Nrf2 activation by sulforaphane restores the age-related decrease of T_H1 immunity: Role of dendritic cells

SFN reverses the age-related decrease in the CHS response. A, Ear-swelling response (mean ± SD). B, Hematoxylin and eosin staining of ear tissue. C and D, Real-time PCR for mRNA levels of genes in the ear (Fig 1, C) and liver (Fig 1, D). Results represent the fold increase (means ± SDs) compared with the CON-Young group (n = 6). ^∗P < .05, ^∗∗P < .01, and ^∗∗∗P < .001. CON, Vehicle-treated control; SFN, SFN treated; DFNB, DNFB sensitized/challenged.

Nrf2 deficiency suppresses the CHS response. A, Ear-swelling response (means ± SDs). B, IFN-γ and IL-4 mRNA levels were measured by means of real-time PCR. Results represent the fold increase (means ± SDs) compared with the CON-Nrf2^+/+ group (n = 6). ^∗P < .05, ^∗∗P < .01, and ^∗∗∗P < .001. CON, Vehicle-treated control; OXA, OXA sensitized/challenged.

DCs from old mice have lower thiol levels and phase II mRNA expression. A, Mean fluorescence intensity for MBB staining in CD11c⁺ splenocytes from young and old mice (means ± SDs). B, Phase II mRNA expression in CD11c⁺ splenocytes from young and old mice. Results represent the fold increase (means ± SDs) of old compared with young mice (n = 4). ^∗P < .05.

DC redox disequilibrium interferes in the CHS response on adoptive transfer. The ear-swelling response in recipient mice (3 months old) receiving DNBS-pulsed DCs from young versus old mice (A) or nrf2^+/+ versus nrf2^−/− mice (B), followed by DNFB challenge, is shown (n = 6). ^∗P < .05, ^∗∗P < .01, and ^∗∗∗P < .001. CON, Vehicle-treated control; DNBS, DNBS pulsed.

NAC or SFN treatment of DCs reverses the age-related decrease in the CHS response on adoptive transfer. NAC-treated (A) or SFN-treated (B) DCs were exposed to DNBS ex vivo and adoptively transferred into mice that were challenged with DNFB (mean ± SD, n = 6). ^∗P < .05, ^∗∗P < .01, and ^∗∗∗P < .001. CON, Vehicle-treated control; DNBS, DNBS pulsed.

Nrf2 deficiency suppresses the CHS response induced by DNFB. The ear-swelling response was expressed as mean ± SD (n = 4). ^∗P < .05, ^∗∗P < .01, and ^∗∗∗P < .001. CON, Vehicle-treated control; DFNB, DNFB sensitized/challenged.

Thiol levels in the BM-DCs decreased by aging, Nrf2 deficiency, or both. Cultured BM-DCs were surface stained with phycoerythrin-labeled anti-CD11c, followed by MBB staining and flow cytometry. A, Mean fluorescence intensity for MBB staining in CD11c⁺ splenocytes from young and old mice (means ± SDs). B, Mean fluorescence intensity for MBB staining in CD11c⁺ splenocytes from old Nrf2^+/+ and Nrf2^−/− mice (mean ± SD, n = 4). ^∗P < .05. MFI, Mean fluorescence intensity.

Increased thiol levels in the BM-DCs by NAC treatment. Cultured BM-DCs were incubated with or without NAC (20 mmol/L for 24 hours) and then washed. Cells were surface stained with phycoerythrin-labeled anti-CD11c, followed by MBB staining and flow cytometry. The graph shows mean fluorescence intensity for MBB staining in CD11c⁺ BM-DCs (means ± SDs, n = 4). ^∗P < .05. CON, Control group.

SFN treatment upregulates p2E message and thiol levels. Cultured BM-DCs were incubated with or without SFN (5 μmol/L for 24 hours) and then washed. A, Total RNA was extracted from CD11c⁺ BM-DCs to perform real-time PCR for p2E. B, Cells were surface stained with phycoerythrin-labeled anti-CD11c, followed by MBB staining and flow cytometry. The graph shows mean fluorescence intensity for MBB staining in CD11c⁺ BM-DCs (means ± SDs, n = 4). ^∗P < .05, ^∗∗∗P < .001. CON, Control group; HO1, heme oxygenase 1.