Developing a next generation in vitro 3D immune organoids system for studying vaccine-induced immune response and immune-ageing across the life-course

接种疫苗是预防传染病最有效的保护措施，它依赖于疫苗诱导的免疫力。所有新疫苗在用于人类临床之前都需要对其保护性免疫进行彻底测试。从候选疫苗的最初选择到新疫苗的免疫原性临床前测试，通常涉及使用大量动物。非常需要非动物的、基于实验室的方法来评估疫苗诱导的免疫应答，包括抗体应答。我们的目标是开发一种模拟人类免疫系统的体外检测系统，能够检测疫苗诱导的免疫反应，因此有可能取代或减少在疫苗测试中使用动物。疫苗诱导的抗感染免疫力主要依赖于适应性免疫系统，包括T和B细胞活化和抗体反应。衰老对免疫力的影响，包括疫苗诱导的免疫应答，也通常表现为T和B细胞功能失调以及抗体应答。众所周知，衰老通常与严重感染（包括COVID-19和流感）的易感性增加有关。一个能够对免疫衰老进行细胞和分子机制研究的体外系统，特别是在免疫衰老的早期阶段（即发生的时间/年龄段），将对理解免疫衰老产生重大影响，从而为对抗严重感染的策略提供信息，并将有助于减少动物研究。疫苗诱导的免疫通常通过测量T细胞应答和在次级淋巴组织如淋巴结中产生的抗体产生来测试。结构上类似于淋巴结，腺样体和扁桃体是位于上呼吸道（鼻咽）的淋巴组织，称为鼻咽相关淋巴组织（NALT），已知是针对呼吸道病原体的免疫诱导部位。我们先前研究并证明了儿童和成人NALT免疫细胞对来自某些气道病原体（如流感）的抗原和疫苗的显著T细胞和抗体应答。因此，我们假设扁桃体免疫细胞可以用作测试疫苗的实验室系统，这将具有巨大的潜力来取代或减少大量的动物实验。在本计画中，我们提出利用常规选择性手术中扁桃体组织的可用性，发展一种试管疫苗诱导免疫反应的实验室方法。通过与在实验室系统方面具有特定专业知识的行业合作伙伴合作，帮助3D细胞生长，我们将使用扁桃体细胞开发下一代无动物细胞培养系统，用于测试疫苗，并能够研究衰老对人类免疫力的影响。

Vaccination is the most effective protection against infectious diseases, which relies on vaccine-induced immunity. All new vaccines need to be thoroughly tested for their protective immunity before their clinical use in humans. From the initial selection of vaccine candidates to pre-clinical testing of new vaccines for immunogenicity, it typically involves the use of a large number of animals. There is a great need for non-animal, laboratory-based methods to evaluate vaccine-induced immune responses including antibody response. We aim to develop an in vitro assay system that mimics human immune system and able to detect vaccine-induced immune responses, and therefore has the potential to replace or reduce the use of animals in vaccine testing. This may include the selection of vaccine candidates and batch testing, and mechanistic studies including immune ageing in humans.Vaccine-induced immunity against infection critically depend on adaptive immune system involving T and B cell activation and antibody response. The effects of ageing on immunity, including vaccine-induced immune responses, are also typically manifested in dysregulated function of T and B cells and antibody response. It is known ageing is generally associated with increased susceptibility to severe infection, including COVID-19 and influenza. An in vitro system enabling the cellular and molecular mechanistic studies on immune ageing, particularly at the early stage of immune senescence (i.e. the timing/age period it occurs) would have a big impact on understanding immune ageing to inform strategies against severe infection, and would help to reduce animal studies. Vaccine-induced immunity is typically tested by measurement of T cell response and antibody production which is produced in the secondary lymphoid tissues such as lymph nodes. Structurally similar to lymph nodes, adenoids and tonsils are lymphoid tissues located in the upper airway (nasopharynx), named nasopharynx-associated lymphoid tissue (NALT) and known to be the induction site for immunity against respiratory tract pathogens. We previously studied and demonstrated marked T cell and antibody responses in NALT immune cells of children and adults to a number of antigens and vaccines derived from some airway pathogens such as influenza. We therefore hypothesize that tonsillar immune cells could be used as a laboratory system to test vaccines, which will have an enormous potential to replace or reduce large numbers of animal experiments. In this project, we propose to take advantage of the availability of tonsillar tissues from routine elective surgery, to develop a lab method in test tube vaccine-induced immune responses. In collaboration with an industry partner with specific expertise in lab systems helping cell growth in 3D, we will use tonsillar cells to develop a next generation, animal-free cell culture system for testing vaccines, and also be able to study effect of aging on immunity in humans.