Yersinia YopJ inhibits pro-inflammatory molecule expression in human bronchial epithelial cells

Abstract Human bronchial epithelial cell pro-inflammatory molecule expression plays a role in the pathogenesis of airway diseases. We hypothesize that Yersinia outer protein-J (YopJ), a Yersinia virulence effector which inhibits mitogen activated protein (MAP) kinase kinases (MKKs), attenuates epithelial cell pro-inflammatory molecule expression. 16HBE14o-cells were co-transfected with cDNAs encoding Yersinia pseudotuberculosis YopJ or empty vector. Expression of YopJ reduced activation of extracellular signal regulated kinase (ERK)-2, Jun amino terminal kinase (JNK)-1 and IκB kinase (IKK)-β. YopJ also blocked transactivation of NF-κB and AP-1 promoter sequences which has been shown to regulate chemokine expression. Finally, expression of YopJ reduced transcription from the IL-8, RANTES (regulated upon activation, normal T cell expressed and secreted) and intercellular adhesion molecule (ICAM)-1 promoters. We conclude that YopJ expression blocks the innate immune response in lung epithelial cells, the site of Yersinia pestis infection. Inhibition of bronchial epithelial cell responses by YopJ is consistent with the notion that MAP kinases regulates bronchial epithelial cell pro-inflammatory molecule expression.