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Published on: September 14, 2014
CD49d Is Upregulated in Circulating T Lymphocytes from HTLV-1-Infected Patients
L T Araújo Janahú1,2, Carlos Araujo Da Costa3, Antonio Carlos Rosário Vallinoto3
1Interdisciplinary Laboratory of Medical Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Introduction:
HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic progressive myelopathy associated with an inflammation of the central nervous system (CNS), being characterized by perivascular infiltration of inflammatory cells. HTLV-1-infected cells have the capacity to migrate through endothelial layers by enhancing adhesion receptor expression and corresponding ligands. T cells interact with the extracellular matrix via integrin receptors and these interactions affect both cell migration and proliferation. The importance of these interactions in retrovirus-induced diseases, however, remains less clear.
Methods:
Herein we studied the expression of 3 integrin alpha chains (CD49d, CD49e, and CD49f) on the membrane of T-cell subsets in patients infected by HTLV-1, both HAM/TSP patients and oligo/asymptomatic subjects who were asymptomatic or presented slight manifestations related to the virus infection.
Results:
We observed higher peripheral blood frequency of CD49dhiCD4+ and CD49dhiCD8+ T cells in HTLV-1-infected patients.
Conclusion:
Our findings suggest that the increased expression of adhesion molecules, such as CD49d on T lymphocytes from HTLV-1-infected patients may contribute to the pathogenesis of the disease, in both oligo/asymptomatic and HAM/TSP-infected subjects. Accordingly, it is conceivable that there is a potential use of CD49d as target for a therapeutic approach aiming at blocking migration of activated T cells from HTLV-1-infected patients into the CNS, thus avoiding the progression to HAM/TSP.

