Identification of monoclonal antibodies cross-reactive with bottlenose dolphin orthologues of the major histocompatibility complex and leukocyte differentiation molecules

- Cross-reactive monoclonal antibodies that recognize bottlenose dolphin major histocompatibility class I and II, CD11a, CD18, CD14, CD16, CD163 and CD172a were identified.
- Bottlenose dolphin monocytes co-express CD14, CD16 and CD163.
- Major histocompatibility class II is expressed on bottlenose dolphin resting and activated lymphocytes in addition to monocytes.

The slow progress in understanding immunotoxic effects of environmental contaminants and their influence on disease susceptibility in whales is largely due to the limited information available on the immune systems and immune function of species included in the Cetancodontamorpha clade. Studies in species in the other major clades included in the Artiodactylamorpha, Ruminantiamorpha, Suinamorpha, and Camelidamorpha have revealed the immune systems are similar, but not identical. The present study was undertaken to expand the available monoclonal antibody reagents needed to gain insight into the composition, function, and evolution of the immune system in Cetancodontamorpha, using the dolphin (Tursiops truncatus) as a model cetacean species. Screening of a set of mAbs that recognize highly conserved epitopes expressed on the major histocompatibility complex (MHC) and leukocyte differentiation molecules (LDMs) in cattle by flow cytometry revealed some of the mAbs recognize epitopes conserved on dolphin orthologues of MHC class I, MHC class II, CD11a, CD14, CD16, CD18, CD163 and CD172a. Comparison of the amino acid sequences of dolphin and bovine orthologues revealed limited changes in sequence have occurred during speciation, suggesting an approach for developing cross-reactive mAbs for use in cetacean research.