Rhesus Monkey Model Research Articles

Anatomical and diffusion MRI brain atlases of the fetal rhesus macaque brain at 85, 110 and 135 days gestation

Recent advances in image reconstruction techniques have enabled high resolution MRI studies of fetal brain development in human subjects. Rhesus macaques (Macaca mulatta) are valuable animal models for use in studies of fetal brain development due to the similarities between this species and humans in brain development and anatomy. There is a need to develop fetal brain templates for the rhesus macaque to facilitate the characterization of the normal brain growth trajectory and departures from this trajectory in rhesus models of neurodevelopmental disorders. Here we have developed unbiased population-based anatomical T2-weighted, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) templates for fetal brain from MR images scanned at 3 time points over the second and third trimesters of the 168 day gestational term. Specifically, atlas images are constructed for brains at gestational ages of 85 days (G85, N = 18, 9 females), 110 days (G110, N = 10, 7 females) and 135 days (G135, N = 16, 7 females). We utilized this atlas to perform segmentation of fetal brain MR images and fetal brain volumetric and microstructure analysis. The T2-weighted template images facilitated characterization of the growth within six fetal brain regions. The template images of diffusion tensor indices provided information related to the maturation of white matter tracts. These growth trajectories are referenced to human studies of fetal brain development. Similarities in the temporal and regional patterns of brain growth over the corresponding periods of central nervous system development are identified between the two species. Atlas images are available online as a reference for registration, reconstruction, segmentation, and for longitudinal analysis of early fetal brain growth over this unique time window.

Developing Broad-Spectrum Antivirals Using Porcine and Rhesus Macaque Models.

ISG15-deficient humans exhibit permanent, low-level expression of antiviral effectors that safely protect them from various viruses. Because the murine ISG15 axis functions differently, we identified animal models that recapitulate the human condition for the development of ISG15-targeting broad-spectrum antivirals. Canine, porcine, and rhesus macaque ISG15, such as human ISG15, stabilize USP18, a potent inhibitor of type I interferon (IFN)-I. Type I Interferon-primed ISG15-knockout porcine and rhesus cells demonstrate enhanced ISG expression and protection against vesicular stomatitis Indiana virus infection compared with wild type. Collectively, we unveil the interspecies diversity of the ability of ISG15/USP18 axis to control IFN-I signaling and reveal the therapeutic potential of ISG15-deficient porcine and rhesus models.

Aggregatibacter actinomycetemcomitans colonization and persistence in a primate model

Aggregatibacter actinomycetemcomitans is associated with aggressive periodontitis resulting in premature tooth loss in adolescents. Tooth adherence and biofilm persistence are prerequisites for survival in the oral domain. Here, using a rhesus monkey model, 16S rRNA sequencing, and weighted network analysis, we assessed colonization of A. actinomycetemcomitans variants and ascertained microbial interactions in biofilm communities. Variants in A. actinomycetemcomitans leukotoxin (ltx) were created, labeled, inoculated, and compared with their progenitor strain for in vivo colonization. Samples of tooth-related plaque were assessed for colonization at baseline and after debridement and inoculation of labeled strains. Null, minimal, and hyper-Ltx-producing strains were created and assessed for hydroxyapatite binding and biofilm formation in vitro. Ltx-hyperproducing strains colonized with greater prevalence and at higher levels than wild type or ltx mutants (P = 0.05). Indigenous and inoculated A. actinomycetemcomitans strains that attached were associated with lactate-producing species (i.e., Leptotrichia, Abiotrophia, and Streptoccocci). A. actinomycetemcomitans was found at 0.13% of the total flora at baseline and at 0.05% 4 wk after inoculation. In vivo data were supported by in vitro results. We conclude that hyper-Ltx production affords these strains with an attachment advantage providing a foothold for competition with members of the indigenous microbiota. Increased attachment can be linked to ltx gene expression and up-regulation of adherence-associated genes. Growth of attached A. actinomycetemcomitans in vivo was enhanced by lactate availability due to consorting species. These associations provide A. actinomycetemcomitans with the constituents required for its colonization and survival in the complex and competitive oral environment.

