The rockefeller university

Pneumonia is associated with a high morbidity and mortality worldwide. Streptococcus pneumoniae remains the most common cause of pneumonia, and pneumococcal antibiotic resistance is increasing. The purified bacteriophage endolysin Cpl-1 rapidly and specifically kills pneumococci. We tested the hypothesis that a single dose of recombinant aerosolized Cpl-1 would rescue mice with severe pneumococcal pneumonia. Female C57Bl/6 mice (aged 812 weeks) were transnasally infected with pneumococci. When severe pneumonia was established 24 h after infection, mice were treated with 25 L of aerosolized Cpl-1. Survival was monitored for 10 days and the pulmonary and systemic bacterial burdens were assessed. Furthermore, cytokines were quantified in bronchoalveolar lavage fluid, and lung morphology was analysed histologically. The endolysin efficiently reduced pulmonary bacterial counts and averted bacteraemia. Although concentrations of inflammatory cytokines were increased shortly after Cpl-1 inhalation, mice recovered rapidly, as shown by increasing body weight, and inflammatory infiltrates resolved in the lungs, leading to a reduction in mortality of 80. Administration of Cpl-1 by inhalation may offer a new therapeutic perspective for the treatment of pneumococcal lung infection.

Chronic stress is a risk factor for several neuropsychiatric diseases, such as depression and psychosis. In response to stress glucocorticoids (GCs) are secreted that bind to mineralocorticoid and glucocorticoid receptors, ligand-activated transcription factors that regulate the transcription of gene networks in the brain necessary for coping with stress, recovery, and adaptation. Chronic stress particularly affects the dentate gyrus (DG) subregion of the hippocampus, causing several functional and morphological changes with consequences for learning and memory, which are likely adaptive but at the same time make DG neurons more vulnerable to subsequent challenges. The aim of this study was to investigate the transcriptional response of DG neurons to a GC challenge in male rats previously exposed to chronic restraint stress (CRS). An intriguing finding of the current study was that having a history of CRS had profound consequences for the subsequent response to acute GC challenge, differentially affecting the expression of several hundreds of genes in the DG compared with challenged nonstressed control animals. This enduring effect of previous stress exposure suggests that epigenetic processes may be involved. In line with this, CRS indeed affected the expression of several genes involved in chromatin structure and epigenetic processes, including Asf1, Ash1l, Hist1h3f, and Tp63. The data presented here indicate that CRS alters the transcriptional response to a subsequent GC injection. We propose that this altered transcriptional potential forms part of the molecular mechanism underlying the enhanced vulnerability for stress-related disorders like depression caused by chronic stress.

In adult skin, self-renewing, undifferentiated hair follicle stem cells (HF-SCs) reside within a specialized niche, where they spend prolonged times as a single layer of polarized, quiescent epithelial cells. When sufficient activating signals accumulate, HF-SCs become mobilized to fuel tissue regeneration and hair growth. Here, we show that architectural organization of the HF-SC niche by transcription factor LHX2 plays a critical role in HF-SC behavior. Using genome-wide chromatin and transcriptional profiling of HF-SCs in vivo, we show that LHX2 directly transactivates genes that orchestrate cytoskeletal dynamics and adhesion. Conditional ablation of LHX2 results in gross cellular disorganization and HF-SC polarization within the niche. LHX2 loss leads to a failure to maintain HF-SC quiescence and hair anchoring, as well as progressive transformation of the niche into a sebaceous gland. These findings suggest that niche organization underlies the requirement for LHX2 in hair follicle structure and function.

Delineation of antibody epitopes at the residue level is key to understanding antigen resistance mutations, designing epitope-specific probes for antibody isolation, and developing epitope-based vaccines. Ideally, epitope residues are determined in the context of the atomic-level structure of the antibody-antigen complex, though structure determination may in many cases be impractical. Here we describe an efficient computational method to predict antibody-specific HIV-1 envelope (Env) epitopes at the residue level, based on neutralization panels of diverse viral strains. The method primarily utilizes neutralization potency data over a set of diverse viral strains representing the antigen, and enhanced accuracy could be achieved by incorporating information from the unbound structure of the antigen. The method was evaluated on 19 HIV-1 Env antibodies with neutralization panels comprising 181 diverse viral strains and with available antibody-antigen complex structures. Prediction accuracy was shown to improve significantly over random selection, with an average of greater-than-8-fold enrichment of true positives at the 0.05 false-positive rate level. The method was used to prospectively predict epitope residues for two HIV-1 antibodies, 8ANC131 and 8ANC195, for which we experimentally validated the predictions. The method is inherently applicable to antigens that exhibit sequence diversity, and its accuracy was found to correlate inversely with sequence conservation of the epitope. Together the results show how knowledge inherent to a neutralization panel and unbound antigen structure can be utilized for residue-level prediction of antibody epitopes.

Despite 30 years of study, there is no HIV-1 vaccine and, until recently, there was little hope for a protective immunization. Renewed optimism in this area of research comes in part from the results of a recent vaccine trial and the use of single-cell antibody-cloning techniques that uncovered naturally arising, broad and potent HIV-1-neutralizing antibodies (bNAbs). These antibodies can protect against infection and suppress established HIV-1 infection in animal models. The finding that these antibodies develop in a fraction of infected individuals supports the idea that new approaches to vaccination might be developed by adapting the natural immune strategies or by structure-based immunogen design. Moreover, the success of passive immunotherapy in small-animal models suggests that bNAbs may become a valuable addition to the armamentarium of drugs that work against HIV-1.

