Brief exposure of skin to near-infrared (NIR) laser light has been shown to augment the immune response to intradermal vaccination and thus act as an immunologic adjuvant. Although evidence indicates that the NIR laser adjuvant has capacity to activate innate subsets including dendritic cells (DCs) in skin as conventional adjuvants do, the precise immunological mechanism by which the NIR laser adjuvant acts is largely unknown. Here we sought to identify the cellular target of the NIR laser adjuvant by using an established mouse model of intradermal influenza vaccination and examining the alteration of responses resulting from genetic ablation of specific DC populations. We found that a continuous wave (CW) NIR laser adjuvant broadly modulates migratory DC populations, specifically increasing and activating the Lang+ and CD11b−Lang− subsets in skin, and that the antibody responses augmented by the CW NIR laser are dependent on DC subsets expressing CCR2 and Langerin. In comparison, a pulsed wave (PW) NIR laser adjuvant showed limited effects on the migratory DC subsets. Our vaccination study demonstrated that the efficacy of CW NIR laser is significantly better than that of PW laser, indicating that the CW NIR laser offers a desirable immunostimulatory microenvironment for migratory DCs. These results demonstrate the unique ability of the NIR laser adjuvant to selectively target specific migratory DC populations in skin depending on its parameters, and highlight the importance of optimization of laser parameters for desirable immune protection induced by a NIR laser-adjuvanted vaccine.

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BackgroundMigraine is common in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) but its treatment responses are not well described, and its relationship to stroke risk unknown. Encephalopathy is a less common presentation; it has been suggested it is related to migraine. We characterised migraine patterns and treatment responses in CADASIL, and examined associations between migraine and both stroke risk and encephalopathy.Methods300 symptomatic CADASIL patients were prospectively recruited from a national referral clinic over a nineteen year period, from 1996 to 2015. Data was collected using a standardised questionnaire. Migraine was classified according to the International Classification of Headache Disorders, 3rd edition (beta version). A cross-sectional analysis was carried out on the data collected.ResultsMigraine was present in 226 (75.3%), and the presenting feature in 203 (67.7%). It was usually accompanied by aura (89.8%). Patients showed variable responses to a variety of drugs for migraine. Of 24 given triptans, 45.5% had consistent or partial responses. None had complications following triptans. Thirty-three (11.0%) patients experienced encephalopathy lasting on average 8.1 ± 3.4 days. Patients with migraine with aura had higher odds of encephalopathy (OR = 5.4; 95%CI 1.6–28.4; p = 0.002). Patients with confusional aura had higher odds of encephalopathy than those with other aura types (OR = 2.5, 95%CI = 1.0–5.8, p = 0.04). There was also no increase in risk of encephalopathy with sex or age at onset of migraine. Migraineurs had a lower stroke risk than non-migraineurs (HR = 0.46, 95%CI 0.3–0.6, p = 2.1x10-6).ConclusionsMigraine with aura is a prominent feature of CADASIL. Treatment responses are similar to those seen in the general migraine population and no complications were observed with triptans. Migraine with aura was associated with increased risk of encephalopathy suggesting they may share pathophysiological mechanisms. There was no increased stroke risk associated with migraine, but risk appeared to be reduced although this finding needs confirming.

Cerebral small vessel disease (SVD) is a common cause of lacunar strokes, vascular cognitive impairment (VCI) and vascular dementia. SVD is thought to result in reduced cerebral blood flow, impaired cerebral autoregulation and increased blood-brain barrier (BBB) permeability. However, the molecular mechanisms underlying SVD are incompletely understood. Recent studies in monogenic forms of SVD, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and 'sporadic' SVD have shed light on possible disease mechanisms in SVD. Proteomic and biochemical studies in post-mortem monogenic SVD patients, as well as in animal models of monogenic disease have suggested that disease pathways are shared between different types of monogenic disease, often involving the impairment of extracellular matrix (ECM) function. In addition, genetic studies in 'sporadic' SVD have also shown that the disease is highly heritable, particularly among young-onset stroke patients, and that common variants in monogenic disease genes may contribute to disease processes in some SVD subtypes. Genetic studies in sporadic lacunar stroke patients have also suggested distinct genetic mechanisms between subtypes of SVD. Genome-wide association studies (GWAS) have also shed light on other potential disease mechanisms that may be shared with other diseases involving the white matter, or with pathways implicated in monogenic disease. This review brings together recent data from studies in monogenic SVD and genetic studies in 'sporadic' SVD. It aims to show how these provide new insights into the pathogenesis of SVD, and highlights the possible convergence of disease mechanisms in monogenic and sporadic SVD.

ObjectivesTo determine the frequency of rare and pertinent disease-causing variants in small vessel disease (SVD)-associated genes (such as NOTCH3, HTRA1, COL4A1, COL4A2, FOXC1, TREX1, and GLA) in cerebral SVD, we performed targeted gene sequencing in 950 patients with younger-onset apparently sporadic SVD stroke using a targeted sequencing panel.MethodsWe designed a high-throughput sequencing panel to identify variants in 15 genes (7 known SVD genes, 8 SVD-related disorder genes). The panel was used to screen a population of 950 patients with younger-onset (≤70 years) MRI-confirmed SVD stroke, recruited from stroke centers across the United Kingdom. Variants were filtered according to their frequency in control databases, predicted effect, presence in curated variant lists, and combined annotation dependent depletion scores. Whole genome sequencing and genotyping were performed on a subset of patients to provide a direct comparison of techniques. The frequency of known disease-causing and pertinent variants of uncertain significance was calculated.ResultsWe identified previously reported variants in 14 patients (8 cysteine-changing NOTCH3 variants in 11 patients, 2 HTRA1 variants in 2 patients, and 1 missense COL4A1 variant in 1 patient). In addition, we identified 29 variants of uncertain significance in 32 patients.ConclusionRare monogenic variants account for about 1.5% of younger onset lacunar stroke. Most are cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy variants, but the second most common gene affected is HTRA1. A high-throughput sequencing technology platform is an efficient, reliable method to screen for such mutations.