{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,30]],"date-time":"2026-05-30T08:01:43Z","timestamp":1780128103174,"version":"3.54.0"},"reference-count":29,"publisher":"IMR Press","issue":"5","license":[{"start":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T00:00:00Z","timestamp":1779321600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Polish National Science Center","award":["2019\/35\/B\/NZ5\/02398"],"award-info":[{"award-number":["2019\/35\/B\/NZ5\/02398"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Front. Biosci. (Landmark Ed)"],"abstract":"<jats:p>Background: Recent evidence indicates that the Mas-related G protein\u2013coupled receptor X2 (MRGPRX2) can be activated by several drugs, including neuromuscular blocking agents, fluoroquinolones, and vancomycin. However, the contribution of this mechanism to drug hypersensitivity reactions (DHRs) observed in clinical practice remains incompletely understood. Single-nucleotide polymorphisms (SNPs) in the MRGPRX2 gene may alter receptor reactivity and thereby influence drug tolerance. In this study, we investigated whether selected SNPs\u2014previously described in patients with DHRs (N62S, S313R), known but not previously tested with drugs (S325L, E164R), and predicted in silico (W248L)\u2014affect in vitro responses to representative drug ligands. Methods: RBL-2H3 cells were transiently transfected with wild-type (WT) MRGPRX2 or its variants. Cell-surface expression of MRGPRX2 was assessed by flow cytometry. Intracellular calcium mobilization was measured after stimulation with ciprofloxacin, atracurium, and vancomycin; substance P served as a reference agonist and assay buffer as a negative control. Results: All variants exhibited comparable levels of cell-surface expression. No responses were observed in the presence of assay buffer. The S313R and S325L variants showed responses comparable to WT, with a tendency toward enhanced responses to substance P. In contrast, the E164R variant displayed a loss-of-function phenotype (p &lt; 0.05 for all ligands vs. WT, S313R, and S325L variants), as did the in silico-predicted W248L variant (p &lt; 0.05 for all ligands vs. WT, S313R, and S325L variants). The N62S variant demonstrated slightly reduced responses to the tested agonists compared with WT. Conclusions: Our findings indicate that under the investigated experimental conditions with ciprofloxacin, atracurium, and vancomycin: (1) N62S-transfected RBL-2H3 cells did not exhibit enhanced responses to the tested drug ligands; (2) the W248L variant exhibited the predicted loss-of-function phenotype, suggesting that in silico modeling may help assess the pathogenicity of specific MRGPRX2 variants; and (3) the remaining variants showed only partial concordance with previously published data, possibly reflecting differences in experimental design or assay conditions and highlighting the need for replication studies.<\/jats:p>","DOI":"10.31083\/fbl51779","type":"journal-article","created":{"date-parts":[[2026,5,30]],"date-time":"2026-05-30T07:25:36Z","timestamp":1780125936000},"source":"Crossref","is-referenced-by-count":0,"title":["Functional Impact of MRGPRX2 Single-Nucleotide Polymorphisms on Drug-Induced Cellular Responses In Vitro"],"prefix":"10.31083","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9675-7790","authenticated-orcid":true,"given":"Alicja","family":"Dziadowiec","sequence":"first","affiliation":[{"name":"Department of Clinical and Environmental Allergology, Jagiellonian University Medical College, 31-503 