An extensive monoclonal antibody panel for the phenotyping of leukocyte subsets in the common marmoset and the cotton-top tamarin

New World monkeys are valuable animal models to study human diseases. To de termine the phenotype of cells involved in immune responses, we used flow c ytometry to screen a large panel of anti-human monoclonal antibodies (mAb) for cross-reactivity with cells of the common marmoset and the cotton-top t amarin. Certain antigens (e.g., CD2, CD8, CD20) are well conserved. However , CD10, CD23, and CD33 showed a clear discrepancy in their reaction pattern s in both species, indicating that significant differences on the epitope l evel occurred during evolution. Epstein-Barr virus-transformed B-cell lines were shown to be a valuable tool for screening B-cell-specific reagents. i n some cases, fluorescein isothiocyanate (FITC) and phycoerythrin (PE) modi fication of mAbs had a negative effect on the binding capacity, which stres sed the importance of choosing the right label. Despite the fact that some CD antigens were not detected, adequate numbers of cross-reactive mAbs were identified to perform extensive studies on immunological functions in both the common marmoset and the cotton-top tamarin. (dagger)(C) British Crown copyright 2001/DSTL-published with the permission of the Controller of Her Majesty's Stationery Office.