Eosinophils Are an Endogenous Source of Interleukin-4 during Filarial Infections and Contribute to the Development of an Optimal T Helper 2 Response.

Introduction: Interleukin-4 (IL-4) is a central regulator of type 2 immunity, crucial for the defense against multicellular parasites like helminths. This study focuses on its roles and cellular sources during Litomosoides sigmodontis infection, a model for human filarial infections.

Methods: Utilizing an IL-4 secretion assay, investigation into the sources of IL-4 during the progression of L.