Our Science

Given the cellular properties critical to the determination of vector binding and transgene delivery or therapeutic cell integration the genetic and immunologic homology of employed test species is of heightened importance for viral and non-viral vector gene therapy candidate testing and cell therapies.

Nonhuman primates are essential to filling this translational gap.

Well established and tolerated immunosuppression protocols enable modeling of immunomodulation regimens for clinical gene and cell interventions, and application of green monkeys for cell xenograft testing and modeling.

The St. Kitts green monkey is of specific value to gene therapy testing with a historic isolation from common viruses employed as gene vectors and low prevalence of neutralizing antibodies to commonly used vector capsids.

Coupled with Virscio’s broad gene and cell therapy experience, our primate test systems allow definition of safe and effective vector and cell delivery methods, achieved biodistribution, immunological response, and cell-specific transgene expression and cell viability, all of which are critical determinants of clinical efficacy and safety.

Intravascular, intraparenchymal, intrathecal, intramuscular, intraarticular, intravitreal, subretinal, and other routes of administration are routinely implemented to achieve clinical translation objectives.

The extent of conservation of these sequence-determined druggable targets and connected cellular and tissue physiology governs the fidelity of model systems in predicting human outcomes.

For this reason, nonhuman primates remain an important test system for monoclonal antibodies, peptides, hormone and vaccine therapies, and mRNA, siRNA and antisense oligonucleotide (ASO) candidates.

Virscio applies extensive experience with the targeted delivery of protein and RNA therapeutics and optimized endpoint evaluation to validate safety and efficacy in highly clinically relevant biology.

Whether administration is single, repeat or sustained release systemic, intrathecal or other route of administration - or evaluation within a specific clinically defined age demographic - Virscio is positioned to perform the most robust possible preclinical modeling of intended clinical delivery to achieve precision medicine objectives.

Research on patients and human tissues has contributed greatly to our knowledge of CNS pathology, but clinical studies of novel treatments are appropriately ethically constrained and are confounded by the inability to experimentally control necessary variables.

While rodent models remain widely deployed, there are limitations to the resulting data, including data from genetic models given that monogenetic causes of CNS pathology are less common than the prevalent polygenetic conditions.

For CNS translational evaluation the use of nonhuman primates such as the green monkey has distinct advantages.

They share greater homology to humans in genomics, pharmacokinetics, pharmacodynamics neurophysiology, neurochemistry, endocrinology, immunology, neuronal network complexity, behavioral specializations, cognitive processing, and synaptic regulation in addition to the organization and function of the hippocampus, prefrontal cortex, and other regions relevant to important disease such as Alzheimer’s, Parkinson’s and schizophrenia.

Virscio applies deep neuroscience expertise and methodological capabilities to healthy and disease relevant CNS test systems to address critical translational objectives. 

The green monkey eye is over half the size of the human eye, with proportionate ratios of neuroretina, vitreous chamber, lens and anterior chamber volumes, and very similar aqueous production and outflow dynamics. This closely shared anatomy includes the presence of a macula, which defines humans and primates as a highly visual species, allowing modeling of macular degeneration and other diseases of the central retina not possible in non-primates.

A similarly closely shared microvascular anatomy of the optic nerve and the presence of a lamina cribrosa, elevates sensitivity to vascular occlusion and compression of the vessels and retinal ganglion axons channeling through the optic nerve, allowing uniquely predictive modeling of human glaucoma and optic neuropathies.

Enabled by this homology, we have validated the green monkey and induced models as test systems for screening ophthalmic therapeutics for multiple indications.

Virscio regularly applies human clinical ophthalmic instrumentation and clinical endpoints to preclinically address questions critical to clinical therapeutic success. 

With age, African green monkeys and macaques develop spontaneous obesity, dyslipidemia, and insulin resistance with end organ manifestations. Green monkeys also respond to sustained high fat, high caloric diets to develop more accelerated obesity, insulin resistance, dyslipidemia, pancreatic pathology, and atherosclerosis.

Many of the physiological factors that predispose humans to metabolic syndromes, including fluctuating hormone levels, menopause, stress, and early life caloric exposure, also predispose green monkeys and are incompletely modeled in lower species.

Likewise, green monkeys respond to disruptions in renin-angiotensin regulation of blood pressure or induced cardiac outflow obstructions with elevations in blood pressure and cardiac remodeling to develop congestive heart failure.

Virscio accesses a diverse demographic to select animals with natural or induced cardiometabolic phenotypes to screen candidate interventions, applying glucose tolerance testing, biomarker profiling, body composition scanning, echocardiography, cardiac telemetry and other translational endpoints.  

Like humans, African green monkeys develop signs of physical decline and age-associated diseases that do not occur in lower species.

With access to a broad age range of green monkeys, Virscio has established epigenetic, proteomic, and functional biomarkers such as gait and muscle strength testing that correlate to human clinical findings and complement traditional safety and physiologic evaluations to enrich interpretation of aging biology and age modifying interventions.

These age-related endpoints, and unique access to older animals enable testing of safety and efficacy to provide rationale for clinical trial. Access to younger animals additionally allows aging biology insights and evaluation of interventions for pediatric indications.