Characterization of human endotoxin lipopolysaccharide receptor CD14 expression in transgenic mice

CD14 is a major receptor for the bacterial endotoxin LPS. Since CD14 is spe cifically and highly expressed on the surface of monocytic cells, it has be en used as a monocyte/macrophage differentiation marker. To identify elemen ts that are critical for the direction of the tissue-specific expression of CD14, an 80-kb genomic DNA fragment containing the coding region of the CD 14 gene, as well as a considerable amount of both upstream and downstream s equence, was used to generate transgenic mice. The analysis of mice from si x different founder lines demonstrated that this genomic DNA fragment was s ufficient to direct human CD14 gene expression in a monocyte-specific manne r among hematopoietic cells. Furthermore, the data lead us to a new finding that CD14 is highly expressed in the human liver, a primary organ involved in the acute phase response. These transgenic mice provide a useful model to analyze the biological function of human CD14.