Oncolytic Virotherapy Reovirus A Prototypical Wildtype Oncolytic Virus

Cancer ¡Abnormal cell growth ¡Accumulated genetic & epigenetic alterations ¡Healthy cells gone “haywire” ¡Numerous

Conventional Treatments Surgery ¡ Tumor removal ¡ Is ineffective against and can induce metastasis

Conventional Treatments Radiotherapy ¡Uses radiation to kill tumor cells ¡Effective at reducing… ¡…Tumors! ¡…Aaaaand

Conventional Treatments Chemotherapy ¡ Use of pharmaceuticals to kill tumor cells ¡ It works!

Emerging Treatment: Virotherapy ¡ Uses an oncolytic virus (OV) to lyse cancer cells ¡

Hu Coxsackie A virus s vi ru za en Aden r e H s

How does it work? …Get it? ¡ Virus can be… ¡ Naturally occurring ¡

Example: Adenovirus Therapy Targeting Gliomas Source: Maruniak, Jim. "Adenovirus. " MCB 5505, Honors Virology.

Another Mechanism of Tumor Cell OV Susceptibility Source: Chiocca EA. Oncolytic viruses. Nat Rev

Reovirus Background ¡REOvirus = “Respiratory Enteric Orphan Virus” ¡Infect human respiratory & gastrointestinal tracts

Reovirus Taxonomy ¡Family: Reoviridae ¡Genera Infecting Vertebrates (6) ¡ Orthoreovirus ¡ Orbivirus ¡ Coltivirus

Reovirus Structure ¡Spherical, 80 nm diameter ¡Non-enveloped ¡Isometric capsid ¡ Concentric inner and outer

Reovirus Genome ¡RNA ¡Double-Stranded ¡Linear ¡ 10 -12 segments (speciesdependent) ¡Reassortment common in vitro

Reovirus Reproduction ¡Replicates in the cytoplasm ¡ Encodes its own replication machinery ¡ Antiviral

Sources ¡ Cann, Alan. "Reoviruses. " Microbiology. Bytes. 11 Sept. 2007. Web. <http: //www.

Slides: 19

Download presentation

Oncolytic Virotherapy Reovirus: A Prototypical Wild-type Oncolytic Virus By: Stephen Mayper

Cancer ¡Abnormal cell growth ¡Accumulated genetic & epigenetic alterations ¡Healthy cells gone “haywire” ¡Numerous means of immune response evasion

Conventional Treatments Surgery ¡ Tumor removal ¡ Is ineffective against and can induce metastasis ¡ Inherent risk!

Conventional Treatments Radiotherapy ¡Uses radiation to kill tumor cells ¡Effective at reducing… ¡…Tumors! ¡…Aaaaand healthy cells ¡Can carry severe side effects (Creative representation if innocent bystander cell death…)

Conventional Treatments Chemotherapy ¡ Use of pharmaceuticals to kill tumor cells ¡ It works! ¡ …But it kills lots of other cells indiscriminately

Emerging Treatment: Virotherapy ¡ Uses an oncolytic virus (OV) to lyse cancer cells ¡ Advantages: ¡ High specificity means fewer side effects ¡ Self-regulating dosage ¡ Lack of contraindications

Hu Coxsackie A virus s vi ru za en Aden r e H s u r i v flu n a m s e p alley virus In irus Seneca V Mumps virus us My xom av vir Pseudorabies virus rvo Pa SV 40 virus oviru s Viruses currently being explored Vaccinia virus

How does it work? …Get it? ¡ Virus can be… ¡ Naturally occurring ¡ Genetically engineered ¡ Transcription targeting ¡ Attenuation ¡ Specificity generally determined by antiviral pathway deregulation (It’s a virus in “nature!”)

Example: Adenovirus Therapy Targeting Gliomas Source: Maruniak, Jim. "Adenovirus. " MCB 5505, Honors Virology. University of Florida, Gainesville, FL. 19 Feb. 2011. Lecture.

