Multiple Enhancer Motifs in HIV Type 1 Strains from Ethiopia

The authors determined the sequences of the LTR region of Ethiopian HIV-1 subtype C strains and compared them with Swedish HIV-1 subtype B strains and earlier published data. Peripheral blood mononuclear cells (PBMCs) were obtained from seven randomly chosen HIV-1 infected Ethiopian patients, all with pre-AIDS or AIDS. PBMCs were also obtained from three Swedish HIV-1 subtype B-infected patients. Extraction of HIV-1 DNA was performed with the phenol-chloroform plus ethanol precipitation method. In all the Ethiopian HIV-1 subtype C strains, the first five nucleotides were changed to (G/A)CAGA, a finding not observed in the Swedish subtype B strains sequenced at the same time. The most remarkable feature of the Ethiopian NF-KB region was the presence of what appears to be an extra site located upstream of the usual sites I and II. At the same time, the core enhancer sequence GGGACTTTCC at site I was modified by a deletion of the A nucleotide and a change of the first T to a G. The gross LTR organization may be radically different in "African" subtype HIV-1 isolates compared to the American/European HIV-1 subtype B prototype strains. These data from the Ethiopian strains reinforce the validity of this conclusion.