A Transmissible Gastroenteritis Coronavirus Nucleoprotein Epitope Elicits T Helper Cells That Collaborate in the in Vitro Antibody Synthesis to the Three Major Structural Viral Proteins

AbstractFour strong T cell epitopes have been identified studying the blastogenic response of lymphocytes from haplotype-defined transmissible gastroenteritis virus (TGEV) immune miniswine to sixty-one 15-mer synthetic peptides. Three of these epitopes are located on the nucleoprotein (N48 amino acids 46 to 60; N272, amino acids 272 to 286; and N321 amino acid 321 to 335), and one on the membrane protein (M196, amino acids 196 to 210). N321, peptide induced the highest T cell response and was recognized by immune miniswine lymphocytes with haplotypes dd, aa , and cc. T lymphocytes from peptide N321-immune miniswine reconstituted the in vitro synthesis of TGEV-specific antibodies by complementing CD4- TGEV-immune cells. This response was directed at least against the three major structural proteins. The synthesized antibodies specific for S protein preferentially recognized discontinous epitopes and neutralized TGEV infectivity. These results show that peptide N321 defines a functional T helper epitope eliciting T cells capable of collaborating with B cells specific for different proteins of TGEV

Vaccines to prevent severe acute respiratory syndrome coronavirus-induced disease

An important effort has been performed after the emergence of severe acute respiratory syndrome (SARS) epidemic in 2003 to diagnose and prevent virus spreading. Several types of vaccines have been developed including inactivated viruses, subunit vaccines, virus-like particles (VLPs), DNA vaccines, heterologous expression systems, and vaccines derived from SARS-CoV genome by reverse genetics. This review describes several aspects essential to develop SARS-CoV vaccines, such as the correlates of protection, virus serotypes, vaccination side effects, and bio-safeguards that can be engineered into recombinant vaccine approaches based on the SARS-CoV genome. The production of effective and safe vaccines to prevent SARS has led to the development of promising vaccine candidates, in contrast to the design of vaccines for other coronaviruses, that in general has been less successful. After preclinical trials in animal models, efficacy and safety evaluation of the most promising vaccine candidates described has to be performed in humans

Analysis of SARS-CoV E protein ion channel activity by tuning the protein and lipid charge

A partial characterization of the ion channels formed by the SARS coronavirus (CoV) envelope (E) protein was previously reported (C. Verdiá-Báguena et al., 2012 [12]). Here, we provide new significant insights on the involvement of lipids in the structure and function of the CoV E protein channel on the basis of three se- ries of experiments. First, reversal potential measurements over a wide range of pH allow the dissection of the contributions to channel selectivity coming from ionizable residues of the protein transmembrane do- main and also from the negatively charged groups of diphytanoyl phosphatidylserine (DPhPS) lipid. The cor- responding effective pKas are consistent with the model pKas of the acidic residue candidates for titration. Second, the change of channel conductance with salt concentration reveals two distinct regimes (Donnan-controlled electrodiffusion and bulk-like electrodiffusion) fully compatible with the outcomes of selectivity experiments. Third, by measuring channel conductance in mixtures of neutral diphytanoyl phos- phatidylcholine (DPhPC) lipids and negatively charged DPhPS lipids in low and high salt concentrations we conclude that the protein–lipid conformation in the channel is likely the same in charged and neutral lipids. Overall, the whole set of experiments supports the proteolipidic structure of SARS-CoV E channels and ex- plains the large difference in channel conductance observed between neutral and charged membranes

Calidad de vida relacionada con la salud de los pacientes con insuficiencia cardiaca crónica sistólica en España: resultados del estudio VIDA-IC

