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The pathogenesis of Ebola virus disease (EVD) is still incomplete, in spite of the availability of a nonhuman primate modelfor more than 4 decades. To further investigate EVD pathogenesis, a natural history study was conducted using 27 Chinese-origin rhesus macaques. Of these, 24 macaques were exposed intramuscularly to Kikwit Ebola virus and euthanized at predetermined time points or when end-stage clinical disease criteria were met, and 3 sham-exposed macaques were euthanized on study day 0. This study showed for the first time that Ebola virus causes uterine cervicitis, vaginitis, posthitis, and medullary adrenalitis. Not only was Ebola virus detected in the interstitial stromal cells of the genital tract, but it was also present in the epididymal and seminal vesicular tubular epithelial cells, ectocervical and vaginal squamous epithelial cells, and seminal fluid. Furthermore, as early as day 3 after exposure, Ebola virus replicative intermediate RNA was detected in Kupffer cells and hepatocytes. These findings in the nonhuman model provide additional insight into potential sexual transmission, possible disruption of sympathetic hormone production, and early virus replication sites in human EVD patients.

Ongoing Ebola virus disease outbreaks in the Democratic Republic of the Congo follow the largest recorded outbreak in Western Africa (2013&ndash, 2016). To combat outbreaks, testing of medical countermeasures (therapeutics or vaccines) requires a well-defined, reproducible, animal model. Here we present Ebola virus disease kinetics in 24 Chinese-origin rhesus monkeys exposed intramuscularly to a highly characterized, commercially available Kikwit Ebola virus Filovirus Animal Non-Clinical Group (FANG) stock. Until reaching predetermined clinical disease endpoint criteria, six animals underwent anesthesia for repeated clinical sampling and were compared to six that did not. Groups of three animals were euthanized and necropsied on days 3, 4, 5, and 6 post-exposure, respectively. In addition, three uninfected animals served as controls. Here, we present detailed characterization of clinical and laboratory disease kinetics and complete blood counts, serum chemistries, Ebola virus titers, and disease kinetics for future medical countermeasure (MCM) study design and control data. We measured no statistical difference in hematology, chemistry values, or time to clinical endpoint in animals that were anesthetized for clinical sampling during the acute disease compared to those that were not.

Neurological signs and symptoms are the most common complications of Ebola virus disease. However, the mechanisms underlying the neurologic manifestations in Ebola patients are not known. In this study, peripheral ganglia were collected from 12 rhesus macaques that succumbed to Ebola virus (EBOV) disease from 5 to 8 days post exposure. Ganglionitis, characterized by neuronal degeneration, necrosis, and mononuclear leukocyte infiltrates, was observed in the dorsal root, autonomic, and enteric ganglia. By immunohistochemistry, RNAscope in situ hybridization, transmission electron microscopy, and confocal microscopy, we confirmed that CD68+ macrophages are the target cells for EBOV in affected ganglia. Further, we demonstrated that EBOV can induce satellite cell and neuronal apoptosis and microglial activation in infected ganglia. Our results demonstrate that EBOV can infect peripheral ganglia and results in ganglionopathy in rhesus macaques, which may contribute to the neurological signs and symptoms observed in acute and convalescent Ebola virus disease in human patients.

The most commonly reported symptom of post–Ebola virus disease syndrome in survivors is arthralgia, yet involvement of the joints in acute or convalescent Ebola virus infection is not well characterized in human patients or animal models. Through immunohistochemistry, we found that the lining synovial intima of the stifle (knee) is a target for acute infection by Ebola virus/Kikwit, Ebola virus/Makona-C05, and Marburg virus/Angola in the rhesus macaque model. Furthermore, histologic analysis, immunohistochemistry, RNAscope in situ hybridization, and transmission electron microscopy showed that synoviocytes of the stifle, shoulder, and hip are a target for mouse-adapted Ebola virus/Yambuku-Mayinga infection during acute disease in rhesus macaques. A time course of infection study with Ebola virus/Kikwit found that the large joint synovium became immunopositive beginning on postinfection day 6. In total, the synovium of 28 of 30 rhesus macaques with terminal filovirus disease had evidence of infection (64 of 96 joints examined). On the basis of immunofluorescence, infected cell types included CD68(+) type A (macrophage-like) synoviocytes and CD44(+) type B (fibroblast-like) synoviocytes. Cultured primary human fibroblast–like synoviocytes were permissive to infection with Ebola and Marburg viruses in vitro. Because synovial joints include immune privileged sites, these findings are significant for future investigations of filovirus pathogenesis and persistence as well as arthralgias in acute and convalescent filovirus disease.

