Isolation and characterization of a 110 kDa protein, a mast cell lineage marker

• Grant number: 09/10753-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2010
• End date: July 31, 2011
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: Constance Oliver
• Grantee: Elaine Zayas Marcelino da Silva
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Mast cells are multifunctional immune cells implicated in allergy and inflammatory process. They also play a role in auto-immune, gastrointestinal diseases, cardiovascular diseases and diseases of the nervous system. Mast cells originate from an ungranulated committed mast cell precursor in the bone marrow. Granulated progenitor cells migrate through the blood stream to peripheral tissue, where they mature under the influence of microenvironment. The mast cell specific monoclonal antibody, mAb BGD6, binds to an 110kDa protein on the surface of RBL-2H3 and rodent mast cells. This binding is stabilized by the binding of the Fc portion of mAb BGD6 to the low affinity IgG receptor, Fc³RIIB (CD32B). In addition to recognizing mast cells in all maturation stages, mAb BGD6 also recognizes committed mast cell precursors. The aim of this project is to characterize the binding of mAb BGD6 and the physiological effects of this binding on mast cells. The 110 kDa protein that is recognized by mAb BGD6 will be identified and characterized. This protein will be immunoprecipitated from cell lysates, and tryptic digests submitted to mass spectrometry in order to identify the protein. The discovery of a human homolog to the 110 kDa protein could lead to the finding of a mast cell marker which could be an invaluable tool in the diagnosis and prognosis of diseases involving mast cells.