title: Microvesicles released constitutively from prostate cancer cells differ biochemically and functionally to stimulated microvesicles released through sublytic C5b-9.
abstract: We have classified microvesicles into two subtypes: larger MVs released upon stimulation of prostate cancer cells, sMVs, and smaller cMVs, released constitutively. cMVs are released as part of cell metabolism and sMVs, released at 10-fold higher levels, produced upon activation, including sublytic C5b-9. From electron microscopy, nanosight tracking analysis, dynamic light scattering and flow cytometry, cMVs (194-210 nm in diameter) are smaller than sMVs (333-385 nm). Furthermore, using a Quartz Crystal Microbalance measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, an sMV and a cMV are estimated at 0.267 and 0.241 pg, respectively. sMVs carry more calcium and protein, express higher levels of lipid rafts, GPI-anchored CD55 and phosphatidylserine including deposited C5b-9 compared to cMVs. This may allude to biological differences such as increased bound C4BP on sMVs inhibiting complement more effectively.
authors.affiliation: Cellular and Molecular Immunology Research Centre, London Metropolitan University, UK.
authors.forename: Dan
authors.initials: D
authors.lastname: Stratton
authors.affiliation: Cellular and Molecular Immunology Research Centre, London Metropolitan University, UK.
authors.forename: Colin
authors.initials: C
authors.lastname: Moore
authors.affiliation: Cellular and Molecular Immunology Research Centre, London Metropolitan University, UK.
authors.forename: Samuel
authors.initials: S
authors.lastname: Antwi-Baffour
authors.affiliation: University College London School of Pharmacy, London UK.
authors.forename: Sigrun
authors.initials: S
authors.lastname: Lange
authors.affiliation: Cellular and Molecular Immunology Research Centre, London Metropolitan University, UK. Electronic address: j.inal@londonmet.ac.uk.
authors.forename: Jameel
authors.initials: J
authors.lastname: Inal
mesh_terms: D015938:Complement Membrane Attack Complex / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D046529:Microscopy, Electron, Transmission; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D015938:Complement Membrane Attack Complex
keywords: Complement inhibition; Constitutive microvesicles; Stimulated microvesicles