CD40 and IgE: synergism between anti-CD40 monoclonal antibody and interleukin 4 in the induction of IgE synthesis by highly purified human B cells.
A novel pathway of IgE-B cell differentiation has been identified. Engagement of the B cell antigen CD40 by F(ab')2 fragments of monoclonal antibody (mAb) 626.1 in the presence of recombinant interleukin 4 (rIL-4) induced intense IgE synthesis, but modest IgG synthesis, by highly purified human B cells. Surface IgE- B cells isolated by cell sorting were induced to produce IgE by mAb 626.1 and IL-4. Thus, IgE synthesis is unlikely to result from expansion of a B cell population precommitted to IgE in vivo. A neutralizing anti-IL-6 antibody strongly, but not completely, inhibited the IgE response. This indicates that autocrine production of IL-6 plays an important amplification role in IgE synthesis triggered by anti-CD40 mAb and IL-4. Although the exact role played by CD40 in IgE responses in vivo remains to be established, this T cell-independent system represents a useful model to characterize the biochemical and molecular events leading to IgE synthesis in human B cells.
Children's Hospital, Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115.
H H
HH
Jabara
S M
SM
Fu
R S
RS
Geha
D
D
Vercelli
D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D019013:CD40 Antigens; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D015847:Interleukin-4 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D019013:CD40 Antigens; D007140:Immunoglobulin Fab Fragments; D015850:Interleukin-6; D011994:Recombinant Proteins; D015847:Interleukin-4; D007073:Immunoglobulin E