Oral Delivery of Acid Alpha Glucosidase Epitopes Expressed in Plant Chloroplasts Suppresses Antibody Formation in Treatment of Pompe Mice

Deficiency of acid alpha glucosidase (GAA) causes Pompe disease in which the patients systemically accumulate lysosomal glycogen in muscles and nervous systems, often resulting in infant mortality. Although enzyme replacement therapy (ERT) is effective in treating patients with Pompe disease, formation of antibodies against rhGAA complicates treatment. In this report, we investigated induction of tolerance by oral administration of GAA expressed in chloroplasts. Because full-length GAA could not be expressed, N-terminal 410-amino acids of GAA (as determined by T-cell epitope mapping) were fused with the transmucosal carrier CTB. Tobacco transplastomic lines expressing CTB-GAA were generated through site-specific integration of transgenes into the chloroplast genome. Homoplasmic lines were confirmed by Southern blot analysis. Despite low-level expression of CTB-GAA in chloroplasts, yellow or albino phenotype of transplastomic lines was observed due to binding of GAA to a chloroplast protein that has homology to mannose-6 phosphate receptor. Oral administration of the plant-made CTB-GAA fusion protein even at 330-fold lower dose (1.5 μg) significantly suppressed immunoglobulin formation against GAA in Pompe mice injected with 500 μg rhGAA per dose, with several-fold lower titre of GAA-specific IgG1 and IgG2a. Lyophilization increased CTB-GAA concentration by 30-fold (up to 190 μg per g of freeze-dried leaf material), facilitating long-term storage at room temperature and higher dosage in future investigations. This study provides the first evidence that oral delivery of plant cells is effective in reducing antibody responses in ERT for lysosomal storage disorders facilitating further advances in clinical investigations using plant cell culture system or in vitro propagation

Rapid and differential losses of in vivo dopamine transporter (DAT) and vesicular monoamine transporter (VMAT2) radioligand binding in MPTP-treated mice

The dose- and time-dependent changes of in vivo radioligand binding to the neuronal membrane dopamine transporter (DAT) and vesicular monoamine transporter type 2 (VMAT2) were examined in mouse brain after MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) administrations. Regional brain distribution studies were done in male C57BL/6 mice using simultaneous injections of d - threo -[ 3 H]methylphenidate (DAT) and (+)-α-[ 11 C]dihydrotetrabenazine (VMAT2). Single (55 mg/kg i.p.) or multiple (4 × 10 mg/kg i.p., 1-hour intervals) administration of MPTP caused significant reductions in [ 3 H]methylphenidate and [ 11 C]dihydrotetrabenazine specific striatal binding, measured 14 days later. The single high dose of MPTP produced greater losses of [ 11 C]dihydrotetrabenazine binding than did the multiple MPTP dosing regimen. Using the single high dose of MPTP, changes of in vivo binding of the two radioligands were determined at 1, 3, and 14 days after neurotoxin injection. At 1 day, there are large losses of [ 3 H]methylphenidate binding (DAT) but no changes in [ 11 C]dihydrotetrabenazine binding to the VMAT2 site in the striatum. At 3 and 14 days, there were >50% losses of binding of both bot radioligands, but significantly ( P < 0.001) greater losses of VMAT2 binding of [ 11 C]dihydrotetrabenazine. These studies indicate that the losses of the neuronal membrane and vesicular transporters are not always equal, and do not occur in the same time frame, after administration of the neurotoxin MPTP. Synapse 35:250–255, 2000. © 2000 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34986/1/2_ftp.pd

In vitro and ex vivo evaluation of N‐methyl benzilates as potential PET agents for muscarinic receptors

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90199/1/25802601207_ftp.pd

The effect of specimen processing on radiolabeled monoclonal antibody biodistribution

Monoclonal antibodies are assuming increasing importance in experimental and clinical medicine. Generally, tissue biodistribution studies in animals precede human studies. To investigate a concern of ours that varying methods of sample handling in these studies could result in apparent alterations in tissue-binding levels, we compared two methods of tissue processing after the administration of labeled antibodies: one including only blotting away of blood, the other involving several washing steps. The unwashed, blotted specimens were found to have significantly more radioactivity per gram of tissue than the washed, ranging from 22% more in the spleen to 52% more in the lungs and left ventricle. Since in vivo imaging is dependent on the total mount of radioactivity in an organ, we believe the most meaningful determination of tissue radioactivity should be based on unwashed samples. Awareness of this problem is suggested to allow meaningful extrapolations from measured tisue localization data to imaging and therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46846/1/259_2004_Article_BF00252876.pd

Repeated reserpine administration reduces in vivo [18F]GBR 13119 binding to the dopamine uptake site

The effects of repeated reserpine on the in vivo regional brain distribution of [18F]GBR 13119 (1-[(4-[18F]fluorophenyl)(phenyl)methoxy)ethyl]-4-(3-phenylpropyl)piperazine), a dopamine uptake inhibitor, have been examined. Repeated parenteral administration of reserpine (2 mg/kg i.p., once daily for three days) causes a decrease of the in vivo specific binding of [18F]GBR 13119 in mouse striatum, consistent with a down-regulation of available uptake sites in response to dopamine depletion. These results indicate that modification of endogenous dopamine concentrations, either due to pathological disturbance or pharmacological interventions, may affect in vivo studies of the dopamine uptake system using radioligands of the 1,4-dialk(en)ylpiperazine class, and complicate the interpretation of in vivo human studies of these radioligands using positron emission tomography.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30038/1/0000406.pd

Assessment of the biodistribution of an [ 18 F]FDG‐loaded perfluorocarbon double emulsion using dynamic micro‐PET in rats

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97497/1/cmmi1532.pd

(−)‐[ 18 F]Flubatine: evaluation in rhesus monkeys and a report of the first fully automated radiosynthesis validated for clinical use

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101867/1/jlcr3069.pd

Jedi public health: Co-creating an identity-safe culture to promote health equity

© 2016 The Authors. The extent to which socially-assigned and culturally mediated social identity affects health depends on contingencies of social identity that vary across and within populations in day-to-day life. These contingencies are structurally rooted and health damaging inasmuch as they activate physiological stress responses. They also have adverse effects on cognition and emotion, undermining self-confidence and diminishing academic performance. This impact reduces opportunities for social mobility, while ensuring those who "beat the odds" pay a physical price for their positive efforts. Recent applications of social identity theory toward closing racial, ethnic, and gender academic achievement gaps through changing features of educational settings, rather than individual students, have proved fruitful. We sought to integrate this evidence with growing social epidemiological evidence that structurally-rooted biopsychosocial processes have population health effects. We explicate an emergent framework, Jedi Public Health (JPH). JPH focuses on changing features of settings in everyday life, rather than individuals, to promote population health equity, a high priority, yet, elusive national public health objective. We call for an expansion and, in some ways, a re-orienting of efforts to eliminate population health inequity. Policies and interventions to remove and replace discrediting cues in everyday settings hold promise for disrupting the repeated physiological stress process activation that fuels population health inequities with potentially wide application.National Institute on Aging (Grant # R01 AG032632)National Institute on Aging (Grant # T32 AG00221

A Method to Estimate the Chronic Health Impact of Air Pollutants in U.S. Residences

Background: Indoor air pollutants (IAPs) cause multiple health impacts. Prioritizing mitigation options that differentially affect individual pollutants and comparing IAPs with other environmental health hazards require a common metric of harm