The primary sequence of the prion protein affects susceptibility to transmissible spongiform encephalopathies, or prion diseases, in mice, sheep and humans. The Prnp gene sequence of free-ranging, Wisconsin white-tailed deer was determined and the Prnp genotypes of chronic wasting disease (CWD)-positive and CWD-negative deer were compared. Six amino acid changes were identified, two of which were located in pseudogenes. Two alleles, a QRK polymorphism at codon 226 and a single octapeptide repeat insertion into the pseudogene, have not been reported previously. The predominant alleles -wild-type (Q95, G96 and Q226) and a G96S polymorphism -comprised almost 98 % of the Prnp alleles in the Wisconsin white-tailed deer population. Comparison of the allelic frequencies in the CWD-positive and CWD-negative deer suggested that G96S and a Q95H polymorphism were linked to a reduced susceptibility to CWD. The G96S allele did not, however, provide complete resistance, as a CWD-positive G96S/G96S deer was identified. The G96S allele was also linked to slower progression of the disease in CWD-positive deer based on the deposition of PrP CWD in the obex region of the medulla oblongata.Although the reduced susceptibility of deer with at least one copy of the Q95H or G96S allele is insufficient to serve as a genetic barrier, the presence of these alleles may modulate the impact of CWD on white-tailed deer populations.

Analysis of the PRNP gene in cervids naturally infected with chronic wasting disease (CWD) suggested that PRNP polymorphisms affect the susceptibility of deer to infection. To test this effect, we orally inoculated 12 white-tailed deer with CWD agent. Three different PRNP alleles, wild-type (wt; glutamine at amino acid 95 and glycine at 96), Q95H (glutamine to histidine at amino acid position 95) and G96S (glycine to serine at position 96) were represented in the study cohort with 5 wt/wt, 3 wt/G96S, and 1 each wt/Q95H and Q95H/G96S. Two animals were lost to follow-up due to intercurrent disease. The inoculum was prepared from Wisconsin hunter-harvested homozygous wt/wt animals. All infected deer presented with clinical signs of CWD; the orally infected wt/wt had an average survival period of 693 days post inoculation (dpi) and G96S/wt deer had an average survival period of 956 dpi. The Q95H/wt and Q95H/G96S deer succumbed to CWD at 1,508 and 1,596 dpi respectively. These data show that polymorphisms in the PRNP gene affect CWD incubation period. Deer heterozygous for the PRNP alleles had extended incubation periods with the Q95H allele having the greatest effect.

No abstract

Identification of genes expressed in response to prion infection may elucidate biomarkers for disease, identify factors involved in agent replication, mechanisms of neuropathology and therapeutic targets. Although several groups have sought to identify gene expression changes specific to prion disease, expression profiles rife with cell population changes have consistently been identified. Cuprizone, a neurotoxicant, qualitatively mimics the cell population changes observed in prion disease, resulting in both spongiform change and astrocytosis. The use of cuprizone-treated animals as an experimental control during comparative expression profiling allows for the identification of transcripts whose expression increases during prion disease and remains unchanged during cuprizone-triggered neuropathology. In this study, expression profiles from the brains of mice preclinically and clinically infected with Rocky Mountain Laboratory (RML) mouse-adapted scrapie agent and age-matched controls were profiled using Affymetrix gene arrays. In total, 164 genes were differentially regulated during prion infection. Eighty-three of these transcripts have been previously undescribed as differentially regulated during prion disease. A 0.4% cuprizone diet was utilized as a control for comparative expression profiling. Cuprizone treatment induced spongiosis and astrocyte proliferation as indicated by glial fibrillary acidic protein (Gfap) transcriptional activation and immunohistochemistry. Gene expression profiles from brain tissue obtained from cuprizone-treated mice identified 307 differentially regulated transcript changes. After comparative analysis, 17 transcripts unaffected by cuprizone treatment but increasing in expression from preclinical to clinical prion infection were identified. Here we describe the novel use of the prion disease mimetic, cuprizone, to control for cell population changes in the brain during prion infection.

Background: Millions of children in the United States have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with many infections leading to hospitalization. For pediