Intracellular localization of myeloperoxidase in murine peritoneal B-lymphocytes and macrophages.

Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, Alfenas, MG 37130, Brazil.

Cellular immunology 2013 Jan

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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. Copyright © 2013 Elsevier Inc. All rights reserved.

Citation

Tomaz Henrique de Araujo, Sabrina Sayori Okada, Eliver Eid Bou Ghosn, Noemi Nosomi Taniwaki, Maria Rita Rodrigues, Sandro Rogerio de Almeida, Renato Arruda Mortara, Momtchilo Russo, Ana Campa, Renata Chaves Albuquerque. Intracellular localization of myeloperoxidase in murine peritoneal B-lymphocytes and macrophages. Cellular immunology. 2013 Jan;281(1):27-30