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BIBTEX RIS

The frequency of CD127low expressing CD4+CD25high T regulatory cells is inversely correlated with human T lymphotrophic virus type-1 (HTLV-1) proviral load in HTLV-1-infection and HTLV-1-associated myelopathy/tropical spastic paraparesis

2008; BioMed Central; Volume: 9; Issue: 1 Linguagem: Inglês

10.1186/1471-2172-9-41

1471-2172

Jakob Michaëlsson, Hugo Marcelo Ribeiro Barbosa, Kimberley A Jordan, Joan M. Chapman, Milena Karina Coló Brunialti, Walter Kleine Neto, Youko Nukui, Éster Cerdeira Sabino, Marco Antônio Troccoli Chieia, Acary Souza Bullé Oliveira, Douglas F. Nixon, Esper G. Kallás,

Galectins and Cancer Biology

Abstract Background CD4 + CD25 high regulatory T (T Reg ) cells modulate antigen-specific T cell responses, and can suppress anti-viral immunity. In HTLV-1 infection, a selective decrease in the function of T Reg cell mediated HTLV-1-tax inhibition of FOXP3 expression has been described. The purpose of this study was to assess the frequency and phenotype of T Reg cells in HTLV-1 asymptomatic carriers and in HTLV-1-associated neurological disease (HAM/TSP) patients, and to correlate with measures of T cell activation. Results We were able to confirm that HTLV-I drives activation, spontaneous IFNγ production, and proliferation of CD4+ T cells. We also observed a significantly lower proportion of CTLA-4 + T Reg cells (CD4 + CD25 high T cells) in subjects with HAM/TSP patients compared to healthy controls. Ki-67 expression was negatively correlated to the frequency of CTLA-4 + T Reg cells in HAM/TSP only, although Ki-67 expression was inversely correlated with the percentage of CD127 low T Reg cells in healthy control subjects. Finally, the proportion of CD127 low T Reg cells correlated inversely with HTLV-1 proviral load. Conclusion Taken together, the results suggest that T Reg cells may be subverted in HAM/TSP patients, which could explain the marked cellular activation, spontaneous cytokine production, and proliferation of CD4 + T cells, in particular those expressing the CD25 high CD127 low phenotype. T Reg cells represent a potential target for therapeutic intervention for patients with HTLV-1-related neurological diseases.