Merkel cell polyomavirus (MCPyV) is thought to be the etiological agent of Merkel cell carcinoma, but little is known about its distribution and modes of transmission. We conducted seroepidemiological surveys in more than 1000 individuals, from two populations from Cameroon. Overall MCPyV seroprevalence was high in both populations (>75% in adults). Data from the first population, comprising mainly children, indicated that MCPyV infections mostly occurred during early childhood, after the disappearance of specific maternal antibodies. Results from the second family-based population provided evidence for familial aggregation of MCPyV infection status. We observed significant sib-sib correlation (odds ratio = 3.42 [95% CI 1.27-9.19], p = 0.014), particularly for siblings close together in age, and a trend for mother-child correlation (OR = 2.71 [0.86-8.44], p = 0.08). Overall, our results suggest that MCPyV infection is acquired through close contact, possibly involving saliva and/or the skin, especially between young siblings and between mothers and their children. (c) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Previously, we have shown that Dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32) knockout mice required significantly more trials to reach criterion than wild-type mice in an operant reversal-learning task. The present study was conducted to examine adult male and female DARPP-32 knockout mice and wild-type controls in a novel object recognition test. Wild-type and knockout mice exhibited comparable behavior during the initial exploration trials. As expected, wild-type mice exhibited preferential exploration of the novel object during the substitution test, demonstrating recognition memory. In contrast, knockout mice did not show preferential exploration of the novel object, instead exhibiting an increase in exploration of all objects during the test trial. Given that the removal of DARPP-32 is an intracellular manipulation, it seemed possible to pharmacologically restore some cellular activity and behavior by stimulating dopamine receptors. Therefore, a second experiment was conducted examining the effect of methylphenidate. The results show that methylphenidate increased horizontal activity in both wild-type and knockout mice, though this increase was blunted in knockout mice. Pretreatment with methylphenidate significantly impaired novel object recognition in wild-type mice. In contrast, pretreatment with methylphenidate restored the behavior of DARPP-32 knockout mice to that observed in wild-type mice given saline. These results provide additional evidence for a functional role of DARPP-32 in the mediation of processes underlying learning and memory. These results also indicate that the behavioral deficits in DARPP-32 knockout mice may be restored by the administration of methylphenidate. (C) 2013 Elsevier B.V. All rights reserved.

For several decades, the dopamine precursor levodopa has been the primary therapy for Parkinson's disease (PD). However, not all of the motor and non-motor features of PD can be attributed solely to dopaminergic dysfunction. Recent clinical and preclinical advances provide a basis for the identification of additional innovative therapeutic options to improve the management of the disease. Novel pharmacological strategies must be optimized for PD by: (i) targeting disturbances of the serotonergic, noradrenergic, glutamatergic, GABAergic, and cholinergic systems in addition to the dopaminergic system, and (ii) characterizing alterations in the levels of neurotransmitter receptors and transporters that are associated with the various manifestations of the disease.

We used mouse models of pneumococcal colonization and disease combined with full genome sequencing to characterize three major drug resistant clones of S. pneumoniae that were recovered from the nasopharynx of PCV7-immunized children in Portugal. The three clones - serotype 6A (ST2191), serotype 15A (ST63) and serotype 19A (ST276) carried some of the same drug resistance determinants already identified in nasopharyngeal isolates from the pre-PCV7 era. The three clones were able to colonize efficiently the mouse nasopharyngeal mucosa where populations of these pneumococci were retained for as long as 21 days. During this period, the three clones were able to asymptomatically invade the olfactory bulbs, brain, lungs and the middle ear mucosa and established populations in these tissues. The virulence potential of the three clones was poor even at high inoculum (10(5) CFU per mouse) concentrations in the mouse septicemia model and was undetectable in the pneumonia model. Capsular type 3 transformants of clones 6A and 19A prepared in the laboratory produced lethal infection at low cell concentration (10(3) CFU per mouse) but the same transformants became impaired in their potential to colonize, indicating the importance of the capsular polysaccharide in both disease and colonization. The three clones were compared to the genomes of 56 S. pneumoniae strains for which sequence information was available in the public databank. Clone 15A (ST63) only differed from the serotype 19F clone G54 in a very few genes including serotype so that this clone may be considered the product of a capsular switch. While no strain with comparable degree of similarity to clone 19A (ST276) was found among the sequenced isolates, by MLST this clone is a single locust variant (SLV) of Denmark14-ST230 international clone. Clone 6A (ST2191) was most similar to the penicillin resistant Hungarian serotype 19A clone.

It is known that heroin dependence and withdrawal are associated with changes in the hypothalamic-pituitary-adrenal (HPA) axis. The objective of these studies in rats was to systematically investigate the level of HPA activity and response to a heroin challenge at two time points during heroin withdrawal, and to characterize the expression of associated stress-related genes 30 min after each heroin challenge. Rats received chronic (10-day) intermittent escalating-dose heroin administration (3 x 2.5 mg/kg/day on day 1; 3 x 20 mg/kg/day by day 10). Hormonal and neurochemical assessments were performed in acute (12 h after last heroin injection) and chronic (10 days after the last injection) withdrawal. Both plasma ACTH and corticosterone levels were elevated during acute withdrawal, and heroin challenge at 20 mg/kg (the last dose of chronic escalation) at this time point attenuated this HPA hyperactivity. During chronic withdrawal, HPA hormonal levels returned to baseline, but heroin challenge at 5 mg/kg decreased ACTH levels. In contrast, this dose of heroin challenge stimulated the HPA axis in heroin na < ve rats. In the anterior pituitary, pro-opiomelanocortin (POMC) mRNA levels were increased during acute withdrawal and retuned to control levels after chronic withdrawal. In the medial hypothalamus, however, the POMC mRNA levels were decreased during acute withdrawal, and increased after chronic withdrawal. Our results suggest a long-lasting change in HPA abnormal responsivity during chronic heroin withdrawal.