Host gene expression for Mycobacterium avium subsp. paratuberculosis infection in human THP-1 macrophages.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne's disease, which causes considerable economic loss in the dairy industry and has a possible relationship to Crohn's disease (CD) in humans. As MAP has been detected in retail pasteurized milk samples, its transmission via milk is of concern. Despite its possible role in the etiology of CD, there have been few studies examining the interactions between MAP and human cells. In the current study, we applied Ingenuity Pathway Analysis to the transcription profiles generated from a murine model with MAP infection as part of a previously conducted study. Twenty-one genes were selected as potential host immune responses, compared with the transcriptional profiles in naturally MAP-infected cattle, and validated in MAP-infected human monocyte-derived macrophage THP-1 cells. Of these, the potential host responses included up-regulation of genes related to immune response (CD14, S100A8, S100A9, LTF, HP and CHCIL3), up-regulation of Th1-polarizing factor (CCL4, CCL5, CXCL9 and CXCL10), down-regulation of genes related to metabolism (ELANE, IGF1, TCF7L2 and MPO) and no significant response of other genes (GADD45a, GPNMB, HMOX1, IFNG and NQO1) in THP-1 cells infected with MAP.