Protein Kinase C δ: a Gatekeeper of Immune Homeostasis

Human autoimmune disorders present in various forms and are associated with a life-long burden of high morbidity and mortality. Many different circumstances lead to the loss of immune tolerance and often the origin is suspected to be multifactorial. Recently, patients with autosomal recessive mutations in PRKCD encoding protein kinase c delta (PKC) have been identified, representing a monogenic prototype for one of the most prominent forms of humoral systemic autoimmune diseases, systemic lupus erythematosus (SLE). PKC is a signaling kinase with multiple downstream target proteins and with functions in various signaling pathways. Interestingly, mouse models have indicated a special role of the ubiquitously expressed protein in the control of B-cell tolerance revealed by the severe autoimmunity in Prkcd / knockout mice as the major phenotype. As such, the study of PKC deficiency in humans has tremendous potential in enhancing our knowledge on the mechanisms of B-cell tolerance.(VLID)347918

Renal developmental genes are differentially regulated after unilateral ureteral obstruction in neonatal and adult mice

Congenital obstructive nephropathy hinders normal kidney development. The severity and the duration of obstruction determine the compensatory growth of the contralateral, intact opposite kidney. We investigated the regulation of renal developmental genes, that are relevant in congenital anomalies of the kidney and urinary tract (CAKUT) in obstructed and contralateral (intact opposite) kidneys after unilateral ureteral obstruction (UUO) in neonatal and adult mice. Newborn and adult mice were subjected to complete UUO or sham-operation, and were sacrificed 1, 5, 12 and 19 days later. Quantitative RT-PCR was performed in obstructed, intact opposite kidneys and sham controls for Gdnf, Pax2, Six4, Six2, Dach1, Eya1, Bmp4, and Hnf-1 beta. Neonatal UUO induced an early and strong upregulation of all genes. In contrast, adult UUO kidneys showed a delayed and less pronounced upregulation. Intact opposite kidneys of neonatal mice revealed a strong upregulation of all developmental genes, whereas intact opposite kidneys of adult mice demonstrated only a weak response. Only neonatal mice exhibited an increase in BMP4 protein expression whereas adult kidneys strongly upregulated phosphatidylinositol 3 kinase class III, essential for compensatory hypertrophy. In conclusion, gene regulation differs in neonatal and adult mice with UUO. Repair and compensatory hypertrophy involve different genetic programs in developing and adult obstructed kidneys

Detection of Septata intestinalis in Stool Specimens and Coprodiagnostic Monitoring of Successful Treatment with Albendazole

We describe two patients with AIDS and chronic diarrhea in whom the microsporidian Septata intestinalis was detected with use of light and electron microscopic coprodiagnostic techniques. The ultrastructure of the microsporidian spores found in their stool specimens was distinctly different from that of Enterocytozoon bieneusi, another intestinal microsporidian found in patients infected with human immunodeficiency virus. Electron microscopic examination of duodenal biopsy specimens available from one of the patients enabled identification of S. intestinalis and confirmed the similarity of spores found in feces and in duodenal tissue. Both patients' diarrhea stopped when they were treated with albendazole. Coprodiagnostic monitoring indicated disappearance of the parasites and allowed the diagnosis of a relapse in one patient, who responded well to a second course of treatmen

IL-21 restricts T follicular regulatory T cell proliferation through Bcl-6 mediated inhibition of responsiveness to IL-2

T follicular regulatory (Tfr) cells control the magnitude and specificity of the germinal centre reaction, but how regulation is contained to ensure generation of high-affinity antibody is unknown. Here we show that this balance is maintained by the reciprocal influence of interleukin (IL)-2 and IL-21. The number of IL-2-dependent FoxP3+ regulatory T cells is increased in the peripheral blood of human patients with loss-of-function mutations in the IL-21 receptor (IL-21R). In mice, IL-21:IL-21R interactions influence the phenotype of T follicular cells, reducing the expression of CXCR4 and inhibiting the expansion of Tfr cells after T-cell-dependent immunization. The negative effect of IL-21 on Tfr cells in mice is cell intrinsic and associated with decreased expression of the high affinity IL-2 receptor (CD25). Bcl-6, expressed in abundance in Tfr cells, inhibits CD25 expression and IL-21-mediated inhibition of CD25 is Bcl-6 dependent. These findings identify a mechanism by which IL-21 reinforces humoral immunity by restricting Tfr cell proliferation

