Chlamydia pneumoniae genome sequence analysis and identification of HLA-A2-restricted CD8+ T cell epitopes recognized by infection-primed T cells.
In the present study, we performed in silico analysis of Chlamydia pneumoniae genome sequence to identify human HLA-A2-restricted T cell epitopes. Thirty-one Chlamydia-specific protein antigens were selected and peptides were derived thereof using an HLA-A2 epitope predictive algorithm. Firstly, we tested binding of 55 selected 9mer peptides to HLA-A2 in vitro. Next, infection of HLA-A2 transgenic mice with C. pneumoniae elementary bodies and assessment of effector CD8+ T cells allowed us to identify which of the epitopes binding to HLA-A2 in vitro were recognized by C. pneumoniae infection-primed CD8+ T cells. Finally, we could confirm that CD8+ T cells in association with HLA-A2 recognized the most reactive peptides when the corresponding full-length genes were used to DNA-immunize HLA-A2 transgenic mice. By using this approach, a novel HLA-A2-restricted epitope in the outer membrane protein A (OmpA) of C. pneumoniae was identified, which proved to mediate specific lysis of peptide-loaded target cells.
Chiron Vaccines, Via Fiorentina 1, 53100 Siena, Italy.
Sabrina
S
Capo
Sandra
S
Nuti
Maria
M
Scarselli
Simona
S
Tavarini
Silvia
S
Montigiani
Elena
E
Mori
Oretta
O
Finco
Sergio
S
Abrignani
Guido
G
Grandi
Giuliano
G
Bensi
D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D045744:Cell Line, Tumor; D016993:Chlamydophila pneumoniae / Q000235:genetics* / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic; D004269:DNA, Bacterial; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D005434:Flow Cytometry; D016680:Genome, Bacterial; D015789:HLA-A2 Antigen / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D051379:Mice; D008822:Mice, Transgenic; D023421:Models, Animal; D010455:Peptides / Q000276:immunology; D011485:Protein Binding; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology
D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D010455:Peptides; D019444:Vaccines, DNA; C078167:OMPA outer membrane proteins; D007371:Interferon-gamma