Norovirus: Difference between revisions

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==Current Research==
==Current Research==


Enter summarries of the most rescent research here--at least three required
    Previously, the development of an effective therapy for noroviral gastroenteritis had been hampered by the lack of a cell culture system. The Chang and George study in 2007 reported the generation of Norwalk virus replicon-bearing cells in BHK21 and Huh-7 cells and furthermore demonstrated that alpha interferon (IFN-α) effectively inhibited the replication of Norovirus in these cells. IFN-γ also inhibited the replication of Norovirus in the replicon-bearing cells. They discovered that the combination of IFN-α and ribavirin showed additive effects in the inhibition of Norovirus replication. Their findings indicated that IFNs and ribivirin may be good therapeutic options for noroviral gastroenteritis (Chang and George, 2007).
 
    Due to the lack of suitable tissue culture or animal models, the true nature of the norovirus pathogenesis remains unknown. Straub <i>et al.,</i> demonstrates that noroviruses can infect and replicate in a physiologically relevant 3-dimentional organoid model of human small intestine epithelium. This group of researchers achieved this by growing the cells on porous collagen-I coated microcarrier beads under conditions of physiological fluid shear in rotating wall vessel bioreactors. Microscopy, PCR, and fluorescent in situ hybridization provided evidence of norovirus infection. Their results demonstrate overall that the highly differentiated 3-D cell culture model can support the natural growth of human noroviruses, whereas previous attempts that used differentiated monolayer cultures failed (Straub <i> et al., </i>).
   
    To understand the extent of heterotypic norovirus antibody specificity to inter- and intra-genogroup strains and its applicability to vaccine design, LoBue and colleagues collected sera from humans infected with different norovirus strains and from mice inoculated with alphavirus vectors expressing strain-specific recombinant norovirus-like particles (VLPs). They used VLPs that were assembled from Norwalk virus (NV), Hawaii virus (HV), Snow Mountain virus (SM), and Lordsdale virus (LV) as antigens to define and compare heterotypic antibody responses in humans and mice. Furthermore, they examined whether or not heterotypic antibodies could block specific binding of the ABH histo-blood group antigens (receptors for norovirus binding and entry) to norovirus VLPs. Their studies suggest that infection with one of several different genogroup I strains in humans induces heterotypic antibodies which block NV binding to ABH antigens. They also found that inoculating mice with vaccine cocktails encoding multiple norovirus VLPs enhances heterotypic and ligand attachment—better protection from a broader range of noroviruses than monovalent vaccination (LoBue <i> et al., </i>). Vaccination studies in regards to norovirus are very important due to the fact that there currently is no vaccination against norovirus.


==References==
==References==

Revision as of 10:32, 18 December 2008

A Microbial Biorealm page on the genus Norovirus

Classification

Higher order taxa

Domain; Phylum; Class; Order; family [Others may be used. Use NCBI link to find]

Species

NCBI: Taxonomy

Genus species

Description and significance

Describe the appearance, habitat, etc. of the organism, and why you think it is important.

Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?


Virion Structure

Interesting features of cell structure; how it gains energy; what important molecules it produces.

Ecology

Habitat; symbiosis; contributions to the environment.

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Current Research

    Previously, the development of an effective therapy for noroviral gastroenteritis had been hampered by the lack of a cell culture system. The Chang and George study in 2007 reported the generation of Norwalk virus replicon-bearing cells in BHK21 and Huh-7 cells and furthermore demonstrated that alpha interferon (IFN-α) effectively inhibited the replication of Norovirus in these cells. IFN-γ also inhibited the replication of Norovirus in the replicon-bearing cells. They discovered that the combination of IFN-α and ribavirin showed additive effects in the inhibition of Norovirus replication. Their findings indicated that IFNs and ribivirin may be good therapeutic options for noroviral gastroenteritis (Chang and George, 2007).
    Due to the lack of suitable tissue culture or animal models, the true nature of the norovirus pathogenesis remains unknown. Straub et al., demonstrates that noroviruses can infect and replicate in a physiologically relevant 3-dimentional organoid model of human small intestine epithelium. This group of researchers achieved this by growing the cells on porous collagen-I coated microcarrier beads under conditions of physiological fluid shear in rotating wall vessel bioreactors. Microscopy, PCR, and fluorescent in situ hybridization provided evidence of norovirus infection. Their results demonstrate overall that the highly differentiated 3-D cell culture model can support the natural growth of human noroviruses, whereas previous attempts that used differentiated monolayer cultures failed (Straub  et al., ). 
    
