Activation of human B lymphocytes through CD40 and interleukin 4.
We have produced and characterized a new CD40 monoclonal antibody, mAb 89, which in the presence of anti-IgM antibodies co-stimulates to induce B cell proliferation. mAb 89 activates resting B cells as shown by an increase in cell volume and an enhanced subsequent proliferation of B cells in response to anti-IgM antibody. However, mAb 89 does not prepare B cells to respond to the growth-promoting activity of interleukin (IL) 2 or IL 4. Unlike IL 2 and IL 4, mAb 89 only weakly stimulates the proliferation of anti-IgM pre-activated B cells. Thus, the activating properties of anti-CD40 are likely to explain its co-stimulatory effect on B cells. Interestingly, the anti-CD40 mAb 89 was found to act in synergy with IL 4, but not with IL 2, in co-stimulation and restimulation assays. In this respect, anti-CD40 does not induce a significant increase of B cell surface IL 4 receptors while IL 4, but not IL 2, induces a twofold increase of the CD40 antigen expression. Thus the synergistic interaction between IL 4 and anti-CD40 may be related to the IL 4-dependent increase of CD40 antigen expression.
Vallé
A
A
UNICET Dardilly, France.
Zuber
C E
CE
Defrance
T
T
Djossou
O
O
De Rie
M
M
Banchereau
J
J
D000911:Antibodies, Monoclonal / Q000276:immunology; D000944:Antigens, Differentiation, B-Lymphocyte / Q000502:physiology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D019013:CD40 Antigens; D006801:Humans; D066298:In Vitro Techniques; D015847:Interleukin-4; D007378:Interleukins / Q000502:physiology*; D008213:Lymphocyte Activation; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen / Q000378:metabolism; D013997:Time Factors
D000911:Antibodies, Monoclonal; D000944:Antigens, Differentiation, B-Lymphocyte; D019013:CD40 Antigens; D007378:Interleukins; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen; D015847:Interleukin-4