Association of a variable number tandem repeat in the NLRP3 gene in women with susceptibility to RVVC

Vaginal infections with Candida spp. frequently occur in women of childbearing age. A small proportion of these women experience recurrent vulvovaginal candidosis (RVVC), which is characterized by at least three episodes of infection in one year. In addition to known risk factors such as antibiotics, diabetes, or pregnancy, host genetic variation and inflammatory pathways such as the IL-1/Th17 axis have been reported to play a substantial role in the pathogenesis of RVVC. In this study, we assessed a variable number tandem repeat (VNTR) polymorphism in the NLRP3 gene that encodes a component of the inflammasome, processing the proinflammatory cytokines IL-1β and IL-18. A total of 270 RVVC patients and 583 healthy controls were analyzed, and increased diseases susceptibility was associated with the presence of the 12/9 genotype. Furthermore, functional studies demonstrate that IL-1β production at the vaginal surface is higher in RVVC patients bearing the 12/9 genotype compared to controls, whereas IL-1Ra levels were decreased and IL-18 levels remained unchanged. These findings suggest that IL-1β-mediated hyperinflammation conveyed by the NLRP3 gene plays a causal role in the pathogenesis of RVVC and may identify this pathway as a potential therapeutic target in the disease.

Fine-tuning of Th17 Cytokines in Periodontal Disease by IL-10

Periodontitis (PD) is a chronic disease caused by the host inflammatory response to bacteria colonizing the oral cavity. In addition to tolerance to oral microbiome, a fine-tuned balance of IL-10 levels is critical to efficiently mount antimicrobial resistance without causing immunopathology. Clinical and animal studies support that adaptive T-helper (Th) cytokines are involved in the pathogenesis of alveolar bone destruction in PD. However, it remains unclear what type of Th response is related to human PD progression and what role IL-10 has on this process. We addressed the contribution of IL-10 in limiting Th1 and Th17 inflammatory response in murine and human PD. Through a combination of basic and translational approaches involving selected cytokine-deficient mice as well as human genetic epidemiology, our results demonstrate the requirement for IL-10 in fine-tuning the levels of Th17 (IL-17A and IL-17F) cytokines in experimental and human PD. Of novelty, we found that IL-17F correlated with protection in murine and human PD and was positively regulated by IL-10. To our knowledge, this is the first demonstration of the protective role for IL-17F in PD, its positive regulation by IL-10, and the potential differential role for IL-17A and IL-17F in periodontal disease.