Patients with type 2 diabetes (T2D) have disease-associated changes in B-cell function, but the role these changes play in disease pathogenesis is not well established. Data herein show B cells from obese mice produce a proinflammatory cytokine profile compared with B cells from lean mice. Complementary in vivo studies show that obese B cell-null mice have decreased systemic inflammation, inflammatory B-and T-cell cytokines, adipose tissue inflammation, and insulin resistance (IR) compared with obese WT mice. Reduced inflammation in obese/insulin resistant B cell-null mice associates with an increased percentage of anti-inflammatory regulatory T cells (Tregs). This increase contrasts with the sharply decreased percentage of Tregs in obese compared with lean WT mice and suggests that B cells may be critical regulators of T-cell functions previously shown to play important roles in IR. We demonstrate that B cells from T2D (but not non-T2D) subjects support proinflammatory T-cell function in obesity/T2D through contact-dependent mechanisms. In contrast, human monocytes increase proinflammatory T-cell cytokines in both T2D and non-T2D analyses. These data support the conclusion that B cells are critical regulators of inflammation in T2D due to their direct ability to promote proinflammatory T-cell function and secrete a proinflammatory cytokine profile. Thus, B cells are potential therapeutic targets for T2D.immunometabolism | lymphocytes M ultiple studies support the concept that inflammation strongly associates with insulin resistance (IR), which, in addition to loss of islet function, defines type 2 diabetes (T2D) (1). Work implicating B cells in IR/T2D is limited. We showed B cells from T2D subjects secrete a proinflammatory cytokine profile, including an extraordinary inability to secrete the potent anti-inflammatory cytokine IL-10 and an elevated production of proinflammatory IL-8 compared with B cells from non-T2D subjects (2). Given the importance of B-cell IL-10 in preventing numerous inflammatory diseases (3, 4) and the links between IL-8 and T2D (5, 6), these data suggest that altered B-cell cytokine production plays an important role in initiating or promoting IR/T2D. Published analyses further support a role for B cells in IR and include studies of B cell-null New Zealand Obese (NZO) mice, which, in contrast to B cell-sufficient NZOs, fail to develop IR in response to obesity (7). These findings have been recently reproduced in studies showing obese B cell-null or B cell-depleted mice have less inflammation and IR than obese WT mice (8). Interestingly, T-cell cytokine production is decreased in obese B cell-null mouse adipose tissue (AT) (8), which raises the possibility that, in addition to production of a proinflammatory cytokine profile, B cells may function in IR by regulating the T cell-mediated inflammation known to drive disease pathogenesis (9, 10). We identified a proinflammatory T-cell ratio [defined by increased Th17 cells plus decreased regulatory T cells (Tregs)] in T2D patients that mirror...

Accurate and comprehensive extraction of information from high-dimensional single cell datasets necessitates faithful visualizations to assess biological populations. A state-of-the-art algorithm for non-linear dimension reduction, t-SNE, requires multiple heuristics and fails to produce clear representations of datasets when millions of cells are projected. We develop opt-SNE, an automated toolkit for t-SNE parameter selection that utilizes Kullback-Leibler divergence evaluation in real time to tailor the early exaggeration and overall number of gradient descent iterations in a dataset-specific manner. The precise calibration of early exaggeration together with opt-SNE adjustment of gradient descent learning rate dramatically improves computation time and enables high-quality visualization of large cytometry and transcriptomics datasets, overcoming limitations of analysis tools with hard-coded parameters that often produce poorly resolved or misleading maps of fluorescent and mass cytometry data. In summary, opt-SNE enables superior data resolution in t-SNE space and thereby more accurate data interpretation.

Highlights d CD4 + T cells from healthy older people preferentially produce a Th17 profile d Autophagy, but not mitophagy, knockdown activates a Th17 profile in ''young'' cells d Mitochondrial ROS is needed, but not sufficient, for a Th17 profile in ''young'' cells d Metformin improves autophagy and mitochondria in parallel to decrease inflammaging

Low levels of type I interferon (IFN-I) are thought to be a driving force for immune activation and T-cell exhaustion in HIV-1 infected individuals on combination antiretroviral therapy (cART), though the causative mechanisms for persistent IFN-I signaling have remained unclear. Here, we show Rev–CRM1-dependent nuclear export and peripheral membrane association of intron-containing HIV-1 RNA, independent of primary viral sequence or viral protein expression, is subject to sensing and signaling via MAVS, resulting in IFN-I-dependent pro-inflammatory responses in macrophages. Additionally, HIV-1 intron-containing-RNA-induced innate immune activation of macrophages leads to upregulation of inhibitory receptor expression and functional immune exhaustion of co-cultured T cells. Our findings suggest that persistent expression of HIV-1 intron-containing RNA in macrophages contributes to chronic immune activation and T-cell dysfunction and that use of HIV RNA expression inhibitors as adjunct therapy might abrogate aberrant inflammation and restore immune function in HIV-infected individuals on cART.

