Capturing replication strategies used by SARS viruses in their bid to spread

Just over five years ago, an outbreak of severe acute respiratory syndrome (SARS)-coronavirus killed over 750 people. SARS (corona)virus, a positive-stranded RNA virus, replicates in the cytoplasm of host cells, attaching its replication complex to intracellular membranes that it has modified for this purpose.

In a study published this week in PLoS Biology, biologist Eric Snijder and colleagues report how they have used virus-infected cell cultures and developed a sophisticated method to preserve and visualize the fragile replication structures of SARS-coronavirus, both in whole cells (by light microscopy) and in sections of cells (by electron microscopy).

The viral replication complexes are made up largely of viral proteins and enzymes that we know very little about. The authors develop their system as a way to study these proteins and to work out how they interplay with the modified host membranes to ensure viral replication and spread.

Snijder and colleagues use electron microscopy and tomography to study these modifications, providing the striking images found below, which capture for the human eye the viral reorganization of the cellular infrastructure. The authors have begun to tease apart the complicated process of replication by these viruses by analyzing the effects of disrupting specific host cell components in the culture dish. Their results demonstrate the dependence of viral replication on protection by (or support from) the modified membranes, and open the door wider for the development of new antiviral strategies.

Citation:Knoops K, Kikkert M, van den Worm SHE, Zevenhoven-Dobbe JC, van der Meer Y, et al. (2008) SARS-coronavirus replication is supported by a reticulovesicular network of modified endoplasmic reticulum. PLoS Biol 6(9): e226. doi:10.1371/journal.pbio.0060226 http://dx.plos.org/10.1371/journal.pbio.0060226

Source: Public Library of Science

Related stories:

Fruit fly gene study could yield new flu treatments
Scientists may be able to stave off influenza infection by targeting one of more than 100 proteins inside host cells on which the virus depends. These potential drug targets are the result of a study in which researchers tested the ability of a modified influenza virus to infect fruit fly cells.
Gene therapy increases survival for end-stage head and neck cancer
A gene therapy invented at The University of Texas M. D. Anderson Cancer Center is the first to succeed in a U.S. phase III clinical trial for cancer, as announced today at the American Society of Gene Therapy annual meeting in Boston.
Getting wise to the influenza virus' tricks
Influenza is currently a grave concern for governments and health organisations around the world. The worry is the potential for highly virulent bird flu strains, such as H5N1, to develop the ability to infect humans easily. New drugs and vaccines to halt the spread of the virus are badly needed.
Monkeys able to fend off AIDS-like symptoms with enhanced HIV vaccine
Researchers at the University of Pennsylvania School of Medicine have discovered that using an immune system gene to enhance a vaccine used to study HIV in macaque monkeys provides the animals with greater protection against simian HIV (SHIV) than an unmodified vaccine. This multi-year study found that the addition of a molecule called Interleukin-15 effectively boosts the effects of a vaccine derived from the DNA of simian HIV.
New research details parasitic battles
Scientists at MIT’s Department of Civil and Environmental Engineering and the Technion Israel Institute of Technology have for the first time recorded the entire genomic expression of both a host bacterium and an infecting virus over the eight-hour course of infection.
Veterinary scientists explore poultry virus as cancer killer
Virologists in the Virginia-Maryland Regional College of Veterinary Medicine (VMRCVM) at Virginia Tech are looking at how a genetically modified variant of Avian Newcastle disease virus (NDV) can treat human prostate cancer.
Regulating the nuclear architecture of the cell
An organelle called the nucleolus resides deep within the cell nucleus and performs one of the cell's most critical functions: it manufactures ribosomes, the molecular machines that convert the genetic information carried by messenger RNA into proteins that do the work of life.
Breaking BubR1 mimics genetic shuffle seen in cancer cells
A study of how one protein enzyme, BubR1, helps make sure chromosomes are equally distributed during mitosis might explain how the process of cell division goes so awry in cancer, according to researchers from Fox Chase Cancer Center. Their findings might offer a better understanding of the processes behind cancer-cell survival and drug-resistance.

News discussion:

General Science news