Krakow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2743-6934","authenticated-orcid":true,"given":"Mateusz","family":"Kwitniewski","sequence":"additional","affiliation":[{"name":"Department of Immunology, Jagiellonian University, 30-387 Krakow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-1461-1346","authenticated-orcid":true,"given":"Hubert","family":"Rybka","sequence":"additional","affiliation":[{"name":"Doctoral School of Exact and Natural Sciences, Jagiellonian University, 30-387 Krakow, Poland"},{"name":"Department of Organic Chemistry, Jagiellonian University, 30-348 Krakow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ivan","family":"Sinkevich","sequence":"additional","affiliation":[{"name":"Department of Immunology, Jagiellonian University, 30-387 Krakow, Poland"},{"name":"Doctoral School of Exact and Natural Sciences, Jagiellonian University, 30-387 Krakow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6146-0188","authenticated-orcid":true,"given":"Grzegorz","family":"Porebski","sequence":"additional","affiliation":[{"name":"Department of Clinical and Environmental Allergology, Jagiellonian University Medical College, 31-503 Krakow, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"16242","published-online":{"date-parts":[[2026,5,21]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","unstructured":"Dahlin JS, Maurer M, Metcalfe DD, Pejler G, Sagi-Eisenberg R, Nilsson G. The ingenious mast cell: Contemporary insights into mast cell behavior and function. Allergy. 2022; 77: 83\u201399.","DOI":"10.1111\/all.14881"},{"key":"ref2","doi-asserted-by":"publisher","unstructured":"Tatemoto K, Nozaki Y, Tsuda R, Konno S, Tomura K, Furuno M, et al. Immunoglobulin E-independent activation of mast cell is mediated by Mrg receptors. Biochemical and Biophysical Research Communications. 2006; 349: 1322\u20131328.","DOI":"10.1016\/j.bbrc.2006.08.177"},{"key":"ref3","doi-asserted-by":"publisher","unstructured":"Pichler WJ. Immune pathomechanism and classification of drug hypersensitivity. Allergy. 2019; 74: 1457\u20131471.","DOI":"10.1111\/all.13765"},{"key":"ref4","doi-asserted-by":"publisher","unstructured":"McNeil BD, Pundir P, Meeker S, Han L, Undem BJ, Kulka M, et al. Identification of a mast-cell-specific receptor crucial for pseudo-allergic drug reactions. Nature. 2015; 519: 237\u2013241.","DOI":"10.1038\/nature14022"},{"key":"ref5","doi-asserted-by":"publisher","unstructured":"Al-Ahmad M, Edin J, Musa F, Rodriguez-Bouza T. Drug Allergy Profile From a National Drug Allergy Registry. Frontiers in Pharmacology. 2021; 11: 555666.","DOI":"10.3389\/fphar.2020.555666"},{"key":"ref6","doi-asserted-by":"publisher","unstructured":"Worm M, Pazur K, Morakabati P, Redhu D. IgE and non-IgE-mediated pathways in anaphylaxis. Seminars in Immunopathology. 2025; 47: 34.","DOI":"10.1007\/s00281-025-01056-7"},{"key":"ref7","doi-asserted-by":"publisher","unstructured":"Baldo BA. MRGPRX2, drug pseudoallergies, inflammatory diseases, mechanisms and distinguishing MRGPRX2- and IgE\/Fc\u03b5RI-mediated events. British Journal of Clinical Pharmacology. 2023; 89: 3232\u20133246.","DOI":"10.1111\/bcp.15845"},{"key":"ref8","doi-asserted-by":"publisher","unstructured":"Kolkhir P, Ali H, Babina M, Ebo D, Sabato V, Elst J, et al. MRGPRX2 in drug allergy: What we know and what we do not know. The Journal of Allergy and Clinical Immunology. 2023; 151: 410\u2013412.","DOI":"10.1016\/j.jaci.2022.09.004"},{"key":"ref9","doi-asserted-by":"publisher","unstructured":"Dziadowiec A, Kwitniewski M, Kopac P, Rybka H, Sedlackova L, Srotova A, et al. The prevalence of genetic variants of the Mas-related G-protein-coupled receptor X2 in patients does not explain perioperative hypersensitivity reactions to neuromuscular blocking agents. Frontiers in Pharmacology. 