title: B lymphocytes from early vertebrates have potent phagocytic and microbicidal abilities.
abstract: The present paradigm dictates that phagocytosis is accomplished mainly by 'professional' phagocytes (such as macrophages and monocytes), whereas B cells lack phagocytic capabilities. Here we demonstrate that B cells from teleost fish have potent in vitro and in vivo phagocytic activities. Particle uptake by B cells induced activation of 'downstream' degradative pathways, leading to 'phagolysosome' formation and intracellular killing of ingested microbes. Those results indicate a previously unknown function for B cells in the innate immunity of these primitive animals. A considerable proportion of Xenopus laevis B cells were also phagocytic. Our findings support the idea that B cells evolved from an ancestral phagocytic cell type and provide an evolutionary framework for understanding the close relationship between mammalian B lymphocytes and macrophages.
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Barreda
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Zhang
authors.forename: Hani
authors.initials: H
authors.lastname: Boshra
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Gelman
authors.forename: Scott
authors.initials: S
authors.lastname: Lapatra
authors.forename: Lluis
authors.initials: L
authors.lastname: Tort
authors.forename: J Oriol
authors.initials: JO
authors.lastname: Sunyer
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000382:microbiology* / Q000648:ultrastructure; D005075:Biological Evolution; D002397:Catfishes / Q000276:immunology* / Q000382:microbiology; D004926:Escherichia coli / Q000276:immunology; D015870:Gene Expression; D007075:Immunoglobulin M / Q000032:analysis; D007136:Immunoglobulins / Q000235:genetics; D017686:Oncorhynchus mykiss / Q000276:immunology* / Q000382:microbiology; D010587:Phagocytosis / Q000235:genetics / Q000276:immunology*; D011971:Receptors, Immunologic / Q000235:genetics; D014982:Xenopus laevis / Q000276:immunology
chemical_list: D007075:Immunoglobulin M; D007136:Immunoglobulins; D011971:Receptors, Immunologic