RESUMO
BACKGROUND: We previously reported that a Q5 gene product (Q5 antigen) on the surface of tumor cells caused humoral immune reaction in syngeneic tumor-bearing mice. Transcripts of the Q5 gene were observed in various tumor cells. The human counterpart of the Q5 gene has not been clarified yet. MATERIALS AND METHODS: Transcripts of human class Ib genes in various human tumor cell lines were analyzed by the RT-PCR method. Whether anti-HLA-F antibodies were present in sera from cancer patients was investigated through Western blotting with recombinant HLA-F as an antigen. RESULTS: Transcripts of the HLA-F gene were produced by various tumor cell lines. In addition, anti-HLA-F IgG was present in the sera derived from various types of cancer patients (26 positives / 42 tested), but not in the sera derived from healthy donors (0 / 20). CONCLUSION: Anti-HLA-F antibodies should be further investigated as possible diagnostic tumor markers.
Assuntos
Anticorpos Antineoplásicos/sangue , Antígenos HLA/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Neoplasias/imunologia , Adulto , Idoso , Sequência de Aminoácidos , Anticorpos Antineoplásicos/imunologia , Feminino , Expressão Gênica/imunologia , Genes MHC Classe I/genética , Células HeLa , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologiaRESUMO
The ex vivo priming and expansion of human CTL by APC, such as autologous monocyte-derived dendritic cells (DC), has the potential for use in immunotherapy for infectious diseases and cancer. To overcome the difficulty of obtaining sufficient number of autologous DC from patients, we have developed cell-based artificial APC (aAPC), designated Med-APC. These aAPC rapidly activate and expand the corresponding Ag-specific CD8+ T cells when pulsed with CTL epitope peptide(s) as efficiently as mature DC (mDC). We have also shown that Med-APC possess an innate cellular machinery that is sufficient to support the processing of complete Ag into immunodominant peptides, which considerably extends the usefulness of this technology. In addition, we have developed a novel expression vector system that expresses ubiquitinated Ag, resulting in an enhanced APC function of this system. Genetically encoded Ag can be easily introduced into Med-APC by transfection with this vector. Med-APC transfected with ubiquitinated Ag can efficiently expand the corresponding Ag-specific CTL without exogenous peptides. Therefore, Med-APC may have important therapeutic implications for adoptive immunotherapy and can be used for the detection of Ag-specific CTL for immunomonitoring.