One-round determination of seven leukocyte subsets in rhesus macaque bloodby flow cytometry

Background: Rhesus macaques are frequently used in biomedical research as e xperimental models for studying infectious diseases and for preclinical vac cination trials. The infection of these monkeys with simian immunodeficienc y viruses (SIV) or simian-human immunodeficiency viruses (SHIV) reproduces the clinical and immunological characteristics of human infection by human immunodeficiency virus (HIV) Evolution of the immune response in the infect ed animals is generally analyzed by determining the lymphocyte subsets on b lood samples using now cytometry but requiring multiple, blood consuming, d eterminations. Methods: Cell subsets present in whole-blood samples were labeled with a co mbination of anti-human monoclonal antibodies to CD2, CD20, CD4, CD8, and C D14 coupled to FITC or PE and analyzed by flow cytometry. Results: In one round, we obtained the precise determination of macaque blo od cell composition by flow cytometry. Monocytes, granulocytes, eosinophils , B lymphocytes, helper, and cytotoxic T lymphocytes were distinguished. Re sults obtained correlated strongly with those obtained with conventional bl ood cell differential systems and with separate staining of lymphocytes. Th e analysis of blood from healthy rhesus macaques and SHIV-infected animals demonstrated the accuracy of the determination even in very pathological si tuations such as macaques with simian IUDS. Conclusions: Our method allows fast determination of the blood cell composi tion and will be particularly useful to evaluate the cell subset evolution of macaques involved in large-scale experimental trials. (C) 2000Wiley-Liss , Inc.