2025; 16: 1655722.","DOI":"10.3389\/fphar.2025.1655722"},{"key":"ref10","doi-asserted-by":"publisher","unstructured":"Mayorga C, Fernandez-Santamaria R, \u00c7elik GE, Labella M, Murdaca G, Sokolowska M, et al. Endotypes in Immune Mediated Drug Reactions: Present and Future of Relevant Biomarkers. An EAACI Task Force Report. Allergy. 2025; 80: 1831\u20131847.","DOI":"10.1111\/all.16576"},{"key":"ref11","doi-asserted-by":"publisher","unstructured":"Lansu K, Karpiak J, Liu J, Huang XP, McCorvy JD, Kroeze WK, et al. In silico design of novel probes for the atypical opioid receptor MRGPRX2. Nature Chemical Biology. 2017; 13: 529\u2013536.","DOI":"10.1038\/nchembio.2334"},{"key":"ref12","doi-asserted-by":"publisher","unstructured":"Alkanfari I, Gupta K, Jahan T, Ali H. Naturally Occurring Missense MRGPRX2 Variants Display Loss of Function Phenotype for Mast Cell Degranulation in Response to Substance P, Hemokinin-1, Human \u03b2-Defensin-3, and Icatibant. Journal of Immunology (Baltimore, Md.: 1950). 2018; 201: 343\u2013349.","DOI":"10.4049\/jimmunol.1701793"},{"key":"ref13","doi-asserted-by":"publisher","unstructured":"Chompunud Na Ayudhya C, Amponnawarat A, Roy S, Oskeritzian CA, Ali H. MRGPRX2 Activation by Rocuronium: Insights from Studies with Human Skin Mast Cells and Missense Variants. Cells. 2021; 10: 156.","DOI":"10.3390\/cells10010156"},{"key":"ref14","doi-asserted-by":"publisher","unstructured":"Hamamura-Yasuno E, Matsushita J, Sato S, Shimada T, Tsuchiya Y, Fujimoto K, et al. Determination of key residues in MRGPRX2 to enhance pseudo-allergic reactions induced by fluoroquinolones. Scientific Reports. 2022; 12: 6650.","DOI":"10.1038\/s41598-022-10549-6"},{"key":"ref15","doi-asserted-by":"publisher","unstructured":"Yang F, Limjunyawong N, Peng Q, Schroeder JT, Saini S, MacGlashan D, Jr, et al. Biological screening of a unique drug library targeting MRGPRX2. Frontiers in Immunology. 2022; 13: 997389.","DOI":"10.3389\/fimmu.2022.997389"},{"key":"ref16","doi-asserted-by":"publisher","unstructured":"Quan PL, Oll\u00e9 L, Sabat\u00e9-Bresco M, Guruceaga E, Laguna JJ, Do\u00f1a I, et al. Variants of the MRGPRX2 Gene Found in Patients With Hypersensitivity to Quinolones and Vancomycin Show Amplified and Drug-Specific Activation Responses In Vitro. Clinical and Experimental Allergy: Journal of the British Society for Allergy and Clinical Immunology. 2025; 55: 873\u2013876.","DOI":"10.1111\/cea.70068"},{"key":"ref17","doi-asserted-by":"publisher","unstructured":"Chompunud Na Ayudhya C, Roy S, Alkanfari I, Ganguly A, Ali H. Identification of Gain and Loss of Function Missense Variants in MRGPRX2\u2019s Transmembrane and Intracellular Domains for Mast Cell Activation by Substance P. International Journal of Molecular Sciences. 2019; 20: 5247.","DOI":"10.3390\/ijms20215247"},{"key":"ref18","doi-asserted-by":"publisher","unstructured":"Reddy VB, Graham TA, Azimi E, Lerner EA. A single amino acid in MRGPRX2 necessary for binding and activation by pruritogens. The Journal of Allergy and Clinical Immunology. 2017; 140: 1726\u20131728.","DOI":"10.1016\/j.jaci.2017.05.046"},{"key":"ref19","doi-asserted-by":"publisher","unstructured":"Rybka H, Dziadowiec A, Kwitniewski M, Bulanda D, Kitel R, Por\u0119bski G. In silico assessment of neuromuscular blocking agents and fluoroquinolones as ligands of the Mas-related G protein-coupled receptor X2. Pharmacological Reports: PR. 2026; 78: 277\u2013291.","DOI":"10.1007\/s43440-025-00813-7"},{"key":"ref20","unstructured":"Agilent QuikChange Primer Design (RRID:SCR_025323). 