Insulin and growth hormone function as minor growth factors that potentiate lymphocyte activation

The small resting lymphocyte is devoid of cell surface receptors for endocrine peptides such as insulin and growth hormone. During the process of activating these cells by either specific antigen or mitogenic agents the lymphocyte has been shown to display receptors for insulin. The present paper reviews work that indicates a functional role for both insulin and growth hormone during the process of lymphocyte activation. The results of these studies point to potentially important interactions between the immune and neuroendocrine systems and are discussed in terms of endocrine peptides playing a supportive role during the complex series of events that occur during lymphocyte activation.