Expression of metabotropic glutamate receptors in murine thymocytes and thymic stromal cells

RT-PCR combined with immunoblotting showed the expression of group-I (mGlu1 and 5) and group-II (mGlu2? and 3) metabotropic glutamate receptors in who le mouse thymus, isolated thymocytes and TC-1S thymic stromal cell line. Cy tofluorimetric analysis showed that mGlu-5 receptors were absent in CD4(-)/ CD8(-) but present in more mature CD4(+) CD8(+) and CD4(+)CD8(-) thymocytes . mGlu-1a receptors showed an opposite pattern of expression with respect t o mClu5, whereas mGlu2/3 receptor expression did not differ between double negative and double positive cells. mGlu receptors expressed in both thymic cell components were functional, as indicated by measurements of polyphosp hoinositide hydrolysis or cAMP formation. These data suggest a possible rol e for mGlu receptor signalling in the thymus. (C) 2000 Elsevier Science B.V . All rights reserved.