Human T-lymphotropic virus type 1 mitochondrion-localizing protein p13 II is required for viral infectivity in vivo

Hajime Hiraragi, Seung Jae Kim, Andrew J. Phipps, Micol Silic-Benussi, Vincenzo Ciminale, Lee Ratner, Patrick L. Green, Michael Dale Lairmore

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Human T-lymphotropic virus type 1 (HTLV-1), the etiological agent of adult T-cell leukemia, encodes unique regulatory and accessory proteins in the pX region of the provirus, including the open reading frame II product p13 II. p13II localizes to mitochondria, binds farnesyl pyrophosphate synthetase, an enzyme involved in post-translational farnesylation of Ras, and alters Ras-dependent cell signaling and control of apoptosis. The role of p13II in virus infection in vivo remains undetermined. Herein, we analyzed the functional significance of p13II in HTLV-1 infection. We compared the infectivity of a human B-cell line that harbors an infectious molecular clone of HTLV-1 with a selective mutation that prevents the translation of p13II (729.ACH.p13) to the infectivity of a wild-type HTLV-1-expressing cell line (729.ACH). 729.ACH and 729.ACH.p13 producer lines had comparable infectivities for cultured rabbit peripheral blood mononuclear cells (PBMC), and the fidelity of the start codon mutation in ACH.p13 was maintained after PBMC passage. In contrast, zero of six rabbits inoculated with 729.ACH.p13 cells failed to establish viral infection, whereas six of six rabbits inoculated with wild-type HTLV-1-expressing cells (729.ACH) were infected as measured by antibody responses, proviral load, and HTLV-1 p19 matrix antigen production from ex vivo-cultured PBMC. Our data are the first to indicate that the HTLV-1 mitochondrion-localizing protein p13II has an essential biological role during the early phase of virus infection in vivo.

Original languageEnglish (US)
Pages (from-to)3469-3476
Number of pages8
JournalJournal of Virology
Issue number7
StatePublished - Apr 2006
Externally publishedYes

ASJC Scopus subject areas

  • Immunology


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