The rockefeller university

Whereas longstanding dogma has purported that pregnancies protect women from breast cancer, a recent meta-analysis now mandates reconsideration since it reported an actual higher breast cancer risk for more than two decades after childbirth before the relative risk turns negative. Moreover, the risk of breast cancer appears higher for women having their first birth at an older age and with a family history and it is not reduced by breastfeeding. The process of obtaining informed consent for all fertility treatments, therefore, must make patients aware of the facts that every pregnancy, to a small degree, will increase the short-term breast cancer risk. This observation may be even more relevant in cases of surrogacy where women agree to conceive without deriving benefits of offspring from assuming the risk, thus creating a substantially different risk-benefit ratio. Consequently, it appears prudent for professional societies in the field to update recommendations regarding consent information for all fertility treatments but especially for treatments involving surrogacy.

Multicellular eukaryotes emerged late in evolution from an ocean of viruses, bacteria, archaea, and unicellular eukaryotes. These macroorganisms are exposed to and infected by a tremendous diversity of microorganisms. Those that are large enough can even be infected by multicellular fungi and parasites. Each interaction is unique, if only because it operates between two unique living organisms, in an infinite diversity of circumstances. This is neatly illustrated by the extraordinarily high level of interindividual clinical variability in human infections, even for a given pathogen, ranging from a total absence of clinical manifestations to death. We discuss here the idea that the determinism of human life-threatening infectious diseases can be governed by single-gene inborn errors of immunity, which are rarely Mendelian and frequently display incomplete penetrance. We briefly review the evidence in support of this notion obtained over the last two decades, referring to a number of focused and thorough reviews published by eminent colleagues in this issue of Human Genetics. It seems that almost any life-threatening infectious disease can be driven by at least one, and, perhaps, a great many diverse monogenic inborn errors, which may nonetheless be immunologically related. While the proportions of monogenic cases remain unknown, a picture in which genetic heterogeneity is combined with physiological homogeneity is emerging from these studies. A preliminary sketch of the human genetic architecture of severe infectious diseases is perhaps in sight.

The West Africa Ebola outbreak was the largest outbreak ever recorded, with over 28,000 reported infections; this devastating epidemic emphasized the need to understand the mechanisms to counteract virus infection. Here, we screen a library of nearly 400 interferon-stimulated genes (ISGs) against a biologically contained Ebola virus and identify several ISGs not previously known to affect Ebola virus infection. Overexpression of the top ten ISGs attenuates virus titers by up to 1000-fold. Mechanistic studies demonstrate that three ISGs interfere with virus entry, six affect viral transcription/replication, and two inhibit virion formation and budding. A comprehensive study of one ISG (CCDC92) that shows anti-Ebola activity in our screen reveals that CCDC92 can inhibit viral transcription and the formation of complete virions via an interaction with the viral protein NP. Our findings provide insights into Ebola virus infection that could be exploited for the development of therapeutics against this virus. Here, Kuroda et al. screen a library of nearly 400 interferon-stimulated genes (ISGs) and identify several ISGs that inhibit Ebola virus entry, viral transcription/replication, or virion formation. The study provides insights into interactions between Ebola and the host cells.

Clostridioides difficile is an enteric pathogen that can cause significant clinical disease in both humans and animals. However, clinical disease arises most commonly after treatment with broad-spectrum antibiotics. The organism's ability to cause naturally occurring disease in mice is rare, and little is known about its clinical significance in highly immunocompromised mice. We report on 2 outbreaks of diarrhea associated with C. difficile in mice. In outbreak 1, 182 of approximately 2, 400 NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/SzJ (NSG) and related strains of mice became clinically ill after cessation of a 14-d course of 0.12% amoxicillin feed to control an increase in clinical signs associated with Corynebacterium bovis infection. Most mice had been engrafted with human tumors; the remainder were experimentally naive. Affected animals exhibited 1 of 3 clinical syndromes: 1) peracute death; 2) severe diarrhea leading to euthanasia or death; or 3) mild to moderate diarrhea followed by recovery. A given cage could contain both affected and unaffected mice. Outbreak 2 involved a small breeding colony (approximately 50 mice) of NOD.CB17-Prkdc(scid)/NCrCrl (NOD-scid) mice that had not received antibiotics or experimental manipulations. In both outbreaks, C. difficile was isolated, and toxins A and B were detected in intestinal content or feces. Histopathologic lesions highly suggestive of C. difficile enterotoxemia included fibrinonecrotizing and neutrophilic typhlocolitis with characteristic 'volcano' erosions or pseudomembrane formation. Genomic analysis of 4 isolates (3 from outbreak 1 and 1 from outbreak 2) revealed that these isolates were closely related to a pathogenic human isolate, CD 196. To our knowledge, this report is the first to describe naturally occurring outbreaks of C. difficile-associated typhlocolitis with significant morbidity and mortality in highly immunocompromised strains of mice.

Human immunodeficiency virus 1 (HIV-1) is a retrovirus with a ten-kilobase single-stranded RNA genome. HIV-1 must express all of its gene products from a single primary transcript, which undergoes alternative splicing to produce diverse protein products that include structural proteins and regulatory factors(1,2). Despite the critical role of alternative splicing, the mechanisms that drive the choice of splice site are poorly understood. Synonymous RNA mutations that lead to severe defects in splicing and viral replication indicate the presence of unknown cis-regulatory elements(3). Here we use dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) to investigate the structure of HIV-1 RNA in cells, and develop an algorithm that we name `detection of RNA folding ensembles using expectationmaximization' (DREEM), which reveals the alternative conformations that are assumed by the same RNA sequence. Contrary to previous models that have analysed population averages(4), our results reveal heterogeneous regions of RNA structure across the entire HIV-1 genome. In addition to confirming that in vitro characterized(5) alternative structures for the HIV-1 Rev responsive element also exist in cells, we discover alternative conformations at critical splice sites that influence the ratio of transcript isoforms. Our simultaneous measurement of splicing and intracellular RNA structure provides evidence for the long-standing hypothesis(6-8) that heterogeneity in RNA conformation regulates splice-site use and viral gene expression.