S27. Investigating Anxiety-Related Behavior in Young Primates: A Novel, Computer-Automated Approach

Anxiety disorders affect millions of people worldwide, are more common in females, and often develop early in life (Bandelow & Michaelis, 2015; Rice & Miller, 1995). Our group examines the neurobiology of early life anxiety using a well-validated rhesus-monkey model (Macaca mulatta). The scalability of this approach, however, is limited by the need for human experts to score primates’ behavior.

Disentangling the effects of early caregiving experience and heritable factors on brain white matter development in rhesus monkeys

Early social experiences, particularly maternal care, shape behavioral and physiological development in primates. Thus, it is not surprising that adverse caregiving, such as child maltreatment leads to a vast array of poor developmental outcomes, including increased risk for psychopathology across the lifespan. Studies of the underlying neurobiology of this risk have identified structural and functional alterations in cortico-limbic brain circuits that seem particularly sensitive to these early adverse experiences and are associated with anxiety and affective disorders. However, it is not understood how these neurobiological alterations unfold during development as it is very difficult to study these early phases in humans, where the effects of maltreatment experience cannot be disentangled from heritable traits. The current study examined the specific effects of experience (“nurture”) versus heritable factors (“nature”) on the development of brain white matter (WM) tracts with putative roles in socioemotional behavior in primates from birth through the juvenile period. For this we used a randomized crossfostering experimental design in a naturalistic rhesus monkey model of infant maltreatment, where infant monkeys were randomly assigned at birth to either a mother with a history of maltreating her infants, or a competent mother. Using a longitudinal diffusion tensor imaging (DTI) atlas-based tract-profile approach we identified widespread, but also specific, maturational changes on major brain tracts, as well as alterations in a measure of WM integrity (fractional anisotropy, FA) in the middle longitudinal fasciculus (MdLF) and the inferior longitudinal fasciculus (ILF), of maltreated animals, suggesting decreased structural integrity in these tracts due to early adverse experience. Exploratory voxelwise analyses confirmed the tract-based approach, finding additional effects of early adversity, biological mother, social dominance rank, and sex in other WM tracts. These results suggest tract-specific effects of postnatal maternal care experience versus heritable or biological factors on primate WM microstructural development. Further studies are needed to determine the specific behavioral outcomes and biological mechanisms associated with these alterations in WM integrity.

Establishment of a novel mesial temporal lobe epilepsy rhesus monkey model via intra-hippocampal and intra-amygdala kainic acid injection assisted by neurosurgical robot system

BackgroundMesial temporal lobe epilepsy (mTLE) is the most common type of refractory epilepsy, and non-human primate (NHP) models are important to investigate its mechanism and therapy. However, previous mTLE-NHP models have some defects. MethodsThirteen rhesus monkeys were randomly assigned to a control group and epilepsy group. Kainic acid (KA) was injected into the left hippocampus and amygdala assisted by a neurosurgical robot system, while the control group received normal saline injection. Stereoelectroencephalography (SEEG) electrodes were implanted into the hippocampus in the acute and chronic stages to monitor epileptic discharges, with continuous behavior monitoring. The changes in hippocampal volume were evaluated by magnetic resonance imaging. Transmission electron microscopy, western blotting and immunofluorescence were performed 3 months after injection to investigate neuronal ultrastructural alteration, blood–brain barrier (BBB) disruption, neuronal loss and gliosis in multiple brain regions. ResultsIn the epilepsy group, status epilepticus (SE) and spontaneously recurrent seizures (SRSs) were detected in the acute and chronic stages via video monitoring. SEEG confirmed that the epileptic zone was focused on the injection area. The hippocampal volume was significantly decreased in the chronic stage compared with baseline. Neuronal ultrastructure and BBB integrity deteriorated in the hippocampus and amygdala of epileptic monkeys. The obvious neuronal loss and gliosis in the CA1–CA4 hippocampal regions were confirmed by western blotting and immunofluorescence; however, the temporal cortex was not affected. Moreover, the neuronal ultrastructural deterioration was detected in other limbic system regions (orbitofrontal cortex and posterior cingulate cortex). ConclusionA novel mTLE-NHP model was induced by one-time intra-hippocampal and intra-amygdalar KA injection, with detectable SE and SRS. Severe hippocampal atrophy, neuronal ultrastructural damage, BBB disruption, neuronal loss and gliosis were confirmed in this model, with widespread limbic system damage, which are similar to the pathology of mTLE patients.

