A Therapeutic Vaccine for Chronic Hepatitis B

慢性乙型肝炎的治疗疫苗

• 批准号: 7910291
• 负责人: David R. Milich
• 金额: $ 29.95万
• 依托单位: VLP BIOTECH, INC.
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-15 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7910291
• 关键词: Adjuvant; Adoptive Transfer; Amino Acids; Animal Model; Antibodies; Antibody Formation; Antigen-Antibody Complex; Antigens; Antiviral Agents; Autoantigens; Avidity; B-Lymphocyte Epitopes; B-Lymphocytes; Binding; Bone Marrow Transplantation; CD4 Positive T Lymphocytes; CD8B1 gene; Chronic; Chronic Hepatitis B; Cirrhosis; Clinical Trials; Collaborations; Combined Modality Therapy; Complication; Core Protein; Cytolysis; Cytopathology; DNA; DNA Vaccines; Diabetes Mellitus; Disease; Encephalitis; Environment; Enzymes; Epitopes; Event; Exhibits; Goals; Health; Hepadnaviridae; Hepatitis; Hepatitis B; Hepatitis B Core Antigen; Hepatitis B Surface Antigens; Hepatitis B Vaccines; Hepatitis B Virus; Hepatitis B e Antigens; Hepatocyte; Human; Hybrids; Immune; Immune Tolerance; Immune response; Immunity; Immunization; Immunotherapeutic agent; Immunotherapy; Individual; Infection; Inflammatory; Injury; Laboratories; Lamivudine; Legal patent; Licensing; Ligands; Liver; Liver Failure; Measurement; Measures; Mediating; Methods; Modeling; Molecular; Monitor; Mus; Patients; Pegylated Interferon Alfa; Phase; Plasmids; Primary carcinoma of the liver cells; Production; Proteins; Research Institute; Resolution; Serum; Site; Small Business Innovation Research Grant; Surface Antigens; T cell response; T-Lymphocyte; T-Lymphocyte Epitopes; Technology; Testing; Therapeutic; Therapeutic Effect; Transgenic Mice; Transgenic Organisms; Treatment Efficacy; Vaccine Antigen; Vaccine Research; Vaccines; Variant; Viral; Viral Antibodies; Viral Antigens; Viral Core Proteins; Viral Envelope Proteins; Viral Load result; Virion; Virus; Virus Diseases; Virus-like particle; Woodchuck; Work; adefovir; anti-hepatitis B; autoimmune arthritis; base; cytokine; drug withdrawal; effective therapy; entecavir; immunogenicity; improved; in vivo; in vivo Model; mouse model; neutralizing antibody; novel; particle; public health relevance; recombinant virus; response; self assembly; therapeutic vaccine; vaccine candidate; vaccine evaluation; viral DNA; Adjuvant; Adoptive Transfer; Amino Acids; Animal Model; Antibodies; Antibody Formation; Antigen-Antibody Complex; Antigens; Antiviral Agents; Autoantigens; Avidity; B-Lymphocyte Epitopes; B-Lymphocytes; Binding; Bone Marrow Transplantation; CD4 Positive T Lymphocytes; CD8B1 gene; Chronic; Chronic Hepatitis B; Cirrhosis; Clinical Trials; Collaborations; Combined Modality Therapy; Complication; Core Protein; Cytolysis; Cytopathology; DNA; DNA Vaccines; Diabetes Mellitus; Disease; Encephalitis; Environment; Enzymes; Epitopes; Event; Exhibits; Goals; Health; Hepadnaviridae; Hepatitis; Hepatitis B; Hepatitis B Core Antigen; Hepatitis B Surface Antigens; Hepatitis B Vaccines; Hepatitis B Virus; Hepatitis B e Antigens; Hepatocyte; Human; Hybrids; Immune; Immune Tolerance; Immune response; Immunity; Immunization; Immunotherapeutic