Role of nonspecific cytotoxic cells in intestinal epithelial cell injury in Nippostrongylus brasiliensis infection

We have employed a cultured crypt-like intestinal epithelial rat cell line (IEC-18) to assess whether killing by nonspecific cytotoxic cells contributes to epithelial cell destruction in Nippostrongylus brasiliensis (N.b.) infection. Spleen cells from N.b.-infected Sprague-Dawley rats, 11-13 days postinfection when villus atrophy and crypt hyperplasia were evident, killed IEC-18 in a 4-hr 51Cr-release assay. In contrast, intraepithelial leukocytes (IEL) from N.b.-infected rats showed decreased killing of IEC-18 compared to controls in a 16-hr assay. Spleen NK activity was increased in N.b.-infected rats whereas IEL NK activity was decreased. We conclude that direct cytotoxicity of crypt-like intestinal epithelial cells by nonspecific cytotoxic cells appears to play no significant role in intestinal injury in N.b. infection.