No abstract

IL-17 is proinflammatory cytokine secreted by a unique CD4+ T (Th 17 ) cell subset and proposed to play a role in host defense. We hypothesized that Th 17 cells are lost in HIV-1 infection. HIV-1-infected children with plasma viremia below 50 copies/ml had IL-17 production, whereas those with detectable viremia had minimal secretion. These results imply viral-mediated destruction or impairment of Th 17 cells and argue for complete suppression of viremia for reconstitution of Th 17 cells.IL-17 is a proinflammatory cytokine [1], unique in that it is produced by a distinct subset of human CD4+ (Th 17 ) cells [2]. Recent studies [3][4][5][6][7][8][9] highlight the influence of IL-17 as a mediator of tissue inflammation in several autoimmune disorders and host defense. IL-17 may have a direct role in Candida or Mycobacterial infections, and a loss of Th 17 cells could potentially lead to vulnerability to opportunistic infections [10][11][12][13]. In this study, we assessed the impact of HIV-1 infection on Th 17 cells in a cohort of HIV-1-infected children [14]. First, we stimulated peripheral blood mononuclear cells (PBMCs) from healthy subjects with various monoclonal antibodies (mAb) and mitogenic stimuli for detection of IL-17 production in vitro. We observed that stimulation with anti-CD3/anti-CD28 mAbs induced IL-17 secretion, primarily by CD4+ T cells (data not shown). In response to anti-CD3/anti-CD28 stimulation, the majority of the Th 17 cells did not coexpress IFN-γ. In contrast, stimulation with phorbol myristate acetate/ionomycin induced IL-17 secretion from both CD4+ and CD8+ T cells, as well as dual secreting IL-17/IFN-γ T cell subsets (data not shown). These results suggest that anti-CD3/anti-CD28 stimulation is an effective method to We next tested for the frequency of Th 17 cells in PBMCs using an anti-CD3/anti-CD28 stimulation IL-17 enzyme-linked immunosorbent spot assay in 12 HIV-1-infected children with differing levels of plasma viremia and compared this to a group of HIV-1-uninfected subjects who served as controls. The median number of IL-17-specific spot forming units (SFU) in healthy pediatric and adult subjects was 300 SFU/10 6 (range: 85-970 SFU/10 6 ; n = 12) and 760 SFU/10 6 (range: 110-1370 SFU/10 6 ; n = 7), respectively (Fig. 1a). A marked reduction in Th 17 cells was observed in the HIV-1-infected children (median: 62 SFU/10 6 ; range: 10-270 SFU/10 6 ; n = 12). Strikingly, the infected children with HIV-1 plasma viral loads exceeding 50 copies/ml had minimal numbers of Th 17 cells (median: 35 SFU/10 6 ; range: 10-95 SFU/10 6 ; n = 7), whereas those with suppressed viral loads had higher levels of Th 17 cells (median: 170 SFU/10 6 ; range: 75-270 SFU/10 6 ; n = 5). Interestingly, all groups had robust IFN-γ secretion (Fig. 1b). Flow cytometry assessment confirmed that CD4+ T cells were the primary source of IL-17 following anti-CD3/anti-CD28 mAb stimulation (data not shown). We carried out a univariate logistic regression analysis to test for an association between HIV-1 plasm...

Mycobacterium tuberculosis (MTB) is a leading cause of mortality worldwide from an infectious agent. Natural killer T (NKT) cells recognize mycobacterial antigens and contribute to anti-MTB immunity in mouse models. NKT cells were measured in subjects with pulmonary tuberculosis, MTB-exposed individuals, and healthy controls. NKT cell levels are selectively lower in peripheral blood mononuclear cells from individuals with pulmonary tuberculosis than in both MTB-exposed subjects and healthy control subjects. This apparent loss of NKT cells from the peripheral blood is sustained during the 6 months after the initiation of MTB treatment. These findings indicate that NKT cells may be an important component of antituberculosis immunity.

No abstract