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Found 37769 matches. Displaying 2301-2310
Wu JX, Hayes BW, Phoenix C, Macias GS, Miao YX, Choi HW, Hughes FM, Purves JT, Reinhardt RL, Abraham SN
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A highly polarized T(H)2 bladder response to infection promotes epithelial repair at the expense of preventing new infections

NATURE IMMUNOLOGY 2020 JUN; 21(6):671-683
Urinary tract infections (UTIs) typically evoke prompt and vigorous innate bladder immune responses, including extensive exfoliation of the epithelium. To explain the basis for the extraordinarily high recurrence rates of UTIs, we examined adaptive immune responses in mouse bladders. We found that, following each bladder infection, a highly T helper type 2 (T(H)2)-skewed immune response directed at bladder re-epithelialization is observed, with limited capacity to clear infection. This response is initiated by a distinct subset of CD301b(+)OX40L(+) dendritic cells, which migrate into the bladder epithelium after infection before trafficking to lymph nodes to preferentially activate T(H)2 cells. The bladder epithelial repair response is cumulative and aberrant as, after multiple infections, the epithelium was markedly thickened and bladder capacity was reduced relative to controls. Thus, recurrence of UTIs and associated bladder dysfunction are the outcome of the preferential focus of the adaptive immune response on epithelial repair at the expense of bacterial clearance. Abraham and colleagues show that a highly polarized T(H)2 bladder response to urinary tract infections promotes epithelial repair at the expense of preventing new infections and associated bladder dysfunction.
Khodursky S, Svetec N, Durkin SM, Zhao L
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The evolution of sex-biased gene expression in the Drosophila brain

GENOME RESEARCH 2020 JUN; 30(6):874-884
Genes with sex-biased expression in Drosophila are thought to underlie sexually dimorphic phenotypes and have been shown to possess unique evolutionary properties. However, the forces and constraints governing the evolution of sex-biased genes in the somatic tissues of Drosophila are largely unknown. By using population-scale RNA sequencing data, we show that sex-biased genes in the Drosophila brain are highly enriched on the X Chromosome and that most are biased in a species-specific manner. We show that X-linked male-biased genes, and to a lesser extent female-biased genes, are enriched for signatures of directional selection at the gene expression level. By examining the evolutionary properties of gene-flanking regions on the X Chromosome, we find evidence that adaptive cis-regulatory changes are more likely to drive the expression evolution of X-linked male-biased genes than other X-linked genes. Finally, we examine whether constraint owing to broad expression across multiple tissues and genetic constraint owing to the largely shared male and female genomes could be responsible for the observed patterns of gene expression evolution. We find that expression breadth does not constrain the directional evolution of gene expression in the brain. Additionally, we find that the shared genome between males and females imposes a substantial constraint on the expression evolution of sex-biased genes. Overall, these results significantly advance our understanding of the patterns and forces shaping the evolution of sexual dimorphism in the Drosophila brain.
Thulin NK, Brewer RC, Sherwood R, Bournazos S, Edwards KG, Ramadoss NS, Taubenberger JK, Memoli M, Gentles AJ, Jagannathan P, Zhang S, Libraty DH, Wang TT
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Maternal Anti-Dengue IgG Fucosylation Predicts Susceptibility to Dengue Disease in Infants

CELL REPORTS 2020 MAY 12; 31(6):? Article 107642
Infant mortality from dengue disease is a devastating global health burden that could be minimized with the ability to identify susceptibility for severe disease prior to infection. Although most primary infant dengue infections are asymptomatic, maternally derived anti-dengue immunoglobulin G (IgGs) present during infection can trigger progression to severe disease through antibody-dependent enhancement mechanisms. Importantly, specific characteristics of maternal IgGs that herald progression to severe infant dengue are unknown. Here, we define >= 10% afucosylation of maternal anti-dengue IgGs as a risk factor for susceptibility of infants to symptomatic dengue infections. Mechanistic experiments show that afucosylation of anti-dengue IgGs promotes Fc gamma RIIIa signaling during infection, in turn enhancing dengue virus replication in Fc gamma RIIIa(+) monocytes. These studies identify a post-translational modification of anti-dengue IgGs that correlates with risk for symptomatic infant dengue infections and define a mechanism by which afucosylated antibodies and Fc gamma RIIIa enhance dengue infections.
Yarychkivska O, Shaham S
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Development or Disease: Caspases Balance Growth and Immunity in C. elegans

DEVELOPMENTAL CELL 2020 MAY 4; 53(3):259-260
Caspase proteases execute apoptosis but also function in development. In this issue of Developmental Cell, Weaver et al. report that C. elegans CED-3 caspase promotes animal growth through PMK-1/p38 kinase cleavage, and at the expense of pathogen and stress immunity, revealing an unexpected homeostatic relationship between development and disease.
Jonkman J, Brown CM, Wright GD, Anderson KI, North AJ
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Tutorial: guidance for quantitative confocal microscopy

