Rationale Foxp3+ T regulatory cells (Tregs) are key players in maintaining immune homeostasis. Evidence suggests that Tregs respond to environmental cues to permit or suppress inflammation. In atherosclerosis, Th1-driven inflammation affects Treg homeostasis, but the mechanisms governing this phenomenon are unclear. Objective Here, we address whether atherosclerosis impacts Treg plasticity and functionality in Apoe−/− mice, and what effect Treg plasticity might have on the pathology of atherosclerosis. Methods and Results We demonstrate that atherosclerosis promotes Treg plasticity, resulting in the reduction of CXCR3+ Tregs, and the accumulation of an intermediate Th1-like IFNγ+CCR5+ Treg subset (Th1/Tregs) within the aorta. Importantly, Th1/Tregs arise in atherosclerosis from bona fide Tregs, rather than T effector cells. We show that Th1/Tregs recovered from atherosclerotic mice are dysfunctional in suppression assays. Using an adoptive transfer system and plasticity-prone Mir146a−/− Tregs, we demonstrate that elevated IFNγ+ Mir146a−/− Th1/Tregs are unable to adequately reduce atherosclerosis, arterial Th1, or macrophage content within Apoe−/− mice, in comparison to Mir146a+/+ Tregs. Lastly, via single cell RNA-sequencing and RT-PCR we show that Th1/Tregs possess a unique transcriptional phenotype characterized by co-expression of Treg and Th1 lineage genes, and a down-regulation of Treg-related genes, including Ikzf2, Ikzf4, Tigit, Lilrb4, and Il10. Additionally, an ingenuity pathway analysis further implicates IFNγ, IFNα, IL-2, IL-7, CTLA4, T cell receptor, and Csnk2b-related pathways in regulating Treg plasticity. Conclusions Atherosclerosis drives Treg plasticity, resulting in the accumulation of dysfunctional IFNγ+ Th1/Tregs that may permit further arterial inflammation and atherogenesis.

T follicular helper (Tfh) cells play key role in providing help to B cells during germinal center (GC) reactions. Generation of protective antibodies against various infections is an important aspect of Tfh-mediated immune responses and the dysregulation of Tfh cell responses has been implicated in various autoimmune disorders, inflammation, and malignancy. Thus, their differentiation and maintenance must be closely regulated to ensure appropriate help to B cells. The generation and function of Tfh cells is regulated by multiple checkpoints including their early priming stage in T zones and throughout the effector stage of differentiation in GCs. Signaling pathways activated downstream of cytokine and costimulatory receptors as well as consequent activation of subset-specific transcriptional factors are essential steps for Tfh cell generation. Thus, understanding the mechanisms underlying Tfh cell-mediated immunity and pathology will bring into spotlight potential targets for novel therapies. In this review, we discuss the recent findings related to the molecular mechanisms of Tfh cell differentiation and their role in normal immune responses and antibody-mediated diseases.

Objective Atherosclerosis is characterized by frequent communication between infiltrating leukocytes and vascular cells, through chemokine and cytokine networks. IL-17C is detectable within atherosclerotic lesions; however the potential involvement of this cytokine has not been examined. Thus we sought to investigate the role of IL-17C in atherosclerosis. Approach and Results The expression of IL-17 cytokines was profiled within Apoe−/− aortas and Il17c expression was elevated. Flow cytometry experiments revealed a major population of aortic IL-17C-producing smooth muscle cells. Next, we generated Il17c−/−Apoe−/− mice and demonstrated that atherosclerotic lesion and collagen content was diminished within WD-fed Il17c−/−Apoe−/− aortas and aortic roots in comparison to Apoe−/− controls. Smooth muscle cells and fibroblasts were mainly responsible for the reduced Col1A1 expression in the aorta of Il17c−/−Apoe−/− mice. Importantly, IL-17C treated Apoe−/− aortas upregulated Col1A1 expression ex vivo. Il17c−/−Apoe−/− mice displayed a proportional reduction in aortic macrophages, neutrophils, T cells, Th1, and Tregs, without corresponding changes in the peripheral immune composition. Examination of aortic IL-17A+ TCRγδ T cells and Th17 cells demonstrated a stark reduction in the percentage and number of these subsets within Il17c−/−Apoe−/− versus Apoe−/− mice. Explanted 12 week WD Apoe−/− aortas treated with IL-17C resulted in the induction of multiple vascular chemokines and cytokines. Th17 cells demonstrated attenuated migration towards supernatants from cultures Il17c−/−Apoe−/− smooth muscle cells and short-term homing experiments revealed diminished recruitment of Th17 cells to the aorta of Il17c−/−Apoe−/− recipients. Conclusions Smooth muscle cell-derived IL-17C plays a pro-atherogenic role by supporting the recruitment of Th17 cells to atherosclerotic lesions.

The adaptive immune response is involved in the development and progression of atherosclerosis and IL-17A(+) cells play a role in this disease. Although elevated number of CD4(+) IL-17A(+) (Th17) and IL-17A(+)TCRγδ(+) T cells are found within murine atherosclerotic aortas and human plaques, the mechanisms governing IL-17A(+) T-cell migration to atherosclerotic lesions are unclear. The chemokine receptor CXCR6 is expressed on several T-cell subsets and plays a pro-atherogenic role in atherosclerosis. Here, we used CXCR6-deficient (Cxcr6 (GFP/GFP) ) apolipoprotein E-deficient (Apoe (-/-) ) mice to investigate the involvement of CXCR6 in the recruitment IL-17A(+) T cells to atherosclerotic aortas. Flow cytometric analyses revealed reductions in Th17 and IL-17A(+)TCRγδ(+) T cells within aged Cxcr6 (GFP/GFP) Apoe (-/-) aortas, in comparison with age-matched Cxcr6 (GFP/+) Apoe (-/-) aortas. Although CXCR6-sufficient IL-17A(+) T cells efficiently migrated toward CXCL16, the migration of CXCR6-deficient IL-17A(+) T cells was abolished in transwell assays. Importantly, the recruitment of Cxcr6 (GFP/GFP) Apoe (-/-) IL-17A(+) T cells into the aortas of Apoe (-/-) recipients was markedly reduced in short-term adoptive transfer experiments. Altogether these results demonstrate an important role of CXCR6 in the regulation of pathological Th17 and IL-17A(+)TCRγδ(+) T-cell recruitment into atherosclerotic lesions.

Background: Micropapillary/solid (MP/S) growth patterns of lung adenocarcinoma are vital for making clinical decisions regarding surgical intervention. This study aimed to predict the presence of a MP/S component in lung adenocarcinoma using radiomics analysis.Methods: Between January 2011 and December 2013, patients undergoing curative invasive lung adenocarcinoma resection were included. Using the "PyRadiomics" package, we extracted 90 radiomics features from the preoperative computed tomography (CT) images. Subsequently, four prediction models were built by utilizing conventional machine learning approaches fitting into radiomics analysis: a generalized linear model (GLM), Naïve Bayes, support vector machine (SVM), and random forest classifiers.The models' accuracy was assessed using a receiver operating curve (ROC) analysis, and the models' stability was validated both internally and externally.Results: A total of 268 patients were included as a primary cohort, and 36.6% (98/268) of them had lung adenocarcinoma with an MP/S component. Patients with an MP/S component had a higher rate of lymph node metastasis (18.4% versus 5.3%) and worse recurrence-free and overall survival. Five radiomics features were selected for model building, and in the internal validation, the four models achieved comparable performance of MP/S prediction in terms of area under the curve (AUC):