    To understand the extent of heterotypic norovirus antibody specificity to inter- and intra-genogroup strains and its applicability to vaccine design, LoBue and colleagues collected sera from humans infected with different norovirus strains and from mice inoculated with alphavirus vectors expressing strain-specific recombinant norovirus-like particles (VLPs). They used VLPs that were assembled from Norwalk virus (NV), Hawaii virus (HV), Snow Mountain virus (SM), and Lordsdale virus (LV) as antigens to define and compare heterotypic antibody responses in humans and mice. Furthermore, they examined whether or not heterotypic antibodies could block specific binding of the ABH histo-blood group antigens (receptors for norovirus binding and entry) to norovirus VLPs. Their studies suggest that infection with one of several different genogroup I strains in humans induces heterotypic antibodies which block NV binding to ABH antigens. They also found that inoculating mice with vaccine cocktails encoding multiple norovirus VLPs enhances heterotypic and ligand attachment—better protection from a broader range of noroviruses than monovalent vaccination (LoBue  et al., ). Vaccination studies in regards to norovirus are very important due to the fact that there currently is no vaccination against norovirus.

References

Asanaka, M., Atmar, R.L., Ruvolo, V., Crawford, S.E., Frederick, H.N., and Estes, M.K. "Replication and packaging of Norwalk virus RNA in cultured mammalian cells". Proceedings of the National Academy of Sciences. 2005. Volume 10(29). p. 10327-10332.

Belliot, G., Sosnovtsev, S.V., Mitra, T., Hammer, C., Garfield, M., Green, K.Y. "In vitro proteolytic processing of the MD145 Norovirus ORF1 nonstructural polyprotein yields stable precursors and products similar to those detected in Calcivirus-infected cells." Journal of Virology. 2003. Volume 77. p. 10957-10974. In:Zheng, D., Ando, T., Fankhauser, R.L., Beard, R.S., Glass, R.I., and Monroe, S.S. “Norovirus classification and proposed strain nomenclature”. Virology. 2006. Volume 346. p. 312-323.

Bertolotti-Ciarlet, A., White, L.J., Chen, R., Venkataram Prasad, B.V., and Estes, M.K. “Structural Requirements for the assembly of Norwalk virus-like particles”. Journal of Virology. 2002. Volume 76. p. 4044-4055.

Billgren, M., Chistenson, B., Hedlund, K.O., and Vinje, J. "Epidemiology of Norwalk-like Human Caliciviruses in Hospital Outbreaks of Acute Gastroenteritis in the Stockholm Area in 1996". Journal of Infection. 2002. Volume 44. p. 26-32. In: Asanaka, M., Atmar, R.L., Ruvolo, V., Crawford, S.E., Frederick, H.N., and Estes, M.K. "Replication and packaging of Norwalk virus RNA in cultured mammalian cells". Proceedings of the National Academy of Sciences. 2005. Volume 10(29). p. 10327-10332.

Chang, K., and George, D.W. “Interferons and ribavirin effectively inhibit Norwalk virus replication in replicon-bearing cells”. Journal of Virology. 2007. Volume 81(22). p. 12111-12118.

Clarke, I.N., and Lambden, P.R. “Organization and Expression of Calicivirus Genes”. The Journal of Infectious Diseases. 2000. Volume 181. p. S309-16.

Dolan, R. “Norovirus—challenges to control”. New England Journal of Medicine. 2007. Volume 357(11). p. 1072-1073.

Fankhauser, R.L., Noel, J.S., Monroe, S.S., Ando, T., and Glass, R.I. "Molecular Epidemiology of “Norwalk-like Viruses” in Outbreaks of Gastroenteritis in the United States". Journal of Infectious Diseases. 1998. Volume 178. p. 1571-1578. In: Asanaka, M., Atmar, R.L., Ruvolo, V., Crawford, S.E., Frederick, H.N., and Estes, M.K. "Replication and packaging of Norwalk virus RNA in cultured mammalian cells". Proceedings of the National Academy of Sciences. 2005. Volume 10(29). p. 10327-10332.

