In vitro IgE but not IgG production of canine peripheral blood B cells is inhibited by CD40 ligation.
The aim of this study was to investigate in vitro IgE induction in peripheral canine B cells. CD21(+) B cells were purified from the peripheral blood of beagle dogs by positive selection via magnetic separation to a purity of >/=95%. Subsequently, proliferation, and IgG and IgE production of canine B cells were investigated after stimulation with human recombinant Interleukin-4 (hrIL-4) and human recombinant Interleukin-2 (hrIL-2) in the presence or absence of CD40L-CD8 fusion protein (CD40L) of mouse origin. We could demonstrate that canine B cells react on hrIL-2 alone by proliferation and IgG production but not by IgE secretion, whereas activation with hrIL-4 induced proliferation and mainly IgE production. Together, both cytokines synergistically increased B cell proliferation as well as IgG and IgE production. We could also show that mouse CD40L induces proliferation of dog B cells, which is further enhanced by addition of hrIL-4. Unexpectedly, CD40L led to a dramatic decrease in the IL-4 mediated IgE secretion (82% inhibition on an average). In contrast, IgG production was not affected significantly by CD40L. The same effects of CD40L were observed when B cells were stimulated by a combination of IL-2 and IL-4 and this inhibition could not be abrogated by increasing the amounts of IL-4. In summary, activation of canine B cells from peripheral blood by hrIL-4 in the presence or absence of hrIL-2 led to marked IgE production that is strongly and in a dose-dependent manner inhibited by CD40L. Stimulation of IgG production is not influenced by CD40L.
Goedert
S
S
Allergy Section, Department of Immuno-Dermatology, Novartis Research Institute, Brunnerstr. 59, A-1235, Vienna, Austria. goedert@mpiib-berln.mpg.de
Schiessl
B
B
Zunic
M
M
Schiebl
C
C
Mayer
P
P
de Weck
A L
AL
Liehl
E
E
Mudde
G C
GC
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D019013:CD40 Antigens / Q000276:immunology*; D023201:CD40 Ligand; D016827:CD8 Antigens / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D004285:Dogs / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000008:administration & dosage / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D011993:Recombinant Fusion Proteins / Q000494:pharmacology
D019013:CD40 Antigens; D016827:CD8 Antigens; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D023201:CD40 Ligand; D015847:Interleukin-4; D007073:Immunoglobulin E