IFN-DCs migrate with high efficiency in vivo and induce a potent antibody response toward the HIV-1 gp120/160 and p24 antigens along with a high production of human IFN-γ in hu-PBL-SCID mice.
(A) SCID mice were injected intravenously with 2 × 106IFN-DCs or IL-4-DCs. After 4 hours, the presence of human DNA sequences in the skin and spleen from each mouse was assessed as described in “Materials and methods.” Results of one representative experiment of 3 are shown. For each experiment, there were 3 mice per group. (B) Human antibodies against the HIV-1 gp120/160 and p24 proteins in the sera from hu-PBL-SCID mice immunized on day 0 and boosted on day 7 with 1.5 × 106 autologous DCs pulsed with AT-2-inactivated HIV-1. At days 14 and 21, mice were further boosted with AT-2-inactivated virus. Antibodies to the HIV-1 gp120/160 and p24 proteins were assessed as described in “Materials and methods.” Results represent the values detected in serum from individual mice killed at day 28. There were 3 mice for each group. (C) IFN-γ production in peritoneal washings of immunized and control hu-PBL-SCID mice was evaluated by using a specific enzyme-linked immunosorbent assay, as described in “Materials and methods.” In a previous set of 3 different experiments, the levels of human IFN-γ detected in the peritoneal washings of hu-PBL-SCID mice injected with unpulsed autologous DCs, under identical conditions, were never higher than those found in the peritoneal lavages of mice only injected with hu-PBLs (data not shown).