Lassa fever (LF) survivors develop various clinical manifestations including polyserositis, myalgia, epididymitis, and hearing loss weeks to months after recovery from acute infection. We demonstrate a systemic lymphoplasmacytic and histiocytic arteritis and periarteritis in guinea pigs more than 2 months after recovery from acute Lassa virus (LASV) infection. LASV was detected in the arterial tunica media smooth muscle cells by immunohistochemistry, in situ hybridization, and transmission electron microscopy. Our results suggest that the sequelae of LASV infection may be due to virus persistence resulting in systemic vascular damage. These findings shed light on the pathogenesis of LASV sequelae in convalescent human survivors.

Simian hemorrhagic fever virus (SHFV) causes a fulminant and typically lethal viral hemorrhagic fever (VHF) in macaques (Cercopithecinae: Macaca spp.) but causes subclinical infections in patas monkeys (Cercopithecinae: Erythrocebus patas). This difference in disease course offers a unique opportunity to compare host responses to infection by a VHF-causing virus in biologically similar susceptible and refractory animals. Patas and rhesus monkeys were inoculated side-by-side with SHFV. Unlike the severe disease observed in rhesus monkeys, patas monkeys developed a limited clinical disease characterized by changes in complete blood counts, serum chemistries, and development of lymphadenopathy. Viral RNA was measurable in circulating blood 2 days after exposure, and its duration varied by species. Infectious virus was detected in terminal tissues of both patas and rhesus monkeys. Varying degrees of overlap in changes in serum concentrations of interferon (IFN)-&gamma, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6 were observed between patas and rhesus monkeys, suggesting the presence of common and species-specific cytokine responses to infection. Similarly, quantitative immunohistochemistry of livers from terminal monkeys and whole blood flow cytometry revealed varying degrees of overlap in changes in macrophages, natural killer cells, and T-cells. The unexpected degree of overlap in host response suggests that relatively small subsets of a host&rsquo, s response to infection may be responsible for driving hemorrhagic fever pathogenesis. Furthermore, comparative SHFV infection in patas and rhesus monkeys offers an experimental model to characterize host&ndash, response mechanisms associated with viral hemorrhagic fever and evaluate pan-viral hemorrhagic fever countermeasures.

Sexual transmission of Ebola virus (EBOV) has been demonstrated more than a year after recovery from the acute phase of Ebola virus disease (EVD). The mechanisms underlying EBOV persistence and sexual transmission are not currently understood. Using the acute macaque model of EVD, we hypothesized EBOV would infect the reproductive tissues and sought to localize the infection in these tissues using immunohistochemistry and transmission electron microscopy. In four female and eight male macaques that succumbed to EVD between 6 and 9 days after EBOV challenge, we demonstrate widespread EBOV infection of the interstitial tissues and endothelium in the ovary, uterus, testis, seminal vesicle, epididymis, and prostate gland, with minimal associated tissue immune response or organ pathology. Given the widespread involvement of EBOV in the reproductive tracts of both male and female macaques, it is reasonable to surmise that our understanding of the mechanisms underlying sexual transmission of EVD and persistence of EBOV in immune-privileged sites would be facilitated by the development of a nonhuman primate model in which the macaques survived past the acute stage into convalescence.

