Human recombinant interleukin 4 induces normal B cells to produce soluble CD23/IgE-binding factor analogous to that spontaneously released by lymphoblastoid B cell lines.
Surface-labeled Epstein-Barr virus (EBV)-transformed lymphoblastoid RPMI 8866 cells release in their supernatant a radiolabeled 25-kDa polypeptide which reacts with the Fc epsilon RL/CD23-specific monoclonal antibody (mAb) 25 and which binds to IgE but not IgG (IgE BF/sCD23). IgE BF/sCD23 had an isoelectric point of 4.5-5.0. The reactivity of mAb 25 with IgE BF/sCD23 allowed us to set up a radioimmunoassay for detection of IgE BF/sCD23 in cell culture supernatants. Supernatants from Fc epsilon RL/CD23+ cell lines were found to contain IgE BF/sCD23. Addition of human recombinant interleukin 4 (IL 4) to normal human B cells cultures induced the production of IgE BF/sCD23. Activation of B cells with anti-IgM antibody coupled to beads enhanced the IL 4-induced production of IgE BF/sCD23 when compared to nonactivated B cells. This correlates with the finding that anti-IgM antibody-activated B cells cultured with IL 4 express more Fc epsilon RL/CD23 than B cells cultured with IL 4 alone. The biochemical characteristics of radiolabeled IgE BF/sCD23 immunoprecipitated by mAb 25 from the supernatants of normal B cells cultured with IL 4 were identical to those of the IgE BF/sCD23 isolated from EBV-transformed cell line supernatants. Addition of interferon-gamma to B cells cultured with IL 4 strongly decreased the level of IgE BF/sCD23 in culture supernatants correlating with the observed decrease of Fc epsilon RL/CD23 on B cell surface. These data demonstrate that normal human B cells cultured in the presence of IL 4 produce an IgE-binding factor (sCD23) biochemically and antigenically equivalent to that spontaneously produced by EBV-transformed lymphoblastoid cell lines.
Bonnefoy
J Y
JY
UNICET, Laboratory for Immunological Research, Dardilly, France.
Defrance
T
T
Peronne
C
C
Menetrier
C
C
Rousset
F
F
Pène
J
J
De Vries
J E
JE
Banchereau
J
J
D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D002474:Cell-Free System; D002648:Child; D004854:Herpesvirus 4, Human; D006801:Humans; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D029584:Prostatic Secretory Proteins; D011863:Radioimmunoassay; D011994:Recombinant Proteins / Q000494:pharmacology*
D007378:Interleukins; D008222:Lymphokines; D029584:Prostatic Secretory Proteins; D011994:Recombinant Proteins; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors; D015847:Interleukin-4