Differentiation of thymus cells

Abstract

The process of cellular differentiation in the thymus presumably leads to the development of immunocompetent peripheral “T” lymphocytes (1, 6). Although there are considerable data showing the existence of a small pool of immunocompetent cortisone-resistant, medullary thymocytes which, as a population, bear low concentration of Thy 1.2, lack TL antigens, and exhibit high concentrations of H-2, the identification of their immediate precursors is not yet known (1). Under conditions of parenteral hydrocortisone administration it has been demonstrated that at least some of the cortisone-resistant medullary thymocytes are derived from an intrathymic pool of cortisone-sensitive cortical precursors (7). In this paper we demonstrate the in vivo maturation of at least three lines of “mature” thymus cells from a precursor subclass using selective labeling of these precursors in situ as a marker.

From Session V, Development and Aging in Organ Systems, of the FASEB Conference on Biology of Development and Aging, presented at the 58th Annual Meeting of the Federation of American Societies for Experimental Biology, Atlantic City, N.J., April 11, 1974.

Supported by Public Health Service Grants AI-09072 and GM-17367.