INFLAMMATORY MEDIATORS INCREASE SURFACE EXPRESSION OF INTEGRIN LIGANDS, ADHESION TO LYMPHOCYTES, AND SECRETION OF INTERLEUKIN-6 IN MOUSE SERTOLI CELLS

The expression of the cell adhesion molecules ICAM-1, ICAM-2, and VCAM -1 and the secretion of the cytokine interleukin 6 have been measured in mouse Sertoli cells cultured in vitro, Cytometric analysis revealed that, in basal conditions, low levels of ICAM-1 and VCAM-1 were prese nt on the surface of the cells, whereas treatment with interleukin 1, tumor necrosis factor alpha, lipopolysaccharide, or interferon gamma i nduced, with different kinetics, increases in their expression, ICAM-2 was not detectable in basal conditions, nor was it inducible, Electro n microscopic analysis and binding experiments using Cr-51-labeled lym phocytes demonstrated that increased expression of ICAM-1 and VCAM-1 o n the surface of Sertoli cells, induced by inflammatory mediators, det ermines an augmented adhesion between the two cell types, The same sti muli, with the exception of interferon gamma, produced a rapid and rem arkable increment of interleukin 6 production by Sertoti cells, These results suggest the presence of both direct and paracrine mechanisms o f interaction between Sertoli and immune-competent cells, possibly inv olved in the control of immune reactions in the testis, Such mechanism s are of interest for the understanding of autoimmune pathologies of t he testis and, if confirmed in humans, they could be involved in the s exual transmission of human immunodeficiency virus infection.