Article
A FashiLymphoproliferative Phenotype Reveals Non-Apoptotic Fas Signaling in HTLV-1-Associated Neuroinflammation
Registro en:
MENEZES, S. M. et al. A FashiLymphoproliferative Phenotype Reveals Non-Apoptotic Fas Signaling in HTLV-1-Associated Neuroinflammation. Frontiers in Immunology, v. 8, p. 97, 2017.
1664-3224
10.3389/fimmu.2017.00097
Autor
Menezes, Soraya Maria
Leal, Fabio Eudes
Dierckx, Tim
Cunha, Antonio Ricardo Khouri
Decanine, Daniele
Santos, Gilvaneia Silva
Schnitman, Saul V
Kruschewsky, Ramon
López, Giovanni
Alvarez, Carolina
Talledo, Michael
Gotuzzo, Eduardo
Nixon, Douglas F
Vercauteren, Jurgen
Brassat, David
Liblau, Roland
Vandamme, Anne Mieke
Castro Filho, Bernardo Galvão
Van Weyenbergh, Johan Josef Roza Maria
Resumen
Brazilian National Research Council (CNPq/Science Without Borders, PVE), Fonds voor Wetenschappelijk Onderzoek (FWO, grant G.0778.10N and G0D6817N). Human T-cell lymphotropic virus (HTLV)-1 was the first human retrovirus to be associated to cancer, namely adult T-cell leukemia (ATL), but its pathogenesis remains enigmatic, since only a minority of infected individuals develops either ATL or the neuroinflammatory disorder HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). A functionalFAS-670 polymorphism in an interferon (IFN)-regulated STAT1-binding site has been associated to both ATL and HAM/TSP susceptibility. FashiT stem cell memory (Tscm) cells have been identified as the hierarchical apex of ATL, but have not been investigated in HAM/TSP. In addition, bothFASandSTAT1have been identified in an IFN-inducible HAM/TSP gene signature, but its pathobiological significance remains unclear. We comprehensively explored Fas expression (protein/mRNA) and function in lymphocyte activation, apoptosis, proliferation, and transcriptome, in PBMC from a total of 47 HAM/TSP patients, 40 asymptomatic HTLV-1-infected individuals (AC), and 58 HTLV-1 -uninfected healthy controls. Fas surface expression followed a two-step increase from HC to AC and from AC to HAM/TSP. In HAM/TSP, Fas levels correlated positively to lymphocyte activation markers, but negatively to age of onset, linking Fashicells to earlier, more aggressive disease. Surprisingly, increased lymphocyte Fas expression in HAM/TSP was linked to decreased apoptosis and increased lymphoproliferation uponin vitroculture, but not to proviral load. This Fashiphenotype is HAM/TSP-specific, since bothex vivoandin vitroFas expression was increased as compared to multiple sclerosis (MS), another neuroinflammatory disorder. To elucidate the molecular mechanism underlying non-apoptotic Fas signaling in HAM/TSP, we combined transcriptome analysis with functional assays, i.e., blocking vs. triggering Fas receptorin vitrowith antagonist and agonist-, anti-Fas mAb, respectively. Treatment with agonist anti-Fas mAb restored apoptosis, indicating biased, but not defective Fas signaling in HAM/TSP.In silicoanalysis revealed biased Fas signaling toward proliferation and inflammation, driven by RelA/NF-κB. Correlation of Fas transcript levels with proliferation (but not apoptosis) was confirmed in HAM/TSPex vivotranscriptomes. In conclusion, we demonstrated a two-step increase in Fas expression, revealing a unique Fashilymphocyte phenotype in HAM/TSP, distinguishable from MS. Non-apoptotic Fas signaling might fuel HAM/TSP pathogenesis, through increased lymphoproliferation, inflammation, and early age of onset.