Animal models of allergenicity

Determining the potential allergenicity of proteins, particularly those derived from biotechnology, may be facilitated by obtaining data that can only be acquired by clinical testing. Exposing humans to these novel proteins brings unacceptable risk, and animal models may help to determine allergic response on a molecular level. Researchers Samuel Lehrer from Tulane University School of Medicine and Scott McClain from Monsanto Company, have published their assessment of the utility of using animal models for this purpose.

The paper discusses the strengths and weaknesses of using animal models for allergenicity characterization, with a focus on rodent models which the authors maintain seem to be the most likely candidate for assessing allergenicity. Limitations of using animal models include the costs and ease of using a particular species (handling, husbandry and size), potential limitations on availability of reagents for any particular species, and altered responsiveness in the animal model compared to food exposure in humans. Benefits of using an animal model include the ability to precisely control and standardise sensitization (exposure route, dose, timing, and elicitation), and minimise variability in the allergic model by selecting specific animal strains.

The paper also describes the requirements for standardization and validation of an animal model of human allergy, including acceptable immunization protocols and measurements of allergic response.

The authors caution the usefulness of any such animal model is as a tool to place a protein in relative proportion to its potential allergenicity, and it should be regarded as a test system rather than a human surrogate.

Reference: Lehrer & McClain 2009. Regulatory Toxicology and Pharmacology. Vol. 54(3 Suppl) pp S46-51.

A powerpoint from a public lecture presented by the authors is available for download as a pdf document from www.hesiglobal.org