RESUMO
A polyclonal CD3(+), CD8(+) T-cell line, G2, was derived from the peripheral blood of a seropositive, PCR-positive, HTLV-IIB infected Guahibo Indian from Venezuela. The cell line is productively infected with HTLV-IIB. The entire HTLV-II G2 proviral DNA was sequenced via PCR using overlapping HTLV-II primer pairs. Phylogenetic analyses indicate that HTLV-II G2 is the most divergent HTLV-IIB strain identified to date. Characterization of its deduced proteins and its relationship to other members of the PTLV/BLV genus of retroviruses are discussed.
Assuntos
Genoma Viral , Vírus Linfotrópico T Tipo 2 Humano/genética , Indígenas Sul-Americanos , Sequência de Aminoácidos , Células Cultivadas , DNA Viral/análise , Vírus Linfotrópico T Tipo 2 Humano/classificação , Vírus Linfotrópico T Tipo 2 Humano/isolamento & purificação , Humanos , Imunofenotipagem , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , VenezuelaRESUMO
We previously showed that T cells from chronic nonviremic HBsAg carriers activated with immobilized OKT3 MAb are hyperreactive to monocyte accessory signals, mainly to interleukin-6 (IL-6). We have further characterized this T cell hyperreactivity using phytohemagglutinin (PHA) as the primary activating signal. PHA-stimulated T cells from nonviremic patients had a significantly higher response to addition of monocytes, monocyte supernatants, and IL-6 alone or combined with IL-1 beta when compared to controls. We examined if these effects could be mediated by a differential expression of IL-6 receptor (p80) or gp130 on resting or PHA-stimulated T cells. We found that PHA, IL-6, IL-1 beta, or IL-2 induced only small changes of the dull p80 expression on T cells. In contrast, we found a significant increase of gp130 expression on PHA-activated T cells compared to unstimulated T cells, which was down-regulated by the presence of IL-6. However, no significant differences in p80 or gp130 expression were detected between patients and controls within all the culture conditions tested. Our results confirm that IL-6 is involved in the in vitro T cell hyperreactivity of nonviremic HBV carriers and indicate that this effect is not mediated by disturbances of IL-6 receptor expression.
Assuntos
Antígenos CD/imunologia , Portador Sadio/imunologia , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Interleucina-6/imunologia , Glicoproteínas de Membrana/imunologia , Receptores de Interleucina/imunologia , Linfócitos T/imunologia , Adulto , Divisão Celular , Células Cultivadas , Doença Crônica , Técnicas de Cocultura , Receptor gp130 de Citocina , Citocinas/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/citologia , Monócitos/imunologia , Fito-Hemaglutininas/farmacologia , Receptores de Interleucina-6 , Linfócitos T/efeitos dos fármacos , ViremiaRESUMO
Through a pilot study which includes a clinical, molecular and immunopathological approach to the chronic Hepatitis induced by HBV or by HCV, we determined that 66% of HBsAg carriers are in the "non viremic" phase. The positive HBeAg "viremic" carriers showed HBV-DNA quantitation which varies between > 50 pg to > 100 pg. Both types of carries are infected with the "wild" type HBV. Each subgroup of positive surface antigemia carriers demonstrated a differential immunopathological response. So far, 96% of the HCV carriers investigated, showed HCV-RNA associated to repeatedly positive anti-HCV antibodies. Those patients with increased ALT values uniformly expressed liver histopathological signs of inflammation caused by HCV; demonstrating also the presence of peripheral blood mononuclear cells infected with HCV. At the present, the genotypes investigation indicates a predominance of HCV genotype II (1b). Autoimmune phenomenons associated to HCV have been detected only in 3 patients. The therapeutic approach with interferon alpha applied to the HCV infection preliminary showed similar results to those reported worldwide. Currently, a comprehensive approach to the chronic HBV and chronic HCV infections requires the application of Immunochemistry, Molecular Biology and Cellular Immunology combined technologies.
