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Gleicher N, Kushnir VA, Barad DH
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Redirecting reproductive immunology research toward pregnancy as a period of temporary immune tolerance

JOURNAL OF ASSISTED REPRODUCTION AND GENETICS 2017 APR; 34(4):425-430
Referring to two recent publications, we here propose that clinical reproductive immunology has for decades stagnated because reproductive medicine, including assisted reproduction (AR), has failed to accept embryo implantation as an immune system-driven process, dependent on establishment of maternal tolerance toward the implanting fetal semi-allograft (and complete allograft in cases of oocyte donation). Pregnancy represents a biologically unique period of temporary (to the period of gestation restricted) tolerance, otherwise only known in association with parasitic infections. Rather than investigating the immune pathways necessary to induce this rather unique state of tolerance toward the rapidly growing parasitic antigen load of the fetus, the field, instead, concentrated on irrelevant secondary immune phenomena (i.e., "immunological noise"). It, therefore, does not surprise that interesting recent research, offering new potential insights into maternal tolerance during pregnancy, was mostly published outside of the field of reproductive medicine. This research offers evidence for existence of inducible maternal tolerance pathways with the ability of improving maternal fecundity and, potentially, reducing such late pregnancy complications as premature labor and preeclampsia/eclampsia due to premature abatement of maternal tolerance. Increasing evidence also suggests that tolerance-inducing immune pathways are similar in successful pregnancy, successful organ transplantation and, likely also in the tolerance of "self" (i.e., prevention of autoimmunity). Identifying and isolating these pathways, therefore, may greatly benefit all three of these clinical areas, and research in reproductive immunology should be accordingly redirected.
Fischer JC, Bscheider M, Eisenkolb G, Lin CC, Wintges A, Otten V, Lindemans CA, Heidegger S, Rudelius M, Monette S, Rodriguez KAP, Calafiore M, Liebermann S, Liu C, Lienenklaus S, Weiss S, Kalinke U, Ruland J, Peschel C, Shono Y, Docampo M, Velardi E, Jenq RR, Hanash AM, Dudakov JA, Haas T, van den Brink MRM, Poeck H
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RIG-I/MAVS and STING signaling promote gut integrity during irradiation- and immune-mediated tissue injury

SCIENCE TRANSLATIONAL MEDICINE 2017 APR 19; 9(386):? Article eaag2513
The molecular pathways that regulate the tissue repair function of type I interferon (IFN-I) during acute tissue damage are poorly understood. We describe a protective role for IFN-I and the RIG-I/MAVS signaling pathway during acute tissue damage in mice. Mice lacking mitochondrial antiviral-signaling protein (MAVS) were more sensitive to total body irradiation- and chemotherapy-induced intestinal barrier damage. These mice developed worse graft-versus-host disease (GVHD) in a preclinical model of allogeneic hematopoietic stem cell transplantation (allo-HSCT) than did wild-type mice. This phenotype was not associated with changes in the intestinal microbiota but was associated with reduced gut epithelial integrity. Conversely, targeted activation of the RIG-I pathway during tissue injury promoted gut barrier integrity and reduced GVHD. Recombinant IFN-I or IFN-I expression induced by RIG-I promoted growth of intestinal organoids in vitro and production of the antimicrobial peptide regenerating islet-derived protein 3 y (Reg1117). Our findings were not confined to RIG-I/MAVS signaling because targeted engagement of the STING (stimulator of interferon genes) pathway also protected gut barrier function and reduced GVHD. Consistent with this, STING-deficient mice suffered worse GVHD after allo-HSCT than did wild-type mice. Overall, our data suggest that activation of either RIG-I/MAVS or STING pathways during acute intestinal tissue injury in mice resulted in IFN-I signaling that maintained gut epithelial barrier integrity and reduced GVHD severity. Targeting these pathways may help to prevent acute intestinal injury and GVHD during allogeneic transplantation.
Gleicher N, Metzger J, Croft G, Kushnir VA, Albertini DF, Barad DH
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A single trophectoderm biopsy at blastocyst stage is mathematically unable to determine embryo ploidy accurately enough for clinical use

REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY 2017 APR 27; 15(?):? Article 33
Background: It has become increasingly apparent that the trophectoderm (TE) at blastocyst stage is much more mosaic than has been appreciated. Whether preimplantation genetic screening (PGS), utilizing a single TE biopsy (TEB), can reliably determine embryo ploidy has, therefore, increasingly been questioned in parallel. Methods: We for that reason here established 2 mathematical models to assess probabilities of false-negative and false-positive results of an on average 6-cell biopsy from an approximately 300-cell TE. This study was a collaborative effort between investigators at The Center for Human Reproduction in New York City and the Center for Studies in Physics and Biology and the Brivanlou Laboratory of Stem Cell Biology and Molecular Embryology, the latter two both at Rockefeller University in New York City. Results: Both models revealed that even under best case scenario, assuming even distribution of mosaicism in TE (since mosaicism is usually clonal, a highly unlikely scenario), a biopsy of at least 27 TE cells would be required to reach minimal diagnostic predictability from a single TEB. Conclusions: As currently performed, a single TEB is, therefore, mathematically incapable of reliably determining whether an embryo can be transferred or should be discarded. Since a single TEB, as currently performed, apparently is not representative of the complete TE, this study, thus, raises additional concern about the clinical utilization of PGS.
Sadagopan S, Zarco W, Freiwald WA
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A causal relationship between face-patch activity and face-detection behavior

ELIFE 2017 APR 4; 6(?):? Article e18558
The primate brain contains distinct areas densely populated by face-selective neurons. One of these, face-patch ML, contains neurons selective for contrast relationships between face parts. Such contrast-relationships can serve as powerful heuristics for face detection. However, it is unknown whether neurons with such selectivity actually support face-detection behavior. Here, we devised a naturalistic face-detection task and combined it with fMRI-guided pharmacological inactivation of ML to test whether ML is of critical importance for real-world face detection. We found that inactivation of ML impairs face detection. The effect was anatomically specific, as inactivation of areas outside ML did not affect face detection, and it was categorically specific, as inactivation of ML impaired face detection while sparing body and object detection. These results establish that ML function is crucial for detection of faces in natural scenes, performing a critical first step on which other face processing operations can build.
Wang WW, MacKinnon R
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Cryo-EM Structure of the Open Human Ether-a-go-go-Related K+ Channel hERG

CELL 2017 APR 20; 169(3):422-430.e10
The human ether-a-go-go-related potassium channel (hERG, Kv11.1) is a voltage-dependent channel known for its role in repolarizing the cardiac action potential. hERG alteration by mutation or pharmacological inhibition produces Long QT syndrome and the lethal cardiac arrhythmia torsade de pointes. We have determined the molecular structure of hERG to 3.8 angstrom using cryo-electron microscopy. In this structure, the voltage sensors adopt a depolarized conformation, and the pore is open. The central cavity has an atypically small central volume surrounded by four deep hydrophobic pockets, which may explain hERG's unusual sensitivity to many drugs. A subtle structural feature of the hERG selectivity filter might correlate with its fast inactivation rate, which is key to hERG's role in cardiac action potential repolarization.
Modell JW, Jiang WY, Marraffini LA
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CRISPR-Cas systems exploit viral DNA injection to establish and maintain adaptive immunity

