Cellular immune-endocrine interaction in adrenocortical tissues

Background The detection of important immunocompetence-like features on end ocrine steroid cells raises questions about direct intercellular communicat ion between the adrenal and immune systems. This article summarizes our rec ent work and new data on immune-adrenal interactions. Materials and methods RT-PCR and immunohistochemistry were performed to exa mine MHC class II (HLA-DR) expression in adrenocortical rumours. Coculture systems of NCI-H295 adrenocortical carcinoma cells and HLA-marched lymphocy tes were used to examine effects on steroid production and survival of lymp hocytes. Results HLA-DR m-RNA is found in both benign and malignant adrenals, except the NCI-H295 cell line. Under direct coculture conditions with NCI-H295 ce ll line, spontaneous apoptosis of immune cells was reduced. Synthesis of co rtisol and especially of dehydroepiandrosterone production of tumour cells was markedly increased. Differences by separating CD++ and CD8+ T cells wer e not detected. Conclusions Direct cellular contact between lymphocytes and adrenocortical cells seems to be involved in the peripheral regulation of androgen synthes is in the adrenal. The molecular basis of this interaction is no tknown. Wi th regard to normal adrenals, ligation of MHC class II antigens could be a potential mechanism for a peripheral regulation of androgen secretion.