A live attenuated vaccine for leishmaniasis

利什曼病减毒活疫苗

• 批准号: 9753154
• 负责人: Abhay R Satoskar
• 金额: $ 16.7万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9753154
• 关键词: Adverse event; Animal Model; Animals; Antibiotic Resistance; Antibiotics; Antibodies; Antibody Response; Antigens; Attenuated; Attenuated Live Virus Vaccine; Bacteria; Bite; CD8-Positive T-Lymphocytes; CRISPR/Cas technology; Canis familiaris; Cells; Clinical; Conduct Clinical Trials; Cutaneous; Cutaneous Leishmaniasis; Development; Diffuse; Disease; Dose; Environment; Etiology; Exposure to; FDA approved; Foundations; Genes; Goals; Hamsters; Histopathology; Human; Immune; Immune response; Immunity; Immunization; Immunize; Immunocompromised Host; Infection; Intervention; Leishmania; Leishmania donovani; Leishmania major; Leishmaniasis; Lesion; Life; Measures; Modeling; Monitor; Mucous Membrane; Mus; Mutation; Parasites; Patients; Phenotype; Phlebotomus; Preventive vaccine; Process; Production; Protocols documentation; Regimen; Route; Safety; Salmonella typhi; Sand Flies; Site; Smallpox; T cell response; Testing; Time; Trimethoprim-Sulfamethoxazole; Tunisia; Vaccinated; Vaccination; Vaccines; Virulent; Virus; Visceral; Visceral Leishmaniasis; Zoonoses; cytokine; experience; genome sequencing; global health; human disease; immunogenicity; industry partner; neglected tropical diseases; novel; obligate intracellular parasite; parasite genome; pathogen; peripheral blood; resistance gene; response; safety testing; skin disorder; skin lesion; vaccine candidate; vaccine development; vaccine evaluation; vector; whole genome

Abstract Infections caused by the protozoan parasite Leishmania include cutaneous (CL), mucosal (ML), and visceral leishmaniasis (VL). Over 12 million people currently suffer from leishmaniasis, and approximately 2 million new cases occur annually. Currently no vaccine is available for this disease for humans. However, patients who recover from leishmaniasis develop immunity against reinfection indicating that a vaccine is feasible. In the past, leishmanization, a process in which deliberate infection with a low dose of Leishmania major, etiologic agent of zoonotic cutaneous leishmaniasis (ZCL) causes a controlled skin lesion and provides > 90% protection against reinfection, was a common practice. Although such practice may not be acceptable under the current regulatory environment due to possibility of complications, these observations suggest that live- attenuated parasites that provide a complete array of antigens without causing disease could be an effective vaccine for leishmaniasis. Genetically attenuated L. infantum and L. donovani have shown promise as a vaccine in animal models. However, using these parasites in humans could raise safety concerns due to their visceralizing potential. Attenuated dermatotrophic Leishmania that cross-protects against VL could be a safer vaccine because potential adverse events (e.g. development of a lesion at vaccination site) can be easily monitored and effectively treated using approved topical interventions. Several clinical as well as animal studies have shown that an infection with dermatotrophic Leishmania such as L. major or immunization with antigens from these parasites confers significant cross-protection against VL. However, it is not known whether immunization with attenuated cutaneous disease causing species such centrin gene deficient L. major will protect against VL. Using CRISPR-Cas technology, we have generated antibiotic selection marker free centrin gene deficient L. major (LmCen-/-). In this project, we propose to use a novel canine model of VL to test the safety and efficacy of GLP-grade LmCen-/-. Whole genome sequencing of LmCen-/- has confirmed stable deletion of centrin gene without other mutations in the parasite genome. Our preliminary findings show that LmCen-/- are highly attenuated and fail to cause disease in immunocompromised mice. We have also found that immunization with LmCen-/- parasites induces a disease protective Th1 response in hamster as well as mice and completely protects against homologous challenge with virulent L. major. Our industry partner Gennova Biopharma has already established LmCen-/- production under GLP conditions at their US-FDA approved facility. In this project, we propose to (Aim 1) optimize GLP-LmCen-/- immunogenicity and immunization protocol and determine its safety in dogs and (Aim 2) evaluate efficacy of GLP-LmCen-/- as a vaccine using a novel model of canine VL in which dogs are naturally exposed to bites of L. infantum infected wild Phlebotomus pernicious in VL- hyperendemic regions of Tunisia. The scientific promise of this project, if successful, could provide the foundation for advancing LmCen-/- parasites as a vaccine against leishmaniasis in humans.

