We examined the effects of interleukin-3 (IL-3) and interleukin-4 (IL-4) on connective tissue-type mast cells (CTMC) purified from murine peritoneal cells. Although both factors failed to induce extensive proliferation of CTMC, they stimulated CTMC proliferation synergistically in a dose-dependent manner. Pretreatment of CTMC with IL-3 and/or IL-4 indicated that the sustained presence of both f...

The crystal structure of DARPin 44C12V5 that neutralizes IL-4 signaling has been determined alone and bound to human IL-4. A significant conformational change occurs in the IL-4 upon DARPin binding. The DARPin binds to the face of IL-4 formed by the A and C α-helices. The structure of the DARPin remains virtually unchanged. The conformational changes in IL-4 include a reorientation of the C-hel...

In this investigation, we have examined the integrated relationship between IL-13, IL-4, and IL-5 for the development of airways hyperreactivity (AHR) in a model of asthma in BALB/c mice. Sensitization and aeroallergen challenge of both wild-type (WT) and IL-13 gene-targeted (IL-13-/-) mice induced allergic disease that was characterized by pulmonary eosinophilia and AHR to beta-methacholine. A...

Current evidence suggests that neonatal tolerance to a foreign Ag is the consequence of IL-4-mediated Th2 immunity rather than the thymic deletion of Ag-specific T cells. Here, we addressed the role of IL-4 in neonatal tolerance by testing whether tolerance to a minor histocompatibility Ag can be induced in newborn mice that lack IL-4 (IL-4(-/-)). We found that IL-4 does not play a dominant rol...