NATURE 2017 APR 6; 544(7648):101-104
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems provide protection against viral(1) and plasmid(2) infection by capturing short DNA sequences from these invaders and integrating them into the CRISPR locus of the prokaryotic host(1). These sequences, known as spacers, are transcribed into short CRISPR RNA guides(3-5) that specify the cleavage site of Cas nucleases in the genome of the invader(6-8). It is not known when spacer sequences are acquired during viral infection. Here, to investigate this, we tracked spacer acquisition in Staphylococcus aureus cells harbouring a type II CRISPR-Cas9 system after infection with the staphylococcal bacteriophage f12. We found that new spacers were acquired immediately after infection preferentially from the cos site, the viral free DNA end that is first injected into the cell. Analysis of spacer acquisition after infection with mutant phages demonstrated that most spacers are acquired during DNA injection, but not during other stages of the viral cycle that produce free DNA ends, such as DNA replication or packaging. Finally, we showed that spacers acquired from early-injected genomic regions, which direct Cas9 cleavage of the viral DNA immediately after infection, provide better immunity than spacers acquired from late-injected regions. Our results reveal that CRISPR-Cas systems exploit the phage life cycle to generate a pattern of spacer acquisition that ensures a successful CRISPR immune response.
Bowles NP, McEwen BS, Boutin-Foster C
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Trouble in transit: Organizational barriers to workers' health

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE 2017 APR; 60(4):350-367
BackgroundValuable insights on the health and behavior of transit workers can be obtained from qualitative research that considers the social environment, which affects job performance and determines levels of perceived stress. MethodsUsing a grounded theory approach, semi-structured interviews were conducted with American transit workers (n=32). Recorded interviews were transcribed and analyzed using a constant comparative method. ResultsParticipants described categories related to entrenched organizational practices, particularly managements' leadership style, which created an atmosphere of distrust. High demanding work schedules, as a result of technological advances, were discussed in relation to diminished breaks, fatigue, and unhealthy diets. Transit workers also attributed increased work demands and irregular working hours to compromised time with family and friends. ConclusionsThe described barriers to positive health behaviors and social support underscore the need for interventions that ensure adequate breaks and recovery between shifts and increase safety for transit passengers. Am. J. Ind. Med. 60:350-367, 2017. (c) 2017 Wiley Periodicals, Inc.
Stevenson ML, Wang CQF, Abikhair M, Roudiani N, Felsen D, Krueger JG, Pavlick AC, Carucci JA
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Expression of Programmed Cell Death Ligand in Cutaneous Squamous Cell Carcinoma and Treatment of Locally Advanced Disease With Pembrolizumab

JAMA DERMATOLOGY 2017 APR 1; 153(4):299-303
IMPORTANCE Limited therapies are available in patients with inoperable locally advanced cutaneous squamous cell carcinoma (cSCC). OBJECTIVE To determine the efficacy of programmed cell death 1 receptor (PD-1) inhibitors in locally advanced cSCC. DESIGN, SETTING, AND PARTICIPANTS A single patient with locally advanced cSCC who declined surgery and radiotherapy underwent treatment with pembrolizumab, an anti-PD-1 antibody, at an academic dermatologic surgery section and cancer center. The patient was followed up for clinical and radiologic regression of cSCC. With the use of NanoString to amplify potential biomarkers, immunohistochemistry, and immunofluorescence, the ex vivo expression of PD-1 and a ligand (PD-L2) was assessed in 38 cSCC biopsy specimens from 24 patients with cSCC. Expression of PD-L1 and PD-L2 in the cSCC microenvironment was defined. INTERVENTION Pembrolizumab, 2mg/kg every 3 weeks, for 4 cycles. MAIN OUTCOMES AND MEASURES Expression of PD-L1 and PD-L2 in the cSCC microenvironment. RESULTS In 1 patient with locally advanced cSCC who was treated with pembrolizumab, nearly complete tumor regression was observed after 4 cycles of therapy. The NanoString technology used in 38 cSCC biopsy specimens from 24 patients with cSCC (19 men and 5 women; mean [SD] age, 76.4 [12.2] years) detected increased PD-1 and PD-L2 expression in high-risk cSCC. Immunohistochemical analysis confirmed enhanced expression of PD-1 and its ligands in cSCC with perineural invasion (mean [SEM] expression, 5.06 [1.27]; P =.05), superficial cSCC (mean [SEM] expression, 3.58 [1.50]; P =.15), organ transplant-associated cSCC (mean [SEM] expression, 3.01 [0.54]; P =.005), and infiltrative cSCC (mean [SD] expression, 2.01 [0.30]; P =.006) compared with normal skin specimens. In double-label immunofluorescence staining, CD11c(+), a marker ofmyeloid dendritic cells, colocalized with PD-L1 and PD-L2 in cSCC lesions. CONCLUSIONS AND RELEVANCE The favorable treatment response combined with significant involvement of PD-1 and PD ligands in cSCC lesions suggests that PD-1 blockade may be a viable therapeutic option for locally advanced cSCC and provides rationale for further investigation in future clinical trials.
Vargas FA, Furness AJS, Solomon I, Joshi K, Mekkaoui L, Lesko MH, Rota EM, Dahan R, Georgiou A, Sledzinska A, Ben Aissa A, Franz D, Sunderland MW, Wong YNS, Henry JY, O'Brien T, Nicol D, Challacombe B, Beers SA, Turajlic S, Gore M, Larkin J, Swanton C, Chester KA, Pule M, Ravetch JV, Marafioti T, Peggs KS, Quezada SA
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Fc-Optimized Anti-CD25 Depletes Tumor-Infiltrating Regulatory T Cells and Synergizes with PD-1 Blockade to Eradicate Established Tumors

