The MHC class I chain-related molecule A (MICA) is a highly polymorphic ligand for the activating natural killer (NK)-cell receptor NKG2D. A single nucleotide polymorphism causes a valine to methionine exchange at position 129. Presence of a MICA-129Met allele in patients (n = 452) undergoing hematopoietic stem cell transplantation (HSCT) increased the chance of overall survival (hazard ratio [HR] = 0.77, P = 0.0445) and reduced the risk to die due to acute graft-versus-host disease (aGVHD) (odds ratio [OR] = 0.57, P = 0.0400) although homozygous carriers had an increased risk to experience this complication (OR = 1.92, P = 0.0371). Overall survival of MICA-129Val/Val genotype carriers was improved when treated with anti-thymocyte globulin (HR = 0.54, P = 0.0166). Functionally, the MICA-129Met isoform was characterized by stronger NKG2D signaling, triggering more NK-cell cytotoxicity and interferon-γ release, and faster co-stimulation of CD8(+) T cells. The MICA-129Met variant also induced a faster and stronger down-regulation of NKG2D on NK and CD8(+) T cells than the MICA-129Val isoform. The reduced cell surface expression of NKG2D in response to engagement by MICA-129Met variants appeared to reduce the severity of aGVHD.
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http://dx.doi.org/10.15252/emmm.201505246 | DOI Listing |
Sci Bull (Beijing)
November 2024
Medical Research Center, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China; Department of Gastroenterology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China; General Surgery Department, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China,; Beijing Laboratory of Oral Health, Capital Medical University School of Basic Medicine, Beijing 100069, China. Electronic address:
Hepatic ischemia-reperfusion injury (HIRI) is an important cause of liver injury following liver transplantation and major resections, and neutrophils are the key effector cells in HIRI. Double-negative T regulatory cells (DNT) are increasingly recognized as having critical regulatory functions in the immune system. Whether DNT expresses distinct immunoregulatory mechanisms to modulate neutrophils, as in HIRI, remains largely unknown.
View Article and Find Full Text PDFMAbs
November 2024
Department of Chemistry and Chemical Biology, Barnett Institute for Chemical and Biological Analysis, Northeastern University, Boston, MA, USA.
Natural killer (NK) cells are effector cells of the innate immune system that distinguish between healthy and abnormal cells through activating and inhibitory receptor signaling. NKG2D, a homodimeric activating receptor expressed on NK cells, recognizes a diverse class of stress ligands expressed by cells experiencing infection, malignant transformation, chronic inflammation, and other cellular stresses. Despite the variety of NKG2D ligands, they all bind the receptor asymmetrically in a 1:1 ligand to homodimeric NKG2D stoichiometry.
View Article and Find Full Text PDFHum Immunol
November 2024
São Paulo State University (UNESP), Medical School, Botucatu, Brazil; São Paulo State University (UNESP), Institute of Biosciences, Botucatu, Brazil. Electronic address:
The MICA gene encodes a glycoprotein upregulated upon cellular stress, particularly in oxidative stress, intracellular infections, and tumorigenesis. This stress-signaling molecule interacts with the activating receptor NKG2D from Natural Killer (NK) and some T lymphocytes, stimulating their cytotoxic activity. MICA is encoded within the human Major Histocompatibility Complex next to the HLA-B locus and is highly polymorphic.
View Article and Find Full Text PDFCell Rep Med
November 2024
King's College London, School of Cancer and Pharmaceutical Sciences, CAR Mechanics Lab, London SE1 9RT, UK; Leucid Bio Ltd, Guy's Hospital, London SE1 9RT, UK; Department of Immunology, Eastbourne Hospital, Kings Drive, Eastbourne, East Sussex BN21 2UD, UK. Electronic address:
NKG2D ligands (NKG2DLs) are broadly expressed in cancer. To target these, we describe an adaptor chimeric antigen receptor (CAR) termed NKG2D/Dap10-12. Herein, T cells are engineered to co-express NKG2D with a fusion protein that comprises Dap10 joined to a Dap12 endodomain.
View Article and Find Full Text PDFCell Commun Signal
November 2024
Department of Translational Oncology, Center for Tumor Biology and Immunology, Philipps University, Marburg, Germany.
Background: High levels of the polyunsaturated fatty acid arachidonic acid (AA) within the ovarian carcinoma (OC) microenvironment correlate with reduced relapse-free survival. Furthermore, OC progression is tied to compromised immunosurveillance, partially attributed to the impairment of natural killer (NK) cells. However, potential connections between AA and NK cell dysfunction in OC have not been studied.
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