novel insight to the functional role of stathmin 1 in IgE-mediated activation of RBL-2H3 cells

IgE-mediated cell signaling, induced by cross-linking of high affinity receptor for IgE [FepsilonRI] in the presence of antigen [Ag], is a well known mechanism described for mast cell activation in allergy and hypersensitivity reactions, which induces a spectrum of cellular responses such as secretion and up-regulation of cell surface FepsilonRL Although for several years IgE binding to FepsilonRI was considered to be a passive sensitization process, the outcomes of several recent studies have revealed a variety of different cellular responses to IgE binding compared to IgE plus Antigen binding. The present study applied a functional proteomics-based approach to investigate mast cell signaling events and provided new insights to FcsRI-mediated cell signaling in RBL-2H3.1 cells, and may point to the activation of alternative signaling pathways in response to IgE or IgE plus Ag. Comparative analysis by 2-D PAGE of RBL cells activated with IgE plus Ag for three and four hours compared to non-activated cells was followed by mass spectrometric protein identification and provided evidence for the induction of Stathmin 1 [STMN1] gene expression in response to IgE plus Ag activation. Complementary SDS-PAGE analysis showed a distinct up-regulation of STMN1 induction in response to challenge with IgE plus Ag compared to sensitization with IgE only. Phosphoproteomics analysis gave evidence for significant increase at phosphorylation of STMN1 on ser16 after 1min, though a slight rise at 5 min, and on ser38 after 1 and 5min sensitization with IgE and a similar result was observed for 1min IgE plus Ag-activation. IgE plus Ag-activation was also found to induce the phosphorylation of ser38 to a greater extent than sensitization with IgE. In contrast, IgE alone was more effective than IgE plus Ag at inducing phosphorylation of ser 16. Collectively this study provides further insights into the role of Stathmin 1 in FepsilonRI-mediated activation of cells of mast cell lineage and might shed light on the diverse response of these cells to IgE or IgE plus Ag

The mast cell revisited

The role of mast cells in allergic reactions is reviewed and the origin, distribution and properties of mast cells are reported. The characteristics of two phenotypically distinct mast cell populations are described. The function and properties of the IgE molecule as an antigen receptor on mast cells is discussed. The participation of mast cells in the acute and late phase of the allergic reaction is pointed out. A double role for mast cells in allergic reactions is suggested: they may be responsible for the acute phase reaction through the release of mediators such as histamine and leukotrienes and for the late phase reaction through the release of pro-inflammatory cytokines.

IgE específica múltiple como método de tamizaje en atopía

La prueba más comúnmente utilizada como método de tamizaje de pacientes con posible atopía ha sido la determinación de inmunoglobulina E (IgE) sérica total.La sensibilidad (S) de este método solamente llega al 63 por ciento (1) y su especificidad (E) tampoco es satisfactoria. Por ello,hemos evaluado un método de inmunoensayo enzimático (EIA) múltiple, para detectar IgE específica a varios alergenos (de los más frecuentes sensibilizantes),en un disco único. Estudiamos 62 pacientes: 51 atópicos (alergia respiratoria con o sin eczema atópico) y 11 no atópicos. Los resultados obtenidos mostraron para el método en estudio una S de 90.1 por ciento, E de 100 por ciento, valor predictivo positivo de 100 por ciento. Valor predictivo negativo de 68.7 por ciento y una eficiencia de 91.9 por ciento. Tales resultados nos llevan a considerar que la determinación de IgE específica múltiple es una muy útil y favorable alternativa, que aventaja ampliamente a los niveles séricos de IgE total en el abordaje primario del paciente con posible atopía.