The behavioral response to antidepressants is closely associated with physiological changes in the function of neurons in the hippocampal dentate gyrus (DG). Parvalbumin interneurons are a major class of GABAergic neurons, essential for DG function, and are involved in the pathophysiology of several neuropsychiatric disorders. However, little is known about the role(s) of these neurons in major depressive disorder or in mediating the delayed behavioral response to antidepressants. Here we show, in mice, that hippocampal parvalbumin interneurons express functionally silent serotonin 5A receptors, which translocate to the cell membrane and become active upon chronic, but not acute, treatment with a selective serotonin reuptake inhibitor (SSRI). Activation of these serotonergic receptors in these neurons initiates a signaling cascade through which Gi-protein reduces cAMP levels and attenuates protein kinase A and protein phosphatase 2A activities. This results in increased phosphorylation and inhibition of Kv3.1 beta channels, and thereby reduces the firing of the parvalbumin neurons. Through the loss of this signaling pathway in these neurons, conditional deletion of the serotonin 5A receptor leads to the loss of the physiological and behavioral responses to chronic antidepressants.

The IgG Fc domain has the capacity to interact with diverse types of receptors, including the neonatal Fc receptor (FcRn) and Fc gamma receptors (Fc gamma Rs), which confer pleiotropic biological activities. Whereas FcRn regulates IgG epithelial transport and recycling, Fc effector activities, such as antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis, are mediated by Fc gamma Rs, which upon cross-linking transduce signals that modulate the function of effector leukocytes. Despite the well-defined and nonoverlapping functional properties of FcRn and Fc gamma Rs, recent studies have suggested that Fc ?Rs mediate transplacental IgG transport, as certain Fc glycoforms were reported to be enriched in fetal circulation. To determine the contribution of Fc gamma Rs and FcRn to the maternal-fetal transport of IgG, we characterized the IgG Fc glycosylation in paired maternal-fetal samples from patient cohorts from Uganda and Nicaragua. No differences in IgG1 Fc glycan profiles and minimal differences in IgG2 Fc glycans were noted, whereas the presence or absence of galactose on the Fc glycan of IgG1 did not alter Fc gamma RIIIa or FcRn bind-ing, half-life, or their ability to deplete target cells in Fc gamma R/FcRn humanized mice. Modeling maternal-fetal transport in Fc gamma/FcRn humanized mice confirmed that only FcRn contributed to trans-placental transport of IgG; IgG selectively enhanced for FcRn binding resulted in enhanced accumulation of maternal antibody in the fetus. In contrast, enhancing Fc gamma RIIIa binding did not result in en-hanced maternal-fetal transport. These results argue against a role for Fc gamma Rs in IgG transplacental transport, suggesting Fc engineering of maternally administered antibody to enhance only FcRn binding as a means to improve maternal-fetal transport of IgG.

Elucidating the physiological binding partners of histone post-translational modifications (hPTMs) is key to understanding fundamental epigenetic regulatory pathways. Determining such interactomes will enable the study of how perturbations of these interactions affect disease. Here we use a synthetic biology approach to set a series of hPTM-controlled photo-affinity traps in native chromatin. Using quantitative proteomics, the local interactomes of these chemically customized chromatin landscapes are determined. We show that the approach captures transiently interacting factors such as methyltransferases and demethylases, as well as previously reported and novel hPTM reader proteins. We also apply this in situ proteomics approach to a recently disclosed cancer-associated histone mutation, H3K4M, revealing a number of perturbed interactions with the mutated tail. Collectively our studies demonstrate that modifying and interrogating native chromatin with chemical precision is a powerful tool for exploring epigenetic regulation and dysregulation at the molecular level. Proteins that interact with histone post-translational modifications have now been identified using an approach based on split-intein mediated histone semisynthesis. Histone modifications and disease-relevant mutations were installed into native chromatin with an adjacent photocross-linker to enable in situ cross-linking. This strategy enabled the determination of chromatin-relevant interactomes and represents a powerful tool for exploring epigenetic regulation and dysregulation at the molecular level.

The HIV-1 Vpr accessory protein induces ubiquitin/proteasome-dependent degradation of many cellular proteins by recruiting them to a cullin4A-DDB1-DCAF1 complex. In so doing, Vpr enhances HIV-1 gene expression and induces (G2/M) cell cycle arrest. However, the identities of Vpr target proteins through which these biological effects are exerted are unknown. We show that a chromosome periphery protein, CCDC137/cPERP-B, is targeted for depletion by HIV-1 Vpr, in a cullin4A-DDB1-DCAF1 dependent manner. CCDC137 depletion caused G2/M cellcycle arrest, while Vpr-resistant CCDC137 mutants conferred resistance to Vpr-induced G2/M arrest. CCDC137 depletion also recapitulated the ability of Vpr to enhance HIV-1 gene expression, particularly in macrophages. Our findings indicate that Vpr promotes cell-cycle arrest and HIV-1 gene expression through depletion of CCDC137.