Characterization of an Alternative Adaptive Immune System in Hagfish

盲鳗替代适应性免疫系统的表征

• 批准号: 9040973
• 负责人: Max Dale Cooper
• 金额: $ 29.64万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9040973
• 关键词: Adult; Allogenic; Antibodies; Antibody Repertoire; Antibody Response; Antigen Receptors; Antigens; B-Lymphocytes; Blood; Cell Lineage; Cells; Computer Analysis; Cytosine deaminase; DNA cassette; Development; Diagnostic Reagent; Discrimination; Drug or chemical Tissue Distribution; Eels; Elements; Evolution; Exhibits; Fishes; Gene Expression; Gene Expression Profile; Genes; Genetic Programming; Germ Lines; Gills; Goals; Hagfish; Health; Hemorrhage; Immune; Immune response; Immune system; Immunization; Immunoglobulin Variable Region; Immunoglobulins; In Vitro; Infectious Agent; Jaw; Lampreys; Learning; Leucine-Rich Repeat; Libraries; Lymphocyte; Lymphocyte Activation; Mature Lymphocyte; Mitogens; Molecular; Molecular Probes; Molecular Profiling; Monoclonal Antibodies; Names; Nomenclature; Pathway interactions; Patients; Pilot Projects; Plasma; Population; Proteins; Protocols documentation; Receptor Gene; Receptors, Antigen, B-Cell; Sequence Analysis; Site; Specificity; Structure; Surface; Surveys; T-Cell Receptor; T-Lymphocyte; Technology; Testing; Thymus Gland; Vertebrates; Wit; Yeasts; antigen binding; antigen processing; base; cancer cell; comparative; hematopoietic tissue; in vivo; insight; microbial; novel; pathogen; plasma cell differentiation; receptor; research study; response; screening; time interval

DESCRIPTION (provided by applicant): Widely considered the most basal vertebrates alive today, hagfishes represent a pivotal point in evolution and thus offer a key piece to the puzzle of how our lymphocyte-based adaptive immune system evolved. An alternative adaptive immune system has been identified recently in the two extant jawless vertebrates, lampreys and hagfish, which last shared a common ancestor ~480 million years ago. While immunoglobulin- based antigen receptors are used by jawed vertebrates, jawless vertebrates instead use leucine-rich repeat (LRR)-based variable lymphocyte receptors (VLR) of three types to recognize antigens. VLRA and VLRC are assembled in the lamprey thymus-equivalent gill region by two lymphocyte lineages that resemble mammalian ab and gd T cell lineages. VLRB is assembled in hematopoietic tissues by B-like lymphocytes, which undergo plasma cell differentiation and secrete multivalent VLRB antibodies with structural features and antigen specificities that offer significant advantages for biomedical uses. Hagfish cells expressing the different VLRs have not yet been identified or functionally defined. To elucidate the hagfish immune system, monoclonal antibodies specific for invariant portions of their three VLRs have been made for use in analyzing development, distribution and function of hagfish lymphocytes, with particular emphasis on defining the structure and antigen-binding specificities of hagfish VLRB antibodies. The first aim is to define the tissue distribution and gene expression patterns of hagfish VLRA +, VLRB+ and VLRC+ lymphocytes. A principle objective here is to identify the primary sites in which VLRA and VLRB assembly occurs versus secondary sites in which mature lymphocytes undergo proliferation and differentiation. The second aim is to characterize hagfish lymphocyte responses to antigens, allogeneic cells, and mitogens. To determine why hagfish exhibit weak humoral immune responses to immunization, yet have an abundance of circulating VLRB proteins, these experiments will employ refined immunization protocols that elicit robust VLRB antibody responses in lampreys. Pilot studies imply that the hagfish VLRA+ and VLRC+ lymphocytes preferentially respond to cells from other lampreys, and experiments are proposed to find the 'allo-recognition elements' of jawless vertebrates. The third specific aim is to construct yeast surface display libraries for hagfish VLRs for use in large scale surveys of the receptor repertoires and to isolate antigen-specific clones for structural and functional characterization. Comparative screening of the VLRA and VLRB libraries for antigen binding will allow us to test the hypothesis that the VLRA and VLRC repertoires are clonally selected for reactivity with processed antigen. Elucidation of the hagfish immune system will help us to understand how and why lymphocyte development along T- and B- cell pathways occurred during vertebrate evolution and to exploit VLRB antibodies for biomedical purposes.

描述（由申请人提供）：hagfishes被广泛认为是最基础脊椎动物，它代表了进化中的关键点，因此为难题提供了关键。 我们的基于淋巴细胞的适应性免疫系统如何发展。最近在两个现存的无知的脊椎动物，lamp和hag鱼中发现了一种替代的适应性免疫系统，该系统上次共享一个共同的祖先〜4.8亿年前。虽然可颌脊椎动物使用了免疫球蛋白的抗原受体，而无颌脊椎动物则使用三种类型的富含亮氨酸的重复（LRR）可变淋巴细胞受体（VLR）来识别抗原。 VLRA和VLRC由两个类似于哺乳动物AB和GD T细胞谱系的淋巴细胞谱系组装在七lamp虫胸腺等效的g区。 VLRB由B样淋巴细胞组装在造血组织中，B样淋巴细胞经历了血浆细胞分化，并分泌具有结构特征和抗原特异性的多价VLRB抗体，这些抗体为生物医学使用提供了显着优势。表达不同VLR的hag鱼细胞尚未识别或在功能上定义。为了阐明Hagfish免疫系统，已经用于用于分析Hagfish淋巴细胞的开发，分布和功能的单克隆抗体，特别强调了伙伴Hagfish VLRB VLRB抗体的结构和抗原结合特异性。第一个目的是定义Hagfish VLRA+，VLRB+和VLRC+淋巴细胞的组织分布和基因表达模式。这里的一个主要目标是确定VLRA和VLRB组装发生的主要部位，而成熟的淋巴细胞经历增殖和分化的次要部位。第二个目的是表征对抗原，同种异体细胞和有差异剂的hag鱼淋巴细胞反应。为了确定hag鱼为什么表现出弱的体液免疫反应对免疫接种，但具有丰富的循环VLRB蛋白，这些实验将采用精致的免疫方案，从而在lampreys中引起强大的VLRB抗体反应。试点研究暗示，hagfish vlra+和vlrc+淋巴细胞优先响应其他lamp依的细胞，并提出了实验以找到无知的脊椎动物的“异源识别元件”。第三个具体目的是构建用于hagfish VLR的酵母表面显示库，用于用于大规模调查的受体曲线，并分离抗原特异性克隆以进行结构和功能表征。 VLRA和VLRB文库的抗原结合的比较筛选将使我们能够测试以下假设：VLRA和VLRC曲目是克隆选择以用加工抗原的反应性的。阐明hag鱼免疫系统将有助于我们了解脊椎动物进化过程中T-和B细胞途径沿T和B细胞途径的发展以及为何为生物医学目的利用VLRB抗体。