A plant-produced plague vaccine candidate confers protection to monkeys

Effective Plague Vaccination via Oral Delivery of Plant Cells Expressing F1-V Antigens in Chloroplasts

“…The latter This report of a plant-based plague vaccine demonstrates for the first time that high-level protection of mice from the lethal pathogenic effects of aerosol challenge can be elicited by oral delivery. Virus-based plant expression systems have been used successfully to confer protection against Y. pestis challenge in guinea pigs and macaques upon s.c. immunization with purified F1-V antigens (57,75). There is one previous report of an s.c. prime-oral boost strategy, involving Agrobacterium-transformed tomato nuclei, but no pathogen challenge was performed (1).…”

Antigen-specific Vγ2Vδ2 T effector cells confer homeostatic protection against pneumonic plaque lesions

“…Protective immune responses against fatal inhalation plague remain incompletely understood. In fact, F1/LcrV-based vaccines protect mice and cynomolgus macaques but do not effectively confer protection in African green monkeys (19)(20)(21). Elucidating innate and adaptive immune responses in the settings of vaccination and immune intervention will facilitate ultimate development of antiplague vaccines and immunotherapeutics.…”

“…This finding adds to the rationale for studies of V␥2V␦2 T cells and their potential antiplague immune function during inhalational Y. pestis infection. Becausethe cynomolgus macaque model of Y. pestis infection has proven to be useful for evaluating vaccines against pneumonic plague (20,21), we used this plague model to undertake a proof-of-concept study examining a potential role of V␥2V␦2 T cells in immunity against an extracellular Y. pestis bacilli infection. In this context, we sought to determine whether a delayed HMBPP/IL-2 treatment regimen after inhalational Y. pestis infection could induce activation/ expansion of V␥2V␦2 T cells and confer protection against inhalation plague in the macaque model.…”

Optimization and Utilization of <em>Agrobacterium</em>-mediated Transient Protein Production in <em>Nicotiana</em>

“…The most advanced transient expression system is based on the use of 'launch vectors' that combine components of plant viruses and binary plasmids, and are delivered by agroinfiltration 17,18 . Agroinfiltration of a launch vector based on Tobacco mosaic virus (TMV) has been successfully applied at lab scale to produce vaccine antigens against pathogens such as human papilloma virus 19 , Yersinia pestis 20 , influenza viruses A 21,22 , Bacillus anthracis 23 , and smallpox virus 24 in N. benthamiana leaves. Agrobacterium-mediated transient expression is also a promising method for the simultaneous production of multiple proteins 2, [25][26][27] .…”