Evolution and function of the AID/APOBEC family of cytidine deaminases in lampreys

脊椎动物的免疫系统利用抗体对感染作出反应。七鳃鳗是一种古老的脊椎动物，它们产生的抗体与哺乳动物（如人类）不同。该项目将分析一个酶家族的功能，称为胞苷脱氨酶（CDAs）在七鳃鳗中产生多种抗体。这项在七鳃鳗身上的工作将揭示与胞苷脱氨酶有关的人类酶的功能，这些酶的功能鲜为人知。这一发现可能导致工程七鳃鳗抗体用于诊断和治疗人类疾病。研究生和本科生将接受现代免疫学研究方法的培训，培养下一代科学、技术、工程和数学人才。拓展到挂毯公立特许学校自闭症谱系障碍的目的是让学生接触科学和对自然世界的理解。本项目将研究在无颌脊椎动物中编码抗体的抗原受体基因可变淋巴细胞受体（VLRs）的组装和体细胞多样化。七鳃鳗的VLR组装是由胞苷脱氨酶的多基因家族催化的。在这项研究中，研究人员将使用基因组学来全面表征七鳃鳗胞苷脱氨酶。他们将研究新发现的胞苷脱氨酶1样分子-胞苷脱氨酶3-5和胞苷脱氨酶2的四个新剪接变体在七鳃鳗组织中的表达模式，并测试它们在异种系统和细胞系中的功能。深入了解七鳃鳗不同胞苷脱氨酶家族成员的机制和功能，将有助于深入了解人类同源物的功能，并促进对脊椎动物适应性免疫系统进化的理解。通过本研究获得的知识可以实现高亲和力的七鳃鳗VLR抗体的工程设计，这对人类具有重要的诊断和治疗潜力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The immune system of vertebrates uses antibodies to respond to infections. Lampreys are ancient vertebrates that make antibodies differently from mammals, such as humans. This project will analyze the function of a family of enzymes, called cytidine deaminases (CDAs) in generating a diverse repertoire of antibodies in lampreys. The work in lampreys will shed light on the function of human enzymes related to cytidine deaminases, of which little is known. Findings could lead to engineered lamprey antibodies for use in diagnosing and treating human diseases. Graduate and undergraduate students will be trained in modern immunological research methods, developing the next generation of science, technology, engineering and mathematics workforce. Outreach to the Tapestry Public Charter School for Autism Spectrum Disorder is designed to expose students to science and understanding of the natural world.This project will study the assembly and somatic diversification of antigen receptor genes termed Variable Lymphocyte Receptors (VLRs) that encode antibodies in jawless vertebrates. VLR assembly in lampreys is catalyzed by a multi-gene family of cytidine deaminases. In this research, researchers will use genomics to comprehensively characterize lamprey cytidine deaminases. They will examine the expression pattern of newly identified cytidine deaminase 1-like molecules - cytidine deaminase 3-5 and four new splice variants of cytidine deaminase 2 in lamprey tissues and test their function in heterologous systems and cell lines. A deeper understanding of the mechanism and function of different cytidine deaminases family members in lampreys will provide insight into the function of human homologs and advance understanding of the evolution of the adaptive immune systems in vertebrates. Knowledge gained through this research could enable engineering of higher-affinity lamprey VLR antibodies, which have important diagnostic and therapeutic potential in humans.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.