We have recently demonstrated that dendritic cells (DC) prepared from nonobese diabetic (NOD) mice, a spontaneous model for insulin-dependent diabetes mellitus, exhibit elevated levels of NF-κB activation upon stimulation. In the current study, we investigated the influence of dysregulation of NF-κB activation on the APC function of bone marrow-derived DC prepared from NOD vs BALB/c and nonobese diabetes-resistant mice. NOD DC pulsed with either peptide or virus were found to be more efficient than BALB/c DC at stimulating in vitro naive Ag-specific CD8+ T cells. The T cell stimulatory capacity of NOD DC was suppressed by gene transfer of a modified form of IκBα, indicating a direct role for NF-κB in this process. Furthermore, neutralization of IL-12(p70) to block autocrine-mediated activation of DC also significantly reduced the capacity of NOD DC to stimulate T cells. Despite a reduction in low molecular mass polypeptide-2 expression relative to BALB/c DC, no effect on proteasome-dependent events associated with the NF-κB signaling pathway or Ag processing was detected in NOD DC. Finally, DC from nonobese diabetes-resistant mice, a strain genotypically similar to NOD yet disease resistant, resembled BALB/c and not NOD DC in terms of the level of NF-κB activation, secretion of IL-12(p70) and TNF-α, and the capacity to stimulate T cells. Therefore, elevated NF-κB activation and enhanced APC function are specific for the NOD genotype and correlate with the progression of insulin-dependent diabetes mellitus. These results also provide further evidence indicating a key role for NF-κB in regulating the APC function of DC.

C5a is a proinflammatory mediator that has recently been shown to regulate adaptive immune responses. Here we demonstrate that C5a receptor (C5aR) signaling in DC affects the development of Treg and Th17 cells.

In this study, we have investigated the use of plasmid DNA (pDNA) vaccination to elicit Th2 effector cell function in an Ag-specific manner and in turn prevent insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice. pDNA recombinants were engineered encoding a secreted fusion protein consisting of a fragment of glutamic acid decarboxylase 65 (GAD65) linked to IgGFc, and IL-4. Intramuscular injection of pDNA encoding GAD65-IgGFc and IL-4 effectively prevented diabetes in NOD mice treated at early or late preclinical stages of IDDM. This protection was GAD65-specific since NOD mice immunized with pDNA encoding hen egg lysozyme-IgGFc and IL-4 continued to develop diabetes. Furthermore, disease prevention correlated with suppression of insulitis and induction of GAD65-specific regulatory Th2 cells. Importantly, GAD65-specific immune deviation was dependent on pDNA-encoded IL-4. In fact, GAD65-specific Th1 cell reactivity was significantly enhanced in animals immunized with pDNA encoding only GAD65-IgGFc. Finally, NOD.IL4null mice treated with pDNA encoding GAD65-IgGFc and IL-4 continued to develop diabetes, indicating that endogenous IL-4 was also required for disease prevention. These results demonstrate that pDNA vaccination is an effective strategy to elicit β cell-specific Th2 regulatory cell function for the purpose of preventing IDDM even at a late stage of disease development.

Insulin-dependent diabetes mellitus (IDDM) is characterized by the T cell-mediated destruction of insulin-producing β cells. Accordingly, APCs, such as macrophage, have also been shown to be important in the disease process. However, the role(s) of dendritic cells (DCs) that exhibit potent APC function remains undefined in IDDM. Here we demonstrate that DCs derived from nonobese diabetic (NOD) mice, a model for IDDM, are more sensitive to various forms of stimulation compared with those from C57BL/6 and BALB/c mice, resulting in increased IL-12 secretion. This property is a consequence of hyperactivation of NF-κB, a transcription factor known to regulate IL-12 gene expression. Specifically, NOD DCs exhibit persistent hyperactivation of both IκB kinase and NF-κB in response to stimuli, in addition to selective degradation of IκBε. Transfection of NOD DCs with a modified form of IκBα significantly reduced IL-12 secretion, suggesting that hyperactivation of NF-κB was in part responsible for increased IL-12 production. An enhanced capacity of NOD DCs to secrete IL-12 would be expected to contribute to the development of pathogenic Th1 (Tc1) cells during the diabetogenic response.

