Prothymosin α and Factors from Calf Thymic Cells Decrease Expression of Thy 1.2 Antigen Among Small Thymocs from C57BL/6 Mice

Abstract

In this work we studied the effect of Prothymosin α (ProTα) and other thymic factors on the expression of Thy 1.2 antigen (a T-cell marker) and the activities of adenosine deaminase (ADA, E.C. 3.5.4.4), N-acetyl-ß-D-glucosaminidase (NABG, E.C. 3.2,1.30), ß-glucuronidase (BG, E.C. 3.1.1.1) and serine-esterase (SE, E.C. 3.4.21)., the levels of which change during the T-cell differentiation process among small thymocytes obtained from C57BL/6 mice. Incubation of small thymocytes in the presence of ProTα, Thymus Extracts (TE) or supernatants prepared from thymic stromal cells (TSCS) or thymocytes (TS) reduced the proportion of cells killed by anti-Thy 1.2 monoclonal antibodies but did not affect the enzymatic activities studied. This is the first evidence that ProTα affects Thy 1.2 expression in vitro.