Another Mechanism of Tumor Cell OV Susceptibility Source: Chiocca EA. Oncolytic viruses. Nat Rev Cancer. 2002 Dec; 2(12): 938 -50.

Reovirus

Reovirus Background ¡REOvirus = “Respiratory Enteric Orphan Virus” ¡Infect human respiratory & gastrointestinal tracts ¡“Orphaned” because originally not thought to be associated with any disease ¡ Several disease associations discovered since ¡Reoviruses are pervasive

Reovirus Taxonomy ¡Family: Reoviridae ¡Genera Infecting Vertebrates (6) ¡ Orthoreovirus ¡ Orbivirus ¡ Coltivirus ¡ Rotavirus ¡ Aquareovirus ¡ Seadornavirus • African Horse Sickness • Colorado. Mostly Tick Fever • Blue. Asymptomatic Tongue Disease (Percentage of gastroenteritis deaths) Source: Cann, Alan. "Reoviruses. " Microbiology. Bytes. 11 Sept. 2007. Web. <http: //www. microbiologybytes. com/virology/Reoviruses. html>.

Reovirus Structure ¡Spherical, 80 nm diameter ¡Non-enveloped ¡Isometric capsid ¡ Concentric inner and outer capsids ¡ Sometimes middle capsid ¡ (Inner capsid = “core”) ¡ 4 core proteins ¡ λ-1, λ-3, μ-2, σ-2 ¡ Heat-stable ¡ Stable @ p. H= 3 – 9 ¡ Denatured by ethanol

Reovirus Genome ¡RNA ¡Double-Stranded ¡Linear ¡ 10 -12 segments (speciesdependent) ¡Reassortment common in vitro ¡Encodes viral replication machinery Source: http: //education. expasy. org/images/Orthoreovirus_genome. jpg

Reovirus Reproduction ¡Replicates in the cytoplasm ¡ Encodes its own replication machinery ¡ Antiviral susceptibility ¡Does NOT fully uncoat ¡ Core is resistant to protease digestion ¡ No uncoating ¡ No destruction by host cell ¡Genomic RNA stays in the core ¡Assembled virions form cytoplasmic inclusion bodies ¡Released via cell lysis ¡ 6 – 7 hour replication time

Reovirus Replication Illustrated

Questions? Comments?

Sources ¡ Cann, Alan. "Reoviruses. " Microbiology. Bytes. 11 Sept. 2007. Web. <http: //www. microbiologybytes. com/virology/Reoviruses. html>. ¡ Chiocca EA. Oncolytic viruses. Nat Rev Cancer. 2002 Dec; 2(12): 938 -50. ¡ Hammill AM, Conner J, Cripe TP. Oncolytic virotherapy reaches adolescence. Pediatr Blood Cancer. 2010 Dec 15; 55(7): 1253 -63. doi: 10. 1002/pbc. 22724. Epub 2010 Aug 23. ¡ Maruniak, Jim. "Adenovirus. " MCB 5505, Honors Virology. University of Florida, Gainesville, FL. 19 Feb. 2011. Lecture. ¡ Mertens P. The ds. RNA viruses. Virus Res. 2004 Apr; 101(1): 3 -13. ¡ Nettelbeck DM. Cellular genetic tools to control oncolytic adenoviruses for virotherapy of cancer. J Mol Med. 2008 Apr; 86(4): 363 -77. Epub 2007 Dec 19. ¡ Siegel, Robert. "Reoviruses. " Stanford University. 1 Feb. 1999. Web. 20 Apr. 2011. <http: //www. stanford. edu/group/virus/1999/caryn/reovirus. html>. ¡ Vähä-Koskela MJ, Heikkilä JE, Hinkkanen AE. Oncolytic viruses in cancer therapy. Cancer Lett. 2007 Sep 8; 254(2): 178 -216. Epub 2007 Mar 23.