Other Retroviruses Flashcards
What is a acute transforming oncogenic virus?
What subtypes are there?
A retrovirus that contains a viral oncogene that directly initiates neoplastic transformation in cells/uncontrolled proliferation.
The oncogenes are usually so long that there is not much room for any other genes, and these types of viruses can not reproduce unless there is co-infection with another virus and uptake of that viral oncogene.
These are called DEFECTIVE ACUTE TRANSORMING VIRUSES
The only known NON-DEFECTIVE ACUTE TRANSFORMING VIRUS
is the Rous Sarcoma virus, which causes cancers in chickens.
It carries the SRC oncogene, which is a constituitively active membrane tyrosine kinase.
What are the non-acute transforming viruses?
These are retroviruses that do no carry a direct ongoenic protein, but instead cause ALTERED REGULATION OF PROTO-ONCOGENES IN THE HOST’S GENOME TO BECOME ONCOGENIC.
The HTLV or Human T Cell Lymphotrophic Viruses are divided into three types
based on the type of diseases they produce:
o HTLV-I produces cutaneous T-cell lymphomas, also causes a spastic paralytic disease in the tropics.
o HTLV-II produces hairy T-cell leukemias,
o HTLV-V produces T-cell lymphomas and leukemias.
The HIV or Human Immunodeficiency Viruses are divided into
What are the various Tumor causing viruses? (Not just the retroviruses)
1 RNA virus
5 DNA viruses
RNA viruses
RETROVIRIDAE
Oncoviruses : lymphoid-, myeloid, bone marrow,
erythroid- tumor, sarcomas, carcinomas
DNA viruses
HEPADNAVIRIDAE: hepatocellular carcinoma
ADENOVIRIDAE: solid tumors in NON-HUMANS and cell culture
PAPILLOMAVIRIDAE: solid tumors (polyoma), papilloma, carcinoma
HERPESVIRIDAE: lymphomas, carcinomas
POXVIRIDAE: myxoma, fibroma
What does HTLV-1 cause?
How often does infection cause clinical disease?
An aggressive leukemia of CD4+ T cells. Adult T-cell Leukemia/Lymphoma
HTLV-associated myelopathy (from malginant osteloysis)
Survival time less than one year once ATL is manifested,
BUT
has a very very long incubation period of 10-40 years.
How is HTLV-1 transmitted?
Sexually, much more frequently from males to females.
Breast feeding
Blood to blood contact
IV drug users.
What does HTLV-2 cause?
Atypical Hairy cell leukemia
Atypical B cell leukemia
What do the T-cells look like in HTLV induced disease?
Very large, multi-lobular nuclei.
What are the two major subfamilies of Retroviruses that infect humans?
Oncornaviruses: HTLV-1, HTLV-2, HTLV-5
Lentiviruses:
HIV1 and HIV2.
