Detection of Human P2X7 Nucleotide Receptor Polymorphisms by a Novel Monocyte Pore Assay Predictive of Alterations in Lipopolysaccharide-Induced Cytokine Production
| Autor: | Arturo G. Guadarrama, Kirk J. Hogan, Giuditta Angelini, Dawn N. Green, Usha Prabhu, Loren C. Denlinger, Kathleen Schell, Paul J. Bertics, Douglas B. Coursin |
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| Rok vydání: | 2005 |
| Předmět: |
Adult
Lipopolysaccharides Cell Membrane Permeability Adolescent Lipopolysaccharide medicine.medical_treatment DNA Mutational Analysis Immunology Inflammation Biology Infections Gene dosage Monocytes chemistry.chemical_compound Predictive Value of Tests medicine Extracellular Humans Mass Screening Immunology and Allergy Receptor Whole blood Immunity Cellular Polymorphism Genetic Receptors Purinergic P2 Tumor Necrosis Factor-alpha Monocyte Middle Aged Molecular biology Interleukin-10 Cytokine medicine.anatomical_structure chemistry Cytokines Receptors Purinergic P2X7 medicine.symptom |
| Zdroj: | The Journal of Immunology. 174:4424-4431 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | The nucleotide receptor P2X7 is expressed by most leukocytes and initiates signaling events that amplify numerous LPS responses. We tested the hypothesis that loss-of-function polymorphisms in the human P2X7 gene predispose to the production of an anti-inflammatory mediator balance. Accordingly, we developed a novel P2X7 pore assay in whole blood that magnifies the activity from wild-type alleles and preserves the gene dosage effect for the 1513 C polymorphism (AA, 69 ± 4; AC, 42 ± 4; and CC, 6 ± 1-fold stimulation). Thirty of 200 healthy individuals were identified as having low P2X7 pore activity. Seven low pore subjects were 1513 CC, 3 and 11 participants had the other known variants 946 GA and 1729 TA respectively; the remaining 9 volunteers likely have novel polymorphisms. Because platelets are a large source of extracellular ATP during inflammation, whole blood was treated ex vivo with Salmonella typhimurium LPS in the absence of exogenous nucleotides. LPS-stimulated whole blood from individuals in the low pore activity group generated reduced plasma levels of TNF-α (p = 0.036) and higher amounts of IL-10 (p < 0.001) relative to the high pore controls. This reduction in the TNF-α to IL-10 ratio persisted to at least 24 h and is further decreased by cotreatment with 2-methylthio-ATP. The ability of P2X7 polymorphisms to regulate the LPS-induced TNF-α to IL-10 ratio suggests that 15% of healthy adults may exhibit anti-inflammatory mediator responses during major infectious perturbations of the immune system, which can be predicted by P2X7 pore activity. |
| Databáze: | OpenAIRE |
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