Cellular metabolism has been proposed to govern distinct γδ T cell effector functions, but the underlying molecular mechanisms remain unclear. We show that interleukin-17 (IL-17)–producing γδ T (γδT17) and interferon-γ (IFN-γ)–producing γδ T (γδT1) cells have differential metabolic requirements and that the rate-limiting enzyme isocitrate dehydrogenase 2 (IDH2) acts as a metabolic checkpoint for their effector functions. Intriguingly, the transcription factor c-Maf regulates γδT17 effector function through direct regulation of IDH2 promoter activity. Moreover, mTORC2 affects the expression of c-Maf and IDH2 and subsequent IL-17 production in γδ T cells. Deletion of c-Maf in γδ T cells reduces metastatic lung cancer development, suggesting c-Maf as a potential target for cancer immune therapy. We show that c-Maf also controls IL-17 production in human γδ T cells from peripheral blood and in oral cancers. These results demonstrate a critical role of the transcription factor c-Maf in regulating γδT17 effector function through IDH2-mediated metabolic reprogramming.

Background: This study aimed to illustrate the status of carbapenem-resistant Enterobacterales (CRE) infections in a Chinese tertiary hospital and to investigate the role of outer membrane vesicles (OMVs) in antibiotic resistance in carbapenem-resistant Klebsiella pneumoniae (CRKP). Methods: The data of CRE infections was collected from laboratory records, and the CRE isolates from two distinct periods (2015/07 to 2017/07 and 2020/04 to 2021/04) were enrolled to detect the carbapenemase genes by polymerase chain reaction (PCR). Multilocus sequence typing (MLST) was used to analyze the molecular characterization of CRKP. The conjugation assay was performed to verify the transmission of the antibiotic resistance plasmid. The OMVs of CRKP were isolated with a method combining an electrophoretic technique with a 300 kDa cut-off dialysis bag. The protein components in CRKP OMVs were analyzed by liquid chromatography tandem-mass spectrometry (LC–MS/MS), and the meropenem-hydrolyzing bioactivity of KPC in CRKP OMVs was determined with different treatments in vitro. Results: A total of 178 CRE isolates, including 100 isolates from 2015/07 to 2017/07 and 78 isolates from 2020/04 to 2021/04, were collected for the detection of carbapenemase genes. We found that the carbapenemase gene blaKPC was the most prevalent, followed by blaNDM. By MLST, we found that sequence type (ST) 11 CRKP (96.1%) was the leading type during 2015/07 to 2017/07 and that the ST15 CRKP increased to 46.2% in the late period of 2020/04 to 2021/04. The diameters of Klebsiella pneumoniae OMVs ranged from 100 to 200 nm, and by proteomics analysis the most proteins from OMVs belonged to the “enzyme” group. The KPC enzyme was found in the OMVs from CRKP, and the OMVs could protect inside KPC from proteinase K digestion. Moreover, the KPC enzymes within OMVs, which could be released after Triton X-100 treatment, could hydrolyze meropenem. Conclusions: CRE has increasingly caused infections in hospitals, and blaKPC-positive CRKP infections have constituted a major proportion of infections in the past decade. The OMVs play a critical role in antibiotic resistance in CRKP.

Tendon injuries are often exacerbated by persistent inflammation, which hampers tissue regeneration. In this study, we developed a noninvasive, wirelessly controlled, and self-powered piezoelectric nanofilm fabricated by coaxial electrospinning of polycaprolactone (PCL) and tetragonal barium titanate nanoparticles (BTO), and investigated its roles in modulating inflammation and repairing Achilles tendon defects as well as the mechanism in a rat model. In vitro study and in vivo study upon subcutaneous implantation showed that the piezoelectric PCL/BTO nanofilms could inhibit M1 macrophage polarization and reduce the secretion of inflammatory factors. Moreover, when bridging an Achilles tendon defect, the nanofilms could promote tenogenic gene expression including collagen deposition, and collagen remodeling, facilitate functional tendon recovery and significantly reduce tissue inflammation by suppressing M1 macrophage polarization and promoting M2 polarization. Moreover, the piezoelectric stimulation could also enhance tendon regeneration by inhibiting angiogenesis, reducing lipid deposition, and decreasing ectopic ossification. Mechanistically, the piezoelectric nanofilms reduced tissue inflammation mainly via inhibiting the nuclear factor (NF)-κB signaling pathway that is mediated by interleukin (IL)-17A secreted from CD3⁺ T cells, and thus to reduce proinflammatory factors, such as IL-1β and IL-6, inducible nitric oxide synthase, monocyte chemoattractant protein-1, and tumor necrosis factor-α. These findings indicate the potential of piezoelectric stimulation in immunomodulation, and in promoting tendon regeneration via IL-17A/NF-κB-mediated pathway.

