TLR9 Polymorphisms Might Contribute to the Ethnicity Bias for EBV-Infected Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world, but is endemic in some ethnic groups. The association of NPC with the Epstein-Barr virus (EBV) is firmly established; however, the mechanism is still unclear. TLR9 is well known for its essential role in viral pathogen recognition and activation of innate immunity. Here, we report a set of TLR9 polymorphisms in the TIR-2 domain of the TLR9 protein collected from the EBV-infected NPC samples from northeast Indian populations sharing the aforesaid ethnicity. The occurrence of mutations is significantly high in these samples as we found a p value of <0.0001 at a significance level of 0.05. These might play an important role for the lack of function of TLR9 and thus for the higher occurrence of EBV-mediated NPC in such ethnic groups.