The National Centre for the Replacement, Refinement, and Reduction of Animals in Research has awarded a £545,105 grant to Dr Rachel Tanner to develop a method of screening cattle vaccines without the use of animal testing. The work will be performed in collaboration with the Animal Plant and Health Agency (APHA).
Cattle are affected by a range of diseases in the UK and worldwide, including bovine TB and foot and mouth disease. These have major implications for animal health, food security, and the economy.
The most effective strategy for protecting cattle from disease is widely considered to be vaccination. However, in most cases vaccines still need to be developed or improved, and all licenced vaccines need to be regularly batch-tested for quality and consistency. Currently, testing without live animals (for example using cells) cannot capture the complex features of the immune response needed to assess whether a vaccine is effective. Rodents’ immune systems have a several differences to those of cattle, meaning tests are often done with cattle directly – and these come with high ethical, logistical, and economic costs.
The new project will enable a novel tool for screening bovine vaccines, replacing the use of cattle (and rodents) in early vaccine development and vaccine batch-testing. Dr Tanner's group will develop organoids – small versions of organs which are 3D and mimic an organ’s function and complexity – based on cattle secondary lymphoid organs such as the lymph nodes and spleen. Early results have been promising, with researchers able to grow organoids from cryopreserved bovine lymph nodes.
The project, which will focus on bovine TB, has three key aims. The researchers will first optimise the process, identifying the most appropriate tissue type and conditions for growth as well as assessing how well the procedure can be replicated. They will then validate that the method mirrors real immune responses in cattle. Finally, they will implement the process to screen potential bovine TB vaccines, disseminate the method to ensure relevant end-user laboratories can use it, and generate a small-scale bovine lymphoid tissue bank.
The advantage of the process is multi-sided. As well as replacing animal testing and alleviating animal welfare issues, it will enable the acceleration of bovine vaccine development – whilst making it more cost-effective and transferable to resource-limited settings. The model will also be adaptable for wider use across both bovine and other ungulate (hoofed mammals) diseases.
