1 / 14

Human Herpesvirus-8

Human Herpesvirus-8. Krystle Jones. Background. HHV-8 was discovered in 1994 by Yuan Chang and his collaborators at Columbia University. Polymerase Chain Reaction (PCR) technique allowed them to isolate 2 fragments of DNA in tissues infected with both AIDS and Kaposi’s Sarcoma.

Download Presentation

Human Herpesvirus-8

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Human Herpesvirus-8 Krystle Jones

  2. Background • HHV-8 was discovered in 1994 by Yuan Chang and his collaborators at Columbia University. • Polymerase Chain Reaction (PCR) technique allowed them to isolate 2 fragments of DNA in tissues infected with both AIDS and Kaposi’s Sarcoma. • First known human member of the genus Rhadinovirus. • Also known as Kaposi’s Sarcoma-Associated Herpesvirus.

  3. What is a Herpesvirus? • A group of double-stranded DNA viruses that are enveloped and have large, complex genomes. • Belong to family Herpesviridae, which is divided into 3 sub-families: Alphaherpesvirinae, Betaherpesvirinae, and Gammaherpesvirinae. • Herpesviruses are made up of a core, capsid, tegument, and envelope.

  4. Different herpesviruses vary in genomic sequences and proteins, but are highly conservative in terms of structure and organization. Success of these infections depends on 3 strategies: 1-The capability of the virus to enter the host cell quickly and efficiently, and begin replication and production immediately. 2-Ability to avoid attacks from host by inhibiting splicing of mRNA, which blocks the presentation of antigenic peptides on the cell surface. 3-Ability to hide their genome and remain at a latent phase of infection until a phase of immunosuppression occurs.

  5. HHV-8 Genomes -All herpesvirus genomes have 2 regions bound by inverted repeats. -The 2 separated regions are the unique long and unique short regions. -These allow for rearrangements so that the genomes can then exist as a mixture of 4 isomers.

  6. HHV-8 • Is an opportunistic pathogen- after the primary infection, HHV-8 hides in the body until a period of low immunity. • HIV patients tend to be infected by microorganisms such as HHV-8 because of the loss of their CD4 T-cells, and reactivation occurs when the latent virus is no longer controlled by CD8 T-cells.

  7. -HHV-8 has a capsid composed of 4 structural proteins. 3 are encoded by ORF 25, 26, and 62. -Some proteins found in HHV-8 that are similar to those found in cellular proteins are: -complement binding protein -IL6-like cytokine -3 chemokines -Interferon regulatory factor -cell-adhesion-like molecules -G-protein coupled receptor -HHV-8 has been found in B-cells, macrophages, and dendritic cells.

  8. HHV-8 Global Infection HHV-8 is transmitted sexually through semen, and sometimes vertically from mother to child.

  9. Kaposi’s Sarcoma • Is a tumor that generally appears in the tissues below the skin surface of the face and genitalia. • Is closely associated with HHV-8. • There are 4 different forms of KS: • AIDS-related • Classic • Acquired • African

  10. The formation of KS lesions in association with the infection of HHV-8 is commonly seen, and is the source of DNA in HHV-8 research.

  11. Detection and Treatment • Detection of HHV-8 depends on direct identification of the viral DNA. This can be done through blood screening or with the tissue of KS lesions. • Neither KS nor HHV-8 are curable at this point. • Most effective way to suppress both KS and HHV-8 is to treat the symptoms of HIV. • Antibody tests: • ELISA • Immunofluorescent Assay (IFA)

  12. Current Research • In recent studies of lymphoma cancers, a viral protein called vFLIP K13 has been found to mimic the signaling functions of caspase 8, leading to the proliferation of lymphocytes. • The protein activates a cellular pathway called NF-ĸB that is involved in the development of lymphoma. • The NF-ĸB pathway may be a good target for therapies directed at HHV8-associated tumors.

  13. References “Detailed Guide: What is Kaposi’s Sarcoma?” (2005). Medline Plus and American Cancer Society, USA. http://www.cancer.org/docroot/cri/content/cri_2_4_1x_what_is_kaposis_sarcoma_21.asp?sitearea “Herpesvirus Family: Herpesviridae.” (2005). University of Chicago, Chicago, Illinois. <http://www.stdgen.lanl.gov/stgen/bacteria/hhv8/herpes.html>. “Herpesviruses: HHV-8.” (2005). University of Leicester, Leicester, England. <http://www-micro.msb.le.ac.uk/3035/HHV8.html>. "The AIDS Knowledge Base: Section 7.2 - Human Herpesvirus 8 and AIDS-Related Neoplasms." (2001). University of California, San Francisco, CA 94143, USA. <http://hivinsite.ucsf.edu/InSite.jsp?page=kb-06&doc=kb-06-02-01>. Richman, D. et. al. (1997). Clinical Virology. New York: Churchill Livingstone. Paoli, Paolo. “Human herpesvirus 8: an update.” Microbes and Infection 6.3 (2004): 328-335.

More Related