Germinal center cells are a major IL-5-responsive B cell population in peripheral lymph nodes engaged in the immune response.
Germinal center formation and the development of B cell memory in lymphoid tissue is a T cell-dependent process. The specific B cell-T cell interactions, and/or cytokines, resulting in germinal center cell growth have not yet been identified. Germinal center B cells were separated from other lymph node (LN) B cells by panning on peanut agglutinin (PNA)-coated dishes. Resulting fractions enriched for PNA+ (germinal center) B cells, and the PNA- (other) LN B cells from immune SJL mice were assayed for proliferation in the presence of cytokines. PNA+ and PNA- B cells responded equally to IL-4 in the anti-mu co-stimulator assay. In contrast, PNA+ B cells responded to murine (r)IL-5 or human B cell growth factor in the dextran sulfate (DxS) co-stimulator assay, to a much greater degree than did PNA- B cells. The same results were obtained with PNA+ and PNA- cells from LAF1 mice. Unfractionated LN B cells from nonimmunized SJL or BALB/c mice did not respond to IL-5 with or without DxS. B cell populations from BALB/c mice such as from spleen and peritoneal cavity, which are known to be high in Ly-1+B cells, responded to IL-5 alone, and more dramatically, to IL-5 as a co-stimulator with DxS. Such populations of cells from SJL mice, which are known to contain low numbers of Ly-1+B cells, responded markedly less. These results are consistent with those of others which show that in nonimmunized mice, Ly-1+B cells are a major IL-5 responsive subpopulation. IL-1 enhanced the proliferation of PNA+ cells in response to rIL-5 and had no effect on PNA- cells. IL-4 and IL-5 did not enhance each other's effects as co-stimulators of proliferation. In contrast to PNA+ B cells from immune LN, B cells activated by Escherichia coli endotoxin exhibited no responses to rIL-5. The present results indicate that in immune LN, PNA+, germinal center B cells constitute a prominent IL-5-responsive population.
Department of Pathology, New York University Medical Center, New York 10016.
J L
JL
Rabinowitz
V K
VK
Tsiagbe
M H
MH
Nicknam
G J
GJ
Thorbecke
D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D007375:Interleukin-1 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D015848:Interleukin-5 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008198:Lymph Nodes / Q000166:cytology* / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D010529:Peritoneal Cavity / Q000166:cytology; D011975:Receptors, Mitogen / Q000032:analysis; D013154:Spleen / Q000166:cytology
D007375:Interleukin-1; D015848:Interleukin-5; D008070:Lipopolysaccharides; D011975:Receptors, Mitogen; C038223:peanut agglutinin receptor; D015847:Interleukin-4