Variable sequences in the long terminal repeat and its downstream region of some of HIV type 1 CRF01_AE recently distributing among Thai carriers

Human immunodeficiency virus type 1 (HIV-1) proviral DNA sequences in and d ownstream of the 5' long terminal repeat (LTR) were compared among samples obtained from 13 HIV-1 CRF01_AE-infected individuals in Thailand from 1998 to 1999. Eleven individuals had highly conserved sequences compared with pr eviously reported CRF01_AE viruses. However, T cell-specific factor (TCF)-1 alpha motif, which is located just beside the 3' terminus of the nef seque nce, was duplicated in 2 out of the 13 subjects, one of whom had also lost the 24 nucleotides next to the 3' of the primer-binding site. Thus, several characteristics of CRF01_AE LTR and gag-leader sequence were identified in some samples recently obtained in Thailand.