Non-human primates (NHPs) are a valuable research tool, especially in the development of vaccines and treatments for infectious diseases like HIV[1]. Although biomedical researchers have made significant advances in reducing the number of NHPs used in research, some preclinical experiments can only be carried out in these unique animal models.
The rhesus macaque (Macaca mulatta) and cynomolgus macaque (Macaca fascicularis) are two widely used models in biomedical research. Each has a unique evolutionary history and biology that make it suited to different biomedical model applications.
Rhesus macaques
Rhesus macaques originate from a broad geographical area, including India, Pakistan, and China. Indian-origin rhesus macaques are the most frequently used NHP in SIV/HIV and tuberculosis research, as the progression of disease parallels human HIV infection in many ways. Rhesus macaques are a long-lived species with great diversity in their genetic backgrounds, including key immunological genes such as the major histocompatibility complex. As a result, they are a good model for diversity in the human population, and therefore, many different immunological tools and reagents have been developed to study immune cells in rhesus macaques, including for flow cytometry applications.
Cynomolgus macaques
Cynomolgus macaques (Cynos) come from a much narrower geographical range than rhesus macaques, and are found in regions of Vietnam, Cambodia, Indonesia and the Philippines[2]. Cynos have been less commonly used in SIV/HIV research as viral strains tend to be less pathogenic, but they are more genetically homogeneous, which make them better suited to SIV/HIV experiments that investigate role of host genetics on infection. Cynos are also natural hosts to primate malaria (Plasmodium cynomolgi), thus making them a suitable model for malaria research[3]. Many flow cytometry reagents are available for cyno research as well, but may not be as widely available as rhesus reagents. Antibodies for both species can be tested for cross reactivity in flow cytometry experiments.
When deciding to include NHP models in your toxicology or preclinical research, be sure to consider the disease or condition you are studying as well as how available macaque-specific reagents may be for your assay applications.
1. Hatziioannou T, Evans DT. Animal models for HIV/AIDS research. 2012. Nature Reviews Microbiology.10(12):852-867.
2. Street SL, Kyes RC, Grant R, Ferguson B. 2007. Single nucleotide polymorphisms (SNPs) are highly conserved in rhesus. BMC Genomics. 8. 480.
3. Ohta E, Nagayama Y, Koyama N, Kakiuchi D, Hosokawa S. Malaria in cynomolgus monkeys used in toxicity studies in Japan. 2016. Journal of Toxicologic Pathology. 29(1):31-38.
