Leukocyte immune type receptors: gene structure and function

白细胞免疫型受体：基因结构和功能

• 批准号: 1656419
• 负责人: Melanie Wilson
• 金额: $ 79.69万
• 依托单位: University of Mississippi Medical Center
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1656419&HistoricalAwards=false
• 关键词: Leukocyte; immune; type; receptors; gene

Aquaculture is the fastest growing food producing sector in the world, and catfish represent the major fresh water farmed species in the US. Because of the economic importance of catfish to the U.S. aquaculture industry, it has been a long-term focus of this laboratory to functionally characterize the catfish immune system. In humans, white blood cells play important roles in fighting infection. However, very little is known about these cells in fish. The goal of the current study is to better understand how white blood cells in the catfish recognize and kill bacteria and virus-infected cells. Recent studies have shown that a family of proteins termed Leukocyte Immune Type Receptors (LITRs) is expressed on the surface of catfish white blood cells. These LITR expressing cells are capable of killing virus infected cells. This project will determine how the expression patterns of different LITR genes change in immune organs and white blood cells during the course of an infection and also provide information on the types of proteins or molecular structures LITRs recognize. This study will also provide unique research training opportunities for graduate, undergraduate and high school students, including students from groups under-represented in science. The students will learn basic immunology and gain expertise in a variety of molecular and cellular techniques. Graduate and undergraduate students will have their own research projects, learn how to design experiments, interpret data and present their findings at regional or national meetings. Studies of teleost immune responses are important because they provide information about the various immune strategies adapted by different animal groups. This project focuses on the LITR immunoregulatory receptor family that is found in channel catfish and other bony fish. LITRs comprise a highly diverse multigene family and many of the LITRs that have been sequenced are structurally related to mammalian NK receptors encoded within the leukocyte receptor complex. Additionally, certain LITRs, as defined by their reactivity with monoclonal antibody CC41, are expressed on catfish cytotoxic cells that recognize and kill virus infected cells via the secretory-perforin granzyme pathway. This project will first define the complete LITR gene repertoire in catfish and examine LITR expression after viral and bacterial challenge using PacBio single molecule long-read sequencing protocols. Second, the ligands for selected CC41-reactive LITRs will be determined using recombinant fusion proteins either in the form of tetramers or immunoglobulin-fusion proteins. The LITR-ligand complexes will be isolated and immunoselected proteins will be analyzed by LS-MS/MS. Third, since preliminary sequencing has identified a small number of LITRs that resemble mammalian Fc-receptors, representatives from this group will be analyzed for immunoglobulin binding. The successful completion of this project will define the functional properties of LITRs and provide insights into the evolution of innate immune regulatory receptors. Moreover, this project will provide novel information about how ectothermic vertebrates maintain self-tolerance and recognize altered-self.

水产养殖是世界上增长最快的食品生产部门，鲶鱼是美国主要的淡水养殖物种。由于鲶鱼对美国水产养殖业的经济重要性，该实验室长期关注鲶鱼免疫系统的功能特征。在人类中，白色血细胞在抵抗感染中起着重要作用。然而，人们对鱼类中的这些细胞知之甚少。目前研究的目的是更好地了解鲶鱼体内的白色血细胞是如何识别和杀死细菌和病毒感染的细胞的。最近的研究表明，一个称为白细胞免疫型受体（LITR）的蛋白质家族在鲶鱼白色血细胞表面表达。这些表达LITR的细胞能够杀死病毒感染的细胞。该项目将确定在感染过程中不同LITR基因的表达模式如何在免疫器官和白色血细胞中变化，并提供LITR识别的蛋白质或分子结构类型的信息。这项研究还将为研究生，本科生和高中生提供独特的研究培训机会，包括来自科学代表性不足的群体的学生。学生将学习基本的免疫学，并获得各种分子和细胞技术的专业知识。研究生和本科生将有自己的研究项目，学习如何设计实验，解释数据，并在区域或国家会议上展示他们的发现。硬骨鱼免疫反应的研究是重要的，因为它们提供了关于不同动物群体适应的各种免疫策略的信息。该项目的重点是LITR免疫调节受体家族，发现在癍点叉尾鱼和其他硬骨鱼。LITR包括高度多样化的多基因家族，并且许多已测序的LITR在结构上与白细胞受体复合物内编码的哺乳动物NK受体相关。此外，某些LITR，如其与单克隆抗体CC 41的反应性所定义的，在鲶鱼细胞毒性细胞上表达，其通过分泌穿孔素颗粒酶途径识别并杀死病毒感染的细胞。该项目将首先定义鲶鱼中完整的LITR基因库，并使用PacBio单分子长读测序方案检查病毒和细菌挑战后的LITR表达。其次，将使用四聚体或免疫球蛋白融合蛋白形式的重组融合蛋白来确定所选CC 41反应性LITR的配体。将分离LITR-配体复合物，并通过LS-MS/MS分析免疫选择的蛋白质。第三，由于初步测序已经鉴定了少量类似于哺乳动物Fc受体的LITR，因此将分析该组的代表性免疫球蛋白结合。该项目的成功完成将定义LITR的功能特性，并为先天免疫调节受体的进化提供见解。此外，该项目将提供有关变温脊椎动物如何维持自我耐受和识别改变的自我的新信息。

项目成果

Insights into the dynamics of memory, effector and apoptotic cytotoxic T lymphocytes in channel catfish, Ictalurus punctatus

深入了解斑点叉尾鮰记忆、效应和凋亡细胞毒性 T 淋巴细胞的动态

• DOI: 10.1016/j.dci.2018.11.001
• 发表时间: 2019
• 期刊: Developmental & Comparative Immunology
• 影响因子: 2.9
• 作者: Spencer, David A.;Quiniou, Sylvie M.A.;Crider, Jonathan;Musungu, Bryan;Bengten, Eva;Wilson, Melanie
• 通讯作者: Wilson, Melanie

Catfish lymphocytes expressing CC41-reactive leukocyte immune-type receptors (LITRs) proliferate in response to Edwardsiella ictaluri infection in vitro

• DOI: 10.1016/j.dci.2020.103610
• 发表时间: 2020-05-01
• 期刊: DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY
• 影响因子: 2.9
• 作者: Blackmon, Laura E.;Quiniou, Sylvie M. A.;Bengten, Eva
• 通讯作者: Bengten, Eva

A subset of leukocyte immune-type receptors (LITRs) regulates phagocytosis in channel catfish (Ictalurus punctatus) leukocytes

• DOI: 10.1016/j.molimm.2022.12.009
• 发表时间: 2022-12-29
• 期刊: MOLECULAR IMMUNOLOGY
• 影响因子: 3.6
• 作者: Crider，Jonathan;Wilson，Melanie;Bengten，Eva
• 通讯作者: Bengten，Eva