title: Activation of thymic B cells by signals of CD40 molecules plus interleukin-10.
abstract: We have previously found that thymic B cells, particularly thymic CD5+ B cells, show low responsiveness to the usual B cell stimulants such as lipopolysaccharide or anti-IgM plus interleukin (IL)-4, although they proliferate and produce antibodies after direct interaction with major histocompatibility complex class II-restricted T blasts. These findings raise the possibility that a CD40-CD40 ligand (L) interaction is involved in the activation of thymic B cells. In the present study, we therefore examine this possibility using CD40L-transfected Chinese hamster ovary (CHO) cells or anti-CD40 monoclonal antibody (mAb). When B cells in the spleen and peritoneal cavity were stimulated, they proliferated and produced immunoglobulin (Ig) in the presence of CD40L-CHO cells or anti-CD40 mAb alone. However, another signal delivered by IL-10 in addition to CD40L-CHO cells or anti-CD40 mAb was found to be necessary for thymic B cells to proliferate and secrete Ig. Other interleukins acting on B cells, such as IL-4, IL-5, and IL-6, had no effect on the activation of thymic B cells, which thus have unique characteristics not found in peripheral B cells. This report discusses the physiological significance of IL-10- and CD40-driven signals in the activation of thymic B cells.
authors.affiliation: First Department of Pathology, Kansai Medical University, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Inaba
authors.forename: K
authors.initials: K
authors.lastname: Inaba
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuba
authors.forename: S
authors.initials: S
authors.lastname: Mori
authors.forename: H
authors.initials: H
authors.lastname: Haruna
authors.forename: H
authors.initials: H
authors.lastname: Doi
authors.forename: Y
authors.initials: Y
authors.lastname: Adachi
authors.forename: H
authors.initials: H
authors.lastname: Iwai
authors.forename: N
authors.initials: N
authors.lastname: Hosaka
authors.forename: H
authors.initials: H
authors.lastname: Hisha
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D019013:CD40 Antigens; D023201:CD40 Ligand; D016466:CHO Cells; D006224:Cricetinae; D005260:Female; D016753:Interleukin-10 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000235:genetics / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D009928:Organ Specificity; D010529:Peritoneal Cavity / Q000166:cytology; D011994:Recombinant Proteins; D013154:Spleen / Q000166:cytology; D013950:Thymus Gland / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D019013:CD40 Antigens; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D016753:Interleukin-10; D023201:CD40 Ligand