Human recombinant IL-6/B cell stimulatory factor 2 augments murine antigen-specific antibody responses in vitro and in vivo.
The effects of human rIL-6/B cell stimulatory factor 2 (hrIL-6/BSF-2) from Escherichia coli on murine Ag, SRBC-specific antibody responses were examined in vitro and in vivo. HrBSF-2 was effective in augmenting the primary and the anamnestic plaque-forming cells response to SRBC in vitro. The augmentation of the primary response was apparent when B cell-enriched spleen cells (B cells) were cultured with BSF-2 in the presence of IL-2. On the other hand, hrBSF-2 alone strongly enhanced the anamnestic response in a dose-dependent manner when spleen cells from SRBC-immunized mice were used. These effects of BSF-2 were abolished completely by anti-BSF-2 antibody, but not by normal rabbit Ig. Cell depletion experiments indicated that L3T4 (CD4)+ T cells, but not Lyt-2(CD8)+ T cells, and adherent cells (macrophages) have an important role in this BSF-2-induced augmentation of the response. In addition, kinetic studies showed that hrBSF-2 acts on B cells in the anamnestic response even when added relatively late in the culture. Finally, it was determined whether BSF-2 also could be active in modulating antibody responses in vivo. BSF-2 was shown to enhance the primary and secondary antibody responses in mice. The most apparent effect of BSF-2 was observed in the secondary response.
Takatsuki
F
F
Central Research Laboratories, Ajinomoto Co., Inc., Kawasaki, Japan.
Okano
A
A
Suzuki
C
C
Chieda
R
R
Takahara
Y
Y
Hirano
T
T
Kishimoto
T
T
Hamuro
J
J
Akiyama
Y
Y
D000276:Adjuvants, Immunologic / Q000276:immunology / Q000494:pharmacology*; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D001667:Binding, Competitive; D002448:Cell Adhesion; D002469:Cell Separation; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D007117:Immunization, Secondary; D007156:Immunologic Memory; D015850:Interleukin-6; D007378:Interleukins / Q000276:immunology / Q000494:pharmacology*; D007700:Kinetics; D051379:Mice; D008809:Mice, Inbred C3H; D008811:Mice, Inbred DBA; D011994:Recombinant Proteins / Q000276:immunology / Q000494:pharmacology*; D013601:T-Lymphocytes
D000276:Adjuvants, Immunologic; D000939:Epitopes; D007106:Immune Sera; D015850:Interleukin-6; D007378:Interleukins; D011994:Recombinant Proteins