ABSTRACT
Lymphoid chalone extracts, obtained from bovine spleen were purified on chromatographic columns: in the first step of the procedure, exclusion chromatography on Sephadex G75, and ion exchange chromatography on DEAE Sephadex were applied. A purified, active material was thus obtained. Upon thin layer chromatography, this fraction was shown to contain 3-4 UV absorbing components and 2 ninhydrin positive components. Further purification on Biogel P2, on Sephadex G10 and preparative thin layer chromatography, showed that the biological activity was located in small molecular weight components which belong to the polypeptide series. The ultraviolet absorbing components were identified as known nucleosides. The purified material shows an inhibitory effect on the uptake of 3H-thymidine by lymphocytes, as well as on mitogen induced lymphocyte transformation and haemolysin plaque forming cells. Furthermore, this inhibitory effect is specific for lymphoid cells.
Subject(s)
Growth Inhibitors/isolation & purification , Animals , Cattle , Chromatography, Gel , Chromatography, Ion Exchange , Chromatography, Thin Layer , Growth Inhibitors/physiology , Molecular Weight , Spectrophotometry, Ultraviolet , Spleen/analysisABSTRACT
A highly purified extract from bovine spleen (FA) possessing immunosuppressive capacity was studied. Its tissue specificity was analysed in vivo and in vitro and the main components of FA, the well-known nucleosides deoxycytidine, deoxyinosine and thymidine, were tested in vivo. It seems that the molecule responsible for the biological activity of FA is a new substance endowed with strong specific activity and that lymphoid tissue is highly sensitive to the inhibiting capacity of this purified fraction.
