PPAR-γ regulates the effector function of human T helper 9 cells by promoting glycolysis.

T helper 9 (TH9) cells promote allergic tissue inflammation and express the type 2 cytokines, IL-9 and IL-13, as well as the transcription factor, PPAR-γ. However, the functional role of PPAR-γ in human TH9 cells remains unknown. Here, we demonstrate that PPAR-γ drives activation-induced glycolysis, which, in turn, promotes the expression of IL-9, but not IL-13, in an mTORC1-dependent manner. In vitro and ex vivo experiments show that the PPAR-γ-mTORC1-IL-9 pathway is active in TH9 cells in human skin inflammation. Additionally, we find dynamic regulation of tissue glucose levels in acute allergic skin inflammation, suggesting that in situ glucose availability is linked to distinct immunological functions in vivo. Furthermore, paracrine IL-9 induces expression of the lactate transporter, MCT1, in TH cells and promotes their aerobic glycolysis and proliferative capacity. Altogether, our findings uncover a hitherto unknown relationship between PPAR-γ-dependent glucose metabolism and pathogenic effector functions in human TH9 cells.

Nonavalent human papillomavirus vaccination as alternative treatment for genital warts.

Genital warts caused by the human papillomavirus (HPV) are the most common sexually transmitted disease and have a negative impact on quality of life. Of the more than 200 different types of HPV, low-risk types 6 and 11 are mainly responsible for the development of condyloma acuminata. Despite a large arsenal of local therapies such as numerous topical agents, CO2 laser ablation, and surgical removal, genital warts tend to be recalcitrant. HPV vaccination is mainly used as a preventive strategy to prevent genital warts, cervical cancer, and other anogenital cancers. However, in a few cases, HPV vaccination has been shown to be a good treatment alternative for patients with recalcitrant skin warts. Here we report five cases of recalcitrant genital warts that responded well to treatment with the nonavalent HPV vaccine. HPV vaccines could be beneficial as a noninvasive treatment alternative for recalcitrant genital warts.