Journal - Journal of medical virology (United States )

Abstract :

Lower respiratory tract infections are the leading cause of death in children worldwide. Studies on the epidemiology and clinical associations of the four human non-SARS human coronaviruses (HCoVs) using sensitive polymerase chain reaction (PCR) assays are needed to evaluate the clinical significance of HCoV infections worldwide. Pediatric respiratory specimens (1,683) submitted to a diagnostic virology laboratory over a 1-year period (December 2004-November 2005) that were negative for seven respiratory viruses by conventional methods were tested for RNA of four HCoVs using sensitive RT-PCR assays. Coronavirus RNAs were detected in 84 (5.0%) specimens: HCoV-NL63 in 37 specimens, HCoV-OC43 in 34, HCoV-229E in 11, and HCoV-HKU1 in 2. The majority of HCoV infections occurred during winter months, and over 62% were in previously healthy children. Twenty-six (41%) coronavirus positive patients had evidence of a lower respiratory tract infection (LRTI), 17 (26%) presented with vomiting and/or diarrhea, and 5 (8%) presented with meningoencephalitis or seizures. Respiratory specimens from one immunocompromised patient were persistently positive for HCoV-229E RNA for 3 months. HCoV-NL63-positive patients were nearly twice as likely to be hospitalized (P = 0.02) and to have a LRTI (P = 0.04) than HCoV-OC43-positive patients. HCoVs are associated with a small, but significant number (at least 2.4% of total samples submitted), of both upper and lower respiratory tract illnesses in children in Colorado. Our data raise the possibility that HCoV may play a role in gastrointestinal and CNS disease. Additional studies are needed to investigate the potential roles of HCoVs in these diseases.

Abstract :

DESCRIPTION (provided by applicant): Severe acute respiratory syndrome (SARS), caused by a new human coronavirus (SARS-CoV), represents the 21st century's first pandemic caused by a previously unknown etiological agent. The 2002-03 SARS epidemic stimulated research on coronaviruses of humans, animals, and birds. SARS had enormous economic impact and demonstrated the pathogenic potential of this large group of RNA viruses. An indirect result of the SARS epidemic was the discovery of two new human coronaviruses, HCoV-NL63, isolated in 2004, and HCoV-HKU1, discovered in 2005, and the discovery of novel bat coronaviruses in Asia. Interestingly, preliminary phylogenetic analysis suggests that all animal and human coronaviruses may have evolved from progenitor coronaviruses in bats. Studies on the epidemiology and pathogenesis of NL63, HKU1, and bat coronaviruses are still in their infancy. My mentor's laboratory has extensive experience in studying human and animal coronaviruses. Because I am a pediatric infectious disease specialist with a collaboration already established with The Children's Hospital Clinical Virology Laboratory, an outstanding collection of pediatric respiratory and stool specimens is available to me. Additionally, my mentor and I have joined the recently formed Rocky Mountain Bat Research Consortium. These combined advantages provide me with the needed resources and training for this proposed research. In this revised K08 application, I propose epidemiological, functional and molecular characterization studies on NL63, HKU1, and novel Rocky Mountain bat coronaviruses (RM-BtCoV), which I recently discovered. My goals are to develop sensitive and specific new tools for the rapid diagnosis of these viruses; characterize their prevalence, diversity and clinical spectra; and identify candidate receptor(s) for RM-BtCoVs. These studies will generate needed and valuable reagents for further studies on these viruses, provide information regarding the roles of NL63 and HKU1 in pediatric diseases, and provide further insights into the evolutionary relationships of coronaviruses and mechanisms of emergence of zoonotic diseases. The training and research on emerging coronaviruses that I propose here will enable me to study the essential components of emerging infectious diseases caused by other viruses, including their epidemiology, ecology, diagnostics, disease associations, and zoonotic emergence.

Abstract :

This proposal seeks to enhance the understanding of the structure-function relationship of a very highly conserved region of apolipoprotein E (apoE ) by clarifying in-depth the cellular mechanism by which a conformationally constrained synthetic peptide which mimics this region (amino acids 41-60) enhances the binding and internalization of low density lipoproteins (LDL) to both LDL receptor (LDL-R) positive and negative cells. This will be accomplished by identifying through what on the cell surface this interaction is occuring, localizing the site of binding between this peptide and LDL, tracing t he fate of LDL internalized in the presence of this peptide, studying the effect of this peptide on mutated apolipoproteins, and by optimizing the structure of this synthetic peptide for activity. It is hoped that these studies will point to future possible treatments for patients with familial hypercholesterolemia by providing an alternate route for cellular uptake of LDL independent of the LDL-R or for patients with other hyperlidemias due to apoE or apoB mutations by increasing clearance of lipoproteins.

Abstract :

This proposal seeks to enhance the understanding of the structure-function relationship of a very highly conserved region of apolipoprotein E (apoE ) by clarifying in-depth the cellular mechanism by which a conformationally constrained synthetic peptide which mimics this region (amino acids 41-60) enhances the binding and internalization of low density lipoproteins (LDL) to both LDL receptor (LDL-R) positive and negative cells. This will be accomplished by identifying through what on the cell surface this interaction is occuring, localizing the site of binding between this peptide and LDL, tracing t he fate of LDL internalized in the presence of this peptide, studying the effect of this peptide on mutated apolipoproteins, and by optimizing the structure of this synthetic peptide for activity. It is hoped that these studies will point to future possible treatments for patients with familial hypercholesterolemia by providing an alternate route for cellular uptake of LDL independent of the LDL-R or for patients with other hyperlidemias due to apoE or apoB mutations by increasing clearance of lipoproteins.