Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0014070 (encephalomyelitis)
 13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ability of natural-killer cells to regulate adaptive immunity is not well understood. Here we define an interaction between the class Ib major histocompatibility complex (MHC) molecule Qa-1-Qdm on activated T cells responsible for adaptive immunity and CD94-NKG2A inhibitory receptors expressed by natural-killer cells by using Qa-1-deficient and Qa-1 knockin mice containing a point mutation that selectively abolishes Qa-1-Qdm binding to CD94-NKG2A receptors. The Qa-1-NKG2A interaction protected activated CD4+ T cells from lysis by a subset of NKG2A+ NK cells and was essential for T cell expansion and development of immunologic memory. Antibody-dependent blockade of this Qa-1-NKG2A interaction resulted in potent NK-dependent elimination of activated autoreactive T cells and amelioration of experimental autoimmune encephalomyelitis. These findings extend the functional reach of the NK system to include regulation of adaptive T cell responses and suggest a new clinical strategy for elimination of antigen-activated T cells in the context of autoimmune disease and transplantation.
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PMID:Regulation of activated CD4+ T cells by NK cells via the Qa-1-NKG2A inhibitory pathway. 1750 9

Regulation of autoreactive CD4 T cells is essential to maintain self-tolerance and prevent autoimmune disease. Although CD8 T regulatory (Treg) cells that recognize self-peptides restricted by Qa-1 (HLA-E in humans) inhibit autoreactive CD4 cells and attenuate experimental autoimmune encephalomyelitis (EAE), the mechanism of this interaction is unclear. We generated Qa-1 mutant knock-in mice that impair Qa-1 binding to the T cell receptor (TCR) and CD94/NKG2A receptors. Analysis of these mice showed that TCR-dependent recognition of Qa-1-peptide complexes on target CD4 cells is essential for suppression by CD8 Treg cells. Further analysis revealed that genetic disruption of the Qa-1-CD94/NKG2A interaction unleashes robust CD8 Treg cell activity that completely abolishes development of EAE.
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PMID:Regulation of CD8+ regulatory T cells: Interruption of the NKG2A-Qa-1 interaction allows robust suppressive activity and resolution of autoimmune disease. 1904 27

Autoimmune encephalomyelitis may be ameliorated experimentally by enhancing NK cell-mediated elimination of activated autoreactive T cells through a mutation that interrupts the interaction between Qa-1(b) and CD94/NKG2A. Here we evaluate the ability of an anti-NKG2A F(ab')(2) Ab to enhance elimination of autoreactive T cells and reduce experimental autoimmune encephalomyelitis (EAE). Anti-NKG2A F(ab')(2) treatment diminishes progression of both myelin oligodendrocyte glycoprotein (MOG)-induced EAE in intact C57BL/6 mice and after adoptive transfer of disease-causing T cells. Analyses of the underlying mechanism revealed that administration of anti-NKG2A F(ab')(2) Ab reduces CD4(+) T recall responses to MOG and skews the proportion of IL-17- and IFNgamma-producing CD4(+) T cells toward the protective IL-4- and IL-10-secreting CD4(+) T cell subpopulations. CD94/NKG2A-dependent inhibition of inflammatory damage to spinal cord is associated with decreased infiltration of T cells and reduced microglia activation in the central nervous system. Because anti-NKG2A F(ab')(2) treatment had no detectable effect on the numbers or activity of T and B lymphocytes and NK cells in peripheral lymphoid tissues, this anti-NKG2A-based approach may represent a safe and effective therapy for this CNS disorder.
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PMID:Analysis of the cellular mechanism underlying inhibition of EAE after treatment with anti-NKG2A F(ab')2. 2013 87