agent; Immunotherapy; Individual; Infection; Inflammatory; Injury; Laboratories; Lamivudine; Legal patent; Licensing; Ligands; Liver; Liver Failure; Measurement; Measures; Mediating; Methods; Modeling; Molecular; Monitor; Mus; Patients; Pegylated Interferon Alfa; Phase; Plasmids; Primary carcinoma of the liver cells; Production; Proteins; Research Institute; Resolution; Serum; Site; Small Business Innovation Research Grant; Surface Antigens; T cell response; T-Lymphocyte; T-Lymphocyte Epitopes; Technology; Testing; Therapeutic; Therapeutic Effect; Transgenic Mice; Transgenic Organisms; Treatment Efficacy; Vaccine Antigen; Vaccine Research; Vaccines; Variant; Viral; Viral Antibodies; Viral Antigens; Viral Core Proteins; Viral Envelope Proteins; Viral Load result; Virion; Virus; Virus Diseases; Virus-like particle; Woodchuck; Work; adefovir; anti-hepatitis B; autoimmune arthritis; base; cytokine; drug withdrawal; effective therapy; entecavir; immunogenicity; improved; in vivo; in vivo Model; mouse model; neutralizing antibody; novel; particle; public health relevance; recombinant virus; response; self assembly; therapeutic vaccine; vaccine candidate; vaccine evaluation; viral DNA

DESCRIPTION (provided by applicant): The objective of this proposal is to assess the feasibility of using recombinant virus-like-particles (VLPs) to elicit neutralizing antibodies and prime CD4+/CD8+ T cells reactive with hepatitis B viral (HBV) antigens as candidate immunotherapeutics for chronic HBV infection. For this purpose, selected well- defined neutralizing B cell epitopes representing HBV envelope Pre-S (1) and (2) antigens are being inserted onto a species variant of the HBV core protein, namely the woodchuck hepatitis core antigen (WHcAg). Pre-S B cell epitopes were chosen because of their preferential expression on HBV virions. We have previously developed the WHcAg as a VLP vaccine carrier for a number of heterologous B and T cell epitopes and use in this particular application will permit circumvention of the T cell immune tolerance that exists in chronically infected patients. The WHO estimates that more than 400 million individuals are chronically infected with HBV and approximately 20-40% will develop serious complication such as cirrhosis, liver failure and hepatocellular carcinoma. Although a safe and efficacious preventative vaccine for HBV has been available for over 20 years, HBV infections continue (with more than 50 million HBV infections per year) to be a major health problem and no effective treatments for chronic infection exist. Antiviral drugs such as lamivudine, adefovir, entecavir and pegylated interferon-alpha have improved the therapeutic options for chronic HBV, but, their efficacy remains limited due to reactivation of HBV replication upon drug withdrawal. Because chronic HBV infection is an immune-mediated disease and adoptive transfer of immunity to HBV through bone marrow transplantation has achieved resolution of chronic HBV infection, vaccine-based immunotherapy has been suggested as a possible monotherapy or as a combination therapy with antiviral drugs. To this end a number of clinical trials have been conducted using