The rockefeller university

DNA damage response pathways are essential for genome stability and cell survival. Specifically, the ATR kinase is activated by DNA replication stress. An early event in this activation is the recruitment and phosphorylation of RPA, a single stranded DNA binding complex composed of three subunits, RPA70, RPA32 and RPA14. We have previously shown that the LIM protein Ajuba associates with RPA, and that depletion of Ajuba leads to potent activation of ATR. In this study, we provide evidence that the Ajuba-RPA interaction occurs through direct protein contact with RPA70, and that their association is cell cycle-regulated and is reduced upon DNA replication stress. We propose a model in which Ajuba negatively regulates the ATR pathway by directly interacting with RPA70, thereby preventing inappropriate ATR activation. Our results provide a framework to further our understanding of the mechanism of ATR regulation in human cells in the context of cellular transformation.

Methicillin-resistant Staphylococcus aureus (MRSA) can survive for long periods on inanimate objects, and therefore, environmental surfaces constitute an important reservoir for dissemination. However, there is no standardized method for the detection of MRSA from environmental surfaces. The aim of the present study was to evaluate different screening methods to detect environmental MRSA contamination. A total of 294 samples were obtained from inanimate surfaces at a hospital in Luanda, Angola, and a hospital in SAo Tome and Principe, by three different methodologies: (1) sterile swabs moistened in saline solution, (2) sterile cotton gauzes moistened in tryptic soy broth, and (3) commercial premoistened sterile sponges (polywipes). After a broth enrichment step, all samples were plated onto tryptic soy agar and chromogenic selective media for S. aureus and for MRSA. The S. aureus isolates were characterized by pulsed-field gel electrophoresis, spa typing, multilocus sequence typing, and SCCmec typing. Comparing the three screening methods, gauzes were the most effective (16 S. aureus out of 98 samples; 16.3%), followed by polywipes (4/98; 4.1%) and swabs (3/98; 3.1%). Moistened gauzes were the most sensitive method (p<0.00001), while screening with swabs was the least efficient (p=0.00002). The majority of the MRSA isolates (75%) belonged to the main clonal types previously found among patients and healthcare workers in the same hospitals: ST5-IVa (n=7; 44%) and ST88-IVa (n=5; 31%). The finding of MRSA on environmental surfaces is dependent on the screening methodology. Moistened gauzes followed by a broth enrichment step proved to be the most sensitive methodology compared to polywipes and swabs.

Objective Infantile hemangiomas (IHs) are the most common benign vascular neoplasms of infancy, characterized by a rapid growth phase followed by a spontaneous involution, or triggered by propranolol treatment by poorly understood mechanisms. LIN28/let-7 axis plays a central role in the regulation of stem cell self-renewal and tumorigenesis. However, the role of LIN28B/let-7 signaling in IH pathogenesis has not yet been elucidated. Approach and Results LIN28B is highly expressed in proliferative IH and is less expressed in involuted and in propranolol-treated IH samples as measured by immunofluorescence staining and quantitative RT-PCR. Small RNA sequencing analysis of IH samples revealed a decrease in microRNAs that target LIN28B, including let-7, and an increase in microRNAs in the mir-498(46) cistron. Overexpression of LIN28B in HEK293 cells induced the expression of miR-516b in the mir-498(46) cistron. Propranolol treatment of induced pluripotent stem cells, which express mir-498(46) endogenously, reduced the expression of both LIN28B and mir-498(46) and increased the expression of let-7. Furthermore, propranolol treatment reduced the proliferation of induced pluripotent stem cells and induced epithelial-mesenchymal transition. Conclusions This work uncovers the role of the LIN28B/let-7 switch in IH pathogenesis and provides a novel mechanism by which propranolol induces IH involution. Furthermore, it provides therapeutic implications for cancers in which the LIN28/let-7 pathway is imbalanced.

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA- or a mecC-mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC-carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes (fruB, gmk, hpt, purB, prsA, and relA), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA.

Chimeric antigen receptor (CAR) therapy targeting CD19 is an effective treatment for refractory B cell malignancies, especially acute lymphoblastic leukemia (ALL)(1). Although a majority of patients will achieve a complete response following a single infusion of CD19-targeted CAR-modified T cells (CD19 CAR T cells)(2-4), the broad applicability of this treatment is hampered by severe cytokine release syndrome (CRS), which is characterized by fever, hypotension and respiratory insufficiency associated with elevated serum cytokines, including interleukin-6 (IL-6)(2,5). CRS usually occurs within days of T cell infusion at the peak of CAR T cell expansion. In ALL, it is most frequent and more severe in patients with high tumor burden(2-4). CRS may respond to IL-6 receptor blockade but can require further treatment with high dose corticosteroids to curb potentially lethal severity(2-9). Improved therapeutic and preventive treatments require a better understanding of CRS physiopathology, which has so far remained elusive. Here we report a murine model of CRS that develops within 2-3 d of CAR T cell infusion and that is potentially lethal and responsive to IL-6 receptor blockade. We show that its severity is mediated not by CAR T cell-derived cytokines, but by IL-6, IL-1 and nitric oxide (NO) produced by recipient macrophages, which enables new therapeutic interventions.

