Skip to main content


HTLV-1 Tax Protein Induces the Secretion of Th1 Cytokines and β-Chemokines from Dendritic Cells

Article metrics

HTLV-1-associated myelopathy/tropical spastic paraparesis is characterized by highly stimulated immune response that includes elevated levels of inflammatory cytokines/chemokines, and oligoclonal expansion of Tax-specific CD8+ cytotoxic T lymphocytes in the cerebrospinal fluid. Studies have shown that the HTLV-1 transactivator protein Tax is available for immune recognition by antigen presenting cells such as dendritic cells. In this study, we have shown that the treatment of monocyte-derived dendritic cells (MDDCs) with extracellular Tax induces the secretion of Th1 cytokines (IL-12, and TNF-α) and β-chemokines (MIP-Iα, MIP-Iβ, and RANTES). A significant dose-dependent increase was observed with IL-12 (5-, 7-, and 24-fold) and TNF-α (5-, 6-, and 9.6-fold) with Tax treatment for 24 hr at concentrations of 0.1, 1, and 10 mg/ml, respectively. All three chemokines exhibited both dose- and time-dependent increase in the presence of Tax. More specifically, after 24 hr treatment with Tax (0.1, 1 and 10 μg/ml), MIP-1a was induced by 3.7-, 5.3-, and 6-fold, MIP-1b by 2-, 3.7-, and 3.7-fold, and RANTES by 7-, 8-, and 20-fold, respectively. The mRNA expression of these cytokines/chemokines was confirmed by real time PCR and was in direct correlation with observations regarding their protein expression.

Author information

Correspondence to Jaya Ahuja.

Rights and permissions

Reprints and Permissions

About this article


  • Dendritic Cell
  • Antigen Present Cell
  • Antigen Present
  • Immune Recognition
  • Spastic Paraparesis