Interleukins and IgA synthesis. Human and murine interleukin 6 induce high rate IgA secretion in IgA-committed B cells.
Freshly isolated murine PP B cells were cultured with 10 different cytokines, including IL-1 alpha, IL-2, IL-4, IL-5, IL-6, IL-7, IFN-gamma, TNF-alpha, and TGF-beta, to investigate a possible role for these cytokines in induction of Ig synthesis. Of interest was the finding that only IL-5 and both mouse recombinant (mr) and human recombinant (hr) IL-6 enhanced IgA synthesis. The effect was greater with either mrIL-6 or hrIL-6 than with mrIL-5. IL-6 induced cycling mIgA+ PP B cells to secrete high levels of IgA (approximately 7-fold increase over control). Of importance was the finding that mrIL-6 had little effect on secretion of IgM or IgG by PP B cell cultures. hrIL-6 also increased IgA secretion by PP B cells and this enhancement was abolished by a goat anti-hrIL-6 antiserum. mrIL-6 did not cause B cell proliferation but induced a sharp increase in numbers of B cells secreting IgA. Isotype-switching was not a mechanism for this marked increase in IgA synthesis since mIgA- PP B cells were not induced to secrete IgA by mrIL-6. From these studies we conclude that IL-6 plays an important role in promoting the terminal differentiation of PP B cells to IgA-secreting plasma cells.
Beagley
K W
KW
Department of Microbiology, University of Alabama, Birmingham 35294.
Eldridge
J H
JH
Lee
F
F
Kiyono
H
H
Everson
M P
MP
Koopman
W J
WJ
Hirano
T
T
Kishimoto
T
T
McGhee
J R
JR
D000818:Animals; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis*; D015850:Interleukin-6; D007378:Interleukins / Q000494:pharmacology / Q000502:physiology*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D051379:Mice; D008809:Mice, Inbred C3H; D010581:Peyer's Patches / Q000378:metabolism; D010641:Phenotype; D011994:Recombinant Proteins / Q000494:pharmacology; D013045:Species Specificity
D007070:Immunoglobulin A; D015850:Interleukin-6; D007378:Interleukins; D011994:Recombinant Proteins