Differential interleukin-8 response of intestinal epithelial cell line to reactogenic and nonreactogenic candidate vaccine strains of Vibrio cholerae

In this study, we analyzed whether attachment of Vibrio cholerae vaccine st rains to human intestinal epithelial cells can induce an interleukin-l (IL- 8) response. The IL-8 transcripts were detected by PCR amplification of rev erse-transcribed mRNA, and the gene product secretion was measured by an en zyme-linked immunosorbent assay. Infection of monolayers of the undifferent iated HT29-18N2 cell line with reactogenic (JBK70 and 81) and nonreactogeni c (CVD103HgR and 638) vaccine strains of V. cholerae resulted in markedly h igher IL-8 expression by epithelial cells exposed to reactogenic strains th an by cells exposed to the nonreactogenic strains. Additionally, epithelial cells produced IL-8 transcripts following stimulation with cholera vaccine strains in a concentration-dependent manner. These results represent a new insight into the inflammatory component of reactogenicity and could be use d as a predictive marker of vaccine reactogenicity prior to human testing.