Relative sensitivities of Japanese quail to foreign red blood cell challenges for immunotoxicity testing

Given evidence that the immune system is sensitive to environmental contaminants, evaluating immunocompetence in toxicology studies is increasingly important. By incorporating a test of humoral response into controlled reproductive and developmental studies, more comprehensive results can be gathered to assess the potential for disease. The foreign red blood cells (RBC) challenge is a minimally invasive method for evaluating humoral responses to a foreign antigen. Typically, antibody response is assessed following injections of sheep erythrocytes; however, Japanese quail (Coturnix japonica) are only minimally sensitive to sheep RBC. In the present study, adult Japanese quail were treated with 5% solutions of RBC from goose, goat, cow, donkey, or pig in primary and secondary challenges. After each treatment, plasma samples were taken and antibody responses were measured for total immunoglobulins (Ig), IgG, and IgM. Overall, goose RBC generated the poorest responses in both primary and secondary challenges, while the strongest antibody responses were to pig and donkey RBC. Therefore, pig RBC appear to be a superior antigen for testing humoral response in Japanese quail.