Interleukin-9 potentiates the interleukin-4-induced immunoglobulin (IgG, IgM and IgE) production by normal human B lymphocytes.
IgE production by normal peripheral blood lymphocytes (PBL) is known to be triggered upon stimulation by interleukin (IL)-4. In the present study we showed that IL-9, another T cell-derived cytokine, markedly potentiated IgE production induced by suboptimal doses of IL-4, whereas no effect of IL-9 was observed in the absence of IL-4. The potentiating effect of IL-9 appeared to be associated with the increased frequency of IgE-producing cells, as revealed by a specific ELISA-spot assay. Under the same experimental conditions, IL-9 also enhanced the IL-4-induced IgG production but did not elicit IgM production. However, IL-9 did not amplify the IL-4-dependent expression of membrane-bound and soluble low affinity receptor for IgE (CD23). IL-4-induced IgE production was also potentiated by IL-6 but not by tumor necrosis factor-alpha and IL-1 beta. The possibility that the activity of IL-9 was mediated by IL-6 released from accessory cells was excluded by the observations that monocyte depletion did not abolish the effect of IL-9 and that IL-9 was still active on fluorescence-assisted cell sorted CD20+ B lymphocytes co-cultured with irradiated murine EL4 cells. In addition, IL-9 was shown to potentiate the IL-4-induced IgG and IgM production by normal human B lymphocytes preactivated with Staphylococcus aureus Cowan strain. Taken together, these data suggest that IL-9 plays a regulatory role in the IL-4-dependent immunoglobulin production.
Dugas
B
B
INSERM/CJF 92-10, Hôpital Arnaud de Villeneuve, Montpellier, France.
Renauld
J C
JC
Pène
J
J
Bonnefoy
J Y
JY
Peti-Frère
C
C
Braquet
P
P
Bousquet
J
J
Van Snick
J
J
Mencia-Huerta
J M
JM
D000917:Antibody Formation / Q000187:drug effects*; D015703:Antigens, CD / Q000502:physiology; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D004357:Drug Synergism; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D066298:In Vitro Techniques; D015847:Interleukin-4 / Q000008:administration & dosage*; D016906:Interleukin-9 / Q000008:administration & dosage*; D008213:Lymphocyte Activation; D009000:Monocytes / Q000502:physiology; D015846:Monokines / Q000494:pharmacology; D017455:Receptors, IgE / Q000378:metabolism
D015703:Antigens, CD; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016906:Interleukin-9; D015846:Monokines; D017455:Receptors, IgE; D015847:Interleukin-4; D007073:Immunoglobulin E