 molecules. Interestingly, antigen presentation of ARH pulsed with naturally processed HPLC fraction 29 peptides was not inhibited by treatment with brefeldin A. The amino acid sequence of the HLA-A2-bound peptide in fraction 29 was in part consistent with the predictive algorithm of HLA-A2-binding peptide motifs.
Aosai
F
F
Department of Medical Zoology, Nagasaki University School of Medicine, Japan.
Yang
T H
TH
Ueda
M
M
Yano
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D000939:Epitopes / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D016393:Lymphoma, B-Cell / Q000469:parasitology* / Q000473:pathology; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000097:blood / Q000276:immunology; D014407:Tumor Cells, Cultured
D000953:Antigens, Protozoan; D000939:Epitopes; D015395:Histocompatibility Antigens Class I; D015800:Protozoan Proteins