Immunoprofiling of HTLV-1-infected individuals shows altered innate cell responsiveness in HAM/TSP patients.

The Human T-cell Leukemia Virus-1 (HTLV-1)-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a devastating neurodegenerative disease with no effective treatment, which affects an increasing number of people in Brazil. A biological blood factor allowing the prediction of the disease occurrence is so far not available. In this study, we analyzed innate immunity responses at steady state and after blood cell stimulation using an agonist of the toll-like receptor (TLR)7/8-signaling pathway in blood samples from HTLV-1-infected volunteers, including asymptomatic carriers and HAM/TSP patients. We observed a lower responsiveness in dendritic cells to produce IFN. Moreover, we found higher production of IL-12 and Mip-1 by monocytes together with higher levels of IFN{gamma} produced by Natural Killer cells. These deregulations could represent a signature for progression towards HAM/TSP.