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At least 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Di-22:6-bis(monoacylglycerol)phosphate: A clinical biomarker of drug-induced phospholipidosis for drug development and safety assessment

The inability to routinely monitor drug-induced phospholipidosis (DIPL) presents a challenge in pharmaceutical drug development and in the clinic. Several nonclinical studies have shown di-docosahexaenoyl (22:6) bis(monoacylglycerol) phosphate (di-22:6-BMP) to be a reliable biomarker of tissue DIPL that can be monitored in the plasma/serum and urine. The aim of this study was to show the relevance of di-22:6-BMP as a DIPL biomarker for drug development and safety assessment in humans. DIPL shares many similarities with the inherited lysosomal storage disorder Niemann–Pick type C (NPC) disease. DIPL and NPC result in similar changes in lysosomal function and cholesterol status that lead to the accumulation of multi-lamellar bodies (myeloid bodies) in cells and tissues. To validate di-22:6-BMP as a biomarker of DIPL for clinical studies, NPC patients and healthy donors were classified by receiver operator curve analysis based on urinary di-22:6-BMP concentrations. By showing 96.7-specificity and 100-sensitivity to identify NPC disease, di-22:6-BMP can be used to assess DIPL in human studies. The mean concentration of di-22:6-BMP in the urine of NPC patients was 51.4-fold (p ≤ 0.05) above the healthy baseline range. Additionally, baseline levels of di-22:6-BMP were assessed in healthy non-medicated laboratory animals (rats, mice, dogs, and monkeys) and human subjects to define normal reference ranges for nonclinical/clinical studies. The baseline ranges of di-22:6-BMP in the plasma, serum, and urine of humans and laboratory animals were species dependent. The results of this study support the role of di-22:6-BMP as a biomarker of DIPL for pharmaceutical drug development and health care settings. - Highlights: • A reliable biomarker of drug-induced phospholipidosis (DIPL) is needed for humans. • Di-22:6-BMP is specific/sensitive for DIPL in animals as published in literatures. • The di-22:6-BMP biomarker can be validated for humans via NPC patients. • DIPL shares morphologic/mechanistic similarities with Niemann–Pick type C disease. • Di-22:6-BMP is an effective DIPL biomarker in humans via NPC patient validation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2025

Learned magnetic map cues and two mechanisms of magnetoreception in turtles

Growing evidence indicates that migratory animals exploit the magnetic field of the Earth for navigation, both as a compass to determine direction and as a map to determine geographical position. It has long been proposed that, to navigate using a magnetic map, animals must learn the magnetic coordinates of the destination, yet the pivotal hypothesis that animals can learn magnetic signatures of geographical areas has, to our knowledge, yet to be tested. Here, in this work, we report that an iconic navigating species, the loggerhead turtle ( Caretta caretta ), can learn such information. When fed repeatedly in magnetic fields replicating those that exist in particular oceanic locations, juvenile turtles learned to distinguish magnetic fields in which they encountered food from magnetic fields that exist elsewhere, an ability that might underlie foraging site fidelity. Conditioned responses in this new magnetic map assay were unaffected by radiofrequency oscillating magnetic fields, a treatment expected to disrupt radical-pair-based chemical magnetoreception, suggesting that the magnetic map sense of the turtle does not rely on this mechanism. By contrast, orientation behaviour that required use of the magnetic compass was disrupted by radiofrequency oscillating magnetic fields. The findings provide evidence that two different mechanisms of magnetoreception underlie the magnetic map and magnetic compass in sea turtles.

animal behaviour↗
DOE OSTI2016

Study of potential utility of new radiopharmaceuticals based on technetium-99m labeled derivative of glucose

Purpose: to study the potential utility of 1-thio-D-glucose labeled with {sup 99m}Tc for cancer imaging in laboratory animals. Materials and method: the study was carried out in cell cultures of normal CHO (Chinese hamster ovary cells CHO) and malignant tissues MCF-7 (human breast adenocarcinoma MCF-7). To evaluate the uptake of {sup 99m}Tc-1-thio-D-glucose in normal and tumor tissue cells, 25 MBq of 1-thio-D-glucose labeled with {sup 99m}Tc was added to the vials with 3 million cells and incubated for 30 min at room temperature. After centrifugation of the vials with cells, the supernatant was removed. The radioactivity in vials with normal and tumor cells was then measured. In addition, the study included 40 mice of C57B1/6j lines with tumor lesion of the right femur. For neoplastic lesions, Lewis lung carcinoma model was used. Following anesthesia, mice were injected intravenously with 25 MBq of {sup 99m}Tc-1-thio-D-glucose. Planar scintigraphy was performed 15 minutes later in a matrix of 512x512 pixels for 5 min. Results: when measuring the radioactivity of normal and malignant cells after incubation with {sup 99m}Tc-1-thio-D-glucose, it was found that the radioactivity of malignant cells was higher than that of normal cells. The mean values of radioactivity levels in normal and malignant cells were 0.3 ± 0.15 MBq and 1.07 ± 0.6 MBq, respectively. All examined animals had increased accumulation of {sup 99m}Tc-1-thio-D-glucose at the tumor site. The accumulation of {sup 99m}Tc-1-thio-D-glucose in the tumor was on average twice as high as compared to the symmetric region. Conclusion: The present study demonstrated that {sup 99m}Tc-1-thio-D-glucose is a prospective radiopharmaceutical for cancer visualization. In addition, high accumulation of {sup 99m}Tc-1-thio-D-glucose in the culture of cancer cells and in tumor tissue of animals demonstrates tumor tropism of the radiopharmaceutical.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
NASA NTRS2002

Body mass, energy intake, and water consumption of rats and humans during space flight

Alteration of metabolism has been suggested as a major limiting factor to long-term space flight. In humans and primates, a negative energy balance has been reported. The metabolic response of rats to space flight has been suggested to result in a negative energy balance. We hypothesized that rats flown in space would maintain energy balance as indicated by maintenance of caloric intake and body mass gain. Further, the metabolism of the rat would be similar to that of laboratory-reared animals. We studied the results from 15 space flights lasting 4 to 19 d. There was no difference in average body weight (206 +/- 13.9 versus 206 +/- 14.8 g), body weight gain (5.8 +/- 0.48 versus 5.9 +/- 0.56 g/d), caloric intake (309 +/- 21.0 versus 309 +/- 20.1 kcal/kg of body mass per day), or water intake (200 +/- 8.6 versus 199 +/- 9.3 mL/kg of body mass per day) between flight and ground control animals. Compared with standard laboratory animals of similar body mass, no differences were noted. The observations suggested that the negative balance observed in humans and non-human primates may be due to other factors in the space-flight environment.

Non-NASA Center↗
NASA NTRS2002

Atm heterozygous mice are more sensitive to radiation-induced cataracts than are their wild-type counterparts

It is important to know whether the human population includes genetically predisposed radiosensitive subsets. In vitro studies have shown that cells from individuals homozygous for ataxia telangiectasia (A-T) are much more radiosensitive than cells from unaffected individuals. Although cells heterozygous for the ATM gene (ATM(+/-)) may be slightly more radiosensitive in vitro, it remained to be determined whether the greater susceptibility of ATM(+/-) cells translates into an increased sensitivity for late effects in vivo, though there is a suggestion that radiotherapy patients that are heterozygous for the ATM gene may be more at risk of developing late normal tissue damage. We chose cataractogenesis in the lens as a means to assay for the effects of ATM deficiency in a late-responding tissue. One eye of wild-type, Atm heterozygous and homozygous knockout mice was exposed to 0.5-, 1.0-, 2.0-, or 4.0-Gy x rays. The animals were followed weekly for cataract development by conventional slit-lamp biomicroscopy. Cataract development in the animals of all three groups was strongly dependent on dose. The lenses of homozygous mice were the first to opacify at any given dose. Most important in the present context is that cataracts appeared earlier in the heterozygous versus wild-type animals. The data suggest that ATM heterozygotes in the human population may also be radiosensitive. This may influence the choice of individuals destined to be exposed to higher than normal doses of radiation, such as astronauts, and may also suggest that radiotherapy patients who are ATM heterozygotes could be predisposed to increased late normal tissue damage.