NATURE PROTOCOLS 2020 MAY; 15(5):1585-1611
This tutorial and the accompanying poster (10.1038/s41596-020-0307-7) provide a guide for performing quantitative fluorescence imaging using confocal microscopy. It includes advice and troubleshooting information from sample preparation and microscope setup to data analysis and statistics. When used appropriately, a confocal fluorescence microscope is an excellent tool for making quantitative measurements in cells and tissues. The confocal microscope's ability to block out-of-focus light and thereby perform optical sectioning through a specimen allows the researcher to quantify fluorescence with very high spatial precision. However, generating meaningful data using confocal microscopy requires careful planning and a thorough understanding of the technique. In this tutorial, the researcher is guided through all aspects of acquiring quantitative confocal microscopy images, including optimizing sample preparation for fixed and live cells, choosing the most suitable microscope for a given application and configuring the microscope parameters. Suggestions are offered for planning unbiased and rigorous confocal microscope experiments. Common pitfalls such as photobleaching and cross-talk are addressed, as well as several troubling instrumentation problems that may prevent the acquisition of quantitative data. Finally, guidelines for analyzing and presenting confocal images in a way that maintains the quantitative nature of the data are presented, and statistical analysis is discussed. A visual summary of this tutorial is available as a poster (10.1038/s41596-020-0307-7).
The pathogenesis of hidradenitis suppurativa (HS) centers around Th17/Treg dysfunction illustrated by lesional elevation of IL-17A, IL-6, and other inflammatory mediators resulting in a chronic feed-forward inflammatory cascade. Similar inflammatory mechanisms have been identified in psoriasis and rheumatoid arthritis (RA) in which traditional immunosuppressants (including methotrexate) are routinely used with reasonable levels of disease control. Methotrexate's mechanism of action in these instances includes downregulation of the Th17 axis via alterations in dendritic cell and T-cell activity and maturation. Published data suggest methotrexate in an ineffective therapy in HS, which does not pair with our current understanding of the mechanisms of disease. The reasons behind this, including are discussed. Some HS patients may benefit from drugs such as methotrexate, and acknowledgment of the potential of disease heterogeneity will allow exploration of which factors may enable identification of such individuals.
Markowitz M, Gettie A, St Bernard L, Andrews CD, Mohri H, Horowitz A, Grasperge BF, Blanchard JL, Niu T, Sun L, Fillgrove K, Hazuda DJ, Grobler JA
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Once-Weekly Oral Dosing of MK-8591 Protects Male Rhesus Macaques From Intrarectal Challenge With SHIV109CP3

JOURNAL OF INFECTIOUS DISEASES 2020 MAY 1; 221(9):1398-1406
Background. MK-8591 (4'-ethynyl-2-fluoro-2'-deoxyadenosine [EFdA]) is a novel reverse transcriptase-translocation inhibitor. Methods. We assessed MK-8591 as preexposure prophylaxis in the rhesus macaque model of intrarectal challenge with simian/human immunodeficiency virus (SHIV). In study 1, 8 rhesus macaques received 3.9 mg/kg of MK-8591 orally on day 0 and once weekly for the next 14 weeks. Eight controls were treated with vehicle. All rhesus macaques were challenged with SHIV109CP3 on day 6 and weekly for up to 12 challenges or until infection was confirmed. The dose of MK-8591 was reduced to 1.3 and 0.43 mg/kg/week in study 2 and further to 0.1 and 0.025 mg/kg/week in study 3. In studies 2 and 3, each dose was given up to 6 times once weekly, and animals were challenged 4 times once weekly with SHIV109CP3. Results. Control macaques were infected after a median of 1 challenge (range, 1-4 challenges). All treated animals in studies 1 and 2 were protected, consistent with a 41.5-fold lower risk of infection (P < .0001, by the log-rank test). In study 3, at a 0.1-mg/kg dose, 2 rhesus macaques became infected, consistent with a 7.2-fold lower risk of infection (P = .0003, by the log-rank test). The 0.025-mg/kg dose offered no protection. Conclusions. These data support MK-8591's potential as a preexposure prophylaxis agent.
Collins D, Zhang Y, Blendy J, Kreek MJ
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Murine model of OPRM1 A118G alters oxycodone self-administration and locomotor activation, but not conditioned place preference