Immune and cytokine/chemokine responses of PBMCs in rotavirus-infected rhesus infants and their significance in viral pathogenesis.

The rotavirus (RV) is the most important causative agent of severe gastroenteritis in infants and children aged less than 5 years worldwide. However, the response and the roles of peripheral blood mononuclear cell (PBMC) in RV clearance have yet to be fully elucidated. In this study, we established the neonatal rhesus monkey model of RV infection with histopathological changes in the small intestine. Then, we investigated gene expression changes in PBMCs from the monkey model of RV infection. Similar pathways regulatedin rhesus monkeys that received intragastric administration of the RV monkey SA11 strain (G3P[2]) and the human wild-type strain ZTR-68 (G1P[8]). Gene profiling showed differences in functional genes mainly associated with chemokine signaling pathways and cytokine-cytokine receptor interactions post RV infection. Transferrin and C-C motif chemokine ligand 23 (CCL23) gene expression were upregulated in PBMCs of monkeys when stimulated by simian and human RV strains. Monkeys infected with RV had an enhanced and prolonged inflammatory response that was associated with increased levels of CCL20, CCL23, and C-X-C motif chemokine ligand 1; while inhibition of major histocompatibility complex class I expression may be important for immune evasion by RV. The RV infection was also characterized by pathological changes in the small intestine with a cytokine and chemokine storm. This study identified the chemokine signaling pathway and immune response genes involved in RV infection in infant rhesus monkeys. The SA11 RV strain is more suitable for establishing a monkey diarrhea model than the ZTR-68 RV strain.

Pre-Clinical Evaluation of CBD-NT3 Modified Collagen Scaffolds in Completely Spinal Cord Transected Non-Human Primates.

Spinal cord injury (SCI) repair is one of the most desirable but extremely challenging clinical problems. Developing suitable animal models and validating the therapeutic interventions in these models is the prerequisite for SCI repair improvement. Non-human primates, closer to humans than other species, are considered to be ideal models for translating laboratory discoveries into human clinical trials. In this study, the acute thoracic (T9) complete transection model in rhesus monkeys was established to evaluate the effects of linear-ordered collagen scaffold (LOCS) and LOCS combined with collagen binding neurotrophin-3 (CBD-NT3), which has been demonstrated to promote axonal regrowth and functional restoration in rodent models. After 10 months post-surgery, the grafted groups dramatically reduced cystic cavity formation and chondroitin sulfate proteoglycans (CSPGs) deposition and facilitated the ingrowth of axonal fibers at the lesion site. Further, the grafted groups displayed more regenerated fibers, exhibiting remyelination and synapse formation. Notably, the LOCS+CBD-NT3 group showed significant locomotor and electrophysiological recovery compared with the Control and LOCS groups. Therefore, LOCS+CBD-NT3 transplantation represents an effective strategy to promote spinal cord repair in non-human primates. More importantly, this complete transection model in non-human primate will contribute to effectively evaluating the potential interventions and accelerating clinical transformation in the future.