Green, K.Y., Chanock, R.M., Kapikian, A.Z., 2001. In: Knipe, D.M., Howley, P.M. et al. (Eds.), "Human Caliciviruses: Fields Virology, 4th ed., vol. 1. Lippincott Williams and Wilkins, Philadelphia, p. 841-874. In: Zheng, D., Ando, T., Fankhauser, R.L., Beard, R.S., Glass, R.I., and Monroe, S.S. “Norovirus classification and proposed strain nomenclature”. Virology. 2006. Volume 346. p. 312-323.

Harrington, P.R., Lindesmith, L., Yount, B., Moe, C.L., and Baric, R.S. “Binding of Norwalk virus-like particles to ABH histo-blood group antigens is blocked by antisera from infected human volunteers or experimentally vaccinated mice”. Journal of Virology. 2002. Volume 76(23). p. 12335-12343.

Jiang, X., Graham, D.Y., Wang, K., Estes, M.K. "Norwalk virus genome cloning and characterization." Science. 1990. Volume 250. p. 1580-1583. In: Zheng, D., Ando, T., Fankhauser, R.L., Beard, R.S., Glass, R.I., and Monroe, S.S. “Norovirus classification and proposed strain nomenclature”. Virology. 2006. Volume 346. p. 312-323.

Jiang, X., Wang, M., Wang, K., Estes, M.K. "Sequence and genomic organization of Norwalk virus". Virology. 1993. Volume 195. p. 51-61. In: Zheng, D., Ando, T., Fankhauser, R.L., Beard, R.S., Glass, R.I., and Monroe, S.S. “Norovirus classification and proposed strain nomenclature”. Virology. 2006. Volume 346. p. 312-323.

Kapikian, A.Z., Wyatt, R.G., Dolin, R., Thornhill, T.S., Kalica, A.R., Chanock, R.M. "Visualization by immune electron microscopy of a 27-nm particle associated with acute infectious nonbacterial gastroenteritis". Journal of Virology. 1972. Volume 10. p. 1075-81. In:Clarke, I.N., and Lambden, P.R. “Organization and Expression of Calicivirus Genes”. The Journal of Infectious Diseases. 2000. Volume 181. p. S309-16.

Lindesmith, L., Moe, C., Marionneau, S., Ruvoen, N., Jiang, X., Lindblad, L., Stewart, P., LePendu, J., and Baric, R. “Human susceptibility and resistance to Norwalk virus infection”. Nature Medicine. 2003. Volume 9(5). p. 548-553.

LoBue, A.D., Lindesmith, L., Yount, B., Harrington, P.R., Thompson, J.M., Johnston, R.E., Moe, C.L., and Baric, R.S. “Multivalent Norovirus vaccines induce strong mucosal and systemic blocking antibodies against multiple strains”. Vaccine. 2006. Volume 24. p. 5220-5234.

Prasad, B.V., Rothnagel, V.R., Jiang, X., and Estes, M.K. “Three-dimensional structure of baculovirus-expressed Norwalk virus capsids”. Journal of Virology. 1994. Volume 68. p. 5117-5125. In: Bertolotti-Ciarlet, A., White, L.J., Chen, R., Venkataram Prasad, B.V., and Estes, M.K. “Structural Requirements for the assembly of Norwalk virus-like particles”. Journal of Virology. 2002. Volume 76. p. 4044-4055.

Straub, T.M., Honer zu Bentrup, K., Orosz-Coghlan, P., Dohnalkova, A., Mayer, B.K., Bartholomew, R.A., Valdez, C.O., Bruckner-Lea, C.J., Gerba, C.P., Abbaszadegan, M., and Nickerson, C.A. “In vitro cell culture infectivity assay for human Noroviruses”. Emerging Infectious Diseases. 2007. Volume 13(3). p. 396-403.

Waters, A., Coughlan, S., and Hall, W.W. “Characterization of a novel recombination event in the Norovirus polymerase gene”. Virology. 2007. Volume 363. p. 11-14.

Widdowson, M.A., Monroe, S.S., and Glass, R.I. “Are Noroviruses emerging?”. Emerging Infectious Diseases. 2005. Volume 11(5). p. 735-737.

Zheng, D., Ando, T., Fankhauser, R.L., Beard, R.S., Glass, R.I., and Monroe, S.S. “Norovirus classification and proposed strain nomenclature”. Virology. 2006. Volume 346. p. 312-323.


Edited by Rabia Bajwa, student of Emily Lilly at University of Massachusetts Dartmouth.