Butyrate is an energy source for colonocytes that is formed by bacterial fermentation of dietary fiber in the colon and that exerts broad anti-inflammatory activities. Although the administration of butyrate improves homeostasis in patients and ameliorates IBD (Inflammatory Bowel Disease)-related lesions and symptoms, the anti-inflammatory mechanisms of butyrate still remain unclear. To explore the impact of butyrate on Treg (Regulatory T cell)/Th17 (T helper 17 cell) differentiation and colitis in rats. The effect of butyrate on the expression of markers related to both Tregs and Th17 cells were determined in human monocytes as well as a rat model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid. Rats were treated with butyrate in vivo, whereas the rat splenocytes and human monocytes were treated in vitro. We found that butyrate administration increased peripheral blood Treg cell levels as well as plasma levels of anti-Th17 cytokines (IL-10 and IL-12). Butyrate administration further suppressed IL-17 levels in both plasma and colonic mucosa, and ameliorated colonic colitis lesions in rats. This promotion of Treg activity and inhibition of IL-17 release was also observed in human venous monocytes and rat splenocytes in vitro. Our results suggest that butyrate plays a key role in regulating the Treg/Th17 balance and ultimately protects the colon mucosa against the development of IBD.

The lack of representative nasopharyngeal carcinoma (NPC) models has seriously hampered research on EBV carcinogenesis and preclinical studies in NPC. Here we report the successful growth of five NPC patient-derived xenografts (PDXs) from fifty-eight attempts of transplantation of NPC specimens into NOD/SCID mice. The take rates for primary and recurrent NPC are 4.9% and 17.6%, respectively. Successful establishment of a new EBV-positive NPC cell line, NPC43, is achieved directly from patient NPC tissues by including Rho-associated coiled-coil containing kinases inhibitor (Y-27632) in culture medium. Spontaneous lytic reactivation of EBV can be observed in NPC43 upon withdrawal of Y-27632. Whole-exome sequencing (WES) reveals a close similarity in mutational profiles of these NPC PDXs with their corresponding patient NPC. Whole-genome sequencing (WGS) further delineates the genomic landscape and sequences of EBV genomes in these newly established NPC models, which supports their potential use in future studies of NPC.

Accumulating evidence indicates that oncogenic viral protein plays a crucial role in activating aerobic glycolysis during tumorigenesis, but the underlying mechanisms are largely undefined. Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is a transmembrane protein with potent cell signaling properties and has tumorigenic transformation property. Activation of NF-κB is a major signaling pathway mediating many downstream transformation properties of LMP1. Here we report that activation of mTORC1 by LMP1 is a key modulator for activation of NF-κB signaling to mediate aerobic glycolysis. NF-κB activation is involved in the LMP1-induced upregulation of glucose transporter 1 (Glut-1) transcription and growth of nasopharyngeal carcinoma (NPC) cells. Blocking the activity of mTORC1 signaling effectively suppressed LMP1-induced NF-κB activation and Glut-1 transcription. Interfering NF-κB signaling had no effect on mTORC1 activity but effectively altered Glut-1 transcription. Luciferase promoter assay of Glut-1 also confirmed that the Glut-1 gene is a direct target gene of NF-κB signaling. Furthermore, we demonstrated that C-terminal activating region 2 (CTAR2) of LMP1 is the key domain involved in mTORC1 activation, mainly through IKKβ-mediated phosphorylation of TSC2 at Ser ⁹³⁹ . Depletion of Glut-1 effectively led to suppression of aerobic glycolysis, inhibition of cell proliferation, colony formation, and attenuation of tumorigenic growth property of LMP1-expressing nasopharyngeal epithelial (NPE) cells. These findings suggest that targeting the signaling axis of mTORC1/NF-κB/Glut-1 represents a novel therapeutic target against NPC. IMPORTANCE Aerobic glycolysis is one of the hallmarks of cancer, including NPC. Recent studies suggest a role for LMP1 in mediating aerobic glycolysis. LMP1 expression is common in NPC. The delineation of essential signaling pathways induced by LMP1 in aerobic glycolysis contributes to the understanding of NPC pathogenesis. This study provides evidence that LMP1 upregulates Glut-1 transcription to control aerobic glycolysis and tumorigenic growth of NPC cells through mTORC1/NF-κB signaling. Our results reveal novel therapeutic targets against the mTORC1/NF-κB/Glut-1 signaling axis in the treatment of EBV-infected NPC.

Significance: Inflammatory bowel diseases (IBDs) have been characterized by immune-mediated destruction of intestinal homeostasis. Until now, there have been no optimal therapies due to lack of a comprehensive understanding on pathophysiology during IBDs. The enteric nervous system (ENS) is emerging as a critical participant in intestinal immunomodulation, but the interaction between the ENS and intestinal immunity in IBDs remains unclear. Here, we discover the alteration of the ENS featured with reduced neurons and decreased acetylcholine (ACh) in IBDs. Moreover, ACh directly enhances the antiinflammatory activity of monocytic myeloid-derived suppressor cells by promoting interleukin-10 production through nicotinic ACh receptors, and thus ameliorates colitis. Our data highlight a neuroimmunomodulatory pathway and provide an alternative avenue by locally increasing ACh level for IBD therapy.