2. Rhabdoviridae Michelle Rodriguez MCB5505

3. Taxonomy  Group V  Order: Mononegavirales  Family: Rhabdoviridae  Genus: Lyssavirus  Species: Rabies  Virus Properties:  -ssRNA genome  Enveloped, bullet shaped  ~180 nm in length  Slow, progressive, zoonotic  neurotropic

4. Rabies Facts  Responsible for approximately 60,000 annual deaths worldwide  10 th most common lethal disease  Rabies means “rage” or “anger”  Lyssa is greek goddess of rage, madness  Transmission by humans and animals  Genus Lyssavirus comprises rabies virus and 3 rabies-like viruses  Each capable of causing rabies-like disease in humans http://www.bristol.ac.uk/biology/research/behaviour/batlab/members/harris.s.html

5. Epidemiology http://www.travelhealth.ie/Diseases/rabies.php

6. Virion Structure linear -ssRNA molecule encodes 5 viral proteins Spiked outer envelope: composed of glycoproteins Middle region consists of matrix protein M, and inner ribonucleocapsid complex http://www.cdc.gov/rabies/transmission/virus.html

7. Genome Genome of rabies virus (ERA strain). This contains single-stranded RNA (12 kilobases); N, NS, M, G, and L genes; a leader sequence at the 3' end; and four intergenic regions. http://www.cdc.gov/rabies/transmission/virus.html

8. Protein Translation Negative-stranded RNA linear genome, about 11 kb in size. Encodes for 5 proteins, plus 4 by alternative initiation. The viral RNA dependent RNA polymerase binds the encapsidated genome at the leader region, then sequentially transcribes genes by recognizing start and stop signals flanking viral genes. mRNAs are capped and polyadenylated by the L protein during synthesis. http://viralzone.expasy.org/all_by_species/2.html

9. Viral Protein Functions http://www.austincc.edu/microbio/2993s/rab.htm

10. Replication Steps CYTOPLASMIC 1.Attachment of the viral G glycoproteins to host receptors mediates clathrin- mediated endocytosis of the virus into the host cell. 2.Fusion of virus membrane with the vesicle membrane; ribonucleocapsid is released into the cytoplasm. 3.Sequential transcription of viral mRNAs are capped and polyadenylated by polymerase stuttering in the cytoplasm. 4.Replication presumably starts when enough nucleoprotein is present to encapsulate neo-synthetized antigenomes and genomes. 5.The ribonucleocapsid binds to the matrix protein and buds via host ESCRT pathway occurs at the plasma membrane, releasing new virions.

11. http://imgbuddy.com/rabies-virus-replication.asp

12. Neurotropism of Rabies The cycle of rabies infection begins with viral entry at a peripheral site and proceeds through retrograde axonal transport. Viral replication occurs in the cell body of the primary neuron. Infection proceeds by transsynaptic spread through several neurons before spreading to the acinar cells, which then shed the virus into the saliva http://www.bio.davidson.edu/courses/immunology/students/spring2006/jameson/rabies.html

13. Rabies virus entry into neurons and intra-neuronal transport. Nicotinic acetylcholine receptor (nAchR) is located at the postsynaptic muscle membrane It has been suggested that nAchR enriches rabies virus at the neuromuscular junction or synaptic cleft Enables more efficient infection of the connected motor neurons. Rabies virus enters the neurons using neural cell adhesion molecule (NCAM) or another, unknown receptor. Two different mechanisms have been proposed for the transport of rabies virus through the axon to the cell body: the transport of either the rabies virus capsid or the whole rabies virus virion within the vesicle The evidence favors the transport of intact virions. http://www.nature.com/nrmicro/journal/v8/n1/fig_tab/nrmicro2260_F4.html

14. Comparative Analysis of Rabies Virus Reverse Transcription-PCR and Virus Isolation Using Samples from a Patient Infected with Rabies Virus http://jcm.asm.org/content/48/8/2960/F1.expansion.html

15. Transmission *

16. Diagnostic Methods ELISA specific antibody detection PCR Viral sample from brain taken after death Rabies-specific fluorescence Standard pre-mortem test Fluorescent antibody to demonstrate presence of viral antigen

17. Molecular Imaging/Identification This transmission electron micrograph http:// synapse.koreamed.org/DOIx.php?id=10.4142/jvs.2012.13.1.43&vmode=PUBREADER Rabies-specific fluorescence

18. The Future of Rabies Expression Vectors An overview of the numerous tools that could, in the future, be developed using RABV ΔG vectors. Such possibilities include the expression of genetically encoded tools to aid imaging/microscopy approaches and tools to examine loss-of-function (knockdown) or gain-of-function of a gene/protein of interest. Other possibilities involve retargeting using engineered envelope proteins or the possibility of transfection using naked ribonucleoprotein (RNP) complexes. Some approaches are not possible with RABV ΔG vectors including the integration of lox P sites, cell specific promoters or tet-regulatory sequences, or expression of shRNA. RNP, Ribonucleoprotein, core of the RABV; EM, Electron microscopy; PALM, Photo-activated localization microscopy; VSD, Voltage-sensitive dye; miRNA, micro RNA; shRNA, short hairpin RNA http://journal.frontiersin.org/article/10.3389/fncir.2013.00002/full

19. Prevention Vaccinate your pets. Cats, dogs and ferrets can be vaccinated against rabies Keep your pets confined Protect small pets from predators Report stray animals to local authorities Don't approach wild animals Keep bats out of your home Consider the rabies vaccine if you're traveling (immune globulin)

20. References Dietzschold, B, M Schnell, H Koprowski. (2005). Pathogenesis of Rabies. Current Topics in Microbiology and Immunology. 292: 45-56. Thoulouse, MA, M Lafage, M Schachner, U Hartmann, H Cremer, M Lafon. (1998). The Neural Cell Adhesion Molecule Is a Receptor for Rabies Virus. Journal of Virology. 72(9): 7181-7190. Warrell, MJ and DA Warrell. (2004). Rabies and other lyssavirus diseases. The Lancet. 363(9413): 959- 69. Bassin SL, Rupprecht CE, Bleck TP. Rhabdoviruses. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 163. Tuffereau C., Benejean J., Blondel D., Kieffer B., Flamand A. Low-affinity nerve-growth factor receptor (P75NTR) can serve as a receptor for rabies virus. EMBO J. 1998;17:7250–7259