RESUMO
In this work we eluted peptides from purified class I MHC molecules, isolated from a novel human cervical carcinoma cell line (INBL), generated in our laboratory and positive for HPV-18 infection. A fraction of these peptides was capable of stimulating T lymphocytes obtained from a donor matched for HLA-Cw4 and who was also HPV-18+. Direct N-terminal Edman degradation of these peptides, revealed the sequence (XQFPIFLQF) that matched 85% with the sequence NVFPIFLQM localized in between the 54 and 62 residues of the HPV-18 L1 protein. After stimulation with the synthetic peptide NVFPIFLQM, T lymphocytes from the donor were capable to lyse INBL cells. Our results provide evidence of the existence of naturally occurring viral epitopes presented on cervical cancer cells by the HLA-Cw4 allele, that could be useful for immunotherapy on this type of patient.
Assuntos
Antígenos de Histocompatibilidade Classe I/imunologia , Papillomaviridae/imunologia , Peptídeos/imunologia , Neoplasias do Colo do Útero/virologia , Proteínas Virais/imunologia , Sequência de Aminoácidos , Antígenos Virais/química , Antígenos Virais/imunologia , Citotoxicidade Imunológica , Epitopos/imunologia , Feminino , Antígenos de Histocompatibilidade Classe I/química , Humanos , Ativação Linfocitária , Espectrometria de Massas , Dados de Sequência Molecular , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Peptídeos/química , Peptídeos/isolamento & purificação , Linfócitos T/imunologia , Células Tumorais Cultivadas , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia , Neoplasias do Colo do Útero/imunologia , Proteínas Virais/química , Proteínas Virais/isolamento & purificaçãoRESUMO
In the search for the pathogenic consequences of the molecular mimicry between the Klebsiella pneumoniae nitrogenase and the HLA-B27 antigen, sera from individuals belonging to 16 kindreds with juvenile-onset ankylosing spondylitis cases, were analyzed for antibodies against nitrogenase-positive and -negative K. pneumoniae whole bacterial extracts. An initial screening for nitrogenase producing K. pneumoniae strains was performed in 31 clinical isolates. The best nitrogenase producing strain was selected as well as a non producing one for immunoblot analysis using sera from 82 subjects, 55 HLA-B27 positive, of which 26 had some clinical manifestations. Even though electrophoretic patterns were different in both strains, there was no distinctive differential recognition of the 30-40 kDa proteins where the nitrogenase subcomponent which shares the sequence QTDRED with the HLA-B27 molecule is located. On the other hand, strong recognition of a protein of 60 kDa (p60Kp) was detected in 75% of HLA-B27 positive tested subjects independently of their clinical status. Studies on the nature of this protein and its participation in the pathogenesis of ankylosing spondylitis are now in progress.