CCR5 is necessary for dopamine-mediated increase in HIV entry.

<p>Macrophages were infected with HIV_BaL in the presence of 10⁹ M or 10⁶ M dopamine and analyzed by flow cytometry for CCR5. (A) A representative histogram of CCR5 surface expression in a single donor in response to HIV alone (IgG – dashed grey lines, CCR5 – solid grey lines) is shown. (B) The mean MFI of CCR5 on the surface of macrophages from seven donors infected with HIV alone (white), HIV + 10⁹ M DA (light gray) or HIV + 10⁶ M DA (dark gray) relative HIV alone. Neither concentration of dopamine-induced significant changes in the expression of this protein on the cell surface relative to the macrophages infected with HIV alone. (C) Macrophages were pretreated with 2×10⁷ M TAK779, and then an MOI of 0.01 β-lac HIV was added in the presence or absence of 10⁸ M dopamine. As controls, both macrophages pretreated with TAK779 and macrophages not pretreated were infected with HIV alone. Dopamine significantly increased HIV entry (n = 6, p = 0.0194 *), and pretreatment with 2×10⁷ M of the CCR5 inhibitor TAK779 blocked HIV entry into macrophages infected in both the presence and absence of dopamine (HIV + TAK779, p = 0.0001 **, HIV + TAK779 + DA, p = 0.0003 ***).