Modified Vaccinia Virus Ankara-Based Vaccine Vectors Induce Apoptosis in Dendritic Cells Draining from the Skin via both the Extrinsic and Intrinsic Caspase Pathways, Preventing Efficient Antigen Presentation

Dendritic cells (DC) are potent antigen-presenting cells and central to the induction of immune responses following infection or vaccination. The collection of DC migrating from peripheral tissues by cannulation of the afferent lymphatic vessels provides DC which can be used directly ex vivo without extensive in vitro manipulations. We have previously used bovine migrating DC to show that recombinant human adenovirus 5 vectors efficiently transduce afferent lymph migrating DEC-205(+) CD11c(+) CD8(-) DC (ALDC). We have also shown that recombinant modified vaccinia virus Ankara (MVA) infects ALDC in vitro, causing downregulation of costimulatory molecules, apoptosis, and cell death. We now show that in the bovine system, modified vaccinia virus Ankara-induced apoptosis in DC draining from the skin occurs soon after virus binding via the caspase 8 pathway and is not associated with viral gene expression. We also show that after virus entry, the caspase 9 pathway cascade is initiated. The magnitude of T cell responses to mycobacterial antigen 85A (Ag85A) expressed by recombinant MVA-infected ALDC is increased by blocking caspase-induced apoptosis. Apoptotic bodies generated by recombinant MVA (rMVA)-Ag85A-infected ALDC and containing Ag85A were phagocytosed by noninfected migrating ALDC expressing SIRPα via actin-dependent phagocytosis, and these ALDC in turn presented antigen. However, the addition of fresh ALDC to MVA-infected cultures did not improve on the magnitude of the T cell responses; in contrast, these noninfected DC showed downregulation of major histocompatibility complex class II (MHC-II), CD40, CD80, and CD86. We also observed that MVA-infected ALDC promoted migration of DEC-205(+) SIRPα(+) CD21(+) DC as well as CD4(+) and CD8(+) T cells independently of caspase activation. These in vitro studies show that induction of apoptosis in DC by MVA vectors is detrimental to the subsequent induction of T cell responses

<p>Antithrombotic Treatment after Carotid Stenting in Patients with Concomitant Atrial Fibrillation</p>

BACKGROUND AND PURPOSE: Antithrombotic therapy following carotid artery stent placement with concomitant atrial fibrillation is not well-established. Our aim was to assess the safety and efficacy of the combination of direct oral anticoagulants and a P2Y12 inhibitor at 30?days after carotid artery stent placement in patients with atrial fibrillation.& nbsp;MATERIALS AND METHODS: We designed an observational single-center study including patients who underwent carotid artery stent placement with concomitant atrial fibrillation. We studied 3 groups according to antithrombotic therapy: 1) the direct oral anticoagulants plus clopidogrel (DC) group: receiving direct oral anticoagulants plus a P2Y12 inhibitor; 2) the triple therapy group: anticoagulation and dual antiplatelet therapy; and 3) the dual antiplatelet therapy group: following dual antiplatelet therapy alone. The safety outcome was a major or clinically relevant non-major bleeding event at the first month. The efficacy outcomes were the thromboembolic events (myocardial infarction, stroke, systemic embolism, or stent thrombosis).& nbsp;RESULTS: Of 959 patients with carotid artery stent placement, 91 met the inclusion criteria, including 24 patients in the DC group, 42 patients in the triple therapy group, and 25 in the dual antiplatelet therapy group. The mean age was 72.27 (SD, 8.1?) years, with similar baseline characteristics. The median CHA(2)DS(2)-VASc score for each group was 6 (interquartile range ?= 5?6), 5 (interquartile range = 4?6), and 5 (interquartile range = 4?6), respectively. The median HAS-BLED score was 4 in the 3 groups (P?=?.17). The primary safety end point was 23.8% in the triple therapy group compared with 4% in the dual antiplatelet therapy group (P?=?.032), with no bleeding events in the DC group (P?=?.007). There was 1 stent thrombosis in DC group and a cardioembolic stroke in the dual antiplatelet therapy group (P?=?.41).& nbsp;CONCLUSIONS: Among patients with carotid artery stent placement with atrial fibrillation, triple therapy confers a high bleeding risk. A regimen of direct oral anticoagulants plus a P2Y12 inhibitor might confer a good safety profile with significantly lower rates of bleeding and optimal efficacy

MRI predicts intracranial hemorrhage in patients who receive long-term oral anticoagulation

OBJECTIVE: We tested the hypothesis that the risk of intracranial hemorrhage (ICH) in patients with cardioembolic ischemic stroke who are treated with oral anticoagulants (OAs) can be predicted by evaluating surrogate markers of hemorrhagic-prone cerebral angiopathies using a baseline MRI. METHODS: Patients were participants in a multicenter and prospective observational study. They were older than 64 years, had a recent cardioembolic ischemic stroke, and were new users of OAs. They underwent a baseline MRI analysis to evaluate microbleeds, white matter hyperintensities, and cortical superficial siderosis. We collected demographic variables, clinical characteristics, risk scores, and therapeutic data. The primary endpoint was ICH that occurred during follow-up. We performed bivariate and multivariate Cox regression analyses. RESULTS: We recruited 937 patients (aged 77.6 +/- 6.5 years; 47.9% were men). Microbleeds were detected in 207 patients (22.5%), moderate/severe white matter hyperintensities in 419 (45.1%), and superficial siderosis in 28 patients (3%). After a mean follow-up of 23.1 +/- 6.8 months, 18 patients (1.9%) experienced an ICH. In multivariable analysis, microbleeds (hazard ratio 2.7, 95% confidence interval [CI] 1.1-7, p = 0.034) and moderate/severe white matter hyperintensities (hazard ratio 5.7, 95% CI 1.6-20, p = 0.006) were associated with ICH (C index 0.76, 95% CI 0.66-0.85). Rate of ICH was highest in patients with both microbleed and moderate/severe WMH (3.76 per 100 patient-years, 95% CI 1.62-7.4). CONCLUSION: Patients taking OAs who have advanced cerebral small vessel disease, evidenced by microbleeds and moderate to severe white matter hyperintensities, had an increased risk of ICH. Our results should help to determine the risk of prescribing OA for a patient with cardioembolic stroke. CLINICALTRIALSGOV IDENTIFIER: NCT02238470