title: Modulation of morphology and plasma-membrane enzyme activities of rat thymocytes induced by specific antisera.
abstract: Lewis rat thymocytes were incubated with different ligands: specific rat alloantisera, rabbit xenoantisera against whole-rat thymocytes or against thymocyte plasma-membrane vesicles and the two mitogens: concanavalin A and the Ca++ ionophore A 23187. After treatment, a crude plasma-membrane fraction was repaired, and the activities of two plasma-membrane marker enzymes, alkaline phosphatase and gamma-glutamyl transferase, and a general membrane marker enzyme, lysolecithin acyltransferase, were determined. An increase of all marker enzyme activities was observed only when thymocytes had been incubated with alloantiserum directed against the gene products of their major histocompatibility complex (MHC) or with rabbit antiserum against syngeneic thymocytes. Anti-MHC alloantiserum against a nonrelevant haplotype increased moderately the gamma-glutamyltransferase activity. Alloantiserum directed against the weak histocompatibility antigens had no significant effect as had rabbit antiserum raised against thymocyte plasma-membrane vesicles. The mitogens concanavalin A and A 23187 both increased the activity of the alkaline phosphatase and lysolecithin acyltransferase. Scanning electron microscopy showed that treatment with alloantisera did not alter the cell shape drastically. In contrast, incubation with rabbit xenoantiserum against thymocytes resulted in cell rounding and deformation. Rabbit xenoantiserum against the plasma-membrane vesicles of thymocytes resulted in markedly disturbed or damaged plasma membranes.
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D000961:Antilymphocyte Serum / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology / Q000276:immunology / Q000648:ultrastructure; D006649:Histocompatibility Antigens / Q000276:immunology; D007106:Immune Sera / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D011948:Receptors, Antigen, T-Cell; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology / Q000648:ultrastructure; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D000961:Antilymphocyte Serum; D006649:Histocompatibility Antigens; D007106:Immune Sera; D011948:Receptors, Antigen, T-Cell; D008243:1-Acylglycerophosphocholine O-Acyltransferase; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase