Interferon lambda 1 expression in cervical cells differs between low-risk and high-risk human papillomavirus-positive women

Persistent infection by high-risk (HR) human papillomavirus (HPV) types is a prerequisite for progression to cancer. HR-HPVs may lead to a deregulation of innate immunity by interfering with the epithelial type I interferon (IFN) response, whereas very little is known about type III IFNs, a key component of the mucosal antiviral response. This study reports a first attempt to evaluate the activation of type III IFN genes (IFN lambda 1-3), IFN lambda receptor genes (IFN-lambdaR1 and IL10R2), and IFN-induced genes (MxA, ISG15, ISG56) in HPV-positive and HPV-negative cervical cells from 154 women attending the gynecological unit of a university hospital in Rome. Despite an increased individual variability, a coordinated expression of several IFN lambda-related genes was observed. Furthermore, IFN lambda 1 and IFN-lambdaR1 genes were expressed at higher levels in cervical cells positive to low-risk (LR) HPV compared to HR-HPV and HPV-negative cells. Consistently, ISG15 expression was significantly higher in LR-HPV-infected women than in the other groups. Moreover, IFN lambda 1 expression decreased significantly with abnormal cytological results. This study is the first to show the activation of a type III IFN response in LR-HPV-positive cervical cells and suggests that the lack of this response in HR-HPV infection may be related to lesion progression.