Recombinant human interleukin 6 (rhIL-6) promotes the terminal differentiation of in vivo-activated human B cells into antibody-secreting cells.
Antigen-activated peripheral blood B cells were induced by parenteral immunization of healthy individuals with a polyvalent pneumococcal vaccine, or diphtheria toxoid. Seven to nine days after immunization, high frequencies of antigen-specific antibody-secreting cells, representing in vivo activated lymphoblastoid B cells, were detectable in peripheral blood or spleen. The B cell-enriched fractions were stimulated for 7 days with different concentrations of rhIL-6. Both the frequency of antibody-secreting cells and the secreted amount of antibody to the immunizing antigen were increased by rhIL-6 in a dose-dependent fashion. Stimulation with rhIL-6 did not alter the isotype distribution of antibody-secreting cells. A polyclonal anti-IL-6 serum completely abrogated the stimulatory effect of rhIL-6 on the in vitro antibody secretion. Fluorescence-activated cell sorter analysis revealed that 25-29% of cells in the large B cell fraction which presumably contained the in vivo activated cells bore the IL-6 receptor. Thus, rhIL-6 enhances the terminal differentiation of in vivo activated B cells into antibody-secreting plasma cells.
Lue
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Department of Microbiology, University of Alabama, Birmingham 35294.
Kiyono
H
H
McGhee
J R
JR
Fujihashi
K
K
Kishimoto
T
T
Hirano
T
T
Mestecky
J
J
D000921:Antibody-Producing Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects; D006801:Humans; D015850:Interleukin-6 / Q000276:immunology / Q000494:pharmacology*; D008213:Lymphocyte Activation; D011971:Receptors, Immunologic / Q000032:analysis; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins / Q000494:pharmacology
D015850:Interleukin-6; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins