FIG. 6.

(A) Comparison of V3 loop sequences of SHIV_162P3N, SHIV_BR24N, and well-characterized X4 and R5 viruses. Gaps are indicated as dots, dashes denote similarities in sequence, and the total positive charge of this region was calculated and is shown. Positions 11 and 25 within the V3 loop are indicated, and the N-terminal glycan site is bracketed. The numbers in parentheses represent the number of clones with the indicated V3 loop sequence per the total number sequenced. (B) Relative entry into U87.T4.CCR5 cells (black bars) and U87.T4.CXCR4 cells (white bars) of luciferase reporter viruses expressing the envelope of SHIV_SF162P3N (EnvP3N), SHIV_BR24N (EnvBR24N), and V3 loop recombinant EnvP3N(V3). All data are the means of triplicates + standard errors of the means.