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. 2015 Aug 25;21(4):574–584. doi: 10.1038/mp.2015.111

Figure 1.

Figure 1

Unique Sp motifs isolated from the CNS compartments of HIV patients have reduced basal and Tat-activated transcription compared with lymphoid-derived LTRs, in CNS cells. (a) Nucleotide alignment of the HIV-1 LTR core promoter region relative to a consensus T-cell-derived LTR, HXB2, as indicated: Sp proximal (SpI) in red, Sp medial (SpII) in green and Sp distal (SpIII) in blue. Gray and white shading indicates CNS- and lymphoid-derived LTRs, respectively. Lower case bold lettering indicates mutations within the intervening and adjacent flanking sequences. Dots indicate conserved nucleotides and dashes indicate gaps. Gray arrow indicates the start site of transcription. Numbers in parentheses indicate the number of clones within that patient sample that had the same genetic makeup. (b) Basal and (c) Tat-activated transcriptional activity of LTRs isolated from the CNS and lymphoid compartments of patients with HIV. Lymphoid isolates are in red, CNS isolates in blue. SVG cells were transfected with LTR luciferase constructs containing LTRs from the CNS and lymphoid compartments of patients and subjected to HIV-1 transcription assays either in the presence or absence of Tat. Control promoters based on consensus T-cell isolate HXB2 are indicated by Z (Z1: wild-type sequence; Z1(TAR-): deletion of TAR region; Z5: mutation of SpI; Z6: mutation of SpII and SpIII; Z7: mutation of SpIII and NF-κB). Patient isolates are indicated. Luciferase activity is relative to a T-cell consensus sequence and Tat activation is shown as fold activation over basal for each LTR sequence. Data shown are representative of four independent experiments, each experiment performed in triplicate. Shown are the means and s.e.m. of these data. Significance values (calculated by student's t-test): *P=<0.05, **P=<0.01, ***P=<0.001, ns=not significant. Black values indicate significance of isolates relative to Z1 T-cell tropic consensus sequence (HXB2), red values represent significance of CNS-derived isolates relative to lymphoid-derived isolates from the same patient. CNS, central nervous system; LTR, long terminal repeat.