A role for acidophilic granulocytes in the testis of the gilthead seabream (Sparus aurata L., Teleostei)

Abstract

In mammals, a complex interaction between the immune and the reproductive systems has been described, in which testicular immune cells produce cytokines and growth factors which modulate gonad functions, while specific gonad cells influence the immune response in this organ. In this study we describe the presence of acidophilic granulocytes in the testis of the hermaphrodite teleost fish gilthead seabream (Sparus aurata L.) by using a specific monoclonal antibody. During the post-spawning stage of the testis, this cell type appears in the germinal compart- ment, accumulates interleukin (IL)-1 and does not seem to be involved in the phagocytosis of degenerating cells. Moreover, in vitro, 11-ketotestosterone and 17 -oestradiol, the principal fish sexual steroids, regulate the respiratory burst activity of acidophilic granulocytes obtained from the head-kidney (the bone marrow equivalent in fish) and the intracellular accumulation of IL-1 by these cells. It is likely, therefore, that IL-1 produced by testicular acido- philic granulocytes regulates important functions of the testis in fish.