IMMUNITY 2017 APR 18; 46(4):577-586
CD25 is expressed at high levels on regulatory T (Treg) cells and was initially proposed as a target for cancer immunotherapy. However, anti-CD25 antibodies have displayed limited activity against established tumors. We demonstrated that CD25 expression is largely restricted to tumor-infiltrating Treg cells in mice and humans. While existing anti-CD25 antibodies were observed to deplete Treg cells in the periphery, upregulation of the inhibitory Fc gamma receptor (Fc gamma R) IIb at the tumor site prevented intra-tumoral Treg cell depletion, which may underlie the lack of anti-tumor activity previously observed in pre-clinical models. Use of an anti-CD25 antibody with enhanced binding to activating Fc gamma Rs led to effective depletion of tumor-infiltrating Treg cells, increased effector to Treg cell ratios, and improved control of established tumors. Combination with anti-programmed cell death protein-1 antibodies promoted complete tumor rejection, demonstrating the relevance of CD25 as a therapeutic target and promising substrate for future combination approaches in immune-oncology.
Iaea DB, Mao S, Lund FW, Maxfield FR
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Role of STARD4 in sterol transport between the endocytic recycling compartment and the plasma membrane

MOLECULAR BIOLOGY OF THE CELL 2017 APR 15; 28(8):1111-1122
Cholesterol is an essential constituent of membranes in mammalian cells. The plasma membrane and the endocytic recycling compartment (ERC) are both highly enriched in cholesterol. The abundance and distribution of cholesterol among organelles are tightly controlled by a combination of mechanisms involving vesicular and nonvesicular sterol transport processes. Using the fluorescent cholesterol analogue dehydroergosterol, we examined sterol transport between the plasma membrane and the ERC using fluorescence recovery after photobleaching and a novel sterol efflux assay. We found that sterol transport between these organelles in a U2OS cell line has a t(1/2) = 12-15 min. Approximately 70% of sterol transport is ATP independent and therefore is nonvesicular. Increasing cellular cholesterol levels dramatically increases bidirectional transport rate constants, but decreases in cholesterol levels have only a modest effect. A soluble sterol transport protein, STARD4, accounts for similar to 25% of total sterol transport and similar to 33% of nonvesicular sterol transport between the plasma membrane and ERC. This study shows that nonvesicular sterol transport mechanisms and STARD4 in particular account for a large fraction of sterol transport between the plasma membrane and the ERC.