Antibody cytokine fusion proteins against Cryptococcus neoformans

新型隐球菌抗体细胞因子融合蛋白

• 批准号: 7383656
• 负责人: DAVID Owen BEENHOUWER
• 金额: $ 31.73万
• 依托单位: BRENTWOOD BIOMEDICAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-15 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7383656
• 关键词: Adjuvant; Adverse effects; Animals; Antibodies; Antigen-Antibody Complex; Antigens; Binding; Cells; Cellular Immunity; Central Nervous System Infections; Chemotherapy-Oncologic Procedure; Chimeric Proteins; Chronic; Communicable Diseases; Complement Activation; Complex; Cryptococcal Meningitis; Cryptococcus neoformans; Cryptococcus neoformans infection; Dendritic Cells; Disease; Dose; Effector Cell; Encapsulated; Equilibrium; Fc Receptor; Genetic; Globulins; Goals; Granulocyte-Macrophage Colony-Stimulating Factor; Granulomatous; HIV; HIV Infections; Half-Life; Heating; Human; IgG3; Immune; Immune response; Immunity; Immunocompromised Host; Immunoglobulin G; Immunoglobulin Variable Region; Immunotherapeutic agent; Infection; Interleukin-12; Interleukin-2; Knowledge; Link; Lung; Malignant Neoplasms; Modeling; Mus; Numbers; Organ Transplantation; Organism; Persons; Play; Polysaccharides; Populations at Risk; Prevention; Rate; Research Personnel; Rheumatism; Role; Site; Surface; Talents; Testing; Therapeutic; Therapeutic Uses; Toxic effect; Vaccination; Vaccine Adjuvant; Vaccines; Yeasts; capsule; cytokine; design; experience; glucuronoxylomannan; immunogenic; improved; killings; mortality; mouse model; novel; paracrine; pathogen; practical application; prevent; prophylactic; receptor binding; response; therapeutic vaccine; tumor; uptake; vaccination strategy

DESCRIPTION (provided by applicant): Treatment with cytokines is moderately effective against mouse and human infection with Cryptococcus neoformans. However, systemic delivery of cytokines can be problematic for several reasons. Cytokines act in a local manner. Furthermore, they are rapidly degraded and side effects often limit their use. To overcome these limitations, we propose to construct and test several antibody-cytokine fusion proteins against C. neoformans infection with the goal of developing novel prophylactic and therapeutic vaccination strategies. For these fusion proteins, we will use an antibody specific for the outer capsule of C. neoformans, targeting cytokines directly to the site(s) of infection, while improving cytokine stability; thereby increasing the effective dose while decreasing systemic toxicities. There are currently no effective vaccines in use against C. neoformans. By linking cytokines to C. neoformans antigens, antibody-cytokine fusion proteins may be effective in generating protective immunity. Therefore, to test the efficacy of antibody-cytokine fusion proteins in preventing and treating C. neoformans infection, we propose: 1. To construct, produce and characterize antibody-cytokine fusion proteins specific for C. neoformans capsule. Antibody-cytokine fusion proteins consisting of the hinge-flexible human IgG3 against cryptococcal capsular polysaccharide genetically fused to either interleukin-2 (IL-2), granulocyte- macrophage colony stimulating factor (GM-CSF) or IL-12 will be produced recombinantly. Fusion proteins will be characterized for binding to C. neoformans as well as their functionality as cytokines and antibodies. 2. To determine the potential of antibody-cytokine fusion proteins to generate protective immunity to C. neoformans. Heat-killed C. neoformans or capsular polysaccharide will be opsonized with antibody- cytokine fusion proteins described above and administered to mice. Alternatively, dendritic cells will be loaded ex vivo with these immune complexes and delivered to mice. Host antibody and cellular immune responses specific for C. neoformans will be analyzed and protective efficacy of vaccination determined in mouse models of pulmonary and disseminated infection. 3. To determine the efficacy of cytokines genetically fused to antibody specific for C. neoformans capsule in cryptococcal infection. Antibody-cytokine fusion proteins will be given to mice with new or established infection to determine whether they can directly protect against disseminated cryptococcal infection. Host immune responses will be defined and correlated with efficacy. Mortality from cryptococcal meningitis is 10-20% indicating the need for better therapies. The population at risk for cryptococcal disease continues to grow due to increased survival of persons infected with HIV, new HIV infections, and the continued expansion of the number of persons with immunocompromise due to immuno- suppressive therapies for organ transplantation and rheumatic diseases as well as chemotherapy for cancer. The proposed studies have relevance beyond cryptococcal infection, since a significant long-term objective is to design antibody-cytokine fusion proteins for use in other types of infections.

描述（由申请人提供）：细胞因子治疗对于小鼠和人类新型隐球菌感染具有中等效果。然而，由于多种原因，细胞因子的全身递送可能存在问题。细胞因子以局部方式起作用。此外，它们会迅速降解并且副作用常常限制它们的使用。为了克服这些限制，我们建议构建和测试几种针对新型隐球菌感染的抗体-细胞因子融合蛋白，目的是开发新的预防性和治疗性疫苗接种策略。对于这些融合蛋白，我们将使用一种针对新型隐球菌外囊的特异性抗体，将细胞因子直接靶向感染部位，同时提高细胞因子的稳定性；从而增加有效剂量，同时降低全身毒性。目前还没有针对新型隐球菌的有效疫苗。通过将细胞因子与新型隐球菌抗原连接，抗体-细胞因子融合蛋白可能有效产生保护性免疫。因此，为了测试抗体-细胞因子融合蛋白在预防和治疗新型隐球菌感染中的功效，我们建议： 1.构建、生产并表征针对新型隐球菌荚膜特异性的抗体-细胞因子融合蛋白。抗体-细胞因子融合蛋白由铰链柔性人 IgG3 组成，针对隐球菌荚膜多糖，与白细胞介素 2 (IL-2)、粒细胞-巨噬细胞集落刺激因子 (GM-CSF) 或 IL-12 基因融合，将重组产生。融合蛋白将被表征为与新型隐球菌的结合以及它们作为细胞因子和抗体的功能。 2. 确定抗体-细胞因子融合蛋白对新型隐球菌产生保护性免疫的潜力。热灭活的新型隐球菌或荚膜多糖将用上述抗体-细胞因子融合蛋白调理并施用于小鼠。或者，树突状细胞将在体外装载这些免疫复合物并递送至小鼠。将分析新型隐球菌特异性的宿主抗体和细胞免疫反应，并在肺部和播散性感染的小鼠模型中确定疫苗接种的保护效果。 3. 确定与新型隐球菌荚膜特异性抗体基因融合的细胞因子在隐球菌感染中的功效。将抗体-细胞因子融合蛋白给予新感染或既定感染的小鼠，以确定它们是否可以直接预防播散性隐球菌感染。宿主免疫反应将被定义并与功效相关。隐球菌性脑膜炎的死亡率为 10-20%，表明需要更好的治疗方法。由于艾滋病毒感染者生存率的增加、新发艾滋病毒感染以及因器官移植和风湿性疾病的免疫抑制治疗以及癌症化疗而导致免疫功能低下的人数持续增加，面临隐球菌病风险的人口持续增长。拟议的研究具有超越隐球菌感染的相关性，因为一个重要的长期目标是设计用于其他类型感染的抗体-细胞因子融合蛋白。