Properties of mouse CD40: cellular distribution of CD40 and B cell activation by monoclonal anti-mouse CD40 antibodies.
We describe here the derivation of a rat monoclonal antibody (mAb) against mouse CD40 (designated 3/23), which stains 45-50% of spleen cells of adult mice, approximately 90% of which are B cells. Interestingly, some 5-10% of both CD4+ and CD8+ T cells in the spleens of (some, but not all) adult, unimmunized mice are also CD40+, whereas CD40+ cells were not detectable in the thymus, even following collagenase digestion. Some 35-40% of lymphoid cells in the bone marrow of adult mice are CD40+ and virtually all of these are B220+, and hence of the B cell lineage: triple-color flow cytometry showed that CD40 is expressed at low levels on some 30% of pre-B cells, at intermediate levels on 80% of immature B cells and on essentially all mature B cells in the bone marrow. These results, therefore, suggest that in the mouse CD40 is expressed relatively late during the process of B cell differentiation. The mAb induced marked up-regulation of major histocompatibility complex class II molecules, CD23 and B7.2 antigens on mature B cells. It also stimulated modest levels of DNA synthesis in mature B cells by itself: this was markedly enhanced by suboptimal concentrations of mitogenic (but not non-mitogenic) anti-mu and anti-delta mAb, and moderately enhanced by co-stimulation with interleukin-4. Hypercross-linking of CD40 (using biotinylated mAb and avidin) also enhanced the proliferative response to anti-CD40.
Hasbold
J
J
National Institute for Medical Research, London, GB.
Johnson-Léger
C
C
Atkins
C J
CJ
Clark
E A
EA
Klaus
G G
GG
D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D018122:B7-1 Antigen / Q000276:immunology; D001854:Bone Marrow Cells; D019013:CD40 Antigens; D002454:Cell Differentiation / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D051381:Rats; D011919:Rats, Inbred Strains; D017455:Receptors, IgE / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D018122:B7-1 Antigen; D019013:CD40 Antigens; D000949:Histocompatibility Antigens Class II; D017455:Receptors, IgE