Molecular characterization of the human T cell lymphotropic virus type 2 long terminal repeat region: A discussion about possible influences at viral gene expression

Abstract

This study aimed to identify nucleotide signatures in the promoter region of human T cell lymphotropic virus type 2 (HTLV-2) isolated from infected individuals from Salvador, Brazil and in sequences from the GenBank database. DNA samples from HTLV-2-infected individuals were submitted to nested polymerase chain reaction (PCR) and sequencing, and molecular analyses were performed using bioinformatics tools. The phylogeny of HTLV-2 strains isolated from patients from Salvador reveals that all sequences were subtype c. One hundred and fifty-one sequences from GenBank were selected, among which 30 belong to subtype a, 88 to subtype b, 32 to subtype c, and one to subtype d. Subtype-specific signatures were identified as well as mutations resulting in loss or gain of motifs important to transcription regulation. The subtypes a and b have two E box motifs, while subtypes c and d have only one. These polymorphisms may impact viral fitness and infection outcome and should be more closely investigated.