title: Protein I and protein II from the outer membrane of Escherichia coli are mouse B-lymphocyte mitogens.
abstract: Protein I from the outer membrane of Escherichia coli is a B-lymphocyte mitogen in mice. Polyclonal activation of mouse splenocytes was demonstrated by 3H-thymidine incorporation into DNA, 3H-uridine incorporation into RNA, and by a hemolytic plaque assay in three inbred mouse strains. B-lymphocytes from LPS responder mice (C57Bl/10, STU/nu/nu) and LPS non-responder mice (C3H/HeJ) both responded well to protein I. The presence of serum was not necessary for mitogenicity; bovine serum albumin exhibited a beneficial effect on serum-depleted cultures. Thymocytes of C3H/HeJ mice were not activated by protein I. Protein II* from E. coli was also tested in our systems and showed a weak B-lymphocyte stimulatory activity. Human peripheral blood lymphocytes were not activated.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D002473:Cell Wall; D004926:Escherichia coli; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice / Q000276:immunology; D008934:Mitogens; D013154:Spleen / Q000166:cytology
chemical_list: D001426:Bacterial Proteins; D008934:Mitogens