Assuntos
Hepatite B , Hepatite C , Hepatite Crônica , Adulto , Protocolos Clínicos , DNA Viral/análise , Feminino , Seguimentos , Hepacivirus/genética , Hepatite B/diagnóstico , Hepatite B/terapia , Vírus da Hepatite B/genética , Hepatite C/diagnóstico , Hepatite C/terapia , Hepatite Crônica/diagnóstico , Hepatite Crônica/terapia , Humanos , Testes Imunológicos , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Projetos Piloto , RNA Viral/análise , Proteínas RecombinantesRESUMO
We analyzed T cell responses through the CD3 activation pathway in a group of chronic HBV carriers. PBMC stimulated with the mAb OKT3 showed higher proliferative response in HBV-DNA(-) carriers compared to HBV-DNA(+) carriers and to controls. In contrast, no differences in proliferative responses were observed between HBV-DNA(-) carriers and controls in cell cultures stimulated with immobilized 64.1 mAb (SPB-64.1) which induces proliferation in the absence of monocytes. We further examined T cell responses in the presence of monocytes and their soluble factors to immobilized OKT3 mAb (SPB-OKT3). Purified T cells did not proliferate to SPB-OKT3. When autologous monocytes were added, higher proliferative response, IL-2 production, and IL-2 receptor expression were observed in HBV-DNA(-) carriers than in controls. An enhanced cell proliferation was also obtained when monocyte supernatants were added to T cells cultured with SPB-OKT3. Moreover, when IL-6 alone or combined with IL-1 was added to SPB-OKT3-stimulated T cell cultures, a significantly higher increase in T cell proliferation was detected in HBV-DNA(-) carriers. Our results thus show a T cell hyperreactivity to accessory signals from monocytes (mainly IL-6) in HBV-DNA(-) carriers, that is probably related to an ongoing viral clearance.
Assuntos
Complexo CD3/fisiologia , Portador Sadio/imunologia , Hepatite B/imunologia , Monócitos/imunologia , Linfócitos T/imunologia , Adulto , DNA Viral/análise , Relação Dose-Resposta Imunológica , Feminino , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Humanos , Interleucina-2/biossíntese , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-Idade , Receptores de Interleucina-2/biossínteseRESUMO
Nonfractionated peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE) showed enhanced proliferative responses when stimulated via the CD3 pathway. In contrast, proliferative responses induced by phytohemagglutinin were diminished in SLE patients. Levels of CD3-induced interleukin-2 production and interleukin-2 receptor expression were comparable with normal levels. Highly purified T cells also showed augmented CD3 responses, but only in the presence of phorbol myristate acetate or a combination of phorbol myristate acetate plus calcium ionophore A23187, and not with calcium ionophore alone. The data suggest integrity of the T cell receptor/CD3 pathway for T cell activation in patients with SLE, as examined in cultures stimulated with specific anti-CD3 monoclonal antibodies rather than with multivalent lectins. An increased response via the CD3 complex could contribute to the autoimmune activity in human SLE.
Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Ativação Linfocitária , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/imunologia , Adolescente , Adulto , Anticorpos Monoclonais/farmacologia , Complexo CD3 , Divisão Celular , Humanos , Interleucina-2/biossíntese , Lúpus Eritematoso Sistêmico/metabolismo , Muromonab-CD3 , Receptores de Interleucina-2/metabolismo , Linfócitos T/metabolismo , Linfócitos T/patologiaRESUMO
We examined the effect of treatment with piroxicam, a nonsteroidal antiinflammatory drug (NSAID), on immunoglobulin (Ig) and IgM-rheumatoid factor (IgM-RF) synthesis in vitro by lymphocytes of patients with rheumatoid arthritis (RA). Oral treatment with piroxicam induced a progressive decrease of spontaneous IgM-RF production by unstimulated lymphocyte cultures during 12 weeks of observation. Also, pokeweed mitogen (PWM)-driven Ig synthesis was significantly diminished and the effect on total IgM production was sustained until the end of the study. This modulation of humoral responses is consistent with the drop in RF sera level. In addition, we also showed that treatment with NSAIDs can decrease RF levels in the synovial space. NSAIDs may have a long-term beneficial effect in patients with RA due to their modulatory role of lymphocyte responses.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Reumatoide/metabolismo , Imunoglobulina M/biossíntese , Imunoglobulinas/biossíntese , Fator Reumatoide/biossíntese , Administração Oral , Artrite Reumatoide/sangue , Células Cultivadas , Humanos , Imunoglobulina G/biossíntese , Leucócitos Mononucleares/metabolismo , Piroxicam/uso terapêutico , Mitógenos de Phytolacca americana/farmacologia , Líquido Sinovial/metabolismoRESUMO
In the present study we have examined the effect of human large granular lymphocytes (LGL) from healthy donors on Ig synthesis by autologous B lymphocytes. The results showed that this cell population has a consistent helper activity in pokeweed mitogen-activated cultures even when added at very low numbers. LGL can mediate their effect by secreting soluble helper factors capable of modulating B-cell responses as evidenced by the enhancement of IgG and IgM production by supernatants obtained from LGL cultures. Preincubation with interferon gamma further potentiated the helper activity by LGL.