The rockefeller university

Photosensitivity, or skin sensitivity to ultraviolet radiation (UVR), is a feature of lupus erythematosus and other autoimmune and dermatologic conditions, but the mechanistic underpinnings are poorly understood. We identify a Langerhans cell (LC)-keratinocyte axis that limits UVR-induced keratinocyte apoptosis and skin injury via keratinocyte epidermal growth factor receptor (EGFR) stimulation. We show that the absence of LCs in Langerin-diphtheria toxin subunit A (DTA) mice leads to photosensitivity and that, in vitro, mouse and human LCs can directly protect keratinocytes from UVR-induced apoptosis. LCs express EGFR ligands and a disintegrin and metalloprotease 17 (ADAM17), the metalloprotease that activates EGFR ligands. Deletion of ADAM17 from LCs leads to photosensitivity, and UVR induces LC ADAM17 activation and generation of soluble active EGFR ligands, suggesting that LCs protect by providing activated EGFR ligands to keratinocytes. Photosensitive systemic lupus erythematosus (SLE) models and human SLE skin show reduced epidermal EGFR phosphorylation and LC defects, and a topical EGFR ligand reduces photosensitivity. Together, our data establish a direct tissue-protective function for LCs, reveal a mechanistic basis for photosensitivity, and suggest EGFR stimulation as a treatment for photosensitivity in lupus erythematosus and potentially other autoimmune and dermatologic conditions.

The African trypanosome Trypanosoma brucei spp. is a paradigm for antigenic variation, the orchestrated alteration of cell surface molecules to evade host immunity. The parasite elicits robust antibody-mediated immune responses to its variant surface glycoprotein (VSG) coat, but evades immune clearance by repeatedly accessing a large genetic VSG repertoire and 'switching' to antigenically distinct VSGs. This persistent immune evasion has been ascribed exclusively to amino-acid variance on the VSG surface presented by a conserved underlying protein architecture. We establish here that this model does not account for the scope of VSG structural and biochemical diversity. The 1.4-angstrom-resolution crystal structure of the variant VSG3 manifests divergence in the tertiary fold and oligomeric state. The structure also reveals an O-linked carbohydrate on the top surface of VSG3. Mass spectrometric analysis indicates that this O-glycosylation site is heterogeneously occupied in VSG3 by zero to three hexose residues and is also present in other VSGs. We demonstrate that this O-glycosylation increases parasite virulence by impairing the generation of protective immunity. These data alter the paradigm of antigenic variation by the African trypanosome, expanding VSG variability beyond amino-acid sequence to include surface post-translational modifications with immunomodulatory impact.

Calcitonin gene-related peptide (CGRP) binds to the complex of the calcitonin receptor-like receptor (CLR) with receptor activity-modifying protein 1 (RAMP1). How CGRP interacts with the transmembrane domain (including the extracellular loops) of this family B receptor remains unclear. In this study, a photoaffinity cross-linker, p-azido L-phenylalanine (azF), was incorporated into CLR, chiefly in the second extracellular loop (ECL2) using genetic code expansion and unnatural amino acid mutagenesis. The method was optimized to ensure efficient photolysis of azF residues near the transmembrane bundle of the receptor. A CGRP analogue modified with fluorescein at position 15 was used for detection of ultraviolet-induced cross-linking. The methodology was verified by confirming the known contacts of CGRP to the extracellular domain of CLR. Within ECL2, the chief contacts were 1284 on the loop itself and L291, at the top of the fifth transmembrane helix (TM5). Minor contacts were noted along the lip of ECL2 between 5286 and L290 and also with M223 in TM3 and F349 in TM6. Full length molecular models of the bound receptor complex suggest that CGRP sits at the top of the TM bundle, with Thr(6) of the peptide making contacts with L291 and H295. 1284 is likely to contact Leu(12) and Ala(13) of CGRP, and Leu(16) of CGRP is at the ECL/extracellular domain boundary of CLR. The reduced potency, E-max, and affinity of [Leu(16)Ala]-human alpha CGRP are consistent with this model. Contacts between Thr(6) of CGRP and H295 may be particularly important for receptor activation.

