Proliferation response to interleukin-2 and Jak/Stat activation of T cells immortalized by human T-cell lymphotropic virus type 1 is independent of open reading frame I expression

J Virol. 1999 Nov;73(11):9642-9. doi: 10.1128/JVI.73.11.9642-9649.1999.

Abstract

Human T-cell lymphotropic virus type 1 (HTLV-1), a complex retrovirus, encodes a hydrophobic 12-kD protein from pX open reading frame (ORF) I that localizes to cellular endomembranes and contains four minimal SH3 binding motifs (PXXP). We have demonstrated the importance of ORF I expression in the establishment of infection and hypothesize that p12(I) has a role in T-cell activation. In this study, we tested interleukin-2 (IL-2) receptor expression, IL-2-mediated proliferation, and Jak/Stat activation in T-cell lines immortalized with either wild-type or ORF I mutant clones of HTLV-1. All cell lines exhibited typical patterns of T-cell markers and maintained mutation fidelity. No significant differences between cell lines were observed in IL-2 receptor chain (alpha, beta, or gamma(c)) expression, in IL-2-mediated proliferation, or in IL-2-induced phosphorylated forms of Stat3, Stat5, Jak1, or Jak3. The expression of ORF I is more likely to play a role in early HTLV-1 infection, such as in the activation of quiescent T cells in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Line, Transformed
  • Cell Transformation, Viral
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 1 / immunology
  • Human T-lymphotropic virus 1 / physiology*
  • Humans
  • Interleukin-2 / pharmacology*
  • Lymphocyte Activation*
  • Open Reading Frames / genetics
  • Phosphorylation
  • Protein-Tyrosine Kinases / metabolism*
  • Receptors, Interleukin-2 / metabolism
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism
  • Trans-Activators / metabolism*

Substances

  • Interleukin-2
  • Receptors, Interleukin-2
  • Trans-Activators
  • Protein-Tyrosine Kinases