Figure 5.

Effect of chemokines on neuronal survival. (A) Apoptosis induced by removal of the glial cell feeder layer was reduced by hMDC or mMDC (10 nM), RANTES (10 nM), fractalkine (100 nM), SDF-1α (50 nM), and TGF-β1 (5 ng/ml). Data are expressed as mean ± SEM of the percent of dead cells from five different cultures. In each experiment, two to three coverslips per treatment were evaluated and neurons were counted from 10–12 fields of each coverslip. The neurons analyzed for each data point were: 3409 (control with glia), 2828 (control without glia), 591 (TGF-β1), 1948 (MDC), 2376 (RANTES), 2095 (fractalkine), and 1499 (SDF-1α). ^ = P < 0.0001 vs. control with glia; ∗∗ = P < 0.0001 and ∗ = P < 0.001 vs. control without glia. (B) Neurotoxicity induced by HIV-1_IIIB gp120 and SIV_mac251 gp120 in hippocampal cultures. gp120_IIIB-induced neurotoxicity was inhibited by different types of chemokines. Chemokines (at the same concentrations reported above) and/or gp120 (200 pM) were added to the neuronal cultures at 7 days in culture and apoptotic cells counted after 3–4 days. The mean ± SEM of neuronal death from 12 separate experiments is reported and three to five coverslips (10–12 fields per coverslip) were counted from each experiment. The total number of cells counted for each treatment was: 6,145 (control), 6,812 (gp120_IIIB), 1,778 (gp120_mac251), 2,154 (hMDC), 2,615 (hMDC+gp120_IIIB), 2,367 (RANTES), 2,998 (RANTES+gp120_IIIB), 1,872 (fractalkine), 2,449 (fractalkine + gp120_IIIB), 3,125 (SDF-1α), and 3,750 (SDF-1α+gp120_IIIB). ^ = P < 0.0001 vs. control; ∗∗ = P < 0.0001 vs. gp120_IIIB alone. (C) HIV-1_IIIB gp120-induced neurotoxicity in neuronal cultures in the absence of glia. Neurons were treated for 24 hr with gp120 (200 pM) and/or hMDC (100 nM) or fractalkine (100 nM). Total number of cells counted from three different experiments: control = 2932, gp120 = 2740; MDC = 1,086, MDC + gp120 = 1,068, fractalkine = 1,300, fractalkine + gp120 = 1,631; ∗ = P < 0.01 vs. control.