Many mRNA-based vaccines have been investigated for their specific potential to activate dendritic cells (DCs), the highly-specialized antigen-presenting cells of the immune system that play a key ...role in inducing effective CD4+ and CD8+ T-cell responses. In this paper we report a new vaccine/gene delivery platform that demonstrates the benefits of using a self-amplifying ("replicon") mRNA that is protected in a viral-protein capsid. Purified capsid protein from the plant virus Cowpea Chlorotic Mottle Virus (CCMV) is used to in vitro assemble monodisperse virus-like particles (VLPs) containing reporter proteins (e.g., Luciferase or eYFP) or the tandem-repeat model antigen SIINFEKL in RNA gene form, coupled to the RNA-dependent RNA polymerase from the Nodamura insect virus. Incubation of immature DCs with these VLPs results in increased activation of maturation markers - CD80, CD86 and MHC-II - and enhanced RNA replication levels, relative to incubation with unpackaged replicon mRNA. Higher RNA uptake/replication and enhanced DC activation were detected in a dose-dependent manner when the CCMV-VLPs were pre-incubated with anti-CCMV antibodies. In all experiments the expression of maturation markers correlates with the RNA levels of the DCs. Overall, these studies demonstrate that: VLP protection enhances mRNA uptake by DCs; coupling replicons to the gene of interest increases RNA and protein levels in the cell; and the presence of anti-VLP antibodies enhances mRNA levels and activation of DCs in vitro. Finally, preliminary in vivo experiments involving mouse vaccinations with SIINFEKL-replicon VLPs indicate a small but significant increase in antigen-specific T cells that are doubly positive for IFN and TFN induction.
Aims
Patients with heart failure are at higher risk of progression to end‐stage renal disease (ESRD), regardless of ejection fraction (EF). We assessed the renal effects of angiotensin–neprilysin ...inhibition in a pooled analysis of 13 195 patients with heart failure with reduced and preserved EF.
Methods and results
We combined data from PARADIGM‐HF (EF ≤40%; n = 8399) and PARAGON‐HF (EF ≥45%; n = 4796) in a pre‐specified pooled analysis. We assessed the effect of treatment (sacubitril/valsartan vs. enalapril or valsartan) on a composite of either ≥50% reduction in estimated glomerular filtration rate (eGFR), ESRD, or death from renal causes, in addition to changes in eGFR slope. We assessed whether baseline renal function or EF modified the effect of therapy on renal outcomes. At randomization, eGFR was 68 ± 20 ml/min/1.73 m2 in PARADIGM‐HF and 63 ± 19 ml/min/1.73 m2 in PARAGON‐HF. The composite renal outcome occurred in 70 of 6594 patients (1.1%) in the sacubitril/valsartan group and in 123 of 6601 patients (1.9%) in the valsartan or enalapril group (hazard ratio 0.56, 95% confidence interval CI 0.42–0.75; p < 0.001). The mean eGFR change was −1.8 (95% CI −1.9 to −1.7) ml/min/1.73 m2/year for the sacubitril/valsartan group, compared with −2.4 (95% CI −2.5 to −2.2) ml/min/1.73 m2/year for the valsartan or enalapril group. The treatment effect on the composite renal endpoint was not modified by categories of baseline eGFR (p‐interaction = 0.64), but was most pronounced in those with baseline EF between 30% and 60% (p‐interaction = 0.001).
Conclusions
In patients with heart failure, sacubitril/valsartan reduced the risk of serious adverse renal outcomes and slowed decline in eGFR, compared with valsartan or enalapril, independent of baseline renal function.
The targeted delivery of therapeutic drugs to lymph nodes (LNs) provides an unprecedented opportunity to improve the outcomes of transplantation and immune-mediated diseases. The high endothelial ...venule is a specialized segment of LN vasculature that uniquely expresses peripheral node addressin (PNAd) molecules. PNAd is recognized by MECA79 mAb. We previously generated a MECA79 mAb-coated microparticle (MP) that carries tacrolimus. Although this MP trafficked to LNs, it demonstrated limited therapeutic efficacy in our transplant model. Here, we have synthesized a nanoparticle (NP) as a carrier of anti-CD3, and optimized the conjugation strategy to coat the NP surface with MECA79 mAb (MECA79-anti-CD3-NP) to enhance LN accumulation. As compared with nonconjugated NPs, a significantly higher quantity of MECA79-NPs accumulated in the draining lymph node (DLN). Many MECA79-NPs underwent internalization by T cells and dendritic cells within the LNs. Short-term treatment of murine cardiac allograft recipients with MECA79-anti-CD3-NP resulted in significantly prolonged allograft survival in comparison with the control groups. Prolonged graft survival following treatment with MECA79-anti-CD3-NP was characterized by a significant increase in intragraft and DLN Treg populations. Treg depletion abrogated the prolongation of heart allograft survival. We believe this targeted approach of drug delivery could redefine the methods of administering immune therapeutics in transplantation.
