Natural killer cells induce activated murine B cells to secrete Ig.
We previously demonstrated that dextran-conjugated anti-IgD antibodies (alpha delta-dex) induce proliferation of small, B cell-enriched murine spleen cells (Be cells), and in the presence of IL-2, stimulate Ig secretion in vitro. We have shown that alpha delta-dex-stimulated B cells provide an in vitro model for studying B cell activation by T cell-independent type 2 (TI-2) Ag, as exemplified by the bacterial polysaccharides. We now show that highly purified resting B cells, obtained by electronic cell sorting (Bsp cells), fail to secrete Ig in the presence of alpha delta-dex + IL-2. The alpha delta-dex + IL-2-induced Ig secretory response of Bsp cells is restored upon addition of splenic non-B, non-T cells or a pure population of in vitro-generated NK cells. Similarly, pretreatment of Be cells with anti-AsGm-1 plus complement inhibits Ig secretion in response to alpha delta-dex + IL-2. An IL-2-induced NK cell supernatant (NKSN) is equally potent at stimulating Ig secretion by alpha delta-dex-activated Bsp cells, indicating that cell contact between Bsp and activated NK cells is not required for this effect. IL-2 stimulates not only NK cells, but B cells as well, since addition of anti-IL-2 + anti-IL-2R antibodies to Bsp cell cultures, in the presence of alpha delta-dex + NKSN, inhibits Ig secretion. These data describe a novel animal model for NK cell-induced B cell maturation to Ig secretion and suggest a pathway for Ig production in response to T1-2 Ag.
Snapper
C M
CM
Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
Yamaguchi
H
H
Moorman
M A
MA
Sneed
R
R
Smoot
D
D
Mond
J J
JJ
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D005260:Female; D005677:G(M1) Ganglioside / Q000502:physiology; D007136:Immunoglobulins / Q000096:biosynthesis*; D007376:Interleukin-2 / Q000494:pharmacology; D015848:Interleukin-5 / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA
D000888:Antibodies, Anti-Idiotypic; D007136:Immunoglobulins; D007376:Interleukin-2; D015848:Interleukin-5; C039951:anti-IgD; D005677:G(M1) Ganglioside; C018835:asialo GM1 ganglioside