The morphologic and distributive characterizations of intraepithelial lymphocyte (IEL) in ileum and the dome area of Peyer′s patch in BALB/c mice which took salmonella typhi were observed by electron microscopy and immunohistochemistry, in order to inquire about the role of IEL in the mucosal immune response under antigen inducement. By immunohistochemistry the results suggest that there are two types lymphocytes, T and B in IEL of ileum and the dome area, and B lymphocytes are more obvious. Under electron ...