Cetacean-Reconstituted Severe Combined Immuno-Deficient (SCID) Mice as a Model to Evaluate the Response to Vaccine
Abstract
Marine mammal immunology is a relatively new but rapidly growing discipline.
Recent applications include attempts at better understanding important fields such as the
importance of the immune system in disease, the development of marine mammal vaccines, and the
potential adverse health effects of pollutants or stress. Nevertheless, ethical, logistical and
economical constraints greatly limit the number and extent of experimental studies. There is a
need for a surrogate animal model that will adequately represent the marine mammal immune system
to support research in marine mammal fundamental and applied immunology.
Mice homozygous for the severe combined immunodeficiency (SCID) mutation lack
functional B and T lymphocytes, and are thus unable to generate a specific immune response. They
therefore lack the ability to reject a graft. Taking advantage of this situation, we engrafted
SCID mice with cells of cetacean immune system (collected from blood of live animals or immune
organs of recently dead animals), and demonstrated the ability of those cells to, beyond not
getting rejected, populated the mouse spleen and circulated in blood. In an attempt to verify the
functionality of those cetacean cells, we vaccinated mice with canine distemper virus (CDV). The
generation of antigen-specific T lymphocytes was demonstrated in several, although not all, mice.
We nevertheless failed to demonstrate CDV-specific antibodies in plasma samples from the same
mice.
Cetacean-reconstituted SCID mice represent an attractive and practical in
vivo model to study the functionality of the marine mammal immune system. We intend to pursue
the development of this model for vaccine-related, as well as disease pathophysiology and
immunotoxicological applications.
Acknowledgement
We would like to thank the staff at Mystic Aquarium and Sea World for
providing samples. This study was partially funded by a grant from the Morris Animal Foundation,
and the Oiled Wildlife Research Program.