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Found 37769 matches. Displaying 791-800
Rosas-Umbert M, Gunst JD, Pahus MH, Olesen R, Schleimann M, Denton PW, Ramos V, Ward A, Kinloch NN, Copertino DC, Escriba T, Llano A, Brumme ZL, Jones RB, Mothe B, Brander C, Fox J, Nussenzweig MC, Fidler S, Caskey M, Tolstrup M, Sogaard OS
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Administration of broadly neutralizing anti-HIV-1 antibodies at ART initiation maintains long-term CD8(+) T cell immunity

NATURE COMMUNICATIONS 2022 OCT 29; 13(1):? Article 6473
In simian-human immunodeficiency virus (SHIV)-infected non-human primates, broadly neutralizing antibodies (bNAbs) against the virus appear to stimulate T cell immunity. To determine whether this phenomenon also occurs in humans we measured HIV-1-specific cellular immunity longitudinally in individuals with HIV-1 starting antiviral therapy (ART) with or without adjunctive bNAb 3BNC117 treatment. Using the activation-induced marker (AIM) assay and interferon-gamma release, we observe that frequencies of Pol- and Gag-specific CD8(+) T cells, as well as Gag-induced interferon-gamma responses, are significantly higher among individuals that received adjunctive 3BNC117 compared to ART-alone at 3 and 12 months after starting ART. The observed changes in cellular immunity were directly correlated to pre-treatment 3BNC117-sensitivity. Notably, increased HIV-1-specific immunity is associated with partial or complete ART-free virologic control during treatment interruption for up to 4 years. Our findings suggest that bNAb treatment at the time of ART initiation maintains HIV-1-specific CD8(+) T cell responses that are associated with ART-free virologic control. Broadly neutralising anti-HIV-1 antibody (bNAb) administration in nonhuman primates has been shown to stimulate adaptive T cell-specific immunity, with infection prevention observed. In this work, the authors longitudinally analyse HIV-1 specific cellular immunity in HIV-1- infected individuals starting ART with or without adjunctive bNAb treatment.
Gauhar Z, Tejwani L, Abdullah U, Saeed S, Shafique S, Badshah M, Choi J, Dong WL, Nelson-Williams C, Lifton RP, Lim J, Raja GK
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A Novel Missense Mutation in ERCC8 Co-Segregates with Cerebellar Ataxia in a Consanguineous Pakistani Family

CELLS 2022 OCT; 11(19):? Article 3090
Autosomal-recessive cerebellar ataxias (ARCAs) are heterogeneous rare disorders mainly affecting the cerebellum and manifest as movement disorders in children and young adults. To date, ARCA causing mutations have been identified in nearly 100 genes; however, they account for less than 50% of all cases. We studied a multiplex, consanguineous Pakistani family presenting with a slowly progressive gait ataxia, body imbalance, and dysarthria. Cerebellar atrophy was identified by magnetic resonance imaging of brain. Using whole exome sequencing, a novel homozygous missense mutation ERCC8:c.176T>C (p.M59T) was identified that co-segregated with the disease. Previous studies have identified homozygous mutations in ERCC8 as causal for Cockayne Syndrome type A (CSA), a UV light-sensitive syndrome, and several ARCAs. ERCC8 plays critical roles in the nucleotide excision repair complex. The p.M59T, a substitution mutation, is located in a highly conserved WD1 beta-transducin repeat motif. In silico modeling showed that the structure of this protein is significantly affected by the p.M59T mutation, likely impairing complex formation and protein-protein interactions. In cultured cells, the p.M59T mutation significantly lowered protein stability compared to wildtype ERCC8 protein. These findings expand the role of ERCC8 mutations in ARCAs and indicate that ERCC8-related mutations should be considered in the differential diagnosis of ARCAs.
Renert-Yuval Y, da Rosa JC, Garcet S, Pavel AB, Bares J, Chima M, Hawkes JE, Gilleaudeau P, Sullivan-Whalen M, Singer GK, Krueger JG, Guttman-Yassky E
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Analysis of alopecia areata surveys suggests a threshold for improved patient-reported outcomes

