Development of an in vitro LTP-model of food anaphylaxis and study of mechanisms driving exacerbated responses

[eng] Mast cells (MCs), key immune system cells, can be activated via IgE or the MRGPRX2 receptor, releasing proinflammatory mediators that may trigger severe allergic reactions such as anaphylaxis. The study aims to better understand the cellular and molecular mechanisms governing these responses a...

Descripción completa

Detalles Bibliográficos
Autor: Ollé Boix, Laia
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/224299
Acceso en línea:https://hdl.handle.net/2445/224299
http://hdl.handle.net/10803/695758
Access Level:acceso abierto
Palabra clave:Immunologia
Anafilaxi
Mastòcits
Immunoglobulina E
Al·lèrgia
Immunology
Anaphylaxis
Mast cells
Immunoglobulin E
Allergy
Descripción
Sumario:[eng] Mast cells (MCs), key immune system cells, can be activated via IgE or the MRGPRX2 receptor, releasing proinflammatory mediators that may trigger severe allergic reactions such as anaphylaxis. The study aims to better understand the cellular and molecular mechanisms governing these responses and to identify potential therapeutic targets. This study develops an in vitro model of food allergy mediated by lipid transfer protein (LTP), focusing on the analysis of mast cell (MC) responses in patients with varying degrees of severity. Patients sensitized to Lipid transfer protein (LTP) were classified as anaphylaxis or sensitized depending on the symptoms elicited by LTP-containing food. CD34+-derived MCs from patients and controls were obtained, sensitized with pooled sera, and challenged with Pru p 3 (peach LTP). MCs from anaphylactic patients exhibited increased degranulation and elevated secretion of PGD2, IL-8, and GM-CSF upon stimulation, which could be related to higher-affinity IgE, produced with the help of TFH13 cells, which were more abundant in those patients. In contrast, sensitized MCs showed a protective profile, with higher CCL2 and TGF-β production. At the molecular level, MCs from anaphylactic patients expressed higher levels of genes associated with cell activation, inflammation, and mitochondrial function, including the Microphthalmia-associated transcription factor (MITF). Further dissection shows that inhibition of MITF significantly reduced degranulation, calcium influx, mediator secretion, and mitochondrial activity. In conclusion, allergic response severity is influenced by both humoral and cellular components. Beyond antibody-driven mechanisms, cellular factors such as MITF expression may amplify mast cell activation and exacerbate allergic reactions. Targeting MITF could represent a therapeutic strategy to reduce mast cell hyperactivation and mitigate severe allergic responses.