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Absence of accessory genes in a divergent simian T-lymphotropic virus type 1 isolated from a bonnet macaque (Macaca

Philippe V Afonso1, Zahra Fagrouch2, Martin Deijs3

  • 1Unité EPVO, Institut Pasteur, UMR 3569 CNRS, Paris, France.

Plos Neglected Tropical Diseases
|July 9, 2019
PubMed
Abstract

Insights

Primate T-lymphotropic viruses type 1 (PTLV-1) accessory proteins, crucial for viral persistence, are frequently absent in known PTLV-1 genomes. This challenges their essential role in PTLV-1 biology.

Area of Science:

  • Virology
  • Retroviruses
  • Molecular Biology

Background:

  • Primate T-lymphotropic viruses type 1 (PTLV-1) are complex retroviruses infecting humans (HTLV-1) and simians (STLV-1).
  • PTLV-1 encode regulatory proteins (Tax, Rex, HBZ) and accessory proteins (P12/8, P13, P30), with accessory proteins previously considered essential for in vivo viral persistence.
  • This study investigates the prevalence and significance of these accessory proteins.

Purpose of the Study:

  • To analyze the genetic makeup of a novel STLV-1 strain from Indian bonnet macaques.
  • To determine the conservation and necessity of PTLV-1 accessory open reading frames (ORFs).
  • To re-evaluate the role of accessory proteins in PTLV-1 biology.

Main Methods:

  • Isolation and complete genome sequencing of a novel STLV-1 strain (Mra18C9) from Macaca radiata.
  • Phylogenetic analysis of the Mra18C9 strain against known PTLV-1 sequences.
  • Comprehensive analysis of accessory ORFs across available PTLV-1 genomes in GenBank.

Main Results:

  • A novel STLV-1 strain (Mra18C9) was isolated and sequenced, showing high divergence from known strains.
  • The Mra18C9 strain lacks the three accessory open reading frames (ORFs).
  • Analysis revealed that the absence of one or more accessory ORFs is a common feature among PTLV-1 strains.

Conclusions:

  • The findings challenge the presumed essentiality of accessory proteins for PTLV-1 persistence.
  • The study highlights significant genetic diversity within PTLV-1, particularly concerning accessory gene content.
  • Further research is needed to elucidate the true nature and importance of accessory proteins in PTLV-1 pathogenesis.

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