HTLV-1-Tax and ICAM-1 act on T-cell signal pathways to polarize the microtubule-organizing center at the virological synapse

Mohamed Nejmeddine, Veera S. Negi, Sohini Mukherjee, Yuetsu Tanaka, Kim Orth, Graham P. Taylor, Charles R M Bangham

Research output: Contribution to journalArticlepeer-review

79 Scopus citations


Human T-lymphotropic virus type 1 (HTLV-1) spreads directly between lymphocytes and other cells via a specialized cell-cell contact, termed the virological synapse. The formation of the virological synapse is accompanied by the orientation of the microtubule-organizing center (MTOC) in the infected T cell toward the cell contact region with the noninfected target cell. We previously demonstrated that the combination of intracellular Tax protein expression and the stimulation of the intercellular adhesion molecule-1 (ICAM-1) on the cell surface is sufficient to trigger MTOC polarization in the HTLV-1-infected T cell. However, the mechanism by which Tax and ICAM-1 cause the MTOC polarization is not fully understood. Here we show that the presence of Tax at the MTOC region and its ability to stimulate cyclic AMP-binding protein-dependent pathways are both required for MTOC polarization in the HTLV-1-infected T cell at the virological synapse. Furthermore, we show that the MTOC polarization induced by ICAM-1 engagement depends on activation of the Ras-MEK-ERK signaling pathway. Our findings indicate that efficient MTOC polarization at the virological synapse requires Tax-mediated stimulation of T-cell activation pathways in synergy with ICAM-1 cross-linking. The results also reveal differences in the signaling pathways used to trigger MTOC polarization between the immunologic synapse and the virological synapse.

Original languageEnglish (US)
Pages (from-to)1016-1025
Number of pages10
Issue number5
StatePublished - 2009

ASJC Scopus subject areas

  • Biochemistry
  • Immunology
  • Hematology
  • Cell Biology


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