The University of Georgia College of Veterinary Medicine

eorgia Veterinary Scholars Program

GVSP Summer 2007 Scholars

Georgia Veterinary Scholar

Faculty Mentor

Sarah Waithe
Tuskegee University
Class of 2009

Drs. Corrie Brown and Jian Zhang

Identification of Immune Cells in Teleost Fish Using in Situ Hybridization and Immunohistochemistry
Sarah Waithe*, Jian Zhang, and Corrie Brown, Department of Veterinary Pathology, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, 30602, USA

Abstract
The mucosal immune system of fish varies significantly from that of the mammalian and avian species. This adaptation is most likely due to the exclusive environment in which fish reside. Fish are continuously exposed to microorganisms in their aquatic environment through their gills, skin, and digestive tract. Additionally, antigens stimulate a systemic response where the head kidney is involved along with the spleen. A greater understanding of the distribution of various immune cells in the tissues of teleost fish is of great importance. In this project, all of the immune tissues were examined using two methods; “in situ” hybridization with a riboprobe that corresponds to the messenger RNA for fish immunoglobulin, and immunohistochemistry using polyclonal and monoclonal antibodies for T cells, B cells, and macrophages. We have, identified immunoglobulin-producing cells in formalin-fixed, paraffin-embedded tissues of spleen and head kidney from healthy catfish through the use of in situ hybridization. Our data shows that although several mucosal surfaces are constantly exposed to the microorganisms in the environment of fish, there is no correlation with the distribution of the immune cells in those tissues. Furthermore, the majority of the immune cells identified were mostly found in the organ tissues of the digestive tract.