Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose:
TGF-β is crucial for induction of CD4+Foxp3+ Tregs and maintenance of immunologic tolerance. It is, however, unclear if TGF-β also induces the similar CD8+ Tregs.
Methods:
CD8+Foxp3- cells isolated from Foxp3-GFP knock-in mice were stimulated with anti-CD3/28 antibodies and IL-2 with (Tregs) or without TGF-β (Tcon cells). After 3-4 days, Granzyme A/B, Perforin and other Tregs related markers were examined by FACS staining. GFP+, GFP-, GFP+CD103+, GFP+CD103-, and GFP-CD103- were sorted. Suppressive activity in vitro was examined by adding various ratios of CD8+ subsets to responder T cells. Anti-TGF-β, anti-IL-10R, or the TGF-β receptor I (ALK5) inhibitor was added to some cultures. The effect of CD8+ Tregs in vivo was tested following iv injection with 5 x105 C57BL/6 CD4+CD45RBhighcells to Rag2-/- mice. CD8+ iTregs were also injected to Experimental Allergic Encephalomyelitis (EAE) model and lupus-like chronic Graft-versus-host disease (GVHD) model.
Results: While CD8+ iTregs displayed much low Foxp3 expression compared with compartment CD4+ cells, their suppression activity in vitro and in vivo was equivalent or even better. These cells did not express Granzyme A, B or Perforin A and lacked cytotoxic activity on T response cells. CD8+ iTregs generated from Granzyme B and Perforn A KO mice still suppressed autoimmunity. Transwell experiments revealed that cell-contact is required for their suppression. CD8+ iTregs infusion markedly suppressed experimental colitis, EAE and cGVHD. Both Foxp3- and Foxp3+ subsets from TGF-primed CD8+ cells had suppressive activities. Among CD8+Foxp3- cells, CD103 is crucial for their generation and function since CD8+ but not CD4+ iTreg production decreased on CD103 KO mice. CD4+CD103+Foxp3- subset suppressed colitis through IL-10 signal.
Results:
While CD8+ cells primed with TGF-β (CD8+ iTregs) displayed much low Foxp3 expression compared with compartment CD4+ cells, their suppression activity in vitro and in vivo was equivalent or even better than CD4+ Tregs. These cells did not express Granzyme A, Granzyme B or Perforin A and lacked cytotoxic activity on T response cells. Additionally, CD8+ iTregs generated from Granzyme B and Perforn A KO mice still suppressed autoimmunity. Transwell experiments revealed that cell-contact is required for their suppressive activity. Adoptive transfer of the CD8+ iTregs markedly suppressed experimental colitis, EAE and cGVHD. We further found both Foxp3- and Foxp3+ subsets from TGF-primed CD8+ cells had suppressive activities. Among CD8+Foxp3- cells, we identified CD103 expression is crucial for their generation and function since CD8+ but not CD4+ iTreg production decreased on CD103 KO mice. Adoptive transfer of CD4+CD103+Foxp3- subset suppressed colitis and EAE and IL-10 signal seems to be crucial for this therapeutic effect.
Conclusion:
TGF-β can induce CD8+Foxp3- and CD8+Foxp3+ iTreg subsets that displayed suppressive activity in cell contact-dependent, non-cytotoxic manner and have protective effects on autoimmune diseases. Generation of CD8+ iTregs may have considerable therapeutic potential on patients with autoimmune diseases.
Disclosure:
Y. Liu,
None;
A. P. Xu,
None;
D. A. Horwitz,
None;
S. G. Zheng,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/cd8foxp3-cd103-regulatory-t-cells-generated-ex-vivo-with-tgf-%ce%b2-suppress-autoimmunity-through-il-10-dependet-mechanism/