Effect of inhaled budesonide/formoterol fumarate dihydrate delivered via two different devices on lung function in patients with COPD and low peak inspiratory flow

Background and aims: Low peak inspiratory flow (PIF) is common following severe exacerbations of chronic obstructive pulmonary disease (COPD). Patients with COPD and low PIF may be at risk of suboptimal delivery of inhaled therapies to the airways, especially when using devices such as dry powder inhalers (DPIs), which require greater inspiratory effort than metered dose inhalers (MDIs). We report the results from a 2-week crossover study evaluating the effects of inhaled dual therapy with budesonide/formoterol fumarate dihydrate with an MDI with a spacer versus a DPI in patients with COPD and low PIF. Methods: This randomized, open-label, two-period (each 1 week in duration) crossover efficacy and safety study included patients with severe-to-very severe COPD and PIF < 50 L/min (NCT04078126). Patients were randomized 1:1 to twice-daily budesonide/formoterol fumarate dihydrate MDI (BFF MDI) 320/10 µg with a spacer for 1 week followed by twice-daily budesonide/formoterol fumarate dihydrate DPI (BUD/FORM DPI) 320/9 µg for 1 week, or the inverse. The primary endpoint was peak change from baseline in forced expiratory volume in 1 s (FEV 1 ) within 4 h post-dose following 1 week of treatment. Other assessments included pre-dose lung function, pharmacokinetics, and safety, as assessed by adverse events. Results: The modified intention-to-treat analysis set comprised 30 patients (mean age: 66.9 years; mean baseline FEV 1 : 766 mL; mean COPD assessment test score: 22.20). Following 1 week of treatment, both BFF MDI and BUD/FORM DPI improved mean [95% confidence interval (CI)] peak FEV 1 4 h post-dose [256 (190, 322) mL and 274 (208, 340) mL, respectively]. No clinically meaningful difference between treatments was observed for any lung function endpoint. There were no unexpected safety findings. Conclusion: Dual therapy with BFF MDI and with BUD/FORM DPI led to improvements in lung function in patients with severe-to-very severe COPD and low PIF

Tyrphostin AG490 reduces inflammation and fibrosis in neonatal obstructive nephropathy.

BackgroundCongenital obstructive nephropathy is the main cause of end-stage renal disease in infants and children. Renal insufficiency is due to impaired growth and maturation in the developing kidney with obstruction. Congenital obstructive nephropathy leads to cytokine mediated inflammation and the development of interstitial fibrosis. The Janus kinase-2 (JAK-2) and Signal Transducer and Activator of Transcription'-3 (STAT3) are involved in cytokine production, inflammation, and interstitial fibrosis.MethodsWe studied the role of JAK2/STAT3 in a model of congenital obstructive nephropathy using unilateral ureteral obstruction (UUO) in neonatal mice at the second day of life. Cytokine production, inflammation, and interstitial fibrosis were analyzed in obstructed and sham operated kidneys of neonatal mice treated with or without JAK2/STAT3 inhibitor Tyrphostin AG490. To mimic obstruction and distension, proximal tubular cells were stretched in vitro.ResultsWe show that STAT3 is highly activated in the developing kidney with obstruction and in proximal tubular cells following stretch. JAK2/STAT3 activation mediates cytokine release and leukocyte recruitment into neonatal kidneys after UUO. Pharmacological blockade of JAK2/STAT3 by Tyrphostin AG490 reduced inflammation, tubular apoptosis, and interstitial fibrosis. JAK2/STAT3 blockade decreased pro-inflammatory and profibrotic mediators in tubular cells.ConclusionOur findings provide evidence that JAK2/STAT3 mediates inflammation and fibrosis in the developing kidney with obstruction. Blocking JAK2/STAT3 may prove beneficial in congenital obstructive nephropathy in children