de Araujo TH, Okada SS, Ghosn EEB, Taniwaki NN, Rodrigues MR, de Almeida SR, Mortara RA, Russo M, Campa A, Albuquerque RC. Intracellular localization of myeloperoxidase in murine peritoneal B-lymphocytes and macrophages.
Cell Immunol 2013;
281:27-30. [PMID:
23434459 DOI:
10.1016/j.cellimm.2013.01.002]
[Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/10/2013] [Accepted: 01/16/2013] [Indexed: 01/15/2023]
Abstract
Generation of hypochlorous acid (HOCl), an important microbicidal agent, is considered to be the main function of myeloperoxidase (MPO), an enzyme present in phagocytes. High amounts of MPO are present in neutrophil azurophilic granules, which are mobilized into the phagolysosome vacuole during phagocytosis. MPO is also present in monocytes and macrophages, although to a lesser degree than in neutrophils. In the present study, we investigated the distribution of MPO in murine peritoneal cells using flow cytometry, confocal microscopy (CM) and transmission electron microscopy (TEM). MPO was observed in macrophages, and surprisingly, we detected MPO in B lymphocytes, specifically in B1-a. MPO was present in cytoplasmic granules, vesicles, mitochondria and the nucleus of murine peritoneal cells. Together, these findings suggest that, in addition to its known microbicidal activity, MPO has a myriad of other unanticipated cellular functions.
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