Dual nature of the adaptive immune system in lampreys

• Type of Material: Article
• Authors: Peng Guo, Emory University; Masayuki Hirano, Emory University; Brantley Herrin, Emory University; Jianxu Li, Emory University; Cuiling Yu, Emory University; Andrea Sadlonova, Emory University; Max Cooper, Emory University
• Language: English
• Date: 2009-06-11
• Publisher: Nature Publishing Group
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2009 Macmillan Publishers Limited. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1038/nature08068
• Title of Journal or Parent Work: Nature
• ISSN: 0028-0836
• Volume: 459
• Issue: 7248
• Start Page: 796
• End Page: U1
• Grant/Funding Information: This work is supported by National Institutes of Health and Georgia Research Alliance.
• Keywords: DIVERSIFICATION; EVOLUTION; DIFFERENTIATION; Multidisciplinary Sciences; VARIABLE LYMPHOCYTE RECEPTORS; T-CELL REPERTOIRE; MIGRATION-INHIBITORY FACTOR; RESPONSES; THYMUS; GENES; DIVERSITY
• Research Categories: Health Sciences, Immunology; Health Sciences, Pathology

Abstract

Jawless vertebrates use variable lymphocyte receptors (VLR) comprised of leucine-rich-repeat (LRR) segments as counterparts of the immunoglobulin-based receptors that jawed vertebrates use for antigen recognition. Highly diverse VLR genes are somatically assembled by the insertion of variable LRR sequences into incomplete germline VLRA and VLRB genes. Here we show that in sea lampreys (Petromyzon marinus) VLRA and VLRB anticipatory receptors are expressed by separate lymphocyte populations by monoallelic VLRA or VLRB assembly, together with expression of cytosine deaminase 1 (CDA1) or 2 (CDA2), respectively. Distinctive gene expression profiles for VLRA+ and VLRB+ lymphocytes resemble those of mammalian T and B cells. Although both the VLRA and the VLRB cells proliferate in response to antigenic stimulation, only the VLRB lymphocytes bind native antigens and differentiate into VLR antibody-secreting cells. Conversely, VLRA lymphocytes respond preferentially to a classical T-cell mitogen and upregulate the expression of the pro-inflammatory cytokine genes interleukin-17 (IL-17) and macrophage migration inhibitory factor (MIF). The finding of T-like and B-like lymphocytes in lampreys offers new insight into the evolution of adaptive immunity.