Monocyte chemoattractant protein 1 (MCP-1) is a member of the chemokine family of cytokines that mediate leukocyte chemotaxis.

CD4+CD25+ T regulatory cells (Tregs) prevent autoimmune disease, yet little is known about precisely where they exert their influence naturally in a spontaneous autoimmune disorder. Here, we report that Tregs and T effector cells (Teffs) coexist within the pancreatic lesion before type 1 diabetes onset. We find that BDC2.5 T cell receptor transgenic animals contain a small subset of FoxP3 positive CD4+CD25+CD69− cells in the pancreas, actively turning over, expressing the clonotypic receptor, and containing functional regulatory activity. Gene expression profiling confirms that the CD4+CD25+CD69− cells in pancreatic tissue express transcripts diagnostic of regulatory cells, but with significantly higher levels of interleukin 10 and inducible costimulator (ICOS) than their lymph node counterparts. Blockade of ICOS rapidly converts early insulitis to diabetes, which disrupts the balance of Teffs and Tregs and promotes a very broad shift in the expression of the T regulatory–specific profile. Thus, CD4+CD25+69− Tregs operate directly in the autoimmune lesion and are dependent on ICOS to keep it in a nondestructive state.

Objective:The phase IIIb VELOCE study (NCT02545868) assessed responses to selected vaccines in ocrelizumab (OCR)-treated patients with relapsing multiple sclerosis.Methods:Patients were randomized 2:1 into Group OCR (n=68; OCR 600mg); or Control (n=34; interferon-β or no disease-modifying therapy). All received tetanus toxoid (TT)-containing vaccine, Pneumovax® (23-PPV) and keyhole limpet hemocyanin (KLH). Group OCR was subdivided into OCR1 (n=33) and OCR2 (n=35) at randomization. OCR1 received Prevnar® (13-PCV) 4 weeks after 23-PPV; OCR2 and Control received influenza vaccine. Vaccinations started 12 weeks after OCR initiation (Group OCR) or on Day 1 (Control).Results:Positive response rate to TT vaccine at 8 weeks was 23.9% in OCR vs 54.5% in Control. Positive response rate to ≥5 serotypes in 23-PPV at 4 weeks was 71.6% in OCR and 100% in Control. Prevnar® did not enhance response to pneumococcal serotypes in common with Pneumovax®. Humoral response to KLH was decreased in OCR vs Control. Seroprotection rates at 4 weeks against five influenza strains ranged from 55.6–80.0% in OCR2 and 75.0–97.0% in Control.Conclusion:Peripherally B-cell depleted OCR recipients mounted attenuated humoral responses to clinically relevant vaccines and the neoantigen, KLH, suggesting use of standard non-live vaccines while on OCR treatment remains a consideration. For seasonal influenza vaccines, it is recommended to vaccinate patients on OCR, as a potentially protective humoral response, even if attenuated, can be expected.Classification of evidence:This study provides Class II evidence confirming that the humoral response to non-live vaccines in patients with RMS following ocrelizumab treatment is attenuated compared with untreated or interferon-β–treated patients, though can still be expected to be protective.ClinicalTrials.gov registry number:NCT02545868

Foxp3 is required for the generation and activity of CD4+CD25+ regulatory T (T reg) cells, which are important controllers of autoimmunity, including type-1 diabetes. To determine where T reg cells affect the diabetogenic cascade, we crossed the Foxp3 scurfy mutation, which eliminates T reg cells, with the BDC2.5 T cell receptor (TCR) transgenic mouse line. In this model, the absence of T reg cells did not augment the initial activation or phenotypic characteristics of effector T cells in the draining lymph nodes, nor accelerate the onset of T cell infiltration of the pancreatic islets. However, this insulitis was immediately destructive, causing a dramatic progression to overt diabetes. Microarray analysis revealed that T reg cells in the insulitic lesion adopted a gene expression program different from that in lymph nodes, whereas T reg cells in draining or irrelevant lymph nodes appeared very similar. Thus, T reg cells primarily impinge on autoimmune diabetes by reining in destructive T cells inside the islets, more than during the initial activation in the draining lymph nodes.

Insufficient pancreatic β-cell mass or function results in diabetes mellitus. While significant progress has been made in regulating insulin secretion from β-cells in diabetic patients, no pharmacological agents have been described that increase β-cell replication in humans. Here we report aminopyrazine compounds that stimulate robust β-cell proliferation in adult primary islets, most likely as a result of combined inhibition of DYRK1A and GSK3B. Aminopyrazine-treated human islets retain functionality in vitro and after transplantation into diabetic mice. Oral dosing of these compounds in diabetic mice induces β-cell proliferation, increases β-cell mass and insulin content, and improves glycaemic control. Biochemical, genetic and cell biology data point to Dyrk1a as the key molecular target. This study supports the feasibility of treating diabetes with an oral therapy to restore β-cell mass, and highlights a tractable pathway for future drug discovery efforts.

Adjuvants increase vaccine potency largely by activating innate immunity and promoting inflammation. Limiting the side effects of this inflammation is a major hurdle for adjuvant use in vaccines for humans. It has been difficult to improve on adjuvant safety because of a poor understanding of adjuvant mechanism and the empirical nature of adjuvant discovery and development historically. We describe new principles for the rational optimization of small-molecule immune potentiators (SMIPs) targeting Toll-like receptor 7 as adjuvants with a predicted increase in their therapeutic indices. Unlike traditional drugs, SMIP-based adjuvants need to have limited bioavailability and remain localized for optimal efficacy. These features also lead to temporally and spatially restricted inflammation that should decrease side effects. Through medicinal and formulation chemistry and extensive immunopharmacology, we show that in vivo potency can be increased with little to no systemic exposure, localized innate immune activation and short in vivo residence times of SMIP-based adjuvants. This work provides a systematic and generalizable approach to engineering small molecules for use as vaccine adjuvants.

The identification of factors that promote β cell proliferation could ultimately move type 1 diabetes treatment away from insulin injection therapy and toward a cure. We have performed high-throughput, cell-based screens using rodent β cell lines to identify molecules that induce proliferation of β cells. Herein we report the discovery and characterization of WS6, a novel small molecule that promotes β cell proliferation in rodent and human primary islets. In the RIP-DTA mouse model of β cell ablation, WS6 normalized blood glucose and induced concomitant increases in β cell proliferation and β cell number. Affinity pulldown and kinase profiling studies implicate Erb3 binding protein-1 and the IκB kinase pathway in the mechanism of action of WS6.

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