[Resumen] Introducción y objetivos. La calidad de vida relacionada con la salud de los pacientes con insuficiencia cardiaca está afectada. Hay poca información sobre los factores clínicos asociados a esta mala calidad de vida de la población española con insuficiencia cardiaca. Métodos. Estudio multicéntrico transversal de calidad de vida relacionada con la salud aplicando un cuestionario específico (Kansas City Cardiomyopathy Questionnaire) y otro genérico (EuroQol-5D) a 1.037 pacientes ambulatorios consecutivos con insuficiencia cardiaca sistólica. Resultados. Los pacientes con peor calidad de vida presentaron en su mayoría datos asociados a peor pronóstico y mayor gravedad de la enfermedad. Los pacientes del estudio presentaron mayor incidencia de limitaciones en movilidad, dolor/malestar y ansiedad/depresión cuando se realizó una comparación externa con población general y con pacientes con otras afecciones crónicas. La correlación entre las puntuaciones totales de ambos cuestionarios fue muy alta (r de Pearson = 0,815; p < 0,001). Con regresión lineal multivariable, se observó que mayor edad (β estandarizada = –0,2; p = 0,03), sexo femenino (β estandarizada = –10,3; p < 0,001), peor clase funcional (β estandarizada = –20,4; p < 0,001), mayor comorbilidad según índice de Charlson (β estandarizada = –1,2; p = 0,005) y el ingreso reciente por insuficiencia cardiaca (β estandarizada = 6,28; p = 0,006) son factores independientes predictores de peor calidad de vida relacionada con la salud. Conclusiones. Los pacientes con insuficiencia cardiaca tienen muy afectada su calidad de vida respecto a la población general española y a otras enfermedades crónicas. Sexo femenino, edad avanzada, comorbilidad, síntomas avanzados y hospitalización reciente son factores determinantes en la calidad de vida relacionada con la salud de estos pacientes

Coronavirus E protein forms ion channels with functionally and structurally-involved membrane lipids

Coronavirus (CoV) envelope (E) protein ion channel activity was determined in channels formed in planar lipid bilayers by peptides representing either the transmembrane domain of severe acute respiratory syndrome CoV (SARS-CoV) E protein, or the full-length E protein. Both of them formed a voltage independent ion conductive pore with symmetric ion transport properties. Mutations N15A and V25F located in the transmembrane domain prevented the ion conductivity. E protein derived channels showed no cation preference in non-charged lipid membranes, whereas they behaved as pores with mild cation selectivity in negatively-charged lipid membranes. The ion conductance was also controlled by the lipid composition of the membrane. Lipid charge also regulated the selectivity of a HCoV-229E E protein derived peptide. These results suggested that the lipids are functionally involved in E protein ion channel activity, forming a protein–lipid pore, a novel concept for CoV E protein ion channel entity

Alphacoronavirus protein 7 modulates host innate immune response

Innate immune response is the first line of antiviral defense resulting, in most cases, in pathogen clearance with minimal clinical consequences. Viruses have developed diverse strategies to subvert host defense mechanisms and increase their survival. In the transmissible gastroenteritis virus (TGEV) as a model, we previously reported that accessorygene 7 counteracts the host antiviral response by associating with the catalytic subunit of protein phosphatase 1 (PP1c). In the present work, the effect of the absence of gene 7on the host cell, during infection, was further analyzed by transcriptomic analysis. The pattern of gene expression of cells infected with a recombinant mutant TGEV, lacking gene7 expression (rTGEV-δ7), was compared to that of cells infected with the parental virus (rTGEV-wt). Genes involved in the immune response, the interferon response, and inflammation were upregulated during TGEV infection in the absence of gene 7. An exacerbated innate immune response during infection with rTGEV-δ7 virus was observed both in vitro and invivo. An increase in macrophage recruitment and activation in lung tissues infected with rTGEV-δ7 virus was observed compared to cells infected with the parental virus. In summary, the absence of protein 7 both in vitro and in vivo led to increased proinflammatory responses and acute tissue damage after infection. In a porcine animal model, which is immunologically similar to humans, we present a novel example of how viral proteins counteract host antiviral pathways to determine the infection outcome and pathogenesis

A live attenuated severe acute respiratory syndrome coronavirus is immunogenic and efficacious in Golden Syrian hamsters

The immunogenicity and protective efficacy of a live attenuated vaccine consisting of a recombinant severe acute respiratory syndrome (SARS) coronavirus lacking the E gene (rSARS-CoV-ΔE) were studied using hamsters. Hamsters immunized with rSARS-CoV-ΔE developed high serum-neutralizing antibody titers and were protected from replication of homologous (SARS-CoV Urbani) and heterologous (GD03) SARS-CoV in the upper and lower respiratory tract. rSARS-CoV-ΔE-immunized hamsters remained active following wild-type virus challenge, while mock-immunized hamsters displayed decreased activity. Despite being attenuated in replication in the respiratory tract, rSARS-CoV-ΔE is an immunogenic and efficacious vaccine in hamsters.This research was supported in part by the Intramural Research Program of the NIH, NIAID; by NIH AID AI059136; and by the European Community (projects DISSECT SP22-CT-2004-511060 and Rivigene SSPE-CT-2005-022639)