63 research outputs found

    Probing Anti-inflammatory Properties Independent of NF-κB Through Conformational Constraint of Peptide-Based Interleukin-1 Receptor Biased Ligands

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    Interleukin-1β (IL-1β) binds to the IL-1 receptor (IL-1R) and is a key cytokine mediator of inflammasome activation. IL-1β signaling leads to parturition in preterm birth (PTB) and contributes to the retinal vaso-obliteration characteristic of oxygen-induced retinopathy (OIR) of premature infants. Therapeutics targeting IL-1β and IL-1R are approved to treat rheumatoid arthritis; however, all are large proteins with clinical limitations including immunosuppression, due in part to inhibition of NF-κB signaling, which is required for immuno-vigilance and cytoprotection. The all-D-amino acid peptide 1 (101.10, H-d-Arg-d-Tyr-d-Thr-d-Val-d-Glu-d-Leu-d-Ala-NH2) is an allosteric IL-1R modulator, which exhibits functional selectivity and conserves NF-κB signaling while inhibiting other IL-1-activated pathways. Peptide 1 has proven effective in experimental models of PTB and OIR. Seeking understanding of the structural requirements for the activity and biased signaling of 1, a panel of twelve derivatives was synthesized employing the various stereochemical isomers of α-amino-γ-lactam (Agl) and α-amino-β-hydroxy-γ-lactam (Hgl) residues to constrain the D-Thr-D-Val dipeptide residue. Using circular dichroism spectroscopy, the peptide conformation in solution was observed to be contingent on Agl, Hgl, and Val stereochemistry. Moreover, the lactam mimic structure and configuration influenced biased IL-1 signaling in an in vitro panel of cellular assays as well as in vivo activity in murine models of PTB and OIR. Remarkably, all Agl and Hgl analogs of peptide 1 did not inhibit NF-κB signaling but blocked other pathways, such as JNK and ROCK2 phosphorylation contingent on structure and configuration. Efficacy in preventing preterm labor correlated with a capacity to block IL-1β-induced IL-1β synthesis. Furthermore, the importance of inhibition of JNK and ROCK2 phosphorylation for enhanced activity was highlighted for prevention of vaso-obliteration in the OIR model. Taken together, lactam mimic structure and stereochemistry strongly influenced conformation and biased signaling. Selective modulation of IL-1 signaling was proven to be particularly beneficial for curbing inflammation in models of preterm labor and retinopathy of prematurity (ROP). A class of biased ligands has been created with potential to serve as selective probes for studying IL-1 signaling in disease. Moreover, the small peptide mimic prototypes are promising leads for developing immunomodulatory therapies with easier administration and maintenance of beneficial effects of NF-κB signaling

    Prospects for Pentaquark Production at Meson Factories

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    Following Rosner [hep-ph/0312269], we consider B-decay production channels for the exotic I=0 and I=3/2I=3/2 pentaquarks that have been recently reported. We also discuss new search channels for isovector pentaquarks, such as the Θ++(sˉduuu)\Theta^{*++} (\bar s duuu), that are generically present in chiral soliton models but were not observed in recent experiments. Futhermore, we argue that weak decays of charmed baryons, such as the Λc+\Lambda_c^+ and Ξc0\Xi_c^0, provide another clean way of detecting exotic baryons made of light quarks only. We also discuss discovery channels for charmed pentaquarks, such as the isosinglet Θc0(cˉudud)\Theta_c^0 (\bar c udud), in weak decays of bottom mesons and baryons. Finally, we discuss prospects for inclusive production of pentaquarks in e+ee^+ e^- collisions, with associated production of particles carrying the opposite baryon number.Comment: 15 pages, LaTeX; v2,v3: minor corrections, references added; v4: minor modifications, the version published in Physics Letters

    HIV outbreaks among people who inject drugs in Europe, North America and Israel

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    During 2011–16, HIV outbreaks occurred among people who inject drugs (PWID) in Canada (southeastern Saskatchewan), Greece (Athens), Ireland (Dublin), Israel (Tel Aviv), Luxembourg, Romania (Bucharest), Scotland (Glasgow), and USA (Scott County, Indiana). Factors common to many of these outbreaks included community economic problems, homelessness, and changes in drug injection patterns. The outbreaks differed in size (from under 100 to over 1000 newly reported HIV cases among PWID) and in the extent to which combined prevention had been implemented before, during, and after the outbreaks. Countries need to ensure high coverage of HIV prevention services and coverage higher than the current UNAIDS recommendation might be needed in areas in which short acting drugs are injected. In addition, monitoring of PWID with special attention for changing drug use patterns, risk behaviours, and susceptible subgroups (eg, PWID experiencing homelessness) needs to be in place to prevent or rapidly detect and contain new HIV outbreaks

    Tuberculosis incidence in HIV/AIDS patients in Israel, 1983-2010.

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    OBJECTIVES: People living with HIV/AIDS (PLWHA) who develop tuberculosis disease are at greater mortality-risk. This study aimed to assess tuberculosis disease incidence among all PLWHA in Israel and identify populations at high-risk for developing tuberculosis. DESIGN AND METHODS: Retrospective cohort-study based on the National HIV and Tuberculosis Registries, which were cross-matched and followed for the last 28-years. PLWHA who developed tuberculosis were compared to those who did not by the Cox-proportional analysis to generate hazard-ratios, and survival-analysis was performed by Log-Rank test. RESULTS: Of all the 6579 PLWHA reported between 1983 and 2010, corresponding to 55737 person-years, 384 (5.8%) developed tuberculosis. Of those, 14 were Israeli-born and 370 were non-Israeli born. The overall tuberculosis incidence-density was 6.9 cases/1000 person-years (95% CI 1.8-12.0). The cumulative tuberculosis-incidence among PLWHA in 2010 was 586 times higher than in HIV-negative individuals (3400 and 5.8 cases per 100000 population, respectively). Higher hazard-ratios to developing tuberculosis were found in migrant citizens PLWHA who were males, non-Israeli born, those who were diagnosed with HIV/AIDS after 1997, those who originated in high-tuberculosis prevalence country and those who acquired HIV by heterosexual or drug-injection transmission. PLWHA who developed tuberculosis had higher odds of dying than other PLWHA (36.5% and 16.6%, respectively, p<0.001, odds ratio = 2.8, 95% confidence-interval 2.3-3.6). In survival-analysis, time to develop tuberculosis was shorter among males than females, in PLWHA who were reported with HIV after 1997, in heterosexual who originated in high-tuberculosis countries, followed by injecting drug-users, heterosexual from low-tuberculosis burden countries and men who have sex with men. CONCLUSION: Tuberculosis-incidence is higher among non-Israeli born PLWHA, with decreasing trends from 1991. Despite the moderate TB-rate disease among PLWHA, it remains an important cause for severe morbidity and mortality. Tuberculosis in PLWHA reflects mainly the tuberculosis-burden in the originating country and possibly also the mode of HIV-transmission
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