Human T-lymphotropic viruses type 1 (HTLV-1) and type 2 (HTLV-2) present very similar genomic structures but HTLV-1 is more pathogenic than HTLV-2. Is this difference due to their transactivating Tax proteins, Tax-1 and Tax-2, which are responsible for viral and cellular gene activation? Do Tax-1 and Tax-2 differ in their cellular localization and in their interaction pattern with cellular fact...

INTRODUCTION Human T-lymphotropic virus type 1 and 2 (HTLV-1/2) is endemic in Brazil, but few studies have investigated the seroprevalence of HTLV and its subtypes among blood donors in the capital city Manaus, Amazonas State, Brazil. AIM To estimate the seroprevalence of HTLV-1/2 and to identify circulating subtypes among blood donors in Manaus. MATERIALS AND METHODS Blood donors (2001-200...

We reported two cases of patients with coinfection by human immunodeficiency virus (HIV) type 1 and human T-cell lymphotropic virus (HTLV) type I who developed opportunistic infections despite of relatively high CD4+ cells count. These cases showed clinical evidence to consider an earlier antiretroviral treatment for coinfected patientes regardless CD4+ cells counts.

The isolation and characterization of a human T-cell lymphotropic retrovirus related to human T-cell lymphotropic virus type I (HTLV-I) from cerebrospinal fluid of a Jamaican patient with tropical spastic paraparesis is described. The virus isolate is a typical type C retrovirus as seen by electron microscopy and is related to prototype HTLV-I isolated from patients with adult T-cell leukemia b...

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Infective dermatitis is a chronic exudative eczematous eruption presenting in human T-lymphotropic virus type 1 (HTLV-1)-infected people. It presents with relapsing erythematous, scaly, and crusted lesions affecting simultaneously the scalp, external ear, retroauricular area, eyelid, paranasal skin, neck axilla, and groin. Superimposed Staphylococcus and Streptococcus infection are common. It m...

When the human T cell lymphotropic virus (HTLV) is integrated with the host cell genome (provirus), its proviral DNA is a replication marker. Proviral load appears to be an important factor in the development of diseases related to these retroviruses. In this study, a methodology for absolute quantification of the HTLV-1 and HTLV-2 proviral load using real-time PCR was developed. Fifty-three bl...

The susceptibility to Fas-mediated apoptosis was evaluated in seven T-cell lines (two infected with HTLV-2, one with HTLV-1, and four HTLV-free) as well as in Jurkat cells transfected with a Tax-2 expressing vector. Fas-mediated apoptosis was significantly reduced in the HTLV-1- and HTLV-2-infected lines in comparison with the HTLV-free lines regardless of the surface expression of Fas antigen ...

We investigated the tempo and mode of evolution of the primate T-lymphotropic viruses (PTLVs). Several different models of nucleotide substitution were tested on a general phylogenetic tree obtained using the 20 full-genome HTLV/STLV sequences available. The likelihood ratio test showed that the Tamura and Nei model with discrete gamma-distributed rates among sites is the best-fitting substitut...