Genomic study of oral lichen planus and oral microbiome with RNAseq

Oral lichen planus (OLP) is a common chronic inflammatory disease affecting the oral mucosa. The pathogenesis of OLP is incompletely understood but is thought to be related to the immune system. As the oral cavity is a major reservoir and transmission gateway for bacteria, viruses, and fungi, the microbial composition of the oral cavity could play a role in the pathogenesis of OLP. However, due to limitations of analytic technology and incomplete knowledge of the microbial community in the oral cavity, it is not yet clear which pathogens are associated with OLP. Next-generation sequencing (NGS) is a powerful tool that can help to identify pathogens for many infectious diseases. In this study, we compared host cell gene expression profiles and microbial profiles from OLP patients and matched healthy individuals. We identified activation of the hepatocyte nuclear factor alpha (HNF4A) network in OLP patients and potential pathogens, including Corynebacterium matruchotii, Fusobacterium periodonticum, Streptococcus intermedius, Streptococcus oralis, and Prevotella denticola. P. denticola is capable of activating the HNF4A gene network. Our findings shed light on the previously elusive association of OLP with various diseases like hepatitis, and indicate that OLP is a T-helper type 17 (Th17)-mediated mucosal inflammatory process. The molecular pathways and microbes identified here can inform future investigations into OLP pathogenesis and development of novel therapeutics for OLP treatment.