Li Jun, Barreda Daniel R, Zhang Yong-An, Boshra Hani, Gelman Andrew E, Lapatra Scott, Tort Lluis, Sunyer J Oriol
Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Nat Immunol. 2006 Oct;7(10):1116-24. doi: 10.1038/ni1389. Epub 2006 Sep 17.
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.
目前的范式认为，吞噬作用主要由“专业”吞噬细胞（如巨噬细胞和单核细胞）完成，而B细胞缺乏吞噬能力。在此，我们证明硬骨鱼的B细胞具有强大的体外和体内吞噬活性。B细胞摄取颗粒会诱导“下游”降解途径的激活，导致“吞噬溶酶体”形成以及对摄入微生物的细胞内杀伤。这些结果表明，B细胞在这些原始动物的先天免疫中具有此前未知的功能。相当一部分非洲爪蟾的B细胞也具有吞噬作用。我们的研究结果支持了B细胞从祖先吞噬细胞类型进化而来的观点，并为理解哺乳动物B淋巴细胞与巨噬细胞之间的密切关系提供了一个进化框架。