BRITISH JOURNAL OF DERMATOLOGY 2022 OCT; 187(4):539-547
Background Although alopecia areata (AA) greatly impacts patients' quality of life (QoL), there is no adequate validation of AA-targeted QoL surveys in clinical trials, hindering sufficient representation of patient-reported outcomes. Objectives Better understanding of patient-reported outcomes may guide treatment goals and future clinical trials. Methods In a recent randomized controlled trial testing dupilumab in AA, patients were administered the Alopecia Areata Quality of Life Index (AA-QLI) and the Alopecia Areata Symptom Impact Scale (AASIS) surveys, specifically evaluating QoL in patients with AA. An in-depth analysis was performed to assess the utility of these questionnaires in this patient population, both at baseline and after treatment, and to determine a threshold for improved patient-reported outcomes. Results While AASIS correlated with baseline Severity of Alopecia Tool (SALT) scores and with therapeutic response, AA-QLI showed no correlation with AA severity before or after treatment. Itch strongly correlated with serum IgE levels across both surveys. Using various approaches to estimate a discriminative threshold for decreased impact of AA on QoL (by AASIS) following treatment, a SALT score of 20 points or less post-treatment was associated with improved patient-reported outcomes, including both AA-related symptoms and items within the daily activities/feelings domain such as 'feeling sad' and 'feeling anxious or worry'. Conclusions AASIS is better than AA-QLI to assess patient-reported outcomes. SALT <= 20 following treatment should be considered as a threshold for meaningful therapeutic outcome and as a clinical endpoint in future clinical trials for AA. What is already known about this topic? Alopecia areata greatly compromises quality of life, and affected patients have increased prevalences of depression, anxiety and social phobia. Despite the significant negative impact of the disease on patients' wellbeing, validation of targeted questionnaires in alopecia areata is lacking, and a therapeutic response threshold for improved patient-reported outcomes is unknown. What does this study add? This study investigated the utility of two different alopecia areata-targeted questionnaires - Alopecia Areata Quality of Life Index and Alopecia Areata Symptom Impact Scale (AASIS) - in a clinical trial setting. AASIS was found to correlate strongly with alopecia areata severity and clinical response. What are the clinical implications of this work? Patients with <= 20% scalp hair loss after treatment reported improvement in multiple quality-of-life items, suggesting this as a meaningful therapeutic outcome that may guide clinicians and improve the development of future clinical trials.
Yang N, Garcia A, Meyer C, Tuschl T, Merghoub T, Wolchok JD, Deng L
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Heat-inactivated modified vaccinia virus Ankara boosts Th1 cellular and humoral immunity as a vaccine adjuvant

NPJ VACCINES 2022 OCT 19; 7(1):? Article 120
Protein or peptide-based subunit vaccines have generated excitement and renewed interest in combating human cancer or COVID-19 outbreak. One major concern for subunit vaccine application is the weak immune responses induced by protein or peptides. Developing novel and effective vaccine adjuvants are critical for the success of subunit vaccines. Here we explored the potential of heat-inactivated MVA (heat-iMVA) as a vaccine adjuvant. Heat-iMVA dramatically enhances T cell responses and antibodies responses, mainly toward Th1 immune responses when combined with protein or peptide-based immunogen. The adjuvant effect of Heat-iMVA is stronger than live MVA and is dependent on the cGAS/STING-mediated cytosolic DNA-sensing pathway. In a therapeutic vaccination model based on tumor neoantigen peptide vaccine, Heat-iMVA significantly extended the survival and delayed tumor growth. When combined with SARS-CoV-2 spike protein, Heat-iMVA induced more robust spike-specific antibody production and more potent neutralization antibodies. Our results support that Heat-iMVA can be developed as a safe and potent vaccine adjuvant for subunit vaccines against cancer or SARS-CoV-2.
Hashimoto H, Ramirez DH, Lautier O, Pawlak N, Blobel G, Palancade B, Debler EW
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Structure of the pre-mRNA leakage 39-kDa protein reveals a single domain of integrated zf-C3HC and Rsm1 modules

