Restoration of a PD-L1 defect in HSPCs reverses diabetes in NOD mice and thus may represent a potential cure for T1D.

Objective.: Neutrophil extracellular traps (NET) expose modified antigens for autoantibodies in vasculitis. Little is known about levels and removal pathways of NET in systemic lupus erythematosus (SLE), especially in lupus nephritis (LN). We determined circulating levels and defined NET removal in large subsets of patients with incident SLE (iSLE), some of whom had new-onset nephritis.Methods.: Serum levels of NET (ELISA), DNase1/DNase1L3 (ELISA), and DNase activity (functional assay) were determined in 216 patients with iSLE [103 had incident LN (iLN)], in 50 patients with other primary glomerulonephritis, and in healthy controls.Ex vivoNET production by neutrophils purified from a random selection of patients was quantified as elastase/DNA release and by immunofluorescence techniques.Results.: Serum NET levels were very high in iSLE/iLN compared to all groups of controls and correlated with anti-dsDNA, C3–C4, and proteinuria; iLN had the highest levels. DNase activity was decreased in iLN compared to SLE (20% had one-half DNase activity) despite similar serum levels of DNase1/DNase1L3. In these cases, pretreatment of serum with protein A restored DNase efficiency; 1 patient was homozygous for a c.289_290delAC variant ofDNASE1L3.Ex vivoNET production by neutrophils purified from LN, SLE, and normal controls was similar in all cases.Conclusion.: Patients with iLN have increased circulating NET and reduced DNase activity, the latter being explained by the presence of inhibitory substances in circulation and/or by rareDNase1L3mutations. Accumulation of NET derives from a multifactorial mechanism, and is associated and may contribute to disease severity in SLE, in particular to renal lesions. (Clinical trial registration: The Zeus study was registered atClinicalTrials.gov, study numberNCT02403115).

SUMMARY Although morphological criteria for apoptosis are in general reliable, no systematic comparison of the techniques employed thus far has yet been performed. In this study, using confocal laser microscopy, we compared the performance of annexin V-FITC and calcein-AM for early detection of apoptosis in living adherent cells. Experiments were carried out on two distinct cell lines, PC 12 and NIH3T3, endowed with different shape and adhesion properties. The apoptotic process was followed for a prolonged period in the same cells of a predetermined field by means of a special flow chamber. Our results show that both probes allowed the detection of apoptotic cells in either cell line. However, some cells that clearly exhibited apoptotic changes on calcein visualization were annexin-negative. In NIH3T3 cells, annexin negativity of apoptotic cells was correlated with the preservation of cell shape and adhesion properties. These findings show that, at least in PC12 and NIH3T3 cells, annexin might be less sensitive than calcein-AM for early apoptosis detection and, for NIH3T3 cells, suggest that phosphatidilserine exposure is in some way linked to changes in cell shape and/or adhesion to culture substrate.

Background: Six titanium disks with six different surface treatments were examined: SS: smooth (polished) surface; TPS: plasma spray; C100: sand blasting by aluminum oxide (Al₂O₃) Ø 100 µm and acid etching; C150: sand blasting by Al₂O₃ Ø 150 µm and acid etching; B60: sand blasting by zirconium oxide (ZrO₂) Ø 60 µm and acid etching; and B120: sand blasting by ZrO₂ Ø 120 µm and acid etching.Methods: The surface characteristics were determined by scanning electron microscopy (SEM) observation and a roughness tester. Raman spectroscopy was used to determine the presence of residual substances on the samples. Cells were seeded onto the disk and after 24 hours, 6 days, and 12 days were observed under SEM and growth curves generated with a cell counter. Some samples were used to determine alkaline phosphatase activity (ALP), using a colorimetric assay.Results: SEM observation revealed drastic differences in surface microtopography, with a higher cell density on sand‐blasted and acid‐etched (SLA) samples than SS and TPS, and more regularly aligned cells on B60 and B120 surfaces than on the others. The growth curves showed a greater adhesion of cells on the etched/blasted surfaces compared to the SS and TPS surfaces. The number of cells increased on all the SLA samples, especially B60, throughout the experiment. At the same time, there was considerable ALP activity on the B60 sample, while it remained at extremely low levels on SS and TPS surfaces. Raman analyses revealed Al₂O₃ debris on C100 and C150, partly explaining the poorer performances of these two surface treatments, since this substance was shown to be toxic for cultured osteoblasts.Conclusions: Surface treatments influence the growth and the metabolic activity of cultured osteoblasts, and B60 seems to be the most favorable surface inducing a more pronounced proliferation of cells together with a high differentiation degree. J Periodontol 2004;75:273‐282.