Non-NASA Center↗
NASA NTRS2000

Antiorthostatic suspension for 14 days does not diminish the oxidative response of neutrophils in mice

The effects of long-term spaceflight on inflammatory responses have not been well-studied in either humans or animals. It is thus important to determine if the functions of immune and inflammatory cells are altered in models of spaceflight. One such animal model is antiorthostatic suspension (AOS), in which the experimental animal is subjected to a head-down tilt that mimics both the stress and the cephalad fluid shift experienced in spaceflight. A previous study reported that the peritoneal neutrophils from mice experiencing AOS generated less superoxide than unsuspended controls. We expanded on this study using several different stimuli and measuring the oxidative response of murine neutrophils in a variety of ways. These responses included the rate, lag period, and dose/response characteristics for superoxide generation, FACS analysis with dihydrodichlorofluorescein as a substrate, and a chemiluminescence response with luminol as a substrate. We also examined phagocytosis of three different microorganisms. While some effects of orthostatic suspension (attributable to the stress of the apparatus) were observed, no clear effects of AOS on oxidative function of the peritoneal neutrophils were seen.

NASA Discipline Regulatory Physiology↗
NASA NTRS1993

Alterations in skeletal muscle related to impaired physical mobility: an empirical model

The objective of this investigation was to study impaired physical mobility and the resulting skeletal muscle atrophy. An animal model was used to study morphological adaptations of the soleus and plantaris muscles to decreased loading induced by hindlimb suspension of an adult rat for 7, 14, and 28 consecutive days. Alterations in weight, skeletal muscle growth, and changes in fiber type composition were studied in synergistic plantar flexors of the rat hindlimb. Body weight and the soleus muscle mass to body mass ratio demonstrated significant progressive atrophy over th 28-day experimental period with the most significant changes occurring in the first 7 days of hindlimb suspension. Hindlimb suspension produced atrophy of Type I and Type IIa muscle fibers as demonstrated by significant decreases in fiber cross-sectional area (micron 2). These latter changes account for the loss of contractile force production reported in the rat following hindlimb unloading. When compared to traditional models of hindlimb suspension and immobilization, the ISC model produces a less severe atrophy while maintaining animal mobility and health. We conclude that it is the preferred animal model to address nursing questions of impaired physical mobility.

Non-NASA Center↗
NASA NTRS1992

Investigation of anti-motion sickness drugs in the squirrel monkey

Early attempts to develop an animal model for anti-motion sickness drugs, using dogs and cats; were unsuccessful. Dogs did not show a beneficial effect of scopolamine (probably the best single anti-motion sickness drug for humans thus far) and the findings in cats were not definitive. The authors have developed an animal model using the squirrel monkey (Saimiri sciureus) of the Bolivian phenotype. Unrestrained monkeys in a small lucite cage were tested in an apparatus that induces motion sickness by combining vertical oscillation and horizontal rotation in a visually unrestricted laboratory environment. Signs of motion sickness were scored using a rating scale. Ten susceptible monkeys (weighing 800-1000 g) were given a total of five tests each, to establish the baseline susceptibility level. Based on the anticholinergic activity of scopolamine, the sensitivity of squirrel monkey to scopolamine was investigated, and the appropriate dose of scopolamine for this species was determined. Then various anti-motion sickness preparations were administered in subsequent tests: 100 ug scopolamine per monkey; 140 ug dexedrine; 50 ug scopolamine plus 70 ug dexedrine; 100 ug scopolamine plus 140 ug dexedrine; 3 mg promethazine; 3 mg promethazine plus 3 mg ephedrine. All these preparations were significantly effective in preventing motion sickness in the monkeys. Ephedrine, by itself, which is marginally effective in humans, was ineffective in the monkeys at the doses tried (0.3-6.0 mg). The squirrel monkey appears to be a good animal model for antimotion sickness drugs. Peripherally acting antihistamines such as astemizole and terfenadine were found to be ineffective, whereas flunarizine, and an arginine vasopressin V1 antagonist, showed significant activity in preventing motion sickness.

