Type 1 diabetes mellitus (T1D) is associated with increased type 1 interferon (IFN) levels and subsequent severe defects in lymphocyte function, which increase susceptibility to infections. The blockade of type 1 IFN receptor 1 (IFNAR1) in non-obese diabetic mice has been shown to delay T1D onset and decrease T1D incidence by enhancing spleen CD4+ T cells and restoring B cell function. However, the effect of type 1 IFN blockade during T1D on splenic CD8+ T cells has not previously been studied. Therefore, we investigated, for the first time, the effect of IFNAR1 blockade on the survival and architecture of spleen-homing CD8+ T cells in a streptozotocin-induced T1D mouse model. Three groups of mice were examined: a non-diabetic control group; a diabetic group; and a diabetic group treated with an anti-IFNAR1blocking antibody. We observed that T1D induction was accompanied by a marked destruction of β cells followed by a marked reduction in insulin levels and increased IFN-α and IFN-β levels in the diabetic group. The diabetic mice also exhibited many abnormal changes including an elevation in blood and spleen free radical (reactive oxygen species and nitric oxide) and pro-inflammatory cytokine (IL-6 and TNF-α) levels, a significant decrease in IL-7 levels, and subsequently, a significant decrease in the numbers of spleen-homing CD8+ T cells. This decrease in spleen-homing CD8+ T cells resulted from a marked reduction in the CCL21-mediated entry of CD8+ T cells into the spleen and from increased apoptosis due to a marked reduction in IL-7-mediated STAT5 and AKT phosphorylation. Interestingly, type 1 IFN signaling blockade in diabetic mice significantly restored the numbers of splenic CD8+ T cells by restoring free radical, pro-inflammatory cytokine and IL-7 levels. These effects subsequently rescued splenic CD8+ T cells from apoptosis through a mechanism that was dependent upon CCL21- and IL-7-mediated signaling. Our data suggest that type 1 IFN is an essential mediator of pathogenesis in T1D and that this role results from the negative effect of IFN signaling on the survival of splenic CD8+ T cells.

Type 1 diabetes mellitus (T1D) is associated with increased type 1 interferon (IFN) levels and subsequent severe defects in lymphocyte function, which increase susceptibility to infections. The blockade of type 1 IFN receptor 1 (IFNAR1) in non-obese diabetic mice has been shown to delay T1D onset and decrease T1D incidence by enhancing spleen CD4+ T cells and restoring B cell function. However, the effect of type 1 IFN blockade during T1D on splenic CD8+ T cells has not previously been studied. Therefore, we investigated, for the first time, the effect of IFNAR1 blockade on the survival and architecture of spleen-homing CD8+ T cells in a streptozotocin-induced T1D mouse model. Three groups of mice were examined: a non-diabetic control group; a diabetic group; and a diabetic group treated with an anti-IFNAR1blocking antibody. We observed that T1D induction was accompanied by a marked destruction of β cells followed by a marked reduction in insulin levels and increased IFN-α and IFN-β levels in the diabetic group. The diabetic mice also exhibited many abnormal changes including an elevation in blood and spleen free radical (reactive oxygen species and nitric oxide) and pro-inflammatory cytokine (IL-6 and TNF-α) levels, a significant decrease in IL-7 levels, and subsequently, a significant decrease in the numbers of spleen-homing CD8+ T cells. This decrease in spleen-homing CD8+ T cells resulted from a marked reduction in the CCL21-mediated entry of CD8+ T cells into the spleen and from increased apoptosis due to a marked reduction in IL-7-mediated STAT5 and AKT phosphorylation. Interestingly, type 1 IFN signaling blockade in diabetic mice significantly restored the numbers of splenic CD8+ T cells by restoring free radical, pro-inflammatory cytokine and IL-7 levels. These effects subsequently rescued splenic CD8+ T cells from apoptosis through a mechanism that was dependent upon CCL21- and IL-7-mediated signaling. Our data suggest that type 1 IFN is an essential mediator of pathogenesis in T1D and that this role results from the negative effect of IFN signaling on the survival of splenic CD8+ T cells.

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Carotenoids content of Botryococcus braunii displayed low nitrate demand; the concentration of 3.2 mM nitrate (50% of Chu 13 medium) resulted in most of the growth magnitude whereas carotenoids increments were highest at 25% (1.6 mM) nitrate. P (net photosynthetic oxygen evolution) and carotenoids content responded opposite to each other at supplemental bicarbonate; carotenoids have been enhanced at low concentrations (0, 1 or 5 mM), being highest at 100% nitrate (6.4 mM) while P N was significantly enhanced at higher concentrations (10, 15 and 20 mM) and vice versa. Enhanced P N N at high carbon and nitrogen may have shifted the metabolism to amino acid synthesis thus inhibiting hydrocarbons synthesis. NaCl (0.15 or 0.2 M) increased carotenoids content 5 times that of the control (zero NaCl) whereas higher salinity concentrations (0.25 and 0.3 M NaCl) were relatively inhibitory. Salinity, in addition, abolished the usual preferential effect of nitrate concentrations on carotenoids accumulation since their level was only slightly less at 6.4 mM than at 50% this concentration (3.2 mM). Collectively, NaCl (0.1-0.2 M) induced highest carotenoids and chlorophyll contents, highest P N and lowest R in 50% nitrate whereas does not have such effect in 100% nitrate. Botryococcus braunii proved strong capability of adjusting the pH of the medium, whether acidic or alkaline, back close to the start. Carotenoids content was not responsive to a wide range of pH values (4-12), exhibiting their highest level at pH 6. D

Carotenoids content of Botryococcus braunii displayed low nitrate demand; the concentration of 3.2 mM nitrate (50% of Chu 13 medium) resulted in most of the growth magnitude whereas carotenoids increments were highest at 25% (1.6 mM) nitrate. P (net photosynthetic oxygen evolution) and carotenoids content responded opposite to each other at supplemental bicarbonate; carotenoids have been enhanced at low concentrations (0, 1 or 5 mM), being highest at 100% nitrate (6.4 mM) while P N was significantly enhanced at higher concentrations (10, 15 and 20 mM) and vice versa. Enhanced P N N at high carbon and nitrogen may have shifted the metabolism to amino acid synthesis thus inhibiting hydrocarbons synthesis. NaCl (0.15 or 0.2 M) increased carotenoids content 5 times that of the control (zero NaCl) whereas higher salinity concentrations (0.25 and 0.3 M NaCl) were relatively inhibitory. Salinity, in addition, abolished the usual preferential effect of nitrate concentrations on carotenoids accumulation since their level was only slightly less at 6.4 mM than at 50% this concentration (3.2 mM). Collectively, NaCl (0.1-0.2 M) induced highest carotenoids and chlorophyll contents, highest P N and lowest R in 50% nitrate whereas does not have such effect in 100% nitrate. Botryococcus braunii proved strong capability of adjusting the pH of the medium, whether acidic or alkaline, back close to the start. Carotenoids content was not responsive to a wide range of pH values (4-12), exhibiting their highest level at pH 6. D