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Loss of Nrf2 in bone marrow-derived macrophages impairs antigen-driven CD8+ T cell function by limiting GSH and Cys availability
- Source :
- Free Radical Biology and Medicine. 83:77-88
- Publication Year :
- 2015
- Publisher :
- Elsevier BV, 2015.
-
Abstract
- NF-E2-related factor 2 (Nrf2), known to protect against reactive oxygen species, has recently been reported to resolve acute inflammatory responses in activated macrophages. Consequently, disruption of Nrf2 promotes a proinflammatory macrophage phenotype. In the current study, we addressed the impact of this macrophage phenotype on CD8(+) T cell activation by using an antigen-driven coculture model consisting of Nrf2(-/-) and Nrf2(+/+) bone marrow-derived macrophages (BMDMΦ) and transgenic OT-1 CD8(+) T cells. OT-1 CD8(+) T cells encode a T cell receptor that specifically recognizes MHC class I-presented ovalbumin OVA(257-264) peptide, thereby causing a downstream T cell activation. Interestingly, coculture of OVA(257-264)-pulsed Nrf2(-/-) BMDMΦ with transgenic OT-1 CD8(+) T cells attenuated CD8(+) T cell activation, proliferation, and cytotoxic function. Since the provision of low-molecular-weight thiols such as glutathione (GSH) or cysteine (Cys) by macrophages limits antigen-driven CD8(+) T cell activation, we quantified the amounts of intracellular and extracellular GSH and Cys in both cocultures. Indeed, GSH levels were strongly decreased in Nrf2(-/-) cocultures compared to wild-type counterparts. Supplementation of thiols in Nrf2(-/-) cocultures via addition of glutathione ester, N-acetylcysteine, β-mercaptoethanol, or cysteine itself restored T cell proliferation as well as cytotoxicity by increasing intracellular GSH. Mechanistically, we identified two potential Nrf2-regulated genes involved in thiol synthesis in BMDMΦ: the cystine transporter subunit xCT and the modulatory subunit of the GSH-synthesizing enzyme γ-GCS (GCLM). Pharmacological inhibition of γ-GCS-dependent GSH synthesis as well as knockdown of the cystine antiporter xCT in Nrf2(+/+) BMDMΦ mimicked the effect of Nrf2(-/-) BMDMΦ on CD8(+) T cell function. Our findings demonstrate that reduced levels of GCLM as well as xCT in Nrf2(-/-) BMDMΦ limit GSH availability, thereby inhibiting antigen-induced CD8(+) T cell function.
- Subjects :
- NF-E2-Related Factor 2
Ovalbumin
Antiporter
T cell
Blotting, Western
Receptors, Antigen, T-Cell
Apoptosis
Mice, Transgenic
CD8-Positive T-Lymphocytes
Biology
Real-Time Polymerase Chain Reaction
environment and public health
Biochemistry
Antioxidants
Immunoenzyme Techniques
Mice
chemistry.chemical_compound
Bone Marrow
Physiology (medical)
MHC class I
medicine
Animals
Cytotoxic T cell
RNA, Messenger
Cells, Cultured
Cell Proliferation
Mice, Knockout
Reverse Transcriptase Polymerase Chain Reaction
GCLM
Macrophages
Histocompatibility Antigens Class I
Glutathione
respiratory system
Flow Cytometry
Molecular biology
Mice, Inbred C57BL
Oxidative Stress
medicine.anatomical_structure
chemistry
biology.protein
Cystine
Reactive Oxygen Species
Intracellular
CD8
Signal Transduction
Subjects
Details
- ISSN :
- 08915849
- Volume :
- 83
- Database :
- OpenAIRE
- Journal :
- Free Radical Biology and Medicine
- Accession number :
- edsair.doi.dedup.....8bbac17fcfe3f096824a15b22e4c4035
- Full Text :
- https://doi.org/10.1016/j.freeradbiomed.2015.02.004