Preliminary molecular characterization of a human immunodeficiency virus (HIV-I) associated with neuropathology

A human immunodeficiency virus (HIV-I) was isolated from the brain of a patient with progressive dementia but no obvious immunosuppression. This isolate, designated as HIV-IBR, was molecularly cloned and sequenced, and its long terminal repeat (LTR) and envelope sequences were compared with those of other HIV isolates not uniquely associated with dementia. The HIV-IBR LTR showed marked homology with the LTR sequences of the other HIV-I isolates. The predicted amino acid sequence of the external glycoprotein (gp120) of HIV-IBR revealed a pattern of conserved and variable regions similar to that of other HIV isolates. The sequence of the transmembrane portion of envelope, gp 41, was highly homologous to the counterpart region of other isolates. Further analysis is required to determine whether specific sequence variation can account for neurological manifestations of HIV-IBR infection.