The 2013-2016 West African Ebola virus (EBOV) disease outbreak was the largest filovirus outbreak to date. Over 28 000 suspected, probable, or confirmed cases have been reported, with a 53% case-fatality rate. The magnitude and international impact of this EBOV outbreak has highlighted the urgent need for a safe and efficient EBOV vaccine. To this end, we demonstrate the immunogenicity and protective efficacy of FILORAB1, a recombinant, bivalent, inactivated rabies virus-based EBOV vaccine, in rhesus and cynomolgus monkeys. Our results demonstrate that the use of the synthetic Toll-like receptor 4 agonist glucopyranosyl lipid A in stable emulsion (GLA-SE) as an adjuvant increased the efficacy of FILORAB1 to 100% protection against lethal EBOV challenge, with no to mild clinical signs of disease. Furthermore, all vaccinated subjects developed protective anti-rabies virus antibody titers. Taken together, these results support further development of FILORAB1/GLA-SE as an effective preexposure EBOV vaccine.

We previously demonstrated that small-particle (0.5–3.0 µm) aerosol infection of rhesus monkeys (Macaca mulatta) with cowpox virus (CPXV)-Brighton Red (BR) results in fulminant respiratory tract disease characterized by severe lung parenchymal pathology but only limited systemic virus dissemination and limited classic epidermal pox-like lesion development ( Johnson et al., 2015 ). Based on these results, and to further develop CPXV as an improved model of human smallpox, we evaluated a novel large-particle aerosol (7.0–9.0 µm) exposure of rhesus monkeys to CPXV-BR and monitored for respiratory tract disease by serial computed tomography (CT). As expected, the upper respiratory tract and large airways were the major sites of virus-induced pathology following large-particle aerosol exposure. Large-particle aerosol CPXV exposure of rhesus macaques resulted in severe upper airway and large airway pathology with limited systemic dissemination.

A common treatment of advanced prostate cancer involves the deprivation of androgens. Despite the initial response to hormonal therapy, eventually all the patients relapse. In the present study, we sought to determine whether dietary polyunsaturated fatty acid (PUFA) affects the development of castration-resistant prostate cancer. Cell culture, patient tissue microarray, allograft, xenograft, prostate-specific Pten knockout and omega-3 desaturase transgenic mouse models in conjunction with dietary manipulation, gene knockdown and knockout approaches were used to determine the effect of dietary PUFA on castration-resistant Pten-null prostate cancer. We found that deletion of Pten increased androgen receptor (AR) expression and Pten-null prostate cells were castration resistant. Omega-3 PUFA slowed down the growth of castration-resistant tumors as compared with omega-6 PUFA. Omega-3 PUFA decreased AR protein to a similar extent in tumor cell cytosolic and nuclear fractions but had no effect on AR messenger RNA level. Omega-3 PUFA treatment appeared to accelerate AR protein degradation, which could be blocked by proteasome inhibitor MG132. Knockdown of AR significantly slowed down prostate cancer cell proliferation in the absence of androgens. Our data suggest that omega-3 PUFA inhibits castration-resistant prostate cancer in part by accelerating proteasome-dependent degradation of the AR protein. Dietary omega-3 PUFA supplementation in conjunction with androgen ablation may significantly delay the development of castration-resistant prostate cancer in patients compared with androgen ablation alone.

Baboons are susceptible to natural Ebola virus (EBOV) infection and share 96% genetic homology with humans. Despite these characteristics, baboons have rarely been utilized as experimental models of human EBOV infection to evaluate the efficacy of prophylactics and therapeutics in the United States. This review will summarize what is known about the pathogenesis of EBOV infection in baboons compared to EBOV infection in humans and other Old World nonhuman primates. In addition, we will discuss how closely the baboon model recapitulates human EBOV infection. We will also review some of the housing requirements and behavioral attributes of baboons compared to other Old World nonhuman primates. Due to the lack of data available on the pathogenesis of Marburg virus (MARV) infection in baboons, discussion of the pathogenesis of MARV infection in baboons will be limited.

