Includes abstract.Includes bibliographical references (leaves 101-111).Interleukin-4 receptor alpha (IL-4Ra) signaling, mediated by the ligands IL-4 and IL- 13, is important for effective host protection during murine Nippostrongylus brasiliensis (N. brasiliensis) and Schistosoma mansoni (S. manson!) infection. Among other cell types, IL-4Ra responsive smooth muscle cells influence immunological responses and are needed for host protection during N. brasiliensis and S. mansoni infection
