MHC-mismatched mixed chimerism restores peripheral tolerance of noncross-reactive autoreactive T cells in NOD mice.
Proc Natl Acad Sci U S A
; 115(10): E2329-E2337, 2018 03 06.
Article
em En
| MEDLINE
| ID: mdl-29463744
ABSTRACT
Autoimmune type 1 diabetes (T1D) and other autoimmune diseases are associated with particular MHC haplotypes and expansion of autoreactive T cells. Induction of MHC-mismatched but not -matched mixed chimerism by hematopoietic cell transplantation effectively reverses autoimmunity in diabetic nonobese diabetic (NOD) mice, even those with established diabetes. As expected, MHC-mismatched mixed chimerism mediates deletion in the thymus of host-type autoreactive T cells that have T-cell receptor (TCR) recognizing (cross-reacting with) donor-type antigen presenting cells (APCs), which have come to reside in the thymus. However, how MHC-mismatched mixed chimerism tolerizes host autoreactive T cells that recognize only self-MHC-peptide complexes remains unknown. Here, using NOD.Rag1-/-BDC2.5 or NOD.Rag1-/-BDC12-4.1 mice that have only noncross-reactive transgenic autoreactive T cells, we show that induction of MHC-mismatched but not -matched mixed chimerism restores immune tolerance of peripheral noncross-reactive autoreactive T cells. MHC-mismatched mixed chimerism results in increased percentages of both donor- and host-type Foxp3+ Treg cells and up-regulated expression of programmed death-ligand 1 (PD-L1) by host-type plasmacytoid dendritic cells (pDCs). Furthermore, adoptive transfer experiments showed that engraftment of donor-type dendritic cells (DCs) and expansion of donor-type Treg cells are required for tolerizing the noncross-reactive autoreactive T cells in the periphery, which are in association with up-regulation of host-type DC expression of PD-L1 and increased percentage of host-type Treg cells. Thus, induction of MHC-mismatched mixed chimerism may establish a peripheral tolerogenic DC and Treg network that actively tolerizes autoreactive T cells, even those with no TCR recognition of the donor APCs.
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Base de dados:
MEDLINE
Assunto principal:
Linfócitos T
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Diabetes Mellitus Tipo 1
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Tolerância Periférica
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Complexo Principal de Histocompatibilidade
Limite:
Animals
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Female
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Humans
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article