NASA Discipline Neuroscience↗
DOE OSTI2019

Robotically Assisted Sonic Therapy (RAST) for Noninvasive Hepatic Ablation in a Porcine Model: Mitigation of Body Wall Damage with a Modified Pulse Sequence

Purpose: Robotically assisted sonic therapy (RAST) is a nonthermal, noninvasive ablation method based on histotripsy. Prior animal studies have demonstrated the ability to create hepatic ablation zones at the focal point of an ultrasound therapy transducer; however, these treatments resulted in thermal damage to the body wall within the path of ultrasound energy delivery. The purpose of this study was to evaluate the efficacy and safety of a pulse sequence intended to mitigate prefocal body wall injury. Materials and Methods: Healthy swine (n = 6) underwent hepatic RAST (VortxRx software version 1.0.1.3, HistoSonics, Ann Arbor MI) in the right hepatic lobe. A 3.0 cm spherical ablation zone was prescribed for each. Following treatment, animals underwent MRI which was utilized for ablation zone measurement, evaluation of prefocal injury, and assessment of complications. Each animal was euthanized, underwent necropsy, and the tissue was processed for histopathologic analysis of the ablation zone and any other sites concerning for injury. Results: No prefocal injury was identified by MRI or necropsy in the body wall or tissues overlying the liver. Ablation zones demonstrated uniform cell destruction, were nearly spherical (sphericity index = 0.988), and corresponded closely to the prescribed size (3.0 × 3.1 × 3.4 cm, p = 0.70, 0.36, and 0.01, respectively). Ablation zones were associated with portal vein (n = 3, one occlusive) and hepatic vein thrombosis (n = 4, one occlusive); however, bile ducts remained patent within ablation zones (n = 2). Conclusions: Hepatic RAST performed with a modified ultrasound pulse sequence in a porcine model can mitigate prefocal body wall injuries while maintaining treatment efficacy. Further study of hepatic RAST appears warranted, particularly in tumor models.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Cadmium exposure inhibits MMP2 and MMP9 activities in the prostate and testis

Matrix metalloproteinases (MMPs) are zinc (Zn{sup 2+}) and calcium (Ca{sup 2+}) dependant endopeptidases, capable of degradation of numerous components of the extracellular matrix. Cadmium (Cd{sup 2+}) is a well known environmental contaminant which could impair the activity of MMPs. In this sense, this study was conducted to evaluate if Cd{sup 2+} intake inhibits these endopeptidases activities at the rat prostate and testicles and if it directly inhibits the activity of MMP2 and MMP9 at gelatinolytic assays when present in the incubation buffer. To investigate this hypothesis, Wistar rats (5 weeks old), were given tap water (untreated, n = 9), or 15 ppm CdCl{sub 2} diluted in drinking water, during 10 weeks (n = 9) and 20 weeks (n = 9). The animals were euthanized and their ventral prostate, dorsal prostate, and testicles were removed. These tissue samples were processed for protein extraction and subjected to gelatin zymography evaluation. Additionally, we performed an experiment of gelatin zymography in which 5 μM or 2 mM cadmium chloride (CdCl{sub 2}) was directly dissolved at the incubation buffer, using the prostatic tissue samples from untreated animals that exhibited the highest MMP2 and MMP9 activities in the previous experiment. We have found that CdCl{sub 2} intake in the drinking water led to the inhibition of 35% and 30% of MMP2 and MMP9 (p < 0.05) at the ventral prostate and testis, respectively, in Cd{sup 2+} treated animals when compared to controls. Moreover, the activities of the referred enzymes were 80% and 100% inhibited by 5 μM and 2 mM of CdCl{sub 2}, respectively, even in the presence of 10 mM of CaCl{sub 2} within the incubation buffer solution. These important findings demonstrate that environmental cadmium contamination may deregulate the natural balance in the extracellular matrix turnover, through MMPs downregulation, which could contribute to the toxic effects observed in prostatic and testicular tissue after its exposure. - Highlights: • Wistar rats were given tap water or 15 ppm CdCl{sub 2} diluted in drinking water. • Ventral prostate, dorsal prostate, and testicles were tested for MMPs activity. • CdCl{sub 2} was also directly dissolved at the incubation buffer in another experiment. • Cadmium inhibited the activity of MMP2 and MMP9 in both experiments. • Cadmium contamination may deregulate the natural balance in the ECM turnover.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

