RESUMO
BACKGROUND: Several evidences indicate that hormones and neuropeptides function as immunomodulators. Among these, growth hormone (GH) is known to act on the thymic microenvironment, supporting its role in thymocyte differentiation. The aim of this study was to evaluate the effect of GH on human thymocytes and thymic epithelial cells (TEC) in the presence of laminin. RESULTS: GH increased thymocyte adhesion on BSA-coated and further on laminin-coated surfaces. The number of migrating cells in laminin-coated membrane was higher in GH-treated thymocyte group. In both results, VLA-6 expression on thymocytes was constant. Also, treatment with GH enhanced laminin production by TEC after 24 h in culture. However, VLA-6 integrin expression on TEC remained unchanged. Finally, TEC/thymocyte co-culture model demonstrated that GH elevated absolute number of double-negative (CD4-CD8-) and single-positive CD4+ and CD8+ thymocytes. A decrease in cell number was noted in double-positive (CD4+CD8+) thymocytes. CONCLUSIONS: The results of this study demonstrate that GH is capable of enhancing the migratory capacity of human thymocytes in the presence of laminin and promotes modulation of thymocyte subsets after co-culture with TEC.
Assuntos
Humanos , Recém-Nascido , Lactente , Pré-Escolar , Criança , Timo/citologia , Hormônio do Crescimento/farmacologia , Laminina/biossíntese , Células Epiteliais/efeitos dos fármacos , Timócitos/efeitos dos fármacos , Valores de Referência , Timo/metabolismo , Fatores de Tempo , Imuno-Histoquímica , Linfócitos T CD4-Positivos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Análise de Variância , Laminina/efeitos dos fármacos , Linfócitos T CD8-Positivos , Técnicas de Cocultura , Integrina alfa6beta1/análise , Integrina alfa6beta1/metabolismo , Citometria de Fluxo/métodosRESUMO
This study investigated the possible relationship between the invasiveness of group A