2026. Available at: https:\/\/www.agilent.com\/store\/primerDesignProgram.jsp (Accessed: 3 March 2026)."},{"key":"ref21","unstructured":"Kooistra AJ, Munk C, Hauser AS, Gloriam DE. An online GPCR structure analysis platform. Nature Structural & Molecular Biology. 2021. Available at: https:\/\/gpcrdb.org\/protein\/mrgx2_human\/ (Accessed: 3 March 2026)."},{"key":"ref22","doi-asserted-by":"publisher","unstructured":"Sherry ST, Ward MH, Kholodov M, Baker J, Phan L, Smigielski EM, et al. dbSNP: the NCBI database of genetic variation. Nucleic Acids Research. 2001; 29: 308\u2013311.","DOI":"10.1093\/nar\/29.1.308"},{"key":"ref23","doi-asserted-by":"publisher","unstructured":"Ye D, Zhang Y, Zhao X, Zhou H, Guo J, Yang M, et al. MRGPRX2 gain-of-function mutation drives enhanced mast cell reactivity in chronic spontaneous urticaria. The Journal of Allergy and Clinical Immunology. 2025; 156: 159\u2013170.","DOI":"10.1016\/j.jaci.2025.03.007"},{"key":"ref24","doi-asserted-by":"publisher","unstructured":"Chen E, Chuang LS, Giri M, Villaverde N, Hsu NY, Sabic K, et al. Inflamed Ulcerative Colitis Regions Associated With MRGPRX2-Mediated Mast Cell Degranulation and Cell Activation Modules, Defining a New Therapeutic Target. Gastroenterology. 2021; 160: 1709\u20131724.","DOI":"10.1053\/j.gastro.2020.12.076"},{"key":"ref25","doi-asserted-by":"publisher","unstructured":"Yang F, Guo L, Li Y, Wang G, Wang J, Zhang C, et al. Structure, function and pharmacology of human itch receptor complexes. Nature. 2021; 600: 164\u2013169.","DOI":"10.1038\/s41586-021-04077-y"},{"key":"ref26","doi-asserted-by":"publisher","unstructured":"McNeil BD. MRGPRX2 and Adverse Drug Reactions. Frontiers in Immunology. 2021; 12: 676354.","DOI":"10.3389\/fimmu.2021.676354"},{"key":"ref27","doi-asserted-by":"publisher","unstructured":"Baker M. 1,500 scientists lift the lid on reproducibility. Nature. 2016; 533: 452\u2013454.","DOI":"10.1038\/533452a"},{"key":"ref28","doi-asserted-by":"publisher","unstructured":"Mart\u00edn M, Quan PL, Oll\u00e9 L, Sabat\u00e9-Bresco M, Gastaminza G. Caution in interpreting MRGPRX2 N62S as a disease-driving variant in chronic spontaneous urticaria. The Journal of Allergy and Clinical Immunology. 2026; 157: 781.","DOI":"10.1016\/j.jaci.2025.11.013"},{"key":"ref29","doi-asserted-by":"publisher","unstructured":"Richards S, Aziz N, Bale S, Bick D, Das S, Gastier-Foster J, et al. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genetics in Medicine: Official Journal of the American College of Medical Genetics. 2015; 17: 405\u2013424.","DOI":"10.1038\/gim.2015.30"}],"container-title":["Frontiers in Bioscience-Landmark"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.imrpress.com\/journal\/FBL\/31\/5\/10.31083\/FBL51779","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,30]],"date-time":"2026-05-30T07:26:20Z","timestamp":1780125980000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.imrpress.com\/journal\/FBL\/31\/5\/10.31083\/FBL51779"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,21]]},"references-count":29,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2026]]}},"alternative-id":["S2768-6701(26)02141-6"],"URL":"https:\/\/doi.org\/10.31083\/fbl51779","relation":{},"ISSN":["2768-6701","2768-6698"],"issn-type":[{"value":"2768-6701","type":"print"},{"value":"2768-6698","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,21]]},"article-number":"51779"}}