A chemically defined culture medium containing Rho kinase inhibitor Y-27632 for the fabrication of stratified squamous epithelial cell grafts

With the development of a culture method for stratified squamous epithelial cells, tissue-engineered epithelial cell sheets have been successfully applied as clinical cell grafts. However, the implementation of these cell sheets without the use of any animal-derived materials is highly desirable. In this study, Rho-associated protein kinase inhibitor Y-27632 was used to develop a chemically defined culture medium for the fabrication of stratified epithelial cell grafts consisting of human epidermal and oral keratinocytes, and the proliferation activity, cell morphology, and gene expressions of the keratinocytes were analyzed. The results of a colorimetric assay indicated that Y-27632 significantly promoted the proliferation of the keratinocytes in culture media both with and without fetal bovine serum (FBS), although there were no indications of Y-27632 efficacy on cell morphology and stratification of the keratinocytes in culture medium without any animal-derived materials. The results of quantitative RT-PCR revealed that gene expressions correlated with cell adhesion, cell–cell junction, proliferation markers, and stem/progenitor markers in cultured keratinocytes were not strongly affected by the addition of Y-27632 to the culture medium. Moreover, gene expressions of differentiation markers in stratified keratinocytes cultured in medium without FBS were nearly identical to those of keratinocytes co-cultured with 3T3 feeder cells. Interestingly, the expressions of differentiation markers in cultured stratified keratinocytes were suppressed by FBS, whereas they were reconstructed by either co-culture of a 3T3 feeder layer or addition of Y-27632 into the culture medium containing FBS. These findings indicate that Y-27632 is a useful supplement for the development of a chemically defined culture medium for fabrication of stratified epithelial cell grafts for clinical applications for the purpose of developing the culture medium with a lower risk of pathogen transmission that might arise from animal-derived materials. - Highlights: • Y-27632 promotes the proliferation of human keratinocytes. • Human keratinocytes with Y-27632 can stratify similarly to traditional method. • Y-27632 is useful for culture medium of human keratinocyte in clinical setting.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

A thematic review of life cycle assessment (LCA) applied to pig production

Commercial livestock production is known to have significant impacts on the environment. Pig production is a complex system which involves the production of animal feed, transportation, animal rearing and waste management. One tool for assessing the environmental performance of such complex systems is life cycle assessment (LCA). LCA has been applied to pig production considerably to date. This paper provides a chronological review of state-of-the-art pig production LCAs under three themes: feed production; entire-system livestock rearing; and waste management. The study considers how LCA applications have addressed technological improvements in animal husbandry, and highlights methodological limitations, particularly related to cross-study comparisons. Recent research demonstrates crude protein reduction in feed and anaerobic treatment of pig excreta resulting in bioenergy production are the key targets for environmental performance improvements related to pig production. - Highlights: • An extensive review of LCA applied to pig production is provided chronologically over the past decade. • Individual studies have been categorised into feed, whole-system pig production and waste management themes. • We consider how LCAs have addressed state-of-the-art pig husbandry. • We offer a discussion on key findings, limitations and future research.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Oxytocin modulates the expression of norepinephrine transporter, β3-adrenoceptors and muscarinic M2 receptors in the hearts of socially isolated rats

