Nonhuman primates: a critical role in current disease research

Molecular cloning and characterization of the macaque sperm associated antigen 9 (SPAG9): an orthologue of human SPAG9 gene

The present study was conducted to isolate macaque proteomic homologue of human SPAG9 (EMBL nomenclature human sperm associated antigen 9: hSPAG9; Shankar et al., 1998: Biochem Biophys Res Commun 243:561-565) in order to find out whether the macaque can provide a suitable model for examining its immunocontraception effects. Macaque SPAG9 was cloned and sequenced from the macaque testis cDNA library. The macaque cDNA contained open reading frame encoding 712 amino acids. A 84.9% and 94% homology between macaque and human SPAG9 was found at protein and DNA levels. Northern analysis and RNA in situ hybridization experiments revealed testis- and stage-specific expressions of macaque SPAG9 mRNA, mainly confined to round spermatid suggesting haploid germ cell expression. Anti-human SPAG9 antibodies recognized native SPAG9 in macaque sperm extract in Western blotting and the acrosomal compartment region of macaque sperm in indirect immunofluorescence. Flow cytometry analysis further revealed surface localization of macaque SPAG9 in live macaque sperm. The amino acid sequence data for nonhuman primate SPAG9 suggest that antibodies generated by vaccinating macaque with hSPAG9 will recognize nonhuman primate SPAG9, supporting the testing of SPAG9 contraceptive vaccine based on hSPAG9 in the nonhuman primate model.

Hematologic and lymphocyte immunophenotypic reference values for normal rhesus monkey (Macaca mulatta) umbilical cord blood; gravidity may play a role in study design

Hematology and flow cytometry reference values for rhesus umbilical cord blood (UCB) were established in 17 healthy infant rhesus monkeys delivered by elective cesarean section 10 days preterm. The infants were born to age matched, singly caged primigravid or secundigravid dams. The hematology and flow cytometry values were determined by automated cell counter and by FACS. No significant differences were observed with respect to infant gender. With respect to gravida, the primigravid infants had a significantly higher percentage (P= 0.05) of CD20(+) B lymphocytes in UCB. These results provide useful reference values for future studies of maternal - fetal disease transmission, vaccine and drug evaluation in non-human primate pregnancy, as well as fetal programming and immune modulation, gene therapy and the use of UCB as a source of stem cells for research and transplantation. Importantly, our results suggest that maternal gravidity may be an important variable to consider.

Hematological and serum biochemical values in cynomolgus monkeys anesthetized with ketamine hydrochloride

The effects of ketamine anesthesia on both hematological and serum biochemical variables were investigated in 19 male and 15 female cynomolgus monkeys. Blood samples were obtained from the cephalic vein within 30 minutes of an intramuscular injection of ketamine hydrochloride (10 mg/kg). Ketamine anesthesia caused a reduction in leukocyte counts and a significant reduction in lymphocytes percentages. Ketamine anesthesia also increased the serum activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine phosphokinase (CPK), but reduced the serum concentrations of glucose, inorganic phosphate, sodium and potassium. The alterations of hematological and serum biochemical values will be discussed. These alterations should be considered when designing studies for and interpreting data from cynomolgus monkeys.

Role of the nonhuman primate for research related to women's health

This overview of the current status of medical problems that affect women is related to current studies on pathophysiology and therapeutic interventions using nonhuman primates to demonstrate the utility of the primate model for the study of disease processes in women. The current medical literature on women's health is compared with the literature on nonhuman primate research. The findings reviewed in the articles of ILAR Journal Volume 45 Issue 2 of 2004 are evaluated in the context of the scope and problems associated with disease entities in women. Nonhuman primate research with known information regarding women's disease is discussed, and the utility of the animal model for the study of human disease is highlighted, based on its significant relevance due to similarities of nonhuman primate and human subjects' physiology, metabolism, and responses to therapeutic interventions. Additional advantages of the animal model include the ability to control the experimental environment and the capacity to perform chronic study procedures. These findings allow us to utilize the nonhuman primate as the most relevant model in the animal world for the study of human disease processes.

Use of primates in research: A global overview

We assessed the use of nonhuman primates and nonhuman primate biological material in research by reviewing studies published in 2001 in peer-reviewed journals. The number and species of primates used, the origin of the animals, the type of study, the area of research of the investigation, and the location at which the research was performed were tabulated. Additionally, factors related to the animals that may have affected the outcome of the experiments were recorded. A total of 2,937 articles involving 4,411 studies that employed nonhuman primates or nonhuman primate biological material were identified and analyzed. More than 41,000 animals were represented in the studies published in 2001. In the 14% of studies for which re-use could be determined, 69% involved animals that had been used in previous experiments. Published studies most commonly used nonhuman primates or nonhuman primate biological material from the species Chlorocebus aethiops (19%), Macaca mulatta (18%), M. fascicularis (9%), and Papio spp. (6%). Of these studies, 54% were classified as in vitro studies, 14% as noninvasive, 30% as chronic, and 1% were considered acute. Nonhuman primates were primarily used in research areas in which they appear to be the most appropriate models for humans. The most common areas of research were microbiology (including HIV/AIDS (26%)), neuroscience (19%), and biochemistry/chemistry (12%). Most (84%) of the primate research published in 2001 was conducted in North America, Europe, and Japan. The animals and conditions under which they were housed and used were rarely described. Although it is estimated that nonhuman primates account for an extremely small fraction of all animals used in research, their special status makes it important to report the many husbandry and environmental factors that influence the research results generated. This analysis has identified that editors rarely require authors to provide comprehensive information concerning the subjects (e.g., their origin), treatment conditions, and experimental procedures utilized in the studies they publish. The present analysis addresses the use of primates for research, including the effects of a shortage of suitable nonhuman primate subjects in many research areas.

Microarray analysis of nonhuman primates: validation of experimental models in neurological disorders

Nonhuman primates (NHPs) have provided robust experimental animal models for many human-related diseases due to their similar physiologies. Nonetheless, profound differences remain in the acquisition, progression, and outcome of important diseases such as AIDS and Alzheimer's, for which the underlying basis remains obscure. We explored the utility of human high-density oligonucleotide arrays to survey the transcription profile of NHP genomes. Total RNA from prefrontal cortices of human (Homo sapiens), common chimpanzee (Pan troglodytes), cynomolgous macaque (Macaca fascicularis), and common marmoset (Callithrix jacchus) was labeled and hybridized to Affymetrix U95A GeneChip probe arrays. Corresponding data obtained previously from common chimpanzee and orangutan (Pongo pygmaeus) were added for comparison. Qualitative (present or not detected) and quantitative (expression level) analysis indicated that many genes known to be involved in human neurological disorders were present and regulated in NHPs. A gene involved in dopamine metabolism (catechol-O-methyltransferase) was absent in macaque and marmoset. Glutamate receptor 2 was up-regulated, and transcription-associated genes were down-regulated in NHPs compared with humans. We demonstrate that transcript profiling of NHPs could provide comparative genomic data to validate and better focus experimental animal models of human neurological disorders.