RESUMEN
Objective To study the variation and characteristics of HIV-1 tat exon 1 gene from a patient with AIDS dementia complex( ADC), so as to research the pathogenesis of ADC. Methods The tat gene was amplified with nested PCR from genomic DNA which was extracted from lymph node, spleen and different brain tissues( meninges, grey matter from frontal cortex, white matter from frontal cortex, temporal cortex and basal ganglia) of a patient who died of ADC. PCR products were cloned into the pGEM-T vector,after transformation and selection by ampicillin and blue/white spotting. Five of positive clones were sequenced. HIV-1 tat sequences were processed with BioEdit and MEGA4. With the softwares, Neighbor-Joining tree, p-Distances, values of ds/dn, and analysis of amino acid motifs were all done. Results The samples were all identified as HIV-1 B and genetic variation exists in HIV-1 tat isolated from different tissue;Compared with HXB2, sixteen sites of the amino acid seque nce coded by the HIV-1 tat gene which was isolated from the patient changed. In addition, part of the changes were different between periphery and brain,especially, the five Q54R changes from basal ganglia and one Q54R change from temporal cortex are deserve to follow with interest. Conclusion Variations exist in the HIV-1 tat genes extracted from the ADC patient and the variations from peripheral and central nerve tissues were different, whether the variations concerned with the pathogenesis of ADC need more research.