NEUROPHARMACOLOGY 2020 MAY 1; 167(?):? Article 107864
Mu-opioid receptors (MORs) mediate the rewarding properties of oxycodone and other prescription opioid medications, which have played a central role in the current opioid epidemic in the United States. The human mu-opioid receptor gene (OPRM1) contains a functional single nucleotide polymorphism (SNP), A118G, which has been associated with altered opioid addiction risk, however the mechanisms responsible for this are not well understood. To explore this, we examined oxycodone conditioned place preference (CPP) and self-administration behavior (SA) in A112G mice, which possess a functionally analogous SNP in the mouse mu-opioid receptor gene (Oprm1). For CPP, male and female A112G mice homozygous for the A112 (wild-type; AA) or G112 (GG) allele were conditioned with doses of 1 and 3 mg/kg across an 8-day period. For SA, mice were allowed to self administer oxycodone (unit dose 0.25 mg/kg/infusion, FR1) for 4h/day for 10 consecutive days. We observed no effects of genotype or sex on conditioned place preference behavior. Oxycodone 3 mg/kg increased locomotor activity in AA mice but not GG mice, and both male and female GG mice self-administered significantly more oxycodone compared to their wild-type AA littermates. These studies suggest that the G allele promotes greater opioid intake, which may underlie greater opioid addiction morbidity in G-allele carriers.
Gejman RS, Jones HF, Klatt MG, Chang AY, Oh CY, Chandran SS, Korontsvit T, Zakahleva V, Dao T, Klebanoff CA, Scheinberg DA
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Identification of the Targets of T-cell Receptor Therapeutic Agents and Cells by Use of a High-Throughput Genetic Platform

CANCER IMMUNOLOGY RESEARCH 2020 MAY; 8(5):672-684
T-cell receptor (TCR)-based therapeutic cells and agents have emerged as a new class of effective cancer therapies. These therapies work on cells that express intracellular cancer-associated proteins by targeting peptides displayed on MHC receptors. However, cross-reactivities of these agents to off-target cells and tissues have resulted in serious, sometimes fatal, adverse events. We have developed a high-throughput genetic platform (termed "PresentER") that encodes MHC-I peptide minigenes for functional immunologic assays and determines the reactivities of TCR-like therapeutic agents against large libraries of MHC-I ligands. In this article, we demonstrated that PresentER could be used to identify the on-and-off targets of T cells and TCR-mimic (TCRm) antibodies using in vitro coculture assays or binding assays. We found dozens of MHC-I ligands that were cross-reactive with two TCRm antibodies and two native TCRs and that were not easily predictable by other methods.
Surface LE, Burrow DT, Li J, Park J, Kumar S, Lyu C, Song N, Yu Z, Rajagopal A, Bae YJ, Lee BH, Mumm S, Gu CC, Baker JC, Mohseni M, Sum M, Huskey M, Duan S, Bijanki VN, Civitelli R, Gardner MJ, McAndrew CM, Ricci WM, Gurnett CA, Diemer K, Wan F, Costantino CL, Shannon KM, Raje N, Dodson TB, Haber DA, Carette JE, Varadarajan M, Brummelkamp TR, Birsoy K, Sabatini DM, Haller G, Peterson TR
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ATRAID regulates the action of nitrogen-containing bisphosphonates on bone

SCIENCE TRANSLATIONAL MEDICINE 2020 MAY 20; 12(544):? Article eaav9166
Nitrogen-containing bisphosphonates (N-BPs), such as alendronate, are the most widely prescribed medications for diseases involving bone, with nearly 200 million prescriptions written annually. Recently, widespread use of N-BPs has been challenged due to the risk of rare but traumatic side effects such as atypical femoral fracture (AFF) and osteonecrosis of the jaw (ONJ). N-BPs bind to and inhibit farnesyl diphosphate synthase, resulting in defects in protein prenylation. Yet, it remains poorly understood what other cellular factors might allow N-BPs to exert their pharmacological effects. Here, we performed genome-wide studies in cells and patients to identify the poorly characterized gene, ATRAID. Loss of ATRAID function results in selective resistance to N-BP-mediated loss of cell viability and the prevention of alendronate-mediated inhibition of prenylation. ATRAID is required for alendronate inhibition of osteoclast function, and A TRAID-deficient mice have impaired therapeutic responses to alendronate in both postmenopausal and senile (old age) osteoporosis models. Last, we performed exome sequencing on patients taking N-BPs that suffered ONJ or an AFF. ATRAID is one of three genes that contain rare nonsynonymous coding variants in patients with ONJ or an AFF that is also differentially expressed in poor outcome groups of patients treated with N-BPs. We functionally validated this patient variation in ATRAID as conferring cellular hypersensitivity to N-BPs. Our work adds key insight into the mechanistic action of N-BPs and the processes that might underlie differential responsiveness to N-BPs in people.