SCIENTIFIC REPORTS 2022 OCT 21; 12(1):? Article 17691
In Saccharomyces cerevisiae, the pre-mRNA leakage 39-kDa protein (ScPml39) was reported to retain unspliced pre-mRNA prior to export through nuclear pore complexes (NPCs). Pml39 homologs outside the Saccharomycetaceae family are currently unknown, and mechanistic insight into Pml39 function is lacking. Here we determined the crystal structure of ScPml39 at 2.5 angstrom resolution to facilitate the discovery of orthologs beyond Saccharomycetaceae, e.g. in Schizosaccharomyces pombe or human. The crystal structure revealed integrated zf-C3HC and Rsm1 modules, which are tightly associated through a hydrophobic interface to form a single domain. Both zf-C3HC and Rsm1 modules belong to the Zn-containing BIR (Baculovirus IAP repeat)-like super family, with key residues of the canonical BIR domain being conserved. Features unique to the Pml39 modules refer to the spacing between the Zn-coordinating residues, giving rise to a substantially tilted helix alpha C in the zf-C3HC and Rsm1 modules, and an extra helix alpha ' in the Rsm1 module. Conservation of key residues responsible for its distinct features identifies S. pombe Rsm1 and Homo sapiens NIPA/ZC3HC1 as structural orthologs of ScPml39. Based on the recent functional characterization of NIPA/ZC3HC1 as a scaffold protein that stabilizes the nuclear basket of the NPC, our data suggest an analogous function of ScPml39 in S. cerevisiae.
Obado SO, Rout MP, Field MC
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Sending the message: specialized RNA export mechanisms in trypanosomes

TRENDS IN PARASITOLOGY 2022 OCT; 38(10):854-867
Export of RNA from the nucleus is essential for all eukaryotic cells and has emerged as a major step in the control of gene expression. mRNA molecules are required to complete a complex series of processing events and pass a quality control system to protect the cytoplasm from the translation of aberrant proteins. Many of these events are highly conserved across eukaryotes, reflecting their ancient origin, but significant deviation from a canonical pathway as described from animals and fungi has emerged in the trypanosomatids. With significant implications for the mechanisms that control gene expression and hence differentiation, responses to altered environments and fitness as a parasite, these deviations may also reveal additional, previously unsuspected, mRNA export pathways.
De Obaldia ME, Morita T, Dedmon LC, Boehmler DJ, Jiang CS, Zeledon EV, Cross JR, Vosshall LB
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Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels

CELL 2022 OCT 27; 185(22):4099-+
Some people are more attractive to mosquitoes than others, but the mechanistic basis of this phenomenon is poorly understood. We tested mosquito attraction to human skin odor and identified people who are excep-tionally attractive or unattractive to mosquitoes. These differences were stable over several years. Chemical analysis revealed that highly attractive people produce significantly more carboxylic acids in their skin em-anations. Mutant mosquitoes lacking the chemosensory co-receptors Ir8a , Ir25a , or Ir76b were severely impaired in attraction to human scent, but retained the ability to differentiate highly and weakly attractive people. The link between elevated carboxylic acids in "mosquito-magnet"human skin odor and phenotypes of genetic mutations in carboxylic acid receptors suggests that such compounds contribute to differential mosquito attraction. Understanding why some humans are more attractive than others provides insights into what skin odorants are most important to the mosquito and could inform the development of more effec-tive repellents.
Yang S, Hiotis G, Wang Y, Chen JJ, Wang JH, Kim M, Reinherz EL, Walz T
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Dynamic HIV-1 spike motion creates vulnerability for its membrane-bound tripod to antibody attack

