Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 3: 3232, 2013 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-24240815

RESUMO

Epstein-Barr virus (EBV) is a gamma herpesvirus that causes a life-long latent infection in human hosts. The latent gene products LMP1, LMP2A and EBNA1 are expressed by EBV-associated tumors and peptide epitopes derived from these can be targeted by CD8 Cytotoxic T-Lymphocyte (CTL) lines. Whilst CTL-based methodologies can be utilized to infer the presence of specific latent epitopes, they do not allow a direct visualization or quantitation of these epitopes. Here, we describe the characterization of three TCR-like monoclonal antibodies (mAbs) targeting the latent epitopes LMP1(125-133), LMP2A(426-434) or EBNA1(562-570) in association with HLA-A0201. These are employed to map the expression hierarchy of endogenously generated EBV epitopes. The dominance of EBNA1(562-570) in association with HLA-A0201 was consistently observed in cell lines and EBV-associated tumor biopsies. These data highlight the discordance between MHC-epitope density and frequencies of associated CTL with implications for cell-based immunotherapies and/or vaccines for EBV-associated disease.


Assuntos
Anticorpos Monoclonais/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Latência Viral/imunologia , Animais , Antígenos Virais/imunologia , Linhagem Celular Tumoral , Antígenos Nucleares do Vírus Epstein-Barr/imunologia , Antígeno HLA-A2/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas da Matriz Viral/imunologia
2.
J Lipid Res ; 54(10): 2924-32, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23797850

RESUMO

Tuberculosis is a major cause of mortality and morbidity due to infectious disease. However, current clinical diagnostic methodologies such as PCR, sputum culture, or smear microscopy are not ideal. Antibody-based assays are a suitable alternative but require specific antibodies against a suitable biomarker. Mycolic acid, which has been found in patient sputum samples and comprises a large portion of the mycobacterial cell wall, is an ideal target. However, generating anti-lipid antibodies using traditional hybridoma methodologies is challenging and has limited the exploitation of this lipid as a diagnostic marker. We describe here the isolation and characterization of four anti-mycolic acid antibodies from a nonimmune antibody phage display library that can detect mycolic acids down to a limit of 4.5ng. All antibodies were specific for the methoxy subclass of mycolic acid with weak binding for α mycolic acid and did not show any binding to closely related lipids or other Mycobacterium tuberculosis (Mtb) derived lipids. We also determined the clinical utility of these antibodies based on their limit of detection for mycobacteria colony forming units (CFU). In combination with an optimized alkaline hydrolysis method for rapid lipid extraction, these antibodies can detect 10(5) CFU of Mycobacterium bovis BCG, a close relative of Mtb and therefore represent a novel approach for the development of diagnostic assays for lipid biomarkers.


Assuntos
Anticorpos Antibacterianos/química , Ácidos Micólicos/imunologia , Tuberculose Pulmonar/diagnóstico , Anticorpos Antibacterianos/biossíntese , Especificidade de Anticorpos , Biomarcadores/metabolismo , Técnicas de Visualização da Superfície Celular , Ensaio de Imunoadsorção Enzimática , Células HEK293 , Humanos , Limite de Detecção , Mycobacterium bovis/metabolismo , Mycobacterium smegmatis/metabolismo , Ácidos Micólicos/isolamento & purificação , Ácidos Micólicos/metabolismo , Ligação Proteica , Tuberculose Pulmonar/metabolismo
3.
J Virol ; 87(5): 2693-706, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23255803

RESUMO

Dengue virus (DENV) is the principal arthropod-borne viral pathogen afflicting human populations. While repertoires of antibodies to DENV have been linked to protection or enhanced infection, the role of T lymphocytes in these processes remains poorly defined. This study provides a comprehensive overview of CD4(+) and CD8(+) T cell epitope reactivities against the DENV 2 proteome in adult patients experiencing secondary DENV infection. Dengue virus-specific T cell responses directed against an overlapping 15mer peptide library spanning the DENV 2 proteome were analyzed ex vivo by enzyme-linked immunosorbent spot assay, and recognition of individual peptides was further characterized in specific T cell lines. Thirty novel T cell epitopes were identified, 9 of which are CD4(+) and 21 are CD8(+) T cell epitopes. We observe that whereas CD8(+) T cell epitopes preferentially target nonstructural proteins (NS3 and NS5), CD4(+) epitopes are skewed toward recognition of viral components that are also targeted by B lymphocytes (envelope, capsid, and NS1). Consistently, a large proportion of dengue virus-specific CD4(+) T cells have phenotypic characteristics of circulating follicular helper T cells (CXCR5 expression and production of interleukin-21 or gamma interferon), suggesting that they are interacting with B cells in vivo. This study shows that during a dengue virus infection, the protein targets of human CD4(+) and CD8(+) T cells are largely distinct, thus highlighting key differences in the immunodominance of DENV proteins for these two cell types. This has important implications for our understanding of how the two arms of the human adaptive immune system are differentially targeted and employed as part of our response to DENV infection.


Assuntos
Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Vírus da Dengue/imunologia , Dengue/imunologia , Epitopos de Linfócito T/imunologia , Adulto , Proteínas do Capsídeo/imunologia , Células Cultivadas , Feminino , Humanos , Interferon gama/biossíntese , Interleucinas/biossíntese , Masculino , Pessoa de Meia-Idade , Proteoma/imunologia , RNA Helicases/imunologia , Receptores CXCR5/biossíntese , Serina Endopeptidases/imunologia , Proteínas do Envelope Viral/imunologia , Proteínas não Estruturais Virais/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...