Lipid membranes play key roles in cells, such as in trafficking, division, infection, remodeling of organelles, among others. The key step in all these processes is creating membrane curvature, typically under the control of many anchored, adhered or included proteins. However, it has become clear that the membrane itself can mediate the interactions among proteins to produce highly ordered assemblies. Computer simulations are ideally suited to investigate protein organization and the dynamics of membrane remodeling at near-micron scales, something that is extremely challenging to tackle experimentally. We review recent computational efforts in modeling protein-caused membrane deformation mechanisms, specifically focusing on coarse-grained simulations. We highlight work that exposed the membrane-mediated ordering of proteins into lines, meshwork, spirals and other assemblies, in what seems to be a very generic mechanism driven by a combination of short and long-ranged forces. Modulating the mechanical properties of membranes is an underexplored signaling mechanism in various processes deserving of more attention in the near future.

Data on new-onset seizures after treatment of aneurysmal subarachnoid hemorrhage (aSAH) patients are limited and variable. We examined the association between new-onset seizures after aSAH and aneurysm treatment modality, as well their relationship with initial clinical severity of aSAH and outcomes. This is a retrospective cohort study of all aSAH patients admitted to our institution over a 6-year period. 'Seizures' were defined as any observed clinical seizure or electrographic seizure on continuous electroencephalogram (cEEG) recordings, as determined by the reviewing neurophysiologist. Subgroup analyses were performed in low-grade (Hunt-Hess 1-3) and high-grade (Hunt-Hess 4-5) patients. Outcomes measures were Glasgow Coma Score (GCS) at intensive care unit (ICU) discharge and modified Rankin Scale (mRS) at outpatient follow-up. There were 282 patients with aSAH; 203 (72.0%) suffered low-grade and 79 (28%) high-grade aSAH. Patients were treated with endovascular coiling (N = 194, 68.8%) or surgical clipping (N = 66, 23.4%). Eighteen (6.4%) patients had seizures, of whom 10 (5.5%) had aneurysm coiling and 7 (10.6%) underwent clipping (p = 0.15). In low-grade patients, seizures occurred less frequently (p = 0.016) and were more common after surgical clipping (p = 0.0089). Seizures correlated with lower GCS upon ICU discharge (p < 0.001), in clipped (p = 0.011) and coiled (p < 0.001) patients and in low-grade aSAH (p < 0.001). Seizures correlated with higher mRS on follow-up (p < 0.001), in clipped (p = 0.032) and coiled (p = 0.004) patients and in low-grade aSAH (p = 0.003). New-onset seizures after aSAH occurred infrequently, and their incidence after aneurysm clipping versus coiling was not significantly different. However, in low-grade patients, new seizures were more frequently associated with clipping than coiling. Additionally, non-convulsive seizures did not occur in low-grade patients treated with coiling. These findings may explain, in part, previous work suggesting better outcomes in coiled patients and encourage physicians to have a lower threshold for cEEG utilization in low-grade patients suspected to have acute seizures after surgical clipping.

Spectacular progress has been made in the characterization of human hyper-IgE syndrome (HIES) over the last 50years. HIES is a primary immunodeficiency defined as an association of atopy in a context of very high serum IgE levels, characteristic bacterial and fungal diseases, low-level clinical and biological inflammation, and various non-hematopoietic developmental manifestations. Somewhat arbitrarily, three disorders were successively put forward as the underlying cause of HIES: autosomal dominant (AD) STAT3 deficiency, the only disorder corresponding to the original definition of HIES, and autosomal recessive (AR) DOCK8 and PGM3 deficiencies, in which atopy and high serum IgE levels occur in a context of manifestations not seen in patients with typical HIES. Indeed, these three disorders disrupt different molecular pathways, affect different cell types, and underlie different clinical phenotypes. Surprisingly, several other inherited inborn errors of immunity in which serum IgE levels are high, sometimes almost as high as those in HIES patients, are not considered to belong to the HIES group of diseases. Studies of HIES have been further complicated by the lack of a high serum IgE phenotype in all mouse models of the disease other than two Stat3 mutant strains. The study of infections in mutant mice has helped elucidate only some forms of HIES and infection. Mouse models of these conditions have also been used to study non-hematopoietic phenotypes for STAT3 deficiency, tissue-specific immunity for DOCK8 deficiency, and cell lineage maturation for PGM3 deficiency. We review here the history of the field of HIES since the first clinical description of this condition in 1966, together with the three disorders commonly referred to as HIES, focusing, in particular, on their mouse models. We propose the restriction of the term HIES to patients with an AD STAT3-deficiency phenotype, including the most recently described AR ZNF341 deficiency, thus excluding AR DOCK8 and PGM3 deficiencies from the definition of this disease.

