Receptor-mediated cell entry of paramyxoviruses: Mechanisms, and consequences for tropism and pathogenesis Microbiology

Research in the last decade has uncovered many new paramyxoviruses, airborne agents that cause epidemic diseases in animals including humans. Most paramyxoviruses enter epithelial cells of the airway using sialic acid as a receptor and cause only mild disease. However, others cross the epithelial barrier and cause more severe disease. For some of these viruses, the host receptors have been identified, and the mechanisms of cell entry have been elucidated. The tetrameric attachment proteins of paramyxoviruses have vastly different binding affinities for their cognate receptors, which they contact through different binding surfaces. Nevertheless, all input signals are converted to the same output: conformational changes that trigger refolding of trimeric fusion proteins and membrane fusion. Experiments with selectively receptor-blinded viruses inoculated into their natural hosts have provided insights into tropism, identifying the cells and tissues that support growth and revealing the mechanisms of pathogenesis. These analyses also shed light on diabolically elegant mechanisms used by morbilliviruses, including the measles virus, to promote massive amplification within the host, followed by efficient aerosolization and rapid spread through host populations. In another paradigm of receptor-facilitated severe disease, henipaviruses, including Nipah and Hendra viruses, use different members of one protein family to cause zoonoses. Specific properties of different paramyxoviruses,...
Source: Journal of Biological Chemistry - Category: Chemistry Authors: Tags: JBC Reviews Source Type: research

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Authors: Arab JP, Dirchwolf M, Álvares-da-Silva MR, Barrera F, Benítez C, Castellanos-Fernandez M, Castro-Narro G, Chavez-Tapia N, Chiodi D, Cotrim H, Cusi K, de Oliveira CPMS, Díaz J, Fassio E, Gerona S, Girala M, Hernandez N, Marciano S, Masson W, Mendez-Sanchez N, Leite N, Lozano A, Padilla M, Panduro A, Paraná R, Parise E, Perez M, Poniachik J, Restrepo JC, Ruf A, Silva M, Tagle M, Tapias M, Torres K, Vilar-Gomez E, Costa Gil JE, Gadano A, Arrese M Abstract Non-alcoholic fatty liver disease (NAFLD) currently represents an epidemic worldwide. NAFLD is the most frequently diagnosed chr...
Source: Annals of Hepatology - Category: Gastroenterology Tags: Ann Hepatol Source Type: research
Emergency-use authorizations, a formerly obscure corner of regulatory law, have become a centerpiece of the government ’s response to the pandemic.
Source: NYT - Category: American Health Authors: Tags: your-feed-science Coronavirus Risks and Safety Concerns Food and Drug Administration Hahn, Stephen M (1960- ) Coronavirus (2019-nCoV) Vaccination and Immunization Clinical Trials Drugs (Pharmaceuticals) your-feed-health your-feed-healthc Source Type: news
The use of an immune-system stimulant harvested from shark liver oil in the development of some coronavirus vaccines has animal conservationists pressing for alternatives.(Image credit: Reinhard Dirscherl/ullstein bild via Getty Images)
Source: NPR Health and Science - Category: Consumer Health News Authors: Source Type: news
Authors: Abdeta D, Kebede N, Giday M, Terefe G, Abay SM Abstract Microbial resistance to the few conventional antitrypanosomal drugs, increasing resistance of vectors to insecticides, lack of effective vaccines, and adverse effects of the existing antitrypanosomal drugs justify the urgent need for effective, tolerable, and affordable drugs. We assessed antitrypanosomal effects of the hydromethanolic extract of Echinops kebericho Mesfin roots against Trypanosoma congolense field isolate using in vitro and in vivo techniques. Parasite load, packed cell volume (PCV), body weight, and rectal temperature in Swiss albino...
Source: Evidence-based Complementary and Alternative Medicine - Category: Complementary Medicine Tags: Evid Based Complement Alternat Med Source Type: research
Phoenix Children ’s Hospital held its fourth annual flu POD (point of distribution) this week, with this year's 13-hour blitz holding a special significance amid the global Covid-19 pandemic. On Oct. 7, nurses began vaccinating employees at 6 a.m. and concluded the one-day event at 7 p.m., vaccinating nearly 5,00 0 people. It’s preparation for another potential mass vaccination event: distribution of a safe and effective vaccine for Covid-19. Click through the photo gallery above to see scenes…
Source: bizjournals.com Health Care:Biotechnology headlines - Category: Biotechnology Authors: Source Type: news
In this study, we modeled an alternative strategy to amplify tumor antigen-specific TCR transgenic CD8+ T cells through limited application of a long-acting IL-2 fusion protein, mIL-2/mCD25, which selectively targets the high-affinity IL-2R. Here, mice were vaccinated with a tumor antigen and high-dose mIL-2/mCD25 was applied to coincide with the induction of the high affinity IL-2R on tumor-specific T cells. A single high dose of mIL-2/mCD25, but not an equivalent amount of IL-2, amplified the frequency and function of tumor-reactive CD8+ T effector (Teff) and memory cells. These mIL-2/mCD25-dependent effects relied on di...
Source: Cancer Immunology, Immunotherapy - Category: Cancer & Oncology Source Type: research
According to officials, the Hyderabad-based vaccine maker applied to the Drugs Controller General of India (DCGI) on October 2, seeking its permission to conduct phase-3 randomised double-blind placebo-controlled multicentre trial of its COVID-19 vaccine candidate.
Source: The Economic Times Healthcare and Biotech News - Category: Pharmaceuticals Source Type: news
DiscussionThe results of this realist review will be written up according to RAMESES guidelines and disseminated through a stakeholder workshop in Malawi, through conference presentations and peer-reviewed publications. It is intended to improve the understanding of the potential and limits of working through Care Groups globally and among relevant Malawi Ministry of Health staff and the donor and NGO community, both internationally and within Malawi. This systematic review protocol has been submitted for registration on the PROSPERO database (receipt number: 170261).
Source: Systematic Reviews - Category: International Medicine & Public Health Source Type: research
After being epidemic in China, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) infection has rapidly spread in many countries as a global pandemic, with the number of affected cases dramatically increasing worldwide on a daily basis. Although the median age of hospitalized patients with confirmed infection is usually more advanced 1, with older age reported to be associated to higher mortality rate 2, physiological adaptations occurring during pregnancy have been claimed to be potentially responsible for a more severe respiratory disease, thus leading to higher rates of maternal and fetal complications 3,4.
Source: European Journal of Obstetrics, Gynecology, and Reproductive Biology - Category: OBGYN Authors: Tags: Correspondence Source Type: research
ConclusionsPatients on various solid tumour treatments achieve sero-protection rate congruent with the general population. The sero-protection HIA titres were not sustained at 24  weeks postvaccination.
Source: Supportive Care in Cancer - Category: Cancer & Oncology Source Type: research
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