Expression of T-Cell Markers on Chicken Bone Marrow Precursor Cells Incubated with an Avian Thymic Hormone

Abstract

Thymic extracts from a number of mammals (mice, rats, calves, pigs, and humans) have been shown to contain a variety of hormones or factors which play an important role in the differentiation and maturation of T lymphocytes. Some of the well-characterized hormones or factors include thymosin (Goldstein, 1976), thymulin (Bach et al., 1978), thymopoietin (Goldstein, 1975), and thymic humoral factor (Kook et al., 1975). These and several additional factors have also been demonstrated to be present in the serum of some of the mammals. Most of these hormones are active in bioassays both in vitro and in vivo. Thymosin fraction 5 induces the expression of Thy-1 and Lyt antigens on murine precursor cells and functional maturation of T cells (Ahmed et al., 1978). It also has been shown to induce HTLA surface marker on human bone marrow cells (Touraine et al., 1975) and to enhance the number of E-rosette-forming T cells (Incefy et al., 1975). Similar biological activity has been reported for thymulin (Bach et al., 1978). Mouse bone marrow cells or spleen cells express TL and Thy-1 antigens when incubated in vitro with thymopoietin (Basch and Goldstein, 1974).