A method for assessing recovery of fine motor function of the hand in a rhesus monkey model of cortical injury: an adaptation of the Fugl–Meyer Scale and Eshkol–Wachman Movement Notation

Motor dysfunction of the upper extremity can result from stroke, cortical injury and neurological diseases and causes significant disruption of activities of daily living. While some spontaneous recovery in terms of compensatory movements does occur after injury to cortical motor areas, full recovery is rare. The distinction between complete recovery and compensatory recovery is important as the development of compensatory movements in the upper extremity may not translate into full functional use in human patients. However, current animal models of stroke do not distinguish full recovery from compensatory recovery. We have developed a Non-Human Primate Grasp Assessment Scale (GRAS) to quantify the precise recovery of composite movement, individual digit action, and finger-thumb pinch in our rhesus monkey model of cortical injury. To date, we have applied this GRAS scale to assess the recovery of fine motor function of the hand in young control and cell-therapy treated monkeys with cortical injury confined to the hand representation in the dominant primary motor cortex. We have demonstrated that with this scale we can detect and quantify significant impairments in fine motor function of the hand, the development of compensatory function during recovery and finally a return to full fine motor function of the hand in monkeys treated with a cell therapy.

Neonatal rhesus monkeys as an animal model for rotavirus infection.

AIMTo establish a rotavirus (RV)-induced diarrhea model using RV SA11 in neonatal rhesus monkeys for the study of the pathogenic and immune mechanisms of RV infection and evaluation of candidate vaccines.METHODSNeonatal rhesus monkeys with an average age of 15-20 d and an average weight of 500 g ± 150 g received intragastric administration of varying doses of SA11 RV ( 107 PFUs/mL, 106 PFUs/mL, or 105 PFUs/mL, 10 mL/animal) to determine whether the SA11 strain can effectively infect these animals by observing their clinical symptoms, fecal shedding of virus antigen by ELISA, distribution of RV antigen in the organs by immunofluorescence, variations of viral RNA load in the organs by qRT-PCR, histopathological changes in the small intestine by HE staining, and apoptosis of small intestinal epithelial cells by TUNEL assay.RESULTSThe RV monkey model showed typical clinical diarrhea symptoms in the 108 PFUs SA11 group, where we observed diarrhea 1-4 d post infection (dpi) and viral antigen shed in the feces from 1-7 dpi. RV was found in jejunal epithelial cells. We observed a viral load of approximately 5.85 × 103 copies per 100 mg in the jejunum at 2 dpi, which was increased to 1.09 × 105 copies per 100 mg at 3 dpi. A relatively high viral load was also seen in mesenteric lymph nodes at 2 dpi and 3 dpi. The following histopathological changes were observed in the small intestine following intragastric administration of SA11 RV: vacuolization, edema, and atrophy. Apoptosis in the jejunal villus epithelium was also detectable at 3 dpi.CONCLUSIONOur results indicate that we have successfully established a RV SA11 strain diarrhea model in neonatal rhesus monkeys. Future studies will elucidate the mechanisms underlying the pathogenesis of RV infection, and we will use the model to evaluate the protective effect of candidate vaccines.

Early Developmental Trajectories of Functional Connectivity Along the Visual Pathways in Rhesus Monkeys.

Early social interactions shape the development of social behavior, although the critical periods or the underlying neurodevelopmental processes are not completely understood. Here, we studied the developmental changes in neural pathways underlying visual social engagement in the translational rhesus monkey model. Changes in functional connectivity (FC) along the ventral object and motion pathways and the dorsal attention/visuo-spatial pathways were studied longitudinally using resting-state functional MRI in infant rhesus monkeys, from birth through early weaning (3 months), given the socioemotional changes experienced during this period. Our results revealed that (1) maturation along the visual pathways proceeds in a caudo-rostral progression with primary visual areas (V1-V3) showing strong FC as early as 2 weeks of age, whereas higher-order visual and attentional areas (e.g., MT-AST, LIP-FEF) show weak FC; (2) functional changes were pathway-specific (e.g., robust FC increases detected in the most anterior aspect of the object pathway (TE-AMY), but FC remained weak in the other pathways (e.g., AST-AMY)); (3) FC matures similarly in both right and left hemispheres. Our findings suggest that visual pathways in infant macaques undergo selective remodeling during the first 3 months of life, likely regulated by early social interactions and supporting the transition to independence from the mother.