Social stress produces behavioral alterations, and autonomic and cardiac dysfunction in animals. In addition to the well-known roles of oxytocin on birth and maternal bonding, recent evidence shows that this neuropeptide possesses cardio-protective properties. However less is known about its role in the regulation of the autonomic nervous system. The direct influence of oxytocin on the cardiac catecholamine synthesizing enzyme, transport beta-adrenoceptors and muscarinic receptors in animals exposed to chronic social isolation stress has not yet been studied. In this study, we examined the influence of peripheral chronic oxytocin treatment on anxiety-related behavior, the morphology and content of epinephrine and norepinephrine, mRNA and protein levels of tyrosine hydroxylase (TH), norepinephrine transporter (NET) and receptors 3 (β3-AR) and muscarinic 2 (M2 MR) in the right and left cardiac atrium and ventricle of chronically socially isolated male rats. Our results show that oxytocin treatment exhibits an anxiolytic effect, decreases the heart/body weight ratio and prevents the hypertrophy of cardiomyocytes in the wall of the left ventricle of stressed rats. Epinephrine and TH protein levels were unchanged after prolonged oxytocin treatment. Peripheral oxytocin administration led to the enhancement of gene expression of β3-AR in both atria, NET protein in the left ventricle and gene expression of M2 MR in the right atrium and the left ventricle of chronically socially isolated rats. The study provides evidence that oxytocin treatment in chronically socially isolated animals enhances norepinephrine uptake and expression of cardio-inhibitory receptors in cardiac tissues, which could have a beneficial effect on the cardiovascular system under the increased activity of the sympathoneural system. © 2018 Elsevier Inc.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Recombinant human tripeptidyl peptidase-1 infusion to the monkey CNS: Safety, pharmacokinetics, and distribution

CLN2 disease is caused by deficiency in tripeptidyl peptidase-1 (TPP1), leading to neurodegeneration and death. The safety, pharmacokinetics (PK), and CNS distribution of recombinant human TPP1 (rhTPP1) were characterized following a single intracerebroventricular (ICV) or intrathecal-lumbar (IT-L) infusion to cynomolgus monkeys. Animals received 0, 5, 14, or 20 mg rhTPP1, ICV, or 14 mg IT-L, in artificial cerebrospinal fluid (aCSF) vehicle. Plasma and CSF were collected for PK analysis. Necropsies occurred at 3, 7, and 14 days post-infusion. CNS tissues were sampled for rhTPP1 distribution. TPP1 infusion was well tolerated and without effect on clinical observations or ECG. A mild increase in CSF white blood cells (WBCs) was detected transiently after ICV infusion. Isolated histological changes related to catheter placement and infusion were observed in ICV treated animals, including vehicle controls. The CSF and plasma exposure profiles were equivalent between animals that received an ICV or IT-L infusion. TPP1 levels peaked at the end of infusion, at which point the enzyme was present in plasma at 0.3% to 0.5% of CSF levels. TPP1 was detected in brain tissues with half-lives of 3–14 days. CNS distribution between ICV and IT-L administration was similar, although ICV resulted in distribution to deep brain structures including the thalamus, midbrain, and striatum. Direct CNS infusion of rhTPP1 was well tolerated with no drug related safety findings. The favorable nonclinical profile of ICV rhTPP1 supports the treatment of CLN2 by direct administration to the CNS. - Highlights: • TPP1 enzyme replacement therapy to the CNS is in development for CLN2 disease. • Toxicology, pharmacokinetics, and CNS distribution were assessed in monkeys. • TPP1 infusion directly to the brain did not result in any safety concerns. • A positive pharmacokinetic and distribution profile resulted from TPP1 infusion. • This study demonstrates the feasibility of ICV administered rhTPP1 to treat CLN2.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Nerve cell-mimicking liposomes as biosensor for botulinum neurotoxin complete physiological activity

Botulinum neurotoxins (BoNT) are the most toxic substances known, and their neurotoxic properties and paralysing effects are exploited for medical treatment of a wide spectrum of disorders. To accurately quantify the potency of a pharmaceutical BoNT preparation, its physiological key activities (binding to membrane receptor, translocation, and proteolytic degradation of SNARE proteins) need to be determined. To date, this was only possible using animal models, or, to a limited extent, cell-based assays. We here report a novel in vitro system for BoNT/B analysis, based on nerve-cell mimicking liposomes presenting motoneuronal membrane receptors required for BoNT binding. Following triggered membrane translocation of the toxin's Light Chain, the endopeptidase activity can be quantitatively monitored employing a FRET-based reporter assay within the functionalized liposomes. We were able to detect BoNT/B physiological activity at picomolar concentrations in short time, opening the possibility for future replacement of animal experimentation in pharmaceutical BoNT testing. - Highlights: • A cell-free in vitro system was used to measure BoNT/B physiological function. • The system relies on nerve-cell mimicking liposomes as a novel detection system. • A FRET-based reporter assay is used as final readout of the test system. • BoNT/B physiological activity was detected at picogram quantities in short time. • The method opens the possibility to replace animal experimentation in BoNT testing.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Kinetics of liver macrophages (Kupffer cells) in SIV-infected macaques

