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Viruses 2011, 3(6), 861-885; doi:10.3390/v3060861

Orf-I and Orf-II-Encoded Proteins in HTLV-1 Infection and Persistence

Animal Models and Retroviral Vaccines Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, MD 20892, USA
* Author to whom correspondence should be addressed.
Received: 13 April 2011 / Revised: 25 May 2011 / Accepted: 26 May 2011 / Published: 17 June 2011
(This article belongs to the Special Issue Recent Developments in HTLV Research)
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The 3' end of the human T-cell leukemia/lymphoma virus type-1 (HTLV-1) genome contains four overlapping open reading frames (ORF) that encode regulatory proteins. Here, we review current knowledge of HTLV-1 orf-I and orf-II protein products. Singly spliced mRNA from orf-I encodes p12, which can be proteolytically cleaved to generate p8, while differential splicing of mRNA from orf-II results in production of p13 and p30. These proteins have been demonstrated to modulate transcription, apoptosis, host cell activation and proliferation, virus infectivity and transmission, and host immune responses. Though these proteins are not essential for virus replication in vitro, p8, p12, p13, and p30 have an important role in the establishment and maintenance of HTLV-1 infection in vivo.
Keywords: human T-cell leukemia/lymphoma virus type-1; HTLV-1; ORF-I; ORF-II; p8; p12; p13; p30 human T-cell leukemia/lymphoma virus type-1; HTLV-1; ORF-I; ORF-II; p8; p12; p13; p30
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Edwards, D.; Fenizia, C.; Gold, H.; Castro-Amarante, M.F.; Buchmann, C.; Pise-Masison, C.A.; Franchini, G. Orf-I and Orf-II-Encoded Proteins in HTLV-1 Infection and Persistence. Viruses 2011, 3, 861-885.

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