The human T-lymphotropic virus, human T-cell lymphotropic virus, or human T-cell leukemia-lymphoma virus (HTLV) family of viruses are a group of human retroviruses that are known to cause a type of cancer called adult T-cell leukemia/lymphoma and a demyelinating disease called HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLVs belong to a larger group of primate T-lymphotropic viruses (PTLVs). Members of this family that infect humans are called HTLVs, and the ones that infect Old World monkeys are called Simian T-lymphotropic viruses (STLVs). To date, four types of HTLVs (HTLV-1, HTLV-2, HTLV-3, and HTLV-4) and four types of STLVs (STLV-1, STLV-2, STLV-3, and STLV-5) have been identified. HTLV types HTLV-1 and HTLV-2 viruses are the first retroviruses discovered. Both belong to the oncovirus subfamily of retroviruses and can transform human lymphocytes so that they are self-sustaining in vitro.[1] The HTLVs are believed to originate from interspecies transmission of STLVs. The HTLV-1 genome is diploid, composed of two copies of a single-stranded RNA virus whose genome is copied into a double-stranded DNA form that integrates into the host cell genome, at which point the virus is referred to as a provirus. A closely related virus is bovine leukemia virus BLV. The original name for HIV, the virus that causes AIDS, was HTLV-3.
https://en.wikipedia.org/wiki/Human_T-lymphotropic_virus
(REPOST Condition ID, Text Excerpt, etc..)
Infectious Cancer (respiratory) [Veterinary]
Oncogenic Virus [Cytopathology]
Human papillomaviruses (HPV) also cause many cancers. HPV is well known for causing genital warts and essentially all cases of cervical cancer, but it can also infect and cause cancer in several other parts of the body, including the esophaguslarynx, lining of the mouth, nose, and throat, anus, vulva, vagina, and penis. The Papanicolaou smear ("Pap" smear) is a widely used cancer screening test for cervical cancer. DNA-based tests to identify the virus are also available.[11]
Herpesviruses are a third group of common cancer-causing viruses. Two types of herpesviruses have been associated with cancer: the Epstein–Barr virus(EBV) and human herpesvirus 8 (HHV-8).[12] EBV appears to cause all nonkeratinizing nasopharyngeal carcinomas, Epstein–Barr virus-positive diffuse large B-cell lymphomas, not otherwise specified,[13] diffuse large B-cell lymphomas associated with chronic inflammation,[13] Epstein–Barr virus-positive mucocutaneous ulcers,[14] Lymphomatoid granulomatoses[15] and, in many cases, fibrin-associated diffuse large B-cell lymphoma[16] and intravascular NK/T cell lymphomas.[17] It also appears to cause some cases of lymphoma, including Burkitt's lymphoma (this causal association is especially strong in Africa) and Hodgkin's disease,[12] EBV has been found in a variety of other types of cancer cells, although its role in causing these other cancers is not well established. KSHV/HHV-8[18] causes all cases of Kaposi's sarcoma, and has been found in some cases of a cancer-related condition called Castleman's disease.[12] Studies involving other kinds of cancer, particularly prostate cancer, have been inconsistent.[12] Both of these herpesviruses are commonly found in cancerous cells of primary effusion lymphoma.[12] Herpesviruses also cause cancer in animals, especially leukemias and lymphomas.[12]
Human T cell lymphotropic virus (HTLV-1) was the first human retrovirus discovered by Robert Gallo and colleagues at NIH.[19] The virus causes Adult T-cell leukemia, a disease first described by Takatsuki and colleagues in Japan[20] and other neurological diseases. Closely related to human T-cell leukemia virus, is another deltaretrovirus, bovine leukemia virus (BLV), which recently has met the expected criteria to accept a possible infectious agent causation of breast cancer, using sensitive PCR methods to detect BLV, and having samples from women with breast cancer compared to a control sample of women with no history of breast cancer.[21][22]
Merkel cell polyomavirus is the most recently discovered human cancer virus, isolated from Merkel cell carcinoma tissues in 2008,[23] by the same group that discovered KSHV/HHV-8 in 1994, using a new technology called digital transcriptome subtraction. About 80% of Merkel cell carcinomas are caused by Merkel cell polyomavirus; the remaining tumors have an unknown etiology and possibly a separate histogenesis. This is the only member of this group of viruses known to cause human cancer but other polyomaviruses are suspects for being additional cancer viruses.[citation needed]
HIV does not directly cause cancer, but it is associated with a number of malignancies, especially Kaposi's sarcoma, non-Hodgkin's lymphoma, anal cancer and cervical cancer. Kaposi's sarcoma is caused by human herpesvirus 8. AIDS-related cases of anal cancer and cervical cancer are commonly caused by human papillomavirus. After HIV destroys the immune system, the body is no longer able to control these viruses, and the infections manifest as cancer.[24] Certain other immune deficiency states (e.g. common variable immunodeficiency and IgA deficiency) are also associated with increased risk of malignancy.[25]
Common oncogenic viruses[edit]
In Western developed countries, human papillomavirus (HPV), hepatitis B virus (HBV) and hepatitis C virus (HCV) are the most frequently encountered oncogenic DNA viruses.[26]
https://en.wikipedia.org/wiki/Infectious_causes_of_cancer
https://en.wikipedia.org/wiki/Myxococcus
https://en.wikipedia.org/wiki/Methotrexate
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