Somatostatin modulates T cells development in adult rat thymus

It is well known that somatostatin modulates thymic functions, such as binding to receptors. In order to elucidate the influence of somatostatin on the thymus architecture and the T cells maturation, young adult male rats were treated with somatostatin-28. The results showed that somatostatin-28 decreased thymus weight and cellularity, probably due to alterations in the thymic morphometric parameters. Our results also demonstrated that SRIH treatment reduces number of cells with undetectable αβTCR and cells with low expression of αβTCR, while the number of TCRαβ hi cells remains approximately the same as the values obtained from the control rats. Besides, in the least mature thymocytes (DNTCR TCRαβ −) and among the most mature the SPCD4 TCRαβ hi subset remained unaltered, while SPCD8 TCRαβ hi decreased. At last, it should be noted that SRIH treatment increases DN thymocytes subsets expressing TCRαβ low/hi (TCRαβ +). These results suggest that somatostatin-28 induces reshaping of T cells maturation and, at least partly, contributes to thymic weight loss, through the modulation of the complex neuroendocrine–immune network.