Htlv-1 Alters The Multidrug Resistance Associated Protein 1 (Abcc1/Mrp1) Expression And Activity In Human T Cells

The human T cell lymphotropic/leukaemia virus type I (HTLV-I) causes HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/ TSP). The multidrug resistance associated protein 1 (ABCC1) plays multiple functions in physiopathologic responses. The expression and activity of ABCC1 was studied in T lymphocytes from uninfected and HTLV-I-infected individuals (both asymptomatic and symptomatic/HAM/TSP). ABCC1 expression and activity was reduced to nearly half in T lymphocytes from infected patients compared to control lymphocytes. Only 51.6% of CD4(+) cells from HAM/TSP patients expressed ABCC1 whereas this was seen in 60.3% from asymptomatic individuals, compared to an expression of around 86% in controls. Our results suggest that ABCC1 is negatively regulated in HTVL-I infection, supplying a novel target to investigate the pathogenesis of HTLV-I. (c) 2007 Elsevier B.V. All rights reserved.