Impaired CD40‐Signalling in CD19‐Deficient Mice Selectively Affects Th2‐Dependent Isotype Switching

• DOI: 10.1046/j.1365-3083.2001.00824.x
• Publication Date: 2003-03-12T20:15:28Z
• Authors: E. Gärdby; X.‐J. Chen; N. Y. Lycke
• Keywords: Nippostrongylus brasiliensis; Isotype

Activation of B lymphocytes involves binding antigen to the specific receptor and signalling through several membrane coreceptors, which CD19 has been found play a pivotal role as response regulator. Although previous studies in gene knockout mice have demonstrated that antibody responses T‐cell‐dependent antigens are strongly impaired absence this coreceptor, little is known about consequences deficiency for interaction between T cells. Here we report Th2 co‐ordinated B‐cell differentiation selectively CD19‐deficient mucosal or systemic immunizations following an intestinal infection with Nippostrongylus brasiliensis . Whereas immunoglobulin (Ig)G1 IgE were low absent, IgG2a normal. The selective defect was not caused by poor Th2‐development interleukin (IL)‐4 responsiveness mice. Rather, it result Th2–B cell interaction, owing substantially reduced ability signal via CD40 Thus, our study suggests CD40L–CD40‐interactions more important than Th1 differentiation.