Testing drugs on larger animals such as pigs and dogs could help speed-up the development of human and animal drugs.
It could also speed-up other forms of therapy, notably the use of stem cells in regenerative medicine.
These techniques were discussed at a workshop titled 'Large Animal Models for Biomedicine' held in Freising, Germany, in September.
The workshop, organised by the European Science Foundation (ESF), called for a European pig clinic to facilitate generation and characterisation of models of human disease.
The ESF proposed the clinic should be funded by the EU's Seventh Framework programme, the main source of EU funding for research projects.
The immediate goal in the field was to establish a common standardised way of using animals with clearly defined characteristics (phenotypes), so that results could be compared across Europe.
Angelika Schnieke, one of the workshop's convenors, and chair of Livestock Biotechnology at the Centre of Life Science in Weihenstephan, Germany, said: 'The workshop showed that there is excellent expertise in individual labs, but the phenotypic tests need to be harmonised and standardised to facilitate comparison of results obtained in different labs.' Such standardisation has already been achieved for rodents, particularly the mouse, which is the most commonly used animal for human disease research.
Schnieke said: 'Large animals offer a link between the classic rodent models and application in the clinic.
'In view of the close genetic, anatomical and physiological similarities between dog and pig on the one side and human on the other, large animal models are likely to catalyse drug development.' Large animals could also be used for research in a number of disease categories, including cancer, metabolic disorders such as obesity and regenerative therapies, such as the use of stem cells to replace damaged heart muscles.
The workshop focused on pigs and dogs because they are quite similar in scale and anatomy to humans.
Dogs could be used as models for studying the immediate consequences of infectious diseases, while pigs could be genetically engineered to mimic certain human conditions, such as deficiencies in the immune system.
In such cases pigs would be used like mice are at present, to model certain aspects of human immunity or metabolic disorder, but with the advantage of being more similar to humans.
Schnieke added: 'A possible idea is the generation of pigs with a humanised immune system.
'The proof of principle has been shown in the mouse.
'Immune-deficient mice can be reconstituted with human immune cells and can be used to study immune reactions, for example against tissue xenografts (transplantation of tissue between species, such as pig to human).
'In theory this could also be possible in pigs.
'Therefore the generation of immune-deficient pigs is an important goal.'