Short-term dietary studies of soy-protein-derived isoflavonoids, using rodent and nonhuman primate models, have documented variable effects on the reproductive tract. Long-term effects of dietary soy and/or isoflavonoids on the reproductive tract of nonhuman primates have not been determined. The objective of this study was to assess the effects of long-term consumption of dietary soy isoflavonoids on histomorphology of the mammary glands and prostate gland, testis, and sperm counts in adult male cynomolgus macaques. Ninety-one adult male cynomolgus macaques (Macaca fascicularis) were fed diets for 3 y differing only in protein source: 1) a soy-free, casein-lactalbumin-based diet or 2) a low-soy isoflavonoid diet ( approximately 6 mg . kg(-1) . d(-1)) or 3) a high-soy isoflavonoid diet ( approximately 12 mg . kg(-1) . d(-1)). Serum isoflavonoids were measured by liquid chromatographic-photodiode array electrospray MS. Mammary gland, prostate gland, and testes were obtained at postmortem and evaluated histopathologically and histomorphometrically. Epididymal and testicular sperm counts were performed. Serum isoflavonoid concentrations at 4 h postfeeding differed among all groups (P0.001) and were (means +/- SEM) 67 +/- 23 (soy-free diet), 799 +/- 44 (low-soy isoflavonoid diet), and 1458 +/- 80 nmol . L(-1) (high-soy isoflavonoid diet). Diet did not alter serum estradiol and testosterone concentrations or epididymal and testicular sperm counts. Organ weights and histologic indices did not differ among treatment groups. Mammary gland histopathologic and histomorphometric analysis revealed no abnormalities and no indication of gynecomastia. We found no evidence of an adverse effect of soy isoflavonoids at physiologically relevant doses within the reproductive organs of adult male macaques.

Although a causal role of genetic alterations in human cancer is well established, it is still unclear whether dietary fat can modulate cancer risk in a predisposed population. Epidemiological studies suggest that diets rich in omega-3 polyunsaturated fatty acids reduce cancer incidence. To determine the influence of fatty acids on prostate cancer risk in animals with a defined genetic lesion, we used prostate-specific Pten-knockout mice, an immune-competent, orthotopic prostate cancer model, and diets with defined polyunsaturated fatty acid levels. We found that omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival, whereas omega-6 fatty acids had opposite effects. Introducing an omega-3 desaturase, which converts omega-6 to omega-3 fatty acids, into the Pten-knockout mice reduced tumor growth similarly to the omega-3 diet. Tumors from mice on the omega-3 diet had lower proportions of phosphorylated Bad and higher apoptotic indexes compared with those from mice on omega-6 diet. Knockdown of Bad eliminated omega-3-induced cell death, and introduction of exogenous Bad restored the sensitivity to omega-3 fatty acids. Our data suggest that modulation of prostate cancer development by polyunsaturated fatty acids is mediated in part through Bad-dependent apoptosis. This study highlights the importance of gene-diet interactions in prostate cancer.

Background Influenza results in up to 500,000 deaths annually. Seasonal influenza vaccines have an estimated 60% effectiveness, but provide little or no protection against novel subtypes, and may be less protective in high-risk groups. Neuraminidase inhibitors are recommended for the treatment of severe influenza infection, but are not proven to reduce mortality in severe disease. Preclinical models of severe influenza infection that closely correlate to human disease are needed to assess efficacy of new vaccines and therapeutics. Methods We developed a nonhuman primate model of influenza and bacterial co-infection that recapitulates severe pneumonia in humans. Animals were infected with influenza A virus via intra-bronchial or small-particle aerosol inoculation, methicillin-resistant Staphylococcus aureus , or co-infected with influenza and methicillin-resistant S. aureus combined. We assessed the severity of disease in animals over the course of our study using tools available to evaluate critically ill human patients including high-resolution computed tomography imaging of the lungs, arterial blood gas analyses, and bronchoalveolar lavage. Results Using an intra-bronchial route of inoculation we successfully induced severe pneumonia following influenza infection alone and following influenza and bacterial co-infection. Peak illness was observed at day 6 post-influenza infection, manifested by bilateral pulmonary infiltrates and hypoxemia. The timing of radiographic and physiologic manifestations of disease in our model closely match those observed in severe human influenza infection. Discussion This was the first nonhuman primate study of influenza and bacterial co-infection where high-resolution computed tomography scanning of the lungs was used to quantitatively assess pneumonia over the course of illness and where hypoxemia was correlated with pneumonia severity. With additional validation this model may serve as a pathway for regulatory approval of vaccines and therapeutics for the prevention and treatment of severe influenza pneumonia.