Objective: Sleep can affect quality of life (QoL) during cancer survivorship, and symptoms related to poor sleep can be exacerbated. We examined the prevalence, severity, and nature of subjective sleep complaints in women surviving stage I-III breast cancer who were 1-10 years posttreatment. We also examined the demographic, medical, physical, and psychosocial correlates of poor sleep in these women in order to identify the subgroups that may be most in need of intervention. Method: A total of 200 patients at a comprehensive cancer center who were 1-10 years posttreatment for primary stage I-III breast cancer with no evidence of disease at the time of enrollment completed a battery of questionnaires on demographics, sleep, physical symptoms, mood, cancer-specific fears, and QoL. Results: The women had a mean age of 57 years (SD = 10.0), with a mean of 63.3 months (SD = 28.8) of post-cancer treatment. Some 38% of these patients were identified as having poor-quality sleep. Women with poor sleep took longer to fall asleep, had more awakenings, and acquired 2 hours less sleep per night than those with good sleep. They also had a lower QoL, greater severity of pain, more concerns about health and recurrence, and increased vasomotor symptoms (p < 0.05). Daytime sleepiness and depression were found to be not significantly correlated with sleep quality. Significance of results: Many breast cancer survivors had severe subjective insomnia, and several breast cancer survivor subgroups were identified as having members who might be most in need of sleep-improvement interventions. Addressing physical symptoms (e.g., vasomotor symptoms and pain) and providing education about the behavioral, social, environmental, and medical factors that affect sleep could result in substantial improvement in the life course of breast cancer survivors.

A search for dark matter is conducted in events with large missing transverse momentum and a hadronically decaying, Lorentz-boosted top quark. This study is performed using proton-proton collisions at a center-of-mass energy of 13 TeV, in data recorded by the CMS detector in 2016 at the LHC, corresponding to an integrated luminosity of 36 fb(-1). New substructure techniques, including the novel use of energy correlation functions, are utilized to identify the decay products of the top quark. With no significant deviations observed from predictions of the standard model, limits are placed on the production of new heavy bosons coupling to dark matter particles. For a scenario with purely vector-like or purely axial-vector-like flavor changing neutral currents, mediator masses between 0.20 and 1.75 TeV are excluded at 95% confidence level, given a sufficiently small dark matter mass. Scalar resonances decaying into a top quark and a dark matter fermion are excluded for masses below 3.4 TeV, assuming a dark matter mass of 100 GeV.

The nuclear modification factors of J/psi and psi(2S) mesons are measured in PbPb collisions at a centre-of-mass energy per nucleon pair of root S-NN = 5.02 TeV. The analysis is based on PbPb and pp data samples collected by CMS at the LHC in 2015, corresponding to integrated luminosities of 464 mu b(-1) and 28 pb(-1), respectively. The measurements are performed in the dimuon rapidity range of vertical bar y vertical bar < 2.4 as a function of centrality, rapidity, and transverse momentum (p(T)) from p(T) = 3 GeV/c in the most forward region and up to 50 GeV/c. Both prompt and nonprompt (coming from b hadron decays) J/psi mesons are observed to be increasingly suppressed with centrality, with a magnitude similar to the one observed at root S-NN = 2.76 TeV for the two J/psi meson components. No dependence on rapidity is observed for either prompt or nonprompt J/psi mesons. An indication of a lower prompt J/psi meson suppression at p(T) > 25 GeV/c is seen with respect to that observed at intermediate p(T). The prompt psi(2S) meson yield is found to be more suppressed than that of the prompt J/psi mesons in the entire p(T) range.

The mammalian gut microbiota provides essential metabolites to the host and promotes the differentiation and accumulation of extrathymically generated regulatory T (pTreg) cells. To explore the impact of these cells on intestinal microbial communities, we assessed the composition of the microbiota in pTreg cell-deficient and -sufficient mice. pTreg cell deficiency led to heightened type 2 immune responses triggered by microbial exposure, which disrupted the niche of border-dwelling bacteria early during colonization. Moreover, impaired pTreg cell generation led to pervasive changes in metabolite profiles, altered features of the intestinal epithelium, and reduced body weight in the presence of commensal microbes. Absence of a single species of bacteria depleted in pTreg cell-deficient animals, Mucispirillum schaedleri, partially accounted for the sequelae of pTreg cell deficiency. These observations suggest that pTreg cells modulate the metabolic function of the intestinal microbiota by restraining immune defense mechanisms that may disrupt a particular bacterial niche.