the HBV envelope antigens (i.e., HBsAg, HBsAg- PreS(2) and HBsAg-PreS(2)-PreS(1) containing subviral particles) either singly or in combination delivered as proteins in adjuvant or as DNA constructs, all with rather disappointing results. The most important factor to explain the defective T cell responses to the HBsAgs in chronic HBV carriers is immune tolerance. To circumvent the obstacle of immune tolerance in HBV chronic carriers, we have chosen to construct hybrid VLPs consisting of HBsAg Pre-S neutralizing B cell epitopes inserted onto the WHcAg, which is approximately 66-68% homologous with the HBcAg. The WHcAg and the HBcAg are not crossreactive at the B cell level and, just as importantly for our purposes, are only partially crossreactive at the CD4+ T cell level based on unique WHcAg-specific T cell sites and shared WHcAg/HBcAg-specific T cell sites in regions of the WHcAg that are conserved between WHcAg and HBcAg. Therefore, CD4+ T cells specific for WHcAg-unique T cell sites will provide cognate T-B cell help for anti-PreS antibody production and will not be curtailed by immune tolerance to HBcAg-specific T cell sites. In fact, in preliminary studies in HBcAg-Tg mice, which are tolerant to HBcAg, immunization with hybrid WHcAg-PreS VLPs elicits equivalent high titer anti-PreS antibodies in wildtype and HBcAg-Tg mice. Another advantage of immunizing with a closely related species variant of the HBcAg is that CD4+ and possibly CD8+ T cell sites within the WHcAg that differ only marginally from the sites within the HBcAg (i.e., 1 or 2 amino acids) may elicit so-called "bystander" T cell help and may also even break T cell tolerance of the HBV patient's HBcAg-specific T cells by virtue of higher avidity T cell crossreactivity. Historically, breaking T cell tolerance to self antigens has been accomplished by immunization with closely related species variant proteins (induction of experimental autoimmune arthritis, diabetes, encephalitis etc.). Specifically, in Aim 1 we propose to insert 3 HBsAg-PreS(1) and 1 HBsAg-PreS(2) neutralizing B cell epitopes onto the WHcAg VLP carrier and optimize the constructs based on assembly, yield, stability and immunogenicity. In Aim 2 the therapeutic efficacy of the VLP-based vaccine candidates will be evaluated in a transgenic (Tg) mouse model of HBV replication, in which HBV replicates in hepatocytes at levels comparable to that in the infected livers of chronic HBV patients without evidence of cytopathology. The hybrid WHcAg-PreS VLP candidates have the potential to reduce HBV load in at least 3 ways: (1) anti-PreS antibodies should clear serum HBV through immune complexes; (2) WHc/HBcAg-crossreactive CD4+ T cells may reduce HBV replication in the liver through inflammatory cytokine production; and (3) WHc/HBcAg-crossreactive CD8+ T cells may reduce viral replication in the liver through cytokine production as well as through direct hepatocyte cytolysis. The ability of immunization with the WHcAg-PreS VLP candidates to reduce HBV load through all of these mechanisms will be monitored in the HBV-Tg mouse model (Aim 2). It is anticipated that the combination of