The leading cause of gastroenteritis in children under the age of five is rotavirus infection, accounting for 37% of diarrhoeal deaths in infants and young children globally. Oral rotavirus vaccines have been widely incorporated into national immunisation programs, but whilst these vaccines have excellent efficacy in high-income countries, they protect less than 50% of vaccinated individuals in low- and middle-income countries. In order to facilitate the development of improved vaccine strategies, a greater understanding of the immune response to existing vaccines is urgently needed.
View Article and Find Full Text PDFAntibodies that can bind to viruses but are unable to block infection in cell culture are known as "nonneutralizing antibodies." Such antibodies are nearly universally elicited following viral infection and have been characterized in viral infections such as influenza, rotavirus, cytomegalovirus, HIV, and SARS-CoV-2. It has been widely assumed that these nonneutralizing antibodies do not function in a protective way in vivo and therefore are not desirable targets of antiviral interventions; however, increasing evidence now shows this not to be true.
View Article and Find Full Text PDFFor decades antibodies were largely thought to provide protection in extracellular spaces alone, mediating their effector functions by mechanisms such as entry-blocking, complement activation and phagocyte recruitment. However, a wealth of research has shown that antibodies are also capable of neutralising numerous viruses inside cells. Efficacy has now been demonstrated at virtually all intracellular stages of the viral life cycle.
View Article and Find Full Text PDFSARS-CoV-2 is notable both for its rapid spread, and for the heterogeneity of its patterns of transmission, with multiple published incidences of superspreading behaviour. Here, we applied a novel network reconstruction algorithm to infer patterns of viral transmission occurring between patients and health care workers (HCWs) in the largest clusters of COVID-19 infection identified during the first wave of the epidemic at Cambridge University Hospitals NHS Foundation Trust, UK. Based upon dates of individuals reporting symptoms, recorded individual locations, and viral genome sequence data, we show an uneven pattern of transmission between individuals, with patients being much more likely to be infected by other patients than by HCWs.
View Article and Find Full Text PDFThe humoral immune response to SARS-CoV-2 results in antibodies against spike (S) and nucleoprotein (N). However, whilst there are widely available neutralization assays for S antibodies, there is no assay for N-antibody activity. Here, we present a simple in vitro method called EDNA (electroporated-antibody-dependent neutralization assay) that provides a quantitative measure of N-antibody activity in unpurified serum from SARS-CoV-2 convalescents.
View Article and Find Full Text PDFNucleoprotein (N) is an immunodominant antigen in many enveloped virus infections. While the diagnostic value of anti-N antibodies is clear, their role in immunity is not. This is because while they are non-neutralising, they somehow clear infection by coronavirus, influenza and LCMV in vivo.
View Article and Find Full Text PDFRotavirus is a major cause of gastroenteritis in children, with infection typically inducing high levels of protective antibodies. Antibodies targeting the middle capsid protein VP6 are particularly abundant, and as VP6 is only exposed inside cells, neutralisation must be post-entry. However, while a system of poly immune globulin receptor (pIgR) transcytosis has been proposed for anti-VP6 IgAs, the mechanism by which VP6-specific IgG mediates protection remains less clear.
View Article and Find Full Text PDFBackground: The burden and influence of health-care associated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is unknown. We aimed to examine the use of rapid SARS-CoV-2 sequencing combined with detailed epidemiological analysis to investigate health-care associated SARS-CoV-2 infections and inform infection control measures.
Methods: In this prospective surveillance study, we set up rapid SARS-CoV-2 nanopore sequencing from PCR-positive diagnostic samples collected from our hospital (Cambridge, UK) and a random selection from hospitals in the East of England, enabling sample-to-sequence in less than 24 h.
The therapeutic effects of gene therapy using adeno-associated virus (AAV) vectors are dependent on the efficacy of viral transduction. Currently, we have reached the safe limits of AAV vector dose, beyond which damaging inflammatory responses are seen. To improve the efficacy of AAV transduction, we treated mouse embryonic fibroblasts, primate retinal pigment epithelial cells, and human retinal explants with hydroxychloroquine (HCQ) 1 h prior to transduction with an AAV2 vector encoding GFP driven by a ubiquitous CAG promoter.
View Article and Find Full Text PDFThe complement system is vital for anti-microbial defense. In the classical pathway, pathogen-bound antibody recruits the C1 complex (C1qC1rC1s) that initiates a cleavage cascade involving C2, C3, C4, and C5 and triggering microbial clearance. We demonstrate a C4-dependent antiviral mechanism that is independent of downstream complement components.
View Article and Find Full Text PDFThe 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations.
View Article and Find Full Text PDFBackground: Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target.
View Article and Find Full Text PDFThe Magazine Wharf area, Freetown, Sierra Leone was a focus of ongoing Ebola virus transmission from late June 2015. Viral genomes linked to this area contain a series of 13 T to C substitutions in a 150 base pair intergenic region downstream of viral protein 40 open reading frame, similar to the Ebolavirus/H.sapiens-wt/SLE/2014/Makona-J0169 strain (J0169) detected in the same town in November 2014.
View Article and Find Full Text PDFHuman noroviruses (HuNoVs) are a major cause of viral gastroenteritis, with an estimated 3 million cases per year in the United Kingdom. HuNoVs have recently been isolated from pet dogs in Europe (M. Summa, C.
View Article and Find Full Text PDFAstroviruses are a common cause of gastroenteritis in children worldwide. These viruses can also cause infection in a range of domestic and wild animal species. Canine astrovirus (CaAstV) was first identified in the USA, and has since been reported in dogs from Europe, the Far East and South America.
View Article and Find Full Text PDFMurine norovirus (MNV) is a positive-sense, plus-stranded RNA virus in the Caliciviridae family. It is the most common pathogen in biomedical research colonies. MNV is also related to the human noroviruses, which cause the majority of nonbacterial gastroenteritis worldwide.
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