Approximately 70% of illicit cocaine consumed in the United States is contaminated with levamisole. Most commonly used as a veterinary antihelminthic agent, levamisole is a known immunomodulating ...agent. Prolonged use in humans has been associated with cutaneous vasculitis and agranulocytosis. We describe the development of a systemic autoimmune disease associated with antineutrophil cytoplasmic antibodies (ANCA) in cocaine users. This complication appears to be linked to combined cocaine and levamisole exposure.
Cases were identified between March 2009 and November 2010 at Massachusetts General Hospital's ANCA laboratory. Cocaine exposure was identified from patient history in all cases. Medical records were reviewed for clinical presentation and for laboratory and diagnostic evaluation.
Thirty cases of ANCA positivity associated with cocaine ingestion were identified. All had antimyeloperoxidase antibodies and 50% also had antiproteinase 3 antibodies. Complete clinical and laboratory data were available for 18 patients. Arthralgia (83%) and skin lesions (61%) were the most frequent complaints at presentation. Seventy-two percent of patients reported constitutional symptoms, including fever, night sweats, weight loss, or malaise. Four patients had biopsy-proven vasculitis. Two cases of acute kidney injury and three cases of pulmonary hemorrhage occurred. From the entire cohort of 30, two cases were identified during the first 3 months of our study period and nine cases presented during the last 3 months.
We describe an association between the ingestion of levamisole-contaminated cocaine and ANCA-associated systemic autoimmune disease. Our data suggest that this is a potentially life-threatening complication of cocaine use.
Patients recently hospitalized for heart failure (HF) are at high risk for rehospitalization and death.
The purpose of this study was to investigate clinical outcomes and response to dapagliflozin in ...patients with HF with mildly reduced or preserved left ventricular ejection fraction (LVEF) who were enrolled during or following hospitalization.
The DELIVER (Dapagliflozin Evaluation to Improve the LIVES of Patients With PReserved Ejection Fraction Heart Failure) trial randomized patients with HF and LVEF >40% to dapagliflozin or placebo. DELIVER permitted randomization during or shortly after hospitalization for HF in clinically stable patients off intravenous HF therapies. This prespecified analysis investigated whether recent HF hospitalization modified risk of clinical events or response to dapagliflozin. The primary outcome was worsening HF event or cardiovascular death.
Of 6,263 patients in DELIVER, 654 (10.4%) were randomized during HF hospitalization or within 30 days of discharge. Recent HF hospitalization was associated with greater risk of the primary outcome after multivariable adjustment (HR: 1.88; 95% CI: 1.60-2.21; P < 0.001). Dapagliflozin reduced the primary outcome by 22% in recently hospitalized patients (HR: 0.78; 95% CI: 0.60-1.03) and 18% in patients without recent hospitalization (HR: 0.82; 95% CI: 0.72-0.94; Pinteraction = 0.71). Rates of adverse events, including volume depletion, diabetic ketoacidosis, or renal events, were similar with dapagliflozin and placebo in recently hospitalized patients.
Dapagliflozin safely reduced risk of worsening HF or cardiovascular death similarly in patients with and without history of recent HF hospitalization. Starting dapagliflozin during or shortly after HF hospitalization in patients with mildly reduced or preserved LVEF appears safe and effective. (Dapagliflozin Evaluation to Improve the LIVEs of Patients With PReserved Ejection Fraction Heart Failure DELIVER; NCT03619213)
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Background
Solid‐organ transplant (SOT) recipients with coronavirus disease 2019 (COVID‐19) have higher risk of adverse outcomes compared to the general population. Whether hospitalized SOT ...recipients with COVID‐19 are at higher risk of mortality than SOT recipients hospitalized for other causes, including non‐COVID‐19 pneumonia, remains unclear.
Methods
We used logistic regression to compare outcomes of SOT recipients hospitalized with COVID‐19 to non‐COVID‐19 related admissions and with non‐COVID‐19 pneumonia.
