28th Annual Meeting and Symposium of the
Desert Tortoise Council, February 21-23, 2003
Abstracts

Immunity and the Desert Tortoise: The Unknown Factor in Survival?

Jerry W. Simecka
Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107

The immune system is a critical determinant in the survival of many different species of animals, and therefore is likely vital to the survival of desert tortoises. Immune responses are required in the protection and recovery from infectious and other diseases. For some infectious agents like mycoplasmas, the host immune response can contribute to damaging the host. However, little information is available about the immune system in desert tortoises and its interactions with known agents of disease. Antibodies are produced by tortoises in response to both natural and experimental infections with mycoplasmas and herpes virus. However, virtually no information is available concerning the cell-mediated immune response. Cell-mediated responses are known to be critical in lesion development and host susceptibility to mycoplasma respiratory disease in other animals. This talk will present an overview of immunity and what is known about immune responses in the desert tortoise. As mycoplasma and herpes viruses are implicated in the current losses in desert tortoise populations, the contrasting roles of the immune system in similar diseases found in other animal species will be addressed. Lastly, the effects of seasonal variation, nutrition, and pollutants on immunity and susceptibility to disease in desert tortoises will be discussed. There is the critical need to determine the relationship between immune responses and the survival of the desert tortoise. This understanding may provide additional markers of stress and disease, eventually leading to improved knowledge-based approaches of management or treatment of desert tortoise populations.