Cell autonomous expression of IgD is not essential for the maturation of conventional B cells.
To analyse the function of IgD in vivo, we generated a 'loss of function' mouse model utilizing gene targeting technology. By homologous recombination in a (C57BL/6 x CBA)F1 mouse embryonic stem cell (ES) line one allele of the delta heavy chain gene was rendered non-functional. In chimeric mice obtained after injection of the targeted ES cells into blastocysts derived from severe combined immunodeficient mice we analysed ES cell derived B lymphocytes expressing the targeted or the wild-type allele by using allotype specific reagents. We show that B cells expressing the targeted allele appear in the periphery as IgM+ D- cells at normal frequency. They express the CD23 marker and respond to a T cell dependent antigen. Thus, cell autonomous expression of IgD is neither essential for B cell maturation into an antigen responsive state nor for antigen dependent triggering of the cells into an immune response.
Roes
J
J
Institute for Genetics, University of Cologne, Germany.
Rajewsky
K
K
D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology; D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D002454:Cell Differentiation; D004252:DNA Mutational Analysis; D005796:Genes; D007108:Immune Tolerance; D007072:Immunoglobulin D / Q000502:physiology*; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011961:Receptors, Fc / Q000502:physiology; D017455:Receptors, IgE
D000944:Antigens, Differentiation, B-Lymphocyte; D007072:Immunoglobulin D; D009838:Oligodeoxyribonucleotides; D011961:Receptors, Fc; D017455:Receptors, IgE