Background Hyperuricemia is associated with essential hypertension in children. No previous studies have evaluated the effect of hyperuricemia on progression of chronic kidney disease (CKD) in children. Study Design Prospective observational cohort study. Setting & Participants Children and adolescents (n=678 cross-sectional; n=627 longitudinal) with a median age of 12.3 (IQR, 8.6–15.6) years enrolled at 52 North American sites of the CKD in Children (CKiD) study. Predictor Serum uric acid (<5.5, 5.5–7.5, and >7.5 mg/dL). Outcomes Composite endpoint of either >30% decline in glomerular filtration rate (GFR) or initiation of renal replacement therapy. Measurements Age, sex, race, blood pressure status, GFR, CKD etiology, urine proteincreatinine ratio (<0.5, 0.5 to <2.0, ≥2.0 mg/mg), age- and sex-specific BMI >95th percentile, use of diuretics, and serum uric acid. Results 162, 294, and 171 participants had initial uric acid < 5.5, 5.5–7.5, or > 7.5 mg/dL, respectively. Older age, male sex, lower GFR, and BMI > 95th percentile were associated with higher uric acid. We observed 225 instances of the composite endpoint over five years. In a multivariable parametric time-to-event analysis, compared to participants with initial uric acid <5.5 mg/dL, those with uric acid of 5.5–7.5 or >7.5 mg/dL had 17% shorter (relative time, 0.83; 95% CI, 0.62–1.11) or 38% shorter (relative time, 0.62; 95% CI, 0.45–0.85) times to event, respectively. Hypertension, lower GFR, glomerular CKD etiology, and elevated urine protein-creatinine ratio were also associated with faster times to the composite endpoint. Limitations The study lacked sufficient data to examine how use of specific medications might influence serum uric acid and CKD progression. Conclusions Hyperuricemia is a previously undescribed, independent risk factor for faster progression of CKD in children and adolescents. It is possible that treatment of children and adolescents with CKD with urate-lowering therapy could slow disease progression.

The survival of pediatric patients on chronic dialysis has improved over two decades of dialysis registry data, specifically for children <1year.

Adult and pediatric patients with ESRD have impaired maximum oxygen consumption (VO 2 max), a reflection of the cardiopulmonary system's ability to meet increased metabolic demands. We sought to determine factors associated with decreased VO 2 max in pediatric patients with different stages of CKD. VO 2 max was measured using a standardized exercise testing protocol in patients with stage 2 to 4 chronic kidney disease (CKD) (n ϭ 46), in renal transplant recipients (n ϭ 22), in patients treated with maintenance hemodialysis (n ϭ 12), and in age-matched healthy controls (n ϭ 33). VO 2 max was similar between children with stage 2 CKD and controls, whereas lower VO 2 max was observed among children with stage 3 to 4 CKD, those treated with hemodialysis, and transplant recipients. In univariate analysis, VO 2 max was significantly associated with body mass index, resting heart rate, C-reactive protein, serum triglycerides, serum creatinine, and measures of diastolic function; no significant associations with left ventricular structure or systolic function were identified. In multivariate regression analysis, patient category versus control and the presence of diastolic dysfunction were independent predictors of lower VO 2 max. These results suggest that aerobic capacity is decreased in the early stages of CKD in children and that lower VO 2 max can be predicted by the presence of diastolic dysfunction, even if systolic function is normal. Maximal aerobic capacity (VO 2 max) represents the cardiovascularsystem'sabilitytotakeup,distribute,andutilize oxygen to perform work during maximal exercise. Healthy individuals can sustain a three-fold increase in heart rate (HR) and a two-fold increase in stroke volume to generate maximal aerobic capacity. 1 Therefore, VO 2 max has been used to assess the capacity of the cardiovascular system to respond to metabolic challenge in numerous disease states including ESRD. 2,3 Impaired maximal aerobic capacity was observed in adult and adolescent patients with ESRD as well as after renal transplantation. [4][5][6][7] The significance of these findings was underscored by studies suggesting lower survival rates in adults with ESRD and decreased VO 2 max. 8 The impairedVO 2 maxinthesepatientswasassociatedwithseveralfactors,includinglowerserumalbumin,anemia,and chronic heart failure. 9 Symptomatic heart disease is a rare event in pediatric patients with CKD. However abnormal cardiac structure and function in children with CKD is well recognized. These patients have left ventricular (LV) diastolic dysfunction and increased LV mass even before the onset of ESRD. 10,11 LV systolic function is generally preserved at rest, but altered contractile reserve was observed during exercise in di-

We previously demonstrated that administration of plasmid DNAs (pDNAs) encoding IL-4 and a fragment of glutamic acid decarboxylase 65 (GAD65) fused to IgGFc induces GAD65-specific Th2 cells and prevents insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice. To assess the general applicability of pDNA vaccination to mediate Ag-specific immune deviation, we examined the immunotherapeutic efficacy of recombinants encoding murine insulin A and B chains fused to IgGFc. Insulin was chosen based on studies demonstrating that administration of insulin or insulin B chain by a variety of strategies prevents IDDM in NOD mice. Surprisingly, young NOD mice receiving i.m. injections of pDNA encoding insulin B chain-IgGFc with or without IL-4 exhibited an accelerated progression of insulitis and developed early diabetes. Exacerbation of IDDM correlated with an increased frequency of IFN-γ-secreting CD4+ and CD8+ T cells in response to insulin B chain-specific peptides compared with untreated mice. In contrast, treatment with pDNAs encoding insulin A chain-IgGFc and IL-4 elicited a low frequency of IL-4-secreting Th cells and had no effect on the progression of IDDM. Vaccination with pDNAs encoding GAD65-IgGFc and IL-4, however, prevented IDDM. These results demonstrate that insulin- and GAD65-specific T cell reactivity induced by pDNA vaccination has distinct effects on the progression of IDDM.