A Preliminary Study on the Expression and Regulation of C-X-C Chemokine Genes in a Human Colon Epithelial Cell Line

ABSTRACT

Human colon epithelial cells secrete an array of proinflammatory cytokines that includes IL-8, MCP-1, GM-CSF, TNF alpha and IL-6. This response may serve to attract neutrophils and macrophags to the site of infection. In addition to IL-8 and MCP-1, the chemokine family contains other members, which, alone or in combination, can recruit and/or activate inflammatory and lymphoid cells. In this study, we asked whether colon epithelial cells express a broader array of chemokines than previously described. The colon epithelial cell line, Caco-2, was stimulated for 3h with IL-1 alpha, or was infected with Salmonella dublin. RNA was extracted and chemokine mRNA levels were determined by quantitative reverse transcription-PCR using internal RNA standards. Ex pression of GRO alpha, GRO beta, GRO gamma and IP-10 increased by bacterial infection or IL-l alpha stimulation. These data strongly support the notion that epithelal cells are an important and integral component of the host's natural immune system.