title: Mice deficient in CD23 reveal its modulatory role in IgE production but no role in T and B cell development.
abstract: To assess roles of CD23 in lymphocyte development and immune function in vivo, CD23-deficient mice (CD23-/-) were generated. Mice heterozygous with respect to the defective allele (CD23+/-) display 50% reduced levels of CD23 expression on CD23+ cell types. This pattern is consistent with a lack of parental or tissue-specific imprinting of the CD23 gene. Neither a 50% reduced level nor a complete lack of CD23 caused profound changes in lymphocyte compartments (thymocytes, peripheral T cells, and B-1 and B-2 B cells). The lack of CD23 also did not significantly alter in vitro the proliferative response of B cells triggered via the Ag receptor in combination with CD40 ligand, IL-2, and/or IL-4. Effects on polyclonal Ig production were tested in a Th2 cell-driven immune response in vivo after infection with Nippostrongylus brasiliensis, a parasite that dramatically enhances CD23 expression on B cells. In both primary and secondary immune responses, heterozygous CD23+/- mice developed slightly higher and CD23-/- mice similar serum IgE and IgG1 levels as compared with CD23+/+ (wild-type) mice. The increase in blood eosinophil counts was similar in all three types of mice. These findings show that after N. brasiliensis infection 1) a complete lack of CD23 in vivo neither prohibits nor significantly alters quantitatively polyclonal IgE levels in serum, and 2) a 50% reduction in cell-surface CD23 expression (CD23+/- mice) correlates with slightly increased serum IgE levels.
authors.affiliation: Department of Biotechnology, Ciba-Geigy Ltd., Basel, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Stief
authors.forename: G
authors.initials: G
authors.lastname: Texido
authors.forename: G
authors.initials: G
authors.lastname: Sansig
authors.forename: H
authors.initials: H
authors.lastname: Eibel
authors.forename: G
authors.initials: G
authors.lastname: Le Gros
authors.forename: H
authors.initials: H
authors.lastname: van der Putten
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004802:Eosinophilia / Q000276:immunology; D007073:Immunoglobulin E / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000166:cytology; D008221:Lymphoid Tissue / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009559:Nippostrongylus / Q000276:immunology; D017455:Receptors, IgE / Q000502:physiology*; D017206:Strongylida Infections / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology
chemical_list: D017931:DNA Primers; D017455:Receptors, IgE; D007073:Immunoglobulin E