VECTORIAL PRODUCTION OF INTERLEUKIN-1 AND INTERLEUKIN-6 BY RAT SERTOLI CELLS CULTURED IN A DUAL CULTURE COMPARTMENT SYSTEM

The bidirectional production of interleukin-l (IL-1) and IL-6 by Serto li cells and its regulation by inflammatory and physiological stimuli has been studied using a dual compartment culture system allowing the study of Sertoli cell apical and basal secretory activities. Another S ertoli cell activity, the vectorial transferrin production was also st udied in all culture conditions. A low constitutive IL-I production ap peared equally distributed between both poles, while IL-6 and transfer rin constitutive production was predominantly directed apically. Two a ctivators of macrophages, lipopolysaccharides and zymosan, were found to induce marked increases of IL-1 in the compartment where they had b een added: basal if added to the lower compartment and vice versa. In contrast, after a basal stimulation, IL-6 production was mainly increa sed in the upper compartment that corresponds to a Sertoli cell apical flux. In this system, IL-1 and IL-6 levels mere not modified by FSH; they were not also affected by residual bodies and latex beads, probab ly due to the fact that, in the bicameral system, phagocytosis is rest ricted to the Sertoli cells situated at the surface of the inner compa rtment. IL-1 beta, but not IL-1 alpha, induced IL-6 secretion in the c ompartment of stimulation. In conclusion, the present study demonstrat es that vectorial secretory patterns of IL-1 and IL-6 production great ly differ and that these cytokines are also differently regulated. The se results suggest that Sertoli IL-1 and IL-6 have different targets w ithin the testis and that, in normal and pathophysiological conditions , both the tubular and the interstitial compartments may be influenced by the action of these paracrine factors.