Oral squamous cell carcinoma (OSCC) was the most common malignant type of head and neck squamous cell carcinoma (HNSCC) with a low survival rate. The microbiota in oral cavity or tumor tissues may play a critical role in the OSCC. In this study, we characterized the microbiota from oral cancer tissues, oral swabs and saliva of patients with OSCC using 16S rRNA sequencing. We found differential profiles and amounts of microbiota in oral cancer tissues compared with adjacent tissues, as well as in oral swabs and saliva from OSCC patients compared with healthy individuals. Fusobacterium nucleatum and Porphyromonas endodontalis were found increased in cancer tissues and saliva from OSCC patients. Prevotella melaninogenica was found increased in the saliva and oral swabs from OSCC patients. These data suggested that microbiota varied according to different samples. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated an important role of metabolic pathways in the interaction between microbiota and cancers. Then we analyzed the metabolites from cancer tissues and saliva of OSCC patients by liquid chromatograph-mass spectrometry/mass spectrometry (LC-MS/MS) and gas chromatograph-mass spectrometry (GC-MS). Differential profiles of metabolites were also observed in the cancer tissues compared with adjacent tissues and in the saliva from OSCC patients compared with healthy individuals. It showed that denticulaflavonol was significantly increased while D-mannose was significantly decreased in both cancer tissues and saliva of OSCC patients. Taken together, these results suggested an association between microbiota/metabolites (such as Fusobacterium and mannose) and OSCC, in which the molecular mechanism need further investigated.

Staphylococcus aureus, or methicillin-resistant Staphylococcus aureus (MRSA), is the predominant pathogen in skin and soft tissue infections (SSTIs), and MRSA membrane vesicles (MVs) play a pivotal role in bacterial pathogenesis and the modulation of the host immune response. We aimed to investigate the interaction between MRSA MVs and epithelial cells. In this study, MVs were isolated from an MRSA culture supernatant using the ELD method, comprising an electrophoretic technique used in combination with a 300 kDa cut-off dialysis bag. The proteomic analysis of the MRSA MVs via mass spectrometry showed that shared and distinct proteins exist in the MVs from clinical MRSA isolates with different genetic backgrounds, such as health-care-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA). These MRSA MVs were found to suppress the proliferation and increase the apoptosis of HaCaT cells. We conducted qPCR array, quantitative real-time PCR (qRT-PCR), and Western blotting (WB) analyses, and the results indicated that BCL2 antagonist/killer 1 (Bak1) may be involved in the apoptosis of HaCaT epithelial cells. Our findings suggest that MRSA MVs inhibit the proliferation and induce the apoptosis of epithelial cells.

Given the limited treatment options available for oral lichen planus (OLP), a study was undertaken to obtain preliminary information on the therapeutic efficacy of tinidazole mouth rinse in patients with OLP. A prospective, open-label pilot study was conducted to assess the efficacy of thrice-daily tinidazole mouth rinse for one week in OLP patients (n = 27). Reticulation/erythema/ulceration (REU) scores and visual analog scale (VAS) scores were used to measure lesions at baseline and after one week of treatment. Mucosal samples were collected, and the abundance of Fusobacterium nucleatum was quantified using RT-PCR. Statistical analysis using t-test, Wilcoxon signed rank test and Pearson correlation test. After treatment, VAS scores significantly decreased in both reticular (P = 0.03) and erosive OLP patients (P = 0.003). However, REU scores significantly decreased only in erosive OLP patients (P = 0.002). The relative abundance of Fusobacterium nucleatum on the damaged mucosa surface significantly decreased in all OLP patients (P = 0.01). In erosive OLP patients, the triamcinolone group showed a significantly greater improvement in VAS scores compared to the tinidazole group (P = 0.01). However, there was no statistically significant correlation between the relative abundance of Fusobacterium nucleatum and REU scores in OLP patients (r = 0.0754, P = 0.61). Tinidazole mouth rinse showed potential in reducing disease severity in OLP patients and was well-tolerated, suggesting its viability as a local therapeutic option. However, randomized controlled studies are warranted to confirm these preliminary findings.