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Lipid rafts in mast cell biology.

Silveira E Souza AM, Mazucato VM, Jamur MC, Oliver C - J Lipids (2011)

Bottom Line: Mast cell mediators are also related to many chronic inflammatory conditions.Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis.Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biologia Celular e Molecular e Biagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, Brazil.

ABSTRACT
Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization.

No MeSH data available.


Related in: MedlinePlus

The gangliosides follow the same endocytic pathway as FcεRI. At 15 minutes of incubation with both mAb BC4-gold (which recognizes the α subunit of FcεRI) and mAb AA4-HRP (which recognizes gangliosides derived from GD1b), the BC4-gold (arrows) and AA4-HRP (arrowheads) are colocalized in early endosomes adjacent to the plasma membrane (PM).
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fig5: The gangliosides follow the same endocytic pathway as FcεRI. At 15 minutes of incubation with both mAb BC4-gold (which recognizes the α subunit of FcεRI) and mAb AA4-HRP (which recognizes gangliosides derived from GD1b), the BC4-gold (arrows) and AA4-HRP (arrowheads) are colocalized in early endosomes adjacent to the plasma membrane (PM).

Mentions: When the concept of lipid rafts and the mobility of proteins in the plasma membrane originated, it was observed that plasma membrane associated proteins could suffer a selective reorganization followed by internalization of these proteins [107–109]. Receptor-mediated endocytosis, including endocytosis of FcεRI, is a temporally and spatially organized process [22, 110]. After activation, crosslinked FcεRI is endocytosed through clathrin-coated vesicles and transported by the endosomal system for eventual degradation in lysosomes [111–113]. In unstimulated mast cells, FcεRI is dispersed throughout the plasma membrane but upon activation the receptors rapidly aggregate and can be found on the cell surface in lipid rafts in association with GM1 [114, 115], gangliosides derived from GD1b, protein tyrosine kinase Lyn and LAT, [22, 39, 86]. However, only when the mast cells are activated via FcεRI does a significant internalization of the GD1b derivatives occur [22, 116]. The endocytosis process itself may play an important role in signal transduction [110, 117]. Oliver et al. [22] showed that upon activation of FcεRI, the gangliosides derived from GD1b are internalized together with the receptor, following the same pathway to lysosomes (Figure 5). This may facilitate the structural preservation of signaling complexes and the prolongation of the signal since these gangliosides and the FcεRI are associated in lipid rafts.


Lipid rafts in mast cell biology.

Silveira E Souza AM, Mazucato VM, Jamur MC, Oliver C - J Lipids (2011)

The gangliosides follow the same endocytic pathway as FcεRI. At 15 minutes of incubation with both mAb BC4-gold (which recognizes the α subunit of FcεRI) and mAb AA4-HRP (which recognizes gangliosides derived from GD1b), the BC4-gold (arrows) and AA4-HRP (arrowheads) are colocalized in early endosomes adjacent to the plasma membrane (PM).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3066649&req=5

fig5: The gangliosides follow the same endocytic pathway as FcεRI. At 15 minutes of incubation with both mAb BC4-gold (which recognizes the α subunit of FcεRI) and mAb AA4-HRP (which recognizes gangliosides derived from GD1b), the BC4-gold (arrows) and AA4-HRP (arrowheads) are colocalized in early endosomes adjacent to the plasma membrane (PM).
Mentions: When the concept of lipid rafts and the mobility of proteins in the plasma membrane originated, it was observed that plasma membrane associated proteins could suffer a selective reorganization followed by internalization of these proteins [107–109]. Receptor-mediated endocytosis, including endocytosis of FcεRI, is a temporally and spatially organized process [22, 110]. After activation, crosslinked FcεRI is endocytosed through clathrin-coated vesicles and transported by the endosomal system for eventual degradation in lysosomes [111–113]. In unstimulated mast cells, FcεRI is dispersed throughout the plasma membrane but upon activation the receptors rapidly aggregate and can be found on the cell surface in lipid rafts in association with GM1 [114, 115], gangliosides derived from GD1b, protein tyrosine kinase Lyn and LAT, [22, 39, 86]. However, only when the mast cells are activated via FcεRI does a significant internalization of the GD1b derivatives occur [22, 116]. The endocytosis process itself may play an important role in signal transduction [110, 117]. Oliver et al. [22] showed that upon activation of FcεRI, the gangliosides derived from GD1b are internalized together with the receptor, following the same pathway to lysosomes (Figure 5). This may facilitate the structural preservation of signaling complexes and the prolongation of the signal since these gangliosides and the FcεRI are associated in lipid rafts.

Bottom Line: Mast cell mediators are also related to many chronic inflammatory conditions.Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis.Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biologia Celular e Molecular e Biagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirão Preto, Brazil.

ABSTRACT
Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization.

No MeSH data available.


Related in: MedlinePlus