Granuloma T lymphocytes in murine schistosomiasis mansoni have somatostatin receptors and respond to somatostatin with decreased IFN-gamma secretion.

摘要: The granulomas of mice infected with Schistosoma mansoni for 8 wk have macrophages that secrete somatostatin 1-14 (SOM). Within the granuloma, SOM has no known function. To uncover possible significance produced within this granulomatous inflammation, we sought receptors on distinct cellular components granuloma to identify cells targeted action. [125I]SOM bound dispersed inflammatory specifically and reversibly. Scatchard analysis suggested one receptor type (kDa 4.28 x 10(-9) M). Octreotide, a stable derivative, displaced radioligand 1.01 10(-10) M), but 1-28, substance P, vasoactive intestinal peptide did not. localized exclusively subset CD4+ T lymphocytes. Using IL-5 IFN-gamma ELISA, it was shown can appreciable when stimulated Ag or mitogen. Both octreotide at concentrations as low M substantially decreased secretion from mitogen-stimulated cells, high 10(-6) not affect production. Octreotide administered animals in vivo intensity response. Thus, some receptors. 1-14, product macrophages, may participate regulation response by modulating lymphokines. clinically useful analog, mimics action immune system.