Evolution of a functionally intact but antigenically distinct DENV fusion loop

A hallmark of dengue virus (DENV) pathogenesis is the potential for antibody-dependent enhancement, which is associated with deadly DENV secondary infection, complicates the identification of correlates of protection, and negatively impacts the safety and efficacy of DENV vaccines. Antibody-dependent enhancement is linked to antibodies targeting the fusion loop (FL) motif of the envelope protein, which is completely conserved in mosquito-borne flaviviruses and required for viral entry and fusion. In the current study, we utilized saturation mutagenesis and directed evolution to engineer a functional variant with a mutated FL (D2-FL), which is not neutralized by FL-targeting monoclonal antibodies. The FL mutations were combined with our previously evolved prM cleavage site to create a mature version of D2-FL (D2-FLM), which evades both prM- and FL-Abs but retains sensitivity to other type-specific and quaternary cross-reactive (CR) Abs. CR serum from heterotypic (DENV4)-infected non-human primates (NHP) showed lower neutralization titers against D2-FL and D2-FLM than isogenic wildtype DENV2 while similar neutralization titers were observed in serum from homotypic (DENV2)-infected NHP. We propose D2-FL and D2-FLM as valuable tools to delineate CR Ab subtypes in serum as well as an exciting platform for safer live-attenuated DENV vaccines suitable for naïve individuals and children

Editorial: Purinergic P2X receptors: physiological and pathological roles and potential as therapeutic targets.

P2X receptors for extracellular ATP (P2Xs) are widely distributed ion channels that mediate several processes like neurotransmission, neuromodulation, inflammation, pain sensing, cell proliferation and differentiation. Targeting of P2X receptors by specific modulators has been suggested for a variety of possible therapeutic applications like the treatment of inflammatory, neurological and neurodegenerative diseases, cardiovascular, bone, renal and endocrine disorders, pain and cancer. Purpose of this special issue is to offer a comprehensive overview on P2X receptors considering their structural and functional features, agonist and antagonist ligands, physio-pathological roles, and their potential as therapeutic targets. A review from the founding father of the purinergic field Burnstock opens the issue and gives an overview of the early findings on purinergic signaling, focusing on the roles of P2X receptors in the central nervous system. Functions of P2X receptors in physiological and pathological conditions involving CNS are also brilliant covered. Another wide-ranging manuscript is that of Di Virgilio on the role of P2X receptors in inflammation. This is an overview of P2Xs roles in danger sensing, inflammasome activation and release of inflammatory mediators. The contributes to this special issue from Grimes & Young and Hausman et al. offer an introduction on the structural properties of P2X receptors observed from X-ray data and modeling studies and on the information about trimer stoichiometry and ligand-target interaction coming from mutagenesis studies results. The reviews from Müller and Lambertucci et al. provide a description of the different classes of P2X ligands working with allosteric or orthosteric mechanism, respectively, giving information about compound selectivity and therapeutic potential. Bele & Fabbretti report on the role of P2Xs on pain transmission and on the potential of targeting P2X for novel analgesic drugs. Similarly, the paper from Ralevic focusses on P2X function in the cardiovascular system and vascular smooth muscle contraction, highlighting the function of P2Xs in the regulation of blood pressure. In their manuscript, Fotino et al. give an overview of P2X and ATP signaling in the pathogenesis of diabetes and its complications. The authors discuss the role of P2Xs in insulin secretion and diabetes associated metabolic alterations. The role of P2X receptors on bone biology is described by Jorgensen et al. who give an overview on data derived from P2X null mice and analysis of receptor’s SNPs in bone-associated diseases. Finally, the paper from Adinolfi et al. focusses on the role of P2X receptors in cancer, addressing tumoral growth, progression and related symptoms. All papers suggest the use of P2Xs ligands as therapeutics in a wide-range of pathologies. We are grateful to all the authors for their kind participation and valuable contribution and hope that this issue could represent, for the scientific community, a solid basis for further studies on P2X receptors and the development of P2X targeting therapeutic tools

Effect of image compression of digital lateral cephalograms on the reproducibility of cephalometric points

Objectives: To evaluate the influence of JPEG quality factors 100, 80 and 60 on the reproducibility of identification of cephalometric points on images of lateral cephalograms, compared with the Digital Imaging and Communications in Medicine (DICOM) format. Methods: The sample was composed of 30 images of digital lateral cephalograms obtained from 30 individuals (15 males and 15 females) on a phosphor plate system in DICOM format. The images were converted to JPEG with quality factors 100, 80 and 60 with the aid of software, adding up to 90 images. The 120 images (DICOM, JPEG 100, 80 and 60) were blinded and 12 cephalometric points were identified on each image by three calibrated orthodontists, using the x-y coordinate system, on a cephalometric software. Results: The results revealed that identification of cephalometric points was highly reproducible, except for the point Orbitale (Or) on the x-axis. The different file formats did not present a statistically significant difference. Conclusions: JPEG images of lateral cephalograms with quality factors 100, 80 and 60 did not present alterations in the reproducibility of identification of cephalometric points compared with the DICOM format. Good reproducibility was achieved for the 12 points, except for point Or on the x-axis. Dentomaxillofacial Radiology (2009) 38, 393-400. doi: 10.1259/dmfr/4099663