生物谷综合：七鳃鳗是一种古老的无颚鱼，如今，研究人员鉴别出一种让这种鱼的祖先形成抗体的免疫细胞。新成果发表在2月在线出版的《自然—免疫学》（Nature Immunology）期刊上，它表明在进化过程中，这些鱼可能是地球上最早表达出“适应性免疫系统”的生命体。
这种免疫细胞也被称为“浆细胞”，研究人员在七鳃鳗的鳃部和肾脏中发现了大量的浆细胞，它们显示出早期抗原的特性。新结果表明，浆细胞应该是B细胞的老祖宗，它为七鳃鳗提供了抗体。
Max Cooper和同事发现，浆细胞只针对特定的糖或蛋白质模式作出反应，这些糖或蛋白质会在微生物表面反复出现。这种浆细胞的发育过程中出现了一种遗传多样化过程，这一过程产生了大量多样化的表面“模式识别受体”阵列，它们在七鳃鳗的免疫监督中发挥作用。之后，感染或“免疫”就会从其中选择出少数的细胞。
这种特定分子的非凡识别能力“重复”激发出浆细胞的增生能力和活力，活跃的浆细胞分泌出可溶解抗体，抑制入侵的微生物。（来源：科学时报 王丹红）
生物谷推荐原始出处：
Nature Immunology 9, 319 - 327 (2008)
Published online: 3 February 2008 | doi:10.1038/ni1562
Antibody responses of variable lymphocyte receptors in the lamprey
Matthew N Alder1,2, Brantley R Herrin1,2, Andrea Sadlonova1,2, Cecil R Stockard3, William E Grizzle3, Lanier A Gartland1,2, G Larry Gartland2, Jeremy A Boydston2, Charles L Turnbough, Jr2 & Max D Cooper1,2,3,4
Abstract
Lamprey and hagfish, the living representatives of jawless vertebrates, use genomic leucine-rich-repeat cassettes for the combinatorial assembly of diverse antigen receptor genes encoding variable lymphocyte receptors of two types: VLRA and VLRB. We describe here the VLRB-bearing lineage of lymphocytes in sea lamprey. These cells responded to repetitive carbohydrate or protein determinants on bacteria or mammalian cells with lymphoblastoid transformation, proliferation and differentiation into plasmacytes that secreted multimeric antigen-specific VLRB antibodies. Lacking a thymus and the ability to respond to soluble protein antigens, lampreys seem to have evolved a B cell–like system for adaptive humoral responses.
Office of Fundamental Immunology Research, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA.
Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA.
Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA.
Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, 35294, USA.
Correspondence to: Max D Cooper1,2,3,4 e-mail: max.cooper@ccc.uab.edu