NATURE COMMUNICATIONS 2022 OCT 27; 13(1):? Article 6393
Vaccines targeting HIV-1's gp160 spike protein are stymied by high viral mutation rates and structural chicanery. gp160's membrane-proximal external region (MPER) is the target of naturally arising broadly neutralizing antibodies (bnAbs), yet MPER-based vaccines fail to generate bnAbs. Here, nanodisc-embedded spike protein was investigated by cryo-electron microscopy and molecular-dynamics simulations, revealing spontaneous ectodomain tilting that creates vulnerability for HIV-1. While each MPER protomer radiates centrally towards the three-fold axis contributing to a membrane-associated tripod structure that is occluded in the upright spike, tilting provides access to the opposing MPER. Structures of spike proteins with bound 4E10 bnAb Fabs reveal that the antibody binds exposed MPER, thereby altering MPER dynamics, modifying average ectodomain tilt, and imposing strain on the viral membrane and the spike's transmembrane segments, resulting in the abrogation of membrane fusion and informing future vaccine development. The membrane-proximal external region of HIV-1 spike protein is a broadly neutralizing antibody target. Here, cryo-electron microscopy and molecular dynamics reveal spontaneous ectodomain tilting, a vulnerability exploitable for vaccine design.
Okazaki A, Ott J
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Machine learning approaches to explore digenic inheritance

TRENDS IN GENETICS 2022 OCT; 38(10):1013-1018
Some rare genetic disorders, such as retinitis pigmentosa or Alport syndrome, are caused by the co-inheritance of DNA variants at two different genetic loci (digenic inheritance). To capture the effects of these disease-causing variants and their possible interactive effects, various statistical methods have been developed in human genetics. Analogous developments have taken place in the field of machine learning, particularly for the field that is now called Big Data. In the past, these two areas have grown independently and have started to converge only in recent years. We discuss an overview of each of the two fields, paying special attention to machine learning methods for uncovering the combined effects of pairs of variants on human disease.
Akagbosu B, Tayyebi Z, Shibu G, Iza YAP, Deep D, Parisotto YF, Fisher L, Pasolli HA, Thevin V, Elmentaite R, Knott M, Hemmers S, Jahn L, Friedrich C, Verter J, Wang ZM, van den Brink M, Gasteiger G, Grunewald TGP, Marie JC, Leslie C, Rudensky AY, Brown CC
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Novel antigen-presenting cell imparts T-reg-dependent tolerance to gut microbiota

NATURE 2022 OCT 27; 610(7933):752-+
Establishing and maintaining tolerance to self-antigens or innocuous foreign antigens is vital for the preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing autoimmune regulator (AIRE) have a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (T-reg) cell development(1-4). Within weeks of birth, a separate wave of T-reg cell differentiation occurs in the periphery upon exposure to antigens derived from the diet and commensal microbiota(5-8), yet the cell types responsible for the generation of peripheral T-reg (pT(reg)) cells have not been identified. Here we describe the identification of a class of ROR gamma t(+) antigen-presenting cells called Thetis cells, with transcriptional features of both mTECs and dendritic cells, comprising four major sub-groups (TC I-TC IV). We uncover a developmental wave of Thetis cells within intestinal lymph nodes during a critical window in early life, coinciding with the wave of pT(reg) cell differentiation. Whereas TC I and TC III expressed the signature mTEC nuclear factor AIRE, TC IV lacked AIRE expression and was enriched for molecules required for pT(reg) generation, including the TGF-beta-activating integrin alpha v beta 8. Loss of either major histocompatibility complex class II (MHCII) or ITGB8 by Thetis cells led to a profound impairment in intestinal pT(reg) differentiation, with ensuing colitis. By contrast, MHCII expression by ROR gamma t(+) group 3 innate lymphoid cells (ILC3) and classical dendritic cells was neither sufficient nor required for pT(reg) generation, further implicating TC IV as the tolerogenic ROR gamma t(+) antigen-presenting cell with an essential function in early life. Our studies reveal parallel pathways for the establishment of tolerance to self and foreign antigens in the thymus and periphery, respectively, marked by the involvement of shared cellular and transcriptional programmes.