Summary of HTLV-1 accessory proteins

ProteinapX ORFSubcellular distributionIn vitro functional activityIn vivo effects of proviral clone gene mutation
p12IIER and cis-GolgiCalcium-mediated NFAT activation; decreases IL-2 requirement for T-cell activationAbolished infectivity in rabbit model; reduced infectivity in nondividing primary human T cells
p13IIIIMitochondria and nucleusMitochondrial swelling and disruption of ΔψReduced viral load in rabbit modelb
p30IIIINucleusTranscriptional regulator; binds p300/CBPReduced viral load in rabbit modelb
  • a p27I, predicted to be expressed from pX ORF I, is recognized by T cells derived from infected subjects (103), but limited functional studies have been reported.

  • b Viral load from ACH.30/13 double-knockout proviral clone in rabbit model of infection (12).