NK-CD11c+ Cell Crosstalk in Diabetes Enhances IL-6-Mediated Inflammation during Mycobacterium tuberculosis Infection

In this study, we developed a mouse model of type 2 diabetes mellitus (T2DM) using streptozotocin and nicotinamide and identified factors that increase susceptibility of T2DM mice to infection by Mycobacterium tuberculosis (Mtb). All Mtb-infected T2DM mice and 40% of uninfected T2DM mice died within 10 months, whereas all control mice survived. In Mtb-infected mice, T2DM increased the bacterial burden and pro- and anti-inflammatory cytokine and chemokine production in the lungs relative to those in uninfected T2DM mice and infected control mice. Levels of IL-6 also increased. Anti-IL-6 monoclonal antibody treatment of Mtb-infected acute- and chronic-T2DM mice increased survival (to 100%) and reduced pro- and anti-inflammatory cytokine expression. CD11c+ cells were the major source of IL-6 in Mtb-infected T2DM mice. Pulmonary natural killer (NK) cells in Mtb-infected T2DM mice further increased IL-6 production by autologous CD11c+ cells through their activating receptors. Anti-NK1.1 antibody treatment of Mtb-infected acute-T2DM mice increased survival and reduced pro- and anti-inflammatory cytokine expression. Furthermore, IL-6 increased inflammatory cytokine production by T lymphocytes in pulmonary tuberculosis patients with T2DM. Overall, the results suggest that NK-CD11c+ cell interactions increase IL-6 production, which in turn drives the pathological immune response and mortality associated with Mtb infection in diabetic mice

Th17 cytokines differentiate obesity from obesity-associated type 2 diabetes and promote TNFα production

Objective: T cell inflammation plays pivotal roles in obesity-associated type 2 diabetes (T2DM). The identification of dominant sources of T cell inflammation in humans remains a significant gap in understanding disease pathogenesis. It was hypothesized that cytokine profiles from circulating T cells identify T cell subsets and T cell cytokines that define T2DM-associated inflammation. Methods: Multiplex analyses were used to quantify T cell-associated cytokines in αCD3/αCD28-stimulated PBMCs, or B cell-depleted PBMCs, from subjects with T2DM or BMI-matched controls. Cytokine measurements were subjected to multivariate (principal component and partial least squares) analyses. Flow cytometry detected intracellular TNFα in multiple immune cell subsets in the presence/absence of antibodies that neutralize T cell cytokines. Results: T cell cytokines were generally higher in T2DM samples, but Th17 cytokines are specifically important for classifying individuals correctly as T2DM. Multivariate analyses indicated that B cells support Th17 inflammation in T2DM but not control samples, while monocytes supported Th17 inflammation regardless of T2DM status. Partial least squares regression analysis indicated that both Th17 and Th1 cytokines impact %HbA1c. Conclusions: Among various T cell subsets, Th17 cells are major contributors to inflammation and hyperglycemia and are uniquely supported by B cells in obesity-associated T2DM.National Institutes of Health (U.S.) (Grants R21DK089270, 5R21DE021154, R56 DK096525, R24DK090963, and U01CA182898)Boston University. Genome Science InstituteBoston University. Hematology Training Program (Grant HL007501)National Institute of Diabetes and Digestive and Kidney Diseases (U.S.). Diabetic Complications ConsortiumBoston University. Immunology Training Program (Grant AI007309)United States. Army Research Office (Institute for Collaborative Biotechnologies. Grant W911NF-09-0001

Dividend Policy in Switzerland

Dividends, Payout policy, Signaling, Expected earnings, G14, G35,