Since the liver drains antigens from the intestinal tract, and since the intestinal tract is a major site of viral replication, we examined the dynamics of liver macrophages (Kupffer cells) throughout SIV infection. Absolute numbers of Kupffer cells increased in the livers in acute infection, and in animals with AIDS. Significantly higher percentages of proliferating (BrdU+) Kupffer cells were detected in acute infection and in AIDS with similar trends in blood monocytes. Significantly higher percentages of apoptotic (AC3+) Kupffer cells were also found in acute and AIDS stages. However, productively infected cells were not detected in liver of 41/42 animals examined, despite abundant infected cells in gut and lymph nodes of all animals. Increased rates of Kupffer cell proliferation resulting in an increase in Kupffer cells without productive infection indicate SIV infection affects Kupffer cells, but the liver does not appear to be a major site of productive viral replication. - Highlights: • Kupffer cells increase in the liver of SIV-infected macaques. • Increased proliferation and apoptosis of Kupffer cells occurs in SIV infection. • Productively infected cells are rarely detected in the liver. • The liver is not a major site for SIV replication.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

DNA cleavage enzymes for treatment of persistent viral infections: Recent advances and the pathway forward

Treatment for most persistent viral infections consists of palliative drug options rather than curative approaches. This is often because long-lasting viral DNA in infected cells is not affected by current antivirals, providing a source for viral persistence and reactivation. Targeting latent viral DNA itself could therefore provide a basis for novel curative strategies. DNA cleavage enzymes can be used to induce targeted mutagenesis of specific genes, including those of exogenous viruses. Although initial in vitro and even in vivo studies have been carried out using DNA cleavage enzymes targeting various viruses, many questions still remain concerning the feasibility of these strategies as they transition into preclinical research. Here, we review the most recent findings on DNA cleavage enzymes for human viral infections, consider the most relevant animal models for several human viral infections, and address issues regarding safety and enzyme delivery. Results from well-designed in vivo studies will ideally provide answers to the most urgent remaining questions, and allow continued progress toward clinical application. - Highlights: • Recent in vitro and in vivo results for DNA cleavage enzymes targeting persistent viral infections. • Analysis of the best animal models for testing enzymes for HBV, HSV, HIV and HPV. • Challenges facing in vivo delivery of therapeutic enzymes for persistent viral infections. • Safety issues to be addressed with proper animal studies.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Suppressing active replication of a live attenuated simian immunodeficiency virus vaccine does not abrogate protection from challenge

Although safety concerns preclude the use of live attenuated HIV vaccines in humans, they provide a useful system for identifying the elusive correlates of protective immunity in the SIV/macaque animal model. However, a number of pieces of evidence suggest that protection may result from prior occupancy of susceptible target cells by the vaccine virus rather than the immune response. To address this, we developed a Nef-deletion variant of an RT-SHIV whose active replication could be shut off by treatment with RT-inhibitors. Groups of macaques were inoculated with the ∆Nef-RT-SHIV and immune responses allowed to develop before antiretroviral treatment and subsequent challenge with wild-type SIVmac239. Vaccinated animals either resisted infection fully or significantly controlled the subsequent viremia. However, there was no difference between animals undergoing replication of the vaccine virus and those without. This strongly suggests that competition for available target cells does not play a role in protection. - Highlights: • A Nef-deleted RT-SHIV was used as a live attenuated vaccine in macaques. • Vaccine virus replication was shut down to investigate its role in protection. • Ongoing vaccine virus replication did not appear to be necessary for protection. • An analysis of T- and B-cell responses failed to identify a correlate of protection.

60 APPLIED LIFE SCIENCES↗