RESUMO
The objectives of this study were to activate human colonic intraepithelial lymphocytes at the transcriptional level with HLA-DR+ human colonic epithelial cell line (HT29) in synergy with CD3 monoclonal antibody and to investigate the molecular mechanism for the therapeutic effects of 5-aminosalicylic acid. Lymphocytes were isolated by a mechanical method from resected colon of 22 cases and then cocultured on 10 ng/ml CD3mAb immobilized plates with HT29 which had been induced to express MHC class II molecules by interferon gamma. Flow cytometry analysis suggested that the lymphocyte population had a CD4/CD8 ratio similar to that observed in intact tissue sections and that there was no HT29 contamination of the lymphocytes isolated again from cocultured cells. The activation of intraepithelial lymphocytes showed the gene transcription of interferon gamma and tumor necrosis factor alpha, as measured by means of the reverse-transcriptase polymerase chain reaction, and this activation was antagonized by 5-aminosalicylic acid. Thus, epithelial cells bearing HLA-DR are capable of enhancing CD3-induced activation of human colonic intraepithelial lymphocytes and subject to inhibition by 5-aminosalicylic acid, the active moiety of salicylates used in inflammatory bowel disease.
Assuntos
Ácidos Aminossalicílicos/farmacologia , Citocinas/efeitos dos fármacos , Antígenos HLA-DR/metabolismo , Linfócitos/metabolismo , Actinas/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios não Esteroides/farmacologia , Sequência de Bases , Técnicas de Cocultura , Colite Ulcerativa/imunologia , Colo/citologia , Doença de Crohn/imunologia , Citocinas/genética , Epitélio/fisiologia , Feminino , Regulação da Expressão Gênica , Antígenos HLA-DR/efeitos dos fármacos , Humanos , Interferon gama/análise , Interferon gama/farmacologia , Linfócitos/efeitos dos fármacos , Masculino , Mesalamina , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/análiseRESUMO
Human colonic intraepithelial lymphocytes from control subjects down-regulate the proliferative responses of primed allogeneic peripheral blood mononuclear cells on rechallenge with antigens or phytohaemagglutinin (PHA). In contrast, human colonic intraepithelial lymphocytes from patients with inflammatory bowel disease fail to down-regulate the proliferative responses of primed allogeneic peripheral blood mononuclear cells on rechallenge with antigens. These findings may be important in the development and maintenance of the mucosal immunological activation of inflammatory bowel disease.
Assuntos
Antígenos de Bactérias/imunologia , Colo/imunologia , Doenças Inflamatórias Intestinais/imunologia , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Toxoide Tetânico/imunologia , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Colite Ulcerativa/imunologia , Colo/patologia , Doença de Crohn/imunologia , Regulação para Baixo/imunologia , Epitélio/imunologia , Feminino , Humanos , Mucosa Intestinal/imunologia , Masculino , Pessoa de Meia-Idade , Fito-Hemaglutininas/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
Human colonic intraepithelial lymphocytes have been shown to suppress the proliferation of autologous lamina propria lymphocytes and allogeneic peripheral blood mononuclear cells. This study has shown that, in vitro, intraepithelial lymphocytes suppress IgA and total immunoglobulin synthesis (but not IgG or IgM production) by autologous peripheral blood and lamina propria lymphocytes. This down regulation of IgA production is mediated by a soluble factor secreted by the intraepithelial lymphocytes. There is no difference in immunoglobulin down regulation by intraepithelial lymphocytes of control subjects and patients with inflammatory bowel disease.