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Flashcards in Other Retroviruses Deck (8)
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1
Q

What is a acute transforming oncogenic virus?

What subtypes are there?

A

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.

2
Q

What are the non-acute transforming viruses?

A

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

3
Q

What are the various Tumor causing viruses? (Not just the retroviruses)

1 RNA virus

5 DNA viruses

A

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

4
Q

What does HTLV-1 cause?

How often does infection cause clinical disease?

A

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.

5
Q

How is HTLV-1 transmitted?

A

Sexually, much more frequently from males to females.

Breast feeding

Blood to blood contact

IV drug users.

6
Q

What does HTLV-2 cause?

A

Atypical Hairy cell leukemia

Atypical B cell leukemia

7
Q

What do the T-cells look like in HTLV induced disease?

A

Very large, multi-lobular nuclei.

8
Q

What are the two major subfamilies of Retroviruses that infect humans?

A

Oncornaviruses: HTLV-1, HTLV-2, HTLV-5

Lentiviruses:
HIV1 and HIV2.