The Role of IL-12 Signaling in Enhanced Anti-HIV Immunity

Abstract

<div><p>(A and B) In vivo injection with IL-12 preferentially enhanced gp120-specific CTL and Th responses induced by SOCS1-silenced DCs. C57BL/6 mice were immunized with 1 × 10⁶ of HIV gp120-pulsed (50 μg/ml), transduced DCs derived from BM of WT mice or IL-12 receptor KO mice with ex vivo TNFα maturation (50 ng/ml). On days 1, 3, and 5 after DC immunization, murine IL-12 (1 μg/mouse, Peprotech) was administered intraperitoneally. CD8⁺ T cells (A) or CD4⁺ T cells (B) isolated 2 wk later from the pooled splenocytes of immunized mice (2–3 each group) were subjected to IFN-γ ELISPOT assays. An irrelevant protein, OVA, was used as a negative control. Representative data from two independent experiments are presented. *<i>P</i> < 0.01, LV-SOCS1-siRNA-DC versus LV-SOCS1-siRNA-DC + IL-12, or IL12R KO LV-SOCS1-siRNA-DC + IL-12 versus LV-SOCS1-siRNA-DC + IL-12.</p> <p>(C and D) gp120-specific CTL and Th responses induced by SOCS1-silenced DCs or Ad-IL-12-DCs. BM-derived DCs from WT mice were transfected with LV-SOCS1-siRNA (MOI of 5) or Ad-IL-12 with various MOIs of 10–1,000 or cotransfected with LV-SOCS1-siRNA (MOI of 5) and Ad-IL-12 (MOI of 10) for 4 h. DCs derived from BM of IL-12 receptor KO mice were cotransfected with LV-SOCS1-siRNA (MOI of 5) and Ad-IL-12 (MOI of 10) for 4 h. Groups of C57BL/6 mice were immunized with 1 × 10⁶ of gp120-pulsed (50 μg/ml), transfected DCs with ex vivo TNFα maturation. CD8⁺ T-cells (C) or CD4⁺ T cells (D) isolated 2 wk later from the pooled splenocytes of immunized mice (2–3 each group) were subjected to IFN-γ ELISPOT assays. An irrelevant protein, OVA, was used as a negative control. Representative data from two independent experiments are presented. <i>P</i> < 0.01, Ad-IL-12/SOCS1-siRNA-DC versus IL-12-DCs, or Ad-IL-12/SOCS1-siRNA-DC versus IL12R KO Ad-IL-12/SOCS1-siRNA-DC.</p></div