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.

摘要 由原生动物寄生虫利什曼原虫引起的感染包括皮肤（CL）、粘膜（ML）和内脏（ML）感染。 利什曼病（VL）。目前有1 200多万人患有利什曼病， 案件每年发生。目前还没有针对这种疾病的人类疫苗。然而， 从利什曼病中康复的人对再感染产生免疫力，这表明疫苗是可行的。在 过去，利什曼化，一个故意感染低剂量利什曼原虫的过程，病原学 人畜共患皮肤利什曼病（ZCL）的病原体引起控制的皮肤损伤，并提供> 90% 防止再感染是一种常见的做法。虽然这种做法可能不被接受， 目前的监管环境，由于并发症的可能性，这些观察结果表明，生活- 减毒的寄生虫提供完整的抗原阵列，而不引起疾病，可能是一种有效的 利什曼病疫苗遗传减毒L. infantum和L.多诺万表现出了作为一个 动物模型中的疫苗。然而，在人类中使用这些寄生虫可能会引起安全问题，因为它们 内在化潜能交叉保护VL的减毒皮肤营养利什曼原虫可能是更安全的 疫苗，因为潜在的不良事件（如疫苗接种部位出现病变）很容易被 使用批准的局部干预措施进行监测和有效治疗。一些临床和动物 研究表明，感染皮肤营养型利什曼原虫如利什曼原虫。重大或免疫接种 来自这些寄生虫的抗原赋予针对VL的显著交叉保护。但殊不知 是否用致弱的皮肤病的物种如中心蛋白基因缺陷型L.主要 会保护我们免受VL病毒的侵害使用CRISPR-Cas技术，我们已经产生了无抗生素选择标记的 centrin基因缺陷型L.主要（LmCen-/-）。在这个项目中，我们建议使用一种新的VL犬模型来测试 GLP级LmCen-/-的安全性和有效性。LmCen-/-的全基因组测序已证实稳定 在寄生虫基因组中缺失中心蛋白基因而没有其他突变。我们的初步调查结果显示， LmCen-/-是高度减毒的，并且在免疫受损的小鼠中不会引起疾病。我们还发现 用LmCen-/-寄生虫免疫在仓鼠中诱导疾病保护性Th 1应答， 小鼠和完全保护免受同源攻击与强毒L.少校我们的行业 合作伙伴Gennova Bioglemma已经在GLP条件下建立了LmCen-/-生产， 美国食品药品管理局批准的设施在本项目中，我们提出（目标1）优化GLP-LmCen-/- 免疫原性和免疫方案，并确定其在犬中安全性和（目的2）评价 GLP-LmCen-/-作为疫苗的效力，使用犬VL的新模型，其中犬天然 暴露在L.在VL-高流行地区的婴儿感染野生恶性白蛉 突尼西亚.这个项目的科学承诺，如果成功，可以为推进 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