Background. Mosaic immunogens are bioinformatically engineered human immunodeficiency virus type 1 (HIV-1) sequences designed to elicit clade-independent coverage against globally circulating HIV-1 strains. Methods. This phase 1, double-blinded, randomized, placebo-controlled trial enrolled healthy HIV-uninfected adults who received 2 doses of a modified vaccinia Ankara (MVA)-vectored HIV-1 bivalent mosaic immunogen vaccine or placebo on days 0 and 84. Two groups were enrolled: those who were HIV-1 vaccine naive (n = 15) and those who had received an HIV-1 vaccine (Ad26.ENVA.01) 4-6 years earlier (n = 10). We performed prespecified blinded cellular and humoral immunogenicity analyses at days 0, 14, 28, 84, 98, 112, 168, 270, and 365. Results. All 50 planned vaccinations were administered. Vaccination was safe and generally well tolerated. No vaccine-related serious adverse events occurred. Both cellular and humoral cross-clade immune responses were elicited after 1 or 2 vaccinations in all participants in the HIV-1 vaccine-naive group. Env-specific responses were induced after a single immunization in nearly all subjects who had previously received the prototype Ad26.ENVA.01 vaccine. Conclusions. No safety concerns were identified, and multiclade HIV-1-specific immune responses were elicited.

Research question: What level of IVF pregnancy success is currently possible in women of extremely advanced age? Design: This study reports on outcomes in women aged 43-51 years at the Centre for Human Reproduction, an academically affiliated private clinical fertility and research centre in New York City. Results: During the study years of 2014-2016, 16 pregnancies were established, all through day 3 transfers. Based on 'intent to treat' (cycle start). clinical pregnancy rates were 4/190 (2.1%), 5/234 (2.1%) and 7/304 (2.3%) and live birth rates were 2/190 (1.1%), 1/234 (0.43%) and 4/304 (1.3%) in 2014, 2015 and 2016, respectively. With reference to embryo transfer, clinical pregnancy rates were 4/140 (2.9%), 5/159 (3.1%) and 7/167 (4.2%) and live birth rates were 2/140 (1.4%), 1/159 (0.63%) and 4/167 (2.4%) for the same years. The results for 2016 also included what are probably the two oldest autologous IVF pregnancies ever reported in the literature. These results were obtained with patient ages, percentage of cycle cancellations and other adverse outcome parameters steadily increasing year by year. Conclusions: Female age above 42 is widely viewed as the ultimate barrier to conception with IVF. Data reported here, although small and preliminary, demonstrate that potential outcomes are better than widely perceived, while pregnancy and live birth rates remain significantly inferior to donor egg recipient cycles. However, for selected women at very advanced ages, especially with higher egg/embryo numbers, autologous oocyte IVF offers a better option than widely acknowledged, if they are given individualized age-specific care. (C) 2018 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

The pathogenesis of degenerative disc disease is a complex and multifactorial process in which genetics, mechanical trauma, altered loading and nutrition present significant etiological factors. Infection of the intervertebral disc with the anaerobic bacterium Propionibacteriumacnes is now also emerging as a potentially new etiological factor. This human commensal bacterium is well known for its long association with the inflammatory skin condition acne vulgaris. A key component of inflammatory responses to P. acnes in acne appears to be interleukin (IL)-1 beta. Similarly, in degenerative disc disease (DDD) there is compelling evidence for the fundamental roles of IL-1 beta in its pathology. We therefore propose that P. acnes involvement in DDD is biologically very plausible, and that IL-1 beta is the key inflammatory mechanism driving the host response to P. acnes infection. Since there is a solid theoretical basis for this phenomenon, we further propose that the relationship between P. acnes infection and DDD is causal.