Biomaterial Database

Induction of the activation-related antigen CD69 on human eosinophils by type IIA phospholipase A2. 2000

T Urasaki, and J Takasaki, and T Nagasawa, and H Ninomiya

Division of Hematology, Institute of Clinical Medicine, University of Tsukuba, Japan.

OBJECTIVE High levels of human type IIA phospholipase A2 (PLA2-IIA) have been found in the eosinophil-mediated inflammation sites, although the pathophysiological role of PLA2-IIA in the eosinophil activation has remained poorly understood. We investigated the effects of PLA2-IIA on eosinophil activation. METHODS Eosinophils were incubated with recombinant human PLA2-IIA or other stimuli, and then eosinophil peroxidase (EPO) (by colorimetric assay) and leukotriene C4 (by enzyme immunoassay) released in the incubation buffer were measured. Expression of CD11b and CD69 on the cell surface was also measured by flow cytometry (by mean fluorescence intensity (MFI)). EPO, LTC4, and CD11b are thought to be markers for early phase activation (occurred in an hour after stimulation), and CD69 is to be a marker for late phase activation (occurred after several hours). RESULTS While PLA2-IIA (5 microg/ml) did not induce any early phase activation, it induced significant expression of an activation-related antigen, CD69, on human blood eosinophils. The PLA2-IIA, when enzymatically inactivated by either p-bromophenacyl bromide or EDTA, lost its effect on the CD69 induction. Similarly to PLA2-IIA, several lysophospholipids (1 microg/ml) also induced CD69 on eosinophils significantly (control, 0.71 +/- 0.11; PLA2-IIA, 3.29 +/- 0.37*; lysophosphatidic acid, 2.57 +/- 0.43*; specific MFI +/- S.E.M., n = 4, * indicate p < 0.05 vs. control). CONCLUSIONS PLA2-IIA induces CD69 expression on the eosinophils through its catalytic activity at least partly via the enzymatic products such as several lysophospholipids from the eosinophil membrane phospholipids. PLA2-IIA may contribute to the eosinophilic inflammation synergistically with other factors.

UI	MeSH Term	Description	Entries
D008246	Lysophospholipids	Derivatives of PHOSPHATIDIC ACIDS that lack one of its fatty acyl chains due to its hydrolytic removal.	Lysophosphatidic Acids,Lysophospholipid,Acids, Lysophosphatidic
D010544	Peroxidases		Ovoperoxidase
D010741	Phospholipases A	Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D004804	Eosinophils	Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.	Eosinophil
D005227	Fatty Acids	Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)	Aliphatic Acid,Esterified Fatty Acid,Fatty Acid,Fatty Acids, Esterified,Fatty Acids, Saturated,Saturated Fatty Acid,Aliphatic Acids,Acid, Aliphatic,Acid, Esterified Fatty,Acid, Saturated Fatty,Esterified Fatty Acids,Fatty Acid, Esterified,Fatty Acid, Saturated,Saturated Fatty Acids
D005434	Flow Cytometry	Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.	Cytofluorometry, Flow,Cytometry, Flow,Flow Microfluorimetry,Fluorescence-Activated Cell Sorting,Microfluorometry, Flow,Cell Sorting, Fluorescence-Activated,Cell Sortings, Fluorescence-Activated,Cytofluorometries, Flow,Cytometries, Flow,Flow Cytofluorometries,Flow Cytofluorometry,Flow Cytometries,Flow Microfluorometries,Flow Microfluorometry,Fluorescence Activated Cell Sorting,Fluorescence-Activated Cell Sortings,Microfluorimetry, Flow,Microfluorometries, Flow,Sorting, Fluorescence-Activated Cell,Sortings, Fluorescence-Activated Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000945	Antigens, Differentiation, T-Lymphocyte	Antigens expressed on the cell membrane of T-lymphocytes during differentiation, activation, and normal and neoplastic transformation. Their phenotypic characterization is important in differential diagnosis and studies of thymic ontogeny and T-cell function.	Antigens, Differentiation, T-Cell,Differentiation Antigens, T-Cell,L3T4 Antigens,Leu Antigens, T-Lymphocyte,T-Cell Differentiation Antigens,T-Lymphocyte Differentiation Antigens,T6 Antigens,Antigens, Differentiation, T Lymphocyte,Differentiation Antigens, T Lymphocyte,Antigens, L3T4,Antigens, T-Cell Differentiation,Antigens, T-Lymphocyte Differentiation,Antigens, T-Lymphocyte Leu,Antigens, T6,Differentiation Antigens, T Cell,Differentiation Antigens, T-Lymphocyte,Leu Antigens, T Lymphocyte,T Cell Differentiation Antigens,T Lymphocyte Differentiation Antigens,T-Lymphocyte Leu Antigens