title: Constitutive expression of high levels of soluble mouse CD4 in transgenic mice does not interfere with their immune function.
abstract: Interactions of CD4 with the major histocompatibility complex (MHC) class II molecules are crucial during thymic development and subsequently for the function of single-positive CD4+CD8- T lymphocytes. Here, we have investigated the potential effects of soluble CD4 (sCD4) on the immune system. We generated two different transgenic mouse lines, which constitutively expressed either approximately 100 micrograms/ml of monovalent or approximately 20 micrograms/ml of decavalent mouse sCD4 molecules in their sera. Analysis of these mice revealed no differences compared to control littermates, e.g. the single-positive CD4+ cells developed normally and these cells responded to allogeneic and anti-CD3 antibody stimuli like the cells from control mice. Furthermore, the T helper cell function for antibody responses in vivo were not affected. Our data provide evidence that, in mouse, the CD4-MHC class II-interaction has very low affinity. Since sCD4 is considered to be a therapeutical agent for human immunodeficiency virus infection, these findings are not only of basic, but also of clinical interest.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Weber
authors.forename: A
authors.initials: A
authors.lastname: Traunecker
authors.forename: K
authors.initials: K
authors.lastname: Karjalainen
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000096:biosynthesis*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002678:Chimera / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008822:Mice, Transgenic / Q000276:immunology*; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D015704:CD4 Antigens; D000949:Histocompatibility Antigens Class II; D017260:Receptor-CD3 Complex, Antigen, T-Cell