Results
Of 17,012 hospitalized SOT recipients, 1682 had COVID‐19. Those with COVID‐19 had higher odds of ICU admission (adjusted odds ratio aOR 2.12 95%CI: 1.88–2.39) and mechanical ventilation (aOR 3.75 95%CI: 3.24–4.33). COVID‐19 was associated with higher odds of in‐hospital death, which was more pronounced earlier in the pandemic (aOR 9.74 95%CI: 7.08–13.39 for April/May vs. aOR 7.08 95%CI: 5.62–8.93 for June through November 2020; P‐interaction = .03). Compared to SOT recipients hospitalized with non‐COVID‐19 pneumonia, odds of in‐hospital death were higher in SOT recipients with COVID‐19 (aOR 2.44 95% CI: 1.90–3.13), regardless of time of hospitalization (P‐interaction > .40).
Conclusions
In this large cohort of SOT recipients, hospitalization with COVID‐19 was associated with higher odds of complications and in‐hospital mortality than non‐COVID‐19 related admissions, and 2.5‐fold higher odds of in‐hospital mortality, compared to SOT recipients with non‐COVID‐19 pneumonia.
Although the immune response within draining lymph nodes (DLNs) has been studied for decades, how their stromal compartment contributes to this process remains to be fully explored. Here, we show ...that donor mast cells were prominent activators of collagen I deposition by fibroblastic reticular cells (FRCs) in DLNs shortly following transplantation. Serial analysis of the DLN indicated that the LN stroma did not return to its baseline microarchitecture following organ rejection and that the DLN contained significant fibrosis following repetitive organ transplants. Using several FRC conditional-knockout mice, we show that induction of senescence in the FRCs of the DLN resulted in massive production of collagen I and a proinflammatory milieu within the DLN. Stimulation of herpes virus entry mediator (HVEM) on FRCs by its ligand LIGHT contributed chiefly to the induction of senescence in FRCs and overproduction of collagen I. Systemic administration of ex vivo-expanded FRCs to mice decreased DLN fibrosis and strengthened the effect of anti-CD40L in prolonging heart allograft survival. These data demonstrate that the transformation of FRCs into proinflammatory myofibroblasts is critically important for the maintenance of a proinflammatory milieu within a fibrotic DLN.
Negative costimulatory molecules, acting through so-called inhibitory pathways, play a crucial role in the control of T cell responses. This negative "second signal" opposes T cell receptor ...activation and leads to downregulation of T cell proliferation and promotes antigen specific tolerance. Much interest has focused upon these pathways in recent years as a method to control detrimental alloresponses and promote allograft tolerance. However, recent experimental data highlights the complexity of negative costimulatory pathways in alloimmunity. Varying effects are observed from molecules expressed on donor and recipient tissues and also depending upon the activation status of immune cells involved. There appears to be significant overlap and redundancy within these systems, rendering this a challenging area to understand and exploit therapeutically. In this article, we will review the literature at the current time regarding the major negative costimulation pathways including CTLA-4:B7, PD-1:PD-L1/PD-L2 and PD-L1:B7-1, B7-H3, B7-H4, HVEM:BTLA/CD160, and TIM-3:Galectin-9. We aim to outline the role of these pathways in alloimmunity and discuss their potential applications for tolerance induction in transplantation.
Ischemia reperfusion injuries (IRI) are unavoidable in solid organ transplantation. IRI augments alloimmunity but the mechanisms involved are poorly understood. Herein, we examined the effect of IRI ...on antigen specific alloimmunity. We demonstrate that ischemia promotes alloimmune activation, leading to more severe histological features of rejection, and increased CD4
and CD8
T cell graft infiltration, with a predominantly CD8
IFNγ
infiltrate. This process is dependent on the presence of alloreactive CD4
T cells, where depletion prevented infiltration of ischemic grafts by CD8
IFNγ
T cells. IL-6 is a known driver of ischemia-induced rejection. Herein, depletion of donor antigen-presenting cells reduced ischemia-induced CD8
IFNγ
allograft infiltration, and improved allograft outcomes. Following prolonged ischemia, accelerated rejection was observed despite treatment with CTLA4Ig, indicating that T cell costimulatory blockade failed to overcome the immune activating effect of IRI. However, despite severe ischemic injury, treatment with anti-IL-6 and CTLA4Ig blocked IRI-induced alloimmune injury and markedly improved allograft survival. We describe a novel pathway where IRI activates innate immunity, leading to upregulation of antigen specific alloimmunity, resulting in chronic allograft injury. Based on these findings, we describe a clinically relevant treatment strategy to overcome the deleterious effect of IRI, and provide superior long-term allograft outcomes.
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