these two technologies, the ability to produce hybrid-VLPs (VLP Biotech) and the murine model of chronic HBV infection (TSRI), will enable us to produce and test the therapeutic efficacy of at least 4 hybrid WHcAg-PreS VLPs in a two-year timeframe. PUBLIC HEALTH RELEVANCE: It is estimated by the WHO that worldwide more than 400 million people are chronically infected with the hepatitis B virus (HBV) and approximately 20-40% will develop serious complications such as cirrhosis, liver failure and hepatocellular carcinoma. Although a safe and effective preventative vaccine for HBV is available, the existing treatments for chronic infection are unsatisfactory for a number of reasons. This is a proposal to develop virus-like-particles (VLPs) capable of eliciting neutralizing anti-HBV antibodies and priming CD4+/CD8+ T cells reactive with HBV antigens as a candidate therapeutic vaccine for chronic HBV infection.

描述（由申请人提供）：该提案的目的是评估使用重组病毒样粒子（VLP）的可行性，以引起中和中和抗体的中和抗体和Prime CD4+/CD8+ T细胞用乙型肝炎病毒（HBV）抗原作为候选免疫治疗药的反应性，以使其作为候选免疫治疗药物作为慢性HBV感染。为此，将代表HBV包膜前S（1）和（2）抗原的精确定义的中和中和的B细胞表位插入了HBV核心蛋白的一种物种变体上，即Woodchuck Hepatiso Core核心抗原（WHCAG）。选择前S B细胞的表位是因为它们在HBV病毒体上的优先表达。我们以前已经开发了WHCAG作为VLP疫苗载体，用于许多异源B和T细胞表位，并在此特定应用中使用将允许在长期感染的患者中规避T细胞免疫耐受性。 世卫组织估计，超过4亿人患有HBV，大约20-40％会出现严重的并发症，例如肝硬化，肝衰竭和肝细胞癌。尽管HBV的安全有效的预防性疫苗已经使用了20多年，但HBV感染继续（每年超过5000万HBV感染）是一个主要的健康问题，并且没有有效的慢性感染治疗方法。抗病毒药（如lamivudine，adefovir，entecavir和pegypated干扰素 - α）已改善了慢性HBV的治疗选择，但是由于戒毒后HBV复制的重新激活，它们的疗效仍然有限。由于慢性HBV感染是一种免疫介导的疾病，并且通过骨髓移植对HBV的继发性转移已经解决了慢性HBV感染的分辨率，因此已建议基于疫苗的免疫疗法是一种单药治疗，或者是与抗病毒药物的联合治疗。为此，已经使用HBV包膜抗原（即HbSag，HbSag-Pres（2）和HbSag-Pres（2）-Pres（1）单独或以辅助或DNA构建中的蛋白质为蛋白质，以及相当令人失望的结果，已经进行了许多临床试验。 解释慢性HBV载体中HBSAGS的缺陷T细胞反应的最重要因素是免疫耐受性。为了避免HBV慢性载体中免疫耐受性的障碍，我们选择构建由插入WHCAG的HBSAG Pre-S中和B细胞表位组成的杂种VLP，该缩影大约为66-68％与HBCAG同源。 WHCAG和HBCAG在B细胞水平上没有交叉反应性，同样重要的是，对于我们的目的而言，基于独特的WHCAG特异性T细胞位点和共享WHCAG/HBCAG特异性T细胞站点的whcag区域中，在CD4+ T细胞水平上仅在CD4+ T细胞水平上进行了反应性。因此，针对WHCAG-唯一T细胞位点特异的CD4+ T细胞将为抗PRES抗体的产生提供同源的T-B细胞帮助，并且不会因对H​​BCAG特异性T细胞位点的免疫耐受性而减少。实际上，在对HBCAG耐受性HBCAG的HBCAG-TG小鼠的初步研究中，使用混合WHCAG-PRES VLPS进行免疫接种，引起了WildType和HBCAG-TG小鼠的等效抗体抗体。 与HBCAG的紧密相关物种变体免疫的另一个优点是，CD4+以及WHCAG内的CD8+ T细胞位点仅与HBCAG内的地点差异仅差异（即1或2个氨基酸）（即1或2个氨基酸）（即1或2个氨基酸）可能会引起所谓的“ T细胞”，甚至可能破坏T细胞的旁观者，也可能会破坏T细胞的HIB tbc ever tifien tbc tivient of tbc to tbc ever tiver tive fiver fiver tb vir fiver tbv ever fiver tbc ever fiver tb vir。细胞交叉反应性。从历史上看，通过与密切相关的物种变异蛋白（诱导实验性自身免疫性关节炎，糖尿病，脑炎等）的免疫来实现对T细胞对自抗原的耐受性。 具体而言，在AIM 1中，我们建议将3 HbSAG-PRES（1）和1 HbSAG-PRES（2）中和B细胞表位插入WHCAG VLP载体上，并基于组装，产量，稳定性和免疫原性来优化构建体。在AIM 2中，将在HBV复制的转基因（TG）小鼠模型中评估基于VLP的疫苗的治疗功效，其中HBV在没有细胞病理学证据的慢性HBV患者的感染肝脏中，HBV在肝细胞中以可比的水平复制。混合WHCAG-PRES VLP候选物具有至少3种方式减少HBV载荷的潜力：（1）抗Pres抗体应通过免疫复合物清除血清HBV； （2）WHC/HBCAG-roctRACTIVE CD4+ T细胞可以通过炎症细胞因子的产生减少肝脏中的HBV复制； （3）WHC/HBCAG-cROSSRACTIVE CD8+ T细胞可以通过细胞因子的产生以及直接的肝细胞细胞溶解来减少肝脏中的病毒复制。通过HBV-TG小鼠模型，将通过所有这些机制来监控WHCAG-PRES VLP候选者通过所有这些机制减少HBV负载的能力（AIM 2）。 可以预料，这两种技术的结合，即生产混合VLP（VLP Biotech）的能力和慢性HBV感染（TSRI）的鼠模型，将使我们能够在为期两年的时间段内产生和测试至少4个Hybrid Whcag Pres VLP的治疗功效。 公共卫生相关性：由谁在全球范围内估计超过4亿人患有乙型肝炎病毒（HBV），大约20-40％会出现严重的并发症，例如肝硬化，肝衰竭和肝细胞癌。尽管可以使用安全有效的HBV预防性疫苗，但由于多种原因，现有的慢性感染治疗方法并不令人满意。这是开发能够引起中和抗HBV抗体和启动CD4+/CD8+ T细胞的抗HBV抗原作为候选治疗疫苗的慢性HBV感染的抗HBV抗体和启动抗HBV抗体的建议。