抽象的 原生动物寄生虫Leishmania引起的感染包括皮肤（CL），粘膜（ML）和内脏 利什曼病（VL）。目前有超过1200万人患有利什曼病，大约有200万人 案件每年发生。目前，该疾病尚无疫苗。但是，患者 从利什曼病中恢复，可以免于再感染，表明疫苗是可行的。在 过去，利什曼化，在这种过程中，有意感染了利什曼原虫的大专业，病因 人畜共动性皮肤利什曼病（ZCL）的药物会导致受控的皮肤病变，并提供> 90％ 防止再感染是一种普遍做法。尽管这种做法可能是不可接受的 由于可能发生并发症的可能性，当前的监管环境，这些观察结果表明 减弱提供一系列抗原而不会引起疾病的寄生虫可能是有效的 利什曼病的疫苗。遗传衰减的婴儿乳杆菌和多诺瓦尼乳杆菌已表现为有望 动物模型中的疫苗。但是，在人类中使用这些寄生虫可能会引起安全问题 内脏的潜力。衰减的皮肤营养利什曼尼亚对VL的交叉保护可能更安全 疫苗是因为潜在的不良事件（例如在疫苗接种部位开发病变）很容易被很容易 使用批准的局部干预措施进行监测并有效治疗。几种临床和动物 研究表明，感染了多营养利什曼原虫，例如L. major或免疫。 这些寄生虫的抗原赋予了针对VL的显着交叉保护。但是，这是不知道的 是否通过衰减的皮肤疾病进行免疫，导致这种中心蛋白基因缺乏的物种。 将防止VL。使用CRISPR-CAS技术，我们免费生成了抗生素选择标记物 Centrin基因缺陷L. major（LMCEN - / - ）。在这个项目中，我们建议使用新颖的VL犬模型进行测试 GLP级LMCEN的安全性和功效 - / - 。 LMCEN的整个基因组测序 - / - 已确认稳定 寄生虫基因组中没有其他突变的中心蛋白基因的缺失。我们的初步发现表明 LMCEN - / - 高度减弱，在免疫功能低下的小鼠中未能引起疾病。我们也发现 使用LMCEN - / - 寄生虫免疫可引起仓鼠的疾病保护TH1反应 小鼠并完全防止对有毒的L. Major的同源挑战。我们的行业 伴侣Gennova Biopharma在GLP条件下已经建立了LMCEN - / - 他们的US-FDA批准了设施。在这个项目中，我们建议（AIM 1）优化GLP-LMCEN - / - 免疫原性和免疫方案，并确定其在狗中的安全性，（AIM 2）评估 GLP-LMCEN - / - 作为一种使用新型犬VL模型的疫苗的功效，其中狗自然是 暴露于vl-dempletymemplememic地区的婴儿头李氏菌的叮咬 突尼斯。该项目的科学承诺，如果成功的话，可以为前进的基础提供基础 LMCEN - / - 寄生虫作为针对人类利什曼病的疫苗。

项目成果

Determinants of Innate Immunity in Visceral Leishmaniasis and Their Implication in Vaccine Development.

• DOI: 10.3389/fimmu.2021.748325
• 发表时间: 2021
• 期刊: Frontiers in immunology
• 影响因子: 7.3
• 作者: Volpedo G;Pacheco-Fernandez T;Bhattacharya P;Oljuskin T;Dey R;Gannavaram S;Satoskar AR;Nakhasi HL
• 通讯作者: Nakhasi HL