MiR-1303 regulates BBB permeability and promotes CNS lesions following CA16 infections by directly targeting MMP9

Coxsackievirus A16 (CA16) is a member of the Picornaviridae family and causes mild and self-limiting hand, foot, and mouth disease (HFMD) in infants and young children. CA16 infection can also progress to central nervous system (CNS) complications; however, the underlying mechanism by which CA16 penetrates the blood-brain barrier (BBB) and then causes CNS damage remains unclear. This study aimed to explore the mechanism of CA16 neurotropic tropism by establishing an in vitro BBB model with CA16 infection and an in vivo CA16 rhesus monkey infant infection model. The results showed that CA16 infection induced increased permeability of the BBB accompanied by upregulation of matrix metalloproteinase 9 (MMP9) expression. Subsequently, high-throughput miRNA sequencing technology and bioinformatics analysis revealed that miR-1303 may regulate BBB permeability by targeting MMP9. Next, we used dual-luciferase, qRT-PCR, and western blot assays to provide evidence of MMP9 targeting by miR-1303. Further experiments revealed that CA16 infection promoted the degradation of junctional complexes (Claudin4, Claudin5, VE-Cadherin, and ZO-1), likely by downregulating miR-1303 and upregulating MMP9. Finally, EGFP-CA16 infection could enter the CNS by facilitating the degradation of junctional complexes, eventually causing neuroinflammation and injury to the CNS, which was confirmed using the in vivo rhesus monkey model. Our results indicate that CA16 might penetrate the BBB and then enter the CNS by downregulating miR-1303, which disrupts junctional complexes by directly regulating MMP9 and ultimately causing pathological CNS changes. These results provide new therapeutic targets in HFMD patients following CA16 infection.

Design of Novel HIV-1/2 Fusion Inhibitors with High Therapeutic Efficacy in Rhesus Monkey Models.

T-20 (enfuvirtide) is the only approved viral fusion inhibitor that is used for the treatment of human immunodeficiency virus type 1 (HIV-1) infection; however, it has relatively low antiviral activity and easily induces drug resistance. We recently reported a T-20-based lipopeptide fusion inhibitor (LP-40) showing improved anti-HIV activity (X. Ding et al., J Virol 91:e00831-17, 2017, https://doi.org/10.1128/JVI.00831-17). In this study, we designed LP-50 and LP-51 by refining the structure and function of LP-40. The two new lipopeptides showed dramatically enhanced secondary structure and binding stability and were exceptionally potent inhibitors of HIV-1, HIV-2, simian immunodeficiency virus (SIV), and chimeric simian-human immunodeficiency virus (SHIV), with mean 50% inhibitory concentrations (IC50s) in the very low picomolar range. They also exhibited dramatically increased potencies in inhibiting a panel of T-20- and LP-40-resistant mutant viruses. In line with their in vitro data, LP-50 and LP-51 exhibited extremely potent and long-lasting ex vivo anti-HIV activities in rhesus monkeys: serum dilution peaks that inhibited 50% of virus infection were >15,200-fold higher than those for T-20 and LP-40. Low-dose, short-term monotherapy of LP-51 could sharply reduce viral loads to undetectable levels in acutely and chronically SHIV infected monkey models. To our knowledge, LP-50 and LP-51 are the most potent and broad HIV-1/2 and SIV fusion inhibitors, which can be developed for clinical use and can serve as tools for exploration of the mechanisms of viral entry and inhibition.IMPORTANCE T-20 remains the only membrane fusion inhibitor available for the treatment of viral infection, but its relatively low anti-HIV activity and genetic barrier for drug resistance have significantly limited its clinical application. Here we report two new lipopeptide-based fusion inhibitors (LP-50 and LP-51) showing extremely potent inhibitory activities against diverse HIV-1, HIV-2, SIV, and T-20-resistant variants. Promisingly, both inhibitors exhibited potent and long-lasting ex vivo anti-HIV activity and could efficiently suppress viral loads to undetectable levels in SHIV-infected monkey models. We believe that LP-50 and LP-51 are the most potent and broad-spectrum fusion inhibitors known to date and thus have high potential for clinical development.

Functional Connectivity within the Primate Extended Amygdala Is Heritable and Associated with Early-Life Anxious Temperament.

Children with an extremely inhibited, anxious temperament (AT) are at increased risk for anxiety disorders and depression. Using a rhesus monkey model of early-life AT, we previously demonstrated that metabolism in the central extended amygdala (EAc), including the central nucleus of the amygdala (Ce) and bed nucleus of the stria terminalis (BST), is associated with trait-like variation in AT. Here, we use fMRI to examine relationships between Ce-BST functional connectivity and AT in a large multigenerational family pedigree of rhesus monkeys (n = 170 females and 208 males). Results demonstrate that Ce-BST functional connectivity is heritable, accounts for a significant but modest portion of the variance in AT, and is coheritable with AT. Interestingly, Ce-BST functional connectivity and AT-related BST metabolism were not correlated and accounted for non-overlapping variance in AT. Exploratory analyses suggest that Ce-BST functional connectivity is associated with metabolism in the hypothalamus and periaqueductal gray. Together, these results suggest the importance of coordinated function within the EAc for determining individual differences in AT and metabolism in brain regions associated with its behavioral and neuroendocrine components.SIGNIFICANCE STATEMENT Anxiety disorders directly impact the lives of nearly one in five people, accounting for substantial worldwide suffering and disability. Here, we use a nonhuman primate model of anxious temperament (AT) to understand the neurobiology underlying the early-life risk to develop anxiety disorders. Leveraging the same kinds of neuroimaging measures routinely used in human studies, we demonstrate that coordinated activation between the central nucleus of the amygdala and the bed nucleus of the stria terminalis is correlated with, and coinherited with, early-life AT. Understanding how these central extended amygdala regions work together to produce extreme anxiety provides a neural target for early-life interventions with the promise of preventing lifelong disability in at-risk children.

Circulating monocytes accelerate acute liver failure by IL-6 secretion in monkey.

Acute liver failure (ALF) is associated with high mortality, and a poor understanding of the underlying pathophysiology has resulted in a lack of effective treatments so far. Here, using an amatoxin‐induced rhesus monkey model of ALF, we panoramically revealed the cellular and molecular events that lead to the development of ALF. The challenged monkeys with toxins underwent a typical course of ALF including severe hepatic injury, systemic inflammation and eventual death. Adaptive immune was not noticeably disturbed throughout the progress of ALF. A systematic examination of serum factors and cytokines revealed that IL‐6 increase was the most rapid and drastic. Interestingly, we found that IL‐6 was mainly produced by circulating monocytes. Furthermore, ablation of monocyte‐derived IL‐6 in mice decreased liver injury and systemic inflammation following chemical injection. Our findings reveal a critical role of circulating monocytes in initiating and accelerating ALF, indicating a potential therapeutic target in clinical treatment for ALF.

Labial Salivary Gland Transplantation for Severe Dry Eye in a Rhesus Monkey Model.

To evaluate the effectiveness of autologous labial salivary gland with labial mucous membrane graft in a rhesus monkey model with severe dry eye. Eight eyes of eight rhesus monkeys with severe dry eye were included. Four eyes underwent autologous labial salivary gland and mucous membrane graft (group 1) and four eyes served as controls (group 2). The ocular surface was evaluated before and after transplantation surgery (at 1, 4, 8, 12, and 24 weeks). Conjunctival impression cytology was performed before and 24 weeks after transplantation. Finally, a histological analysis of the cornea, conjunctiva, and transplanted grafts was performed. At inclusion (n = 8) the mean Schirmer test was 1.31 ± 0.53 mm, the mean fluorescein score was 4.7 ± 1.65, and the mean lissamine green staining was 4.38 ± 0.48. After transplantation, a significant increase in tear secretion was observed with the mean Schirmer test results in group 2 significantly higher than those observed for group 1 at all time points (P < 0.05). Similarly, fluorescein and lissamine green scores were significantly lower in group 2 than in group 1 at all time points after transplantation (P < 0.05). Impression cytology specimens showed severe conjunctival squamous metaplasia without goblet cells in both groups. Under light microscopy, no significant difference was observed between the cornea and the conjunctiva of the two groups. Labial salivary gland transplantation provided a basal secretion of tears and improved ocular surface staining scores during the first 3 months in a severe rhesus monkey model of dry eye. However, this was not accompanied by major improvement of ocular surface tissues.

Detection of circulating Mycobacterium tuberculosis-specific DNA by droplet digital PCR for vaccine evaluation in challenged monkeys and TB diagnosis

Mycobacterium tuberculosis (M. tb) is emerging as a more serious pathogen due to the increased multidrug-resistant TB and co-infection of human immunodeficiency virus (HIV). The development of an effective and sensitive detection method is urgently needed for bacterial load evaluation in vaccine development, early TB diagnosis, and TB treatment. Droplet digital polymerase chain reaction (ddPCR) is a newly developed sensitive PCR method for the absolute quantification of nucleic acid concentrations. Here, we used ddPCR to quantify the circulating virulent M. tb-specific CFP10 (10-kDa culture filtrate protein, Rv3874) and Rv1768 DNA copy numbers in the blood samples from Bacille Calmette-Guerin (BCG)-vaccinated and/or virulent M. tb H37Rv-challenged rhesus monkeys. We found that ddPCR was more sensitive compared to real-time fluorescence quantitative PCR (qPCR), as the detection limits of CFP10 were 1.2 copies/μl for ddPCR, but 15.8 copies/μl for qPCR. We demonstrated that ddPCR could detect CFP10 and Rv1768 DNA after 3 weeks of infection and at least two weeks earlier than qPCR in M.tb H37Rv-challenged rhesus monkey models. DdPCR could also successfully quantify CFP10 and Rv1768 DNA copy numbers in clinical TB patients’ blood samples (active pulmonary TB, extrapulmonary TB (EPTB), and infant TB). To our knowledge, this study is the first to demonstrate that ddPCR is an effective and sensitive method of measuring the circulating CFP10 and Rv1768 DNA for vaccine development, bacterial load evaluation in vivo, and early TB (including EPTB and infant TB) diagnosis as well.

Positron emission tomography imaging of cerebral glucose metabolism and type 1 cannabinoid receptor availability during temporal lobe epileptogenesis in the amygdala kindling model in rhesus monkeys.

We investigated changes in the endocannabinoid system and glucose metabolism during temporal lobe epileptogenesis. Because it is rarely possible to study epileptogenesis in humans, we applied the electrical amygdala kindling model in nonhuman primates to image longitudinal changes in type 1 cannabinoid receptor (CB1R) binding and cerebral glucose metabolism. Two rhesus monkeys received [18 F]-MK-9470 and fluorodeoxyglucose-positron emission tomography ([18 F]-FDG -PET) scans in each of the 4 kindling stages to quantify relative changes over time of CB1R binding and cerebral glucose metabolism in vivo. We constructed z-score images relative to a control group (n = 8), and considered only those changes measured in both kindled animals by calculating the binary conjunction image per kindling stage. The seizure-onset zone exhibited an increased CB1R binding and a decreased glucose metabolism, which both aggravated gradually in extent and intensity throughout kindling. The ipsilateral thalamus and insula showed hypometabolism that coincided with an increase and a decrease in CB1R binding, respectively. These changes also became gradually more severe throughout kindling and overlapped with ictal perfusion changes during the final stage of amygdala kindling, with hyperperfusion in the ipsilateral thalamus and hypoperfusion in the ipsilateral insula. The observed changes in CB1R binding may reflect a combination of a protective mechanism of neurons against seizure activity that becomes stronger over time to combat more severe seizures, and on the other hand, a process of epileptogenesis that facilitates seizure activity and generalization, depending on the cell type involved in those specific regions. This study provides unique evidence that the CB1R is dynamically and progressively involved from the start of mesial temporal lobe epileptogenesis.

EB 2017 Article: Changes in advanced glycation end products, beta-defensin-3, and interleukin-17 during diabetic periodontitis development in rhesus monkeys.

The bidirectional relationship between diabetes mellitus (DM) and periodontal disease has drawn great attention; however, the mechanisms underlying their association remain unclear. In this study, we aimed to develop a rhesus monkey model of diabetic periodontitis and explore the potential mechanisms by which DM affects the progression of periodontal disease. Three healthy rhesus monkeys were selected as the control group. Five streptozotocin-induced diabetic rhesus monkeys were chosen as the experimental group. Ligature placement was used to induce periodontitis. The changes in the levels of advanced glycation end products (AGEs), beta-defensin-3 (BD-3), and interleukin-17 (IL-17) were measured using enzyme-linked immunosorbent assays (ELISA) and real-time reverse transcription polymerase chain reaction (RT-PCR) at different stages during disease progression. Periodontitis was confirmed by clinical assessment, radiographic images, and histological examination. Significant changes in the levels of AGEs and BD-3 in serum were observed at the periodontitis stage in diabetic rhesus monkeys ( P < 0.05). The expression of BD-3 mRNA in the gingiva of diabetic group at baseline was significantly high ( P < 0.05). Diabetic monkeys exhibited significantly enhanced IL-17 mRNA expression at the periodontitis stage ( P < 0.05). Our findings indicated that the rhesus monkey can serve as an ideal model for exploring the pathogenesis of diabetic periodontitis, and the hyperglycemic environment may accelerate inflammatory response and weaken the defense system in periodontal tissues. Impact statement The mechanism underlying the association between diabetes mellitus (DM) and periodontal disease is not yet fully understood. Hence, there is a need to establish animal models to reveal the effect of DM on the pathogenesis of periodontitis. In this study, we explored the appropriate methods for inducing periodontitis and shortening the modeling time in rhesus monkeys, to investigate the pathogenesis of diabetic periodontitis and develop innovative therapies. Our results suggest that a hyperglycemic environment might lead to the destruction of periodontal tissues by accelerating inflammatory response and weakening the defense system in periodontal tissues. Therefore, this study has significant treatment implications regarding the regulation of the immune response against periodontal diseases in patients with DM.

Abstract 58: Therapeutic Effect of Selective Middle Cerebral Artery Cooling Infusion in a Primate Stroke Model

Introduction: Selective cooling infusion (SCI) of Lactated Ringer’s solution into ischemic territory supplied by the middle cerebral artery (MCA) has been demonstrated as a safe procedure in stroke patients (Chen et al., Stroke, 2016). In order to conduct clinical trials for this therapy, this novel method should be tested in non-human primate (NHP) ischemic stroke models as suggested by the Stroke Therapy Academic Industry Roundtable (STAIR) committee. In the present study, we first developed a realizable thrombus-thrombolysis ischemic model in rhesus monkeys and then we determined whether a SCI of Lactated Ringer’s solution effectively provided a neuroprotection in the NHP with ischemic stroke. Methods: An autologous clot was made and injected via a micro-catheter (Prowler -10) into the main trunk of MCA to induce focal ischemia in 24 rhesus monkeys. MCA occlusions were confirmed by DSA. Thrombolysis with rt-PA (0.9mg/kg) was completed 3 h after the onset of ischemia. Twelve ischemic animals, in a randomized manner, received SCI at 10 minutes following rt-PA administration. MRI images, NHPSS, Spetzler scores and modified movement assessment panel were used to evaluate brain infarction, neurological deficits and functional outcome through 30 days. Results: Complete, partial, or no recanalization of MCA were found in eight animals in each ischemic group with or without SCI. SCI significantly reduced infarct volume and neurological deficits, as well as improved motor function when complete or partial reperfusion were established. However, SCI did not protect ischemic brain if reperfusion was not achieved. Conclusion: Clot embolism and different status of thrombolytic outcomes with rt-PA were developed in rhesus monkeys. SCI is a feasible and practicable neuroprotectant in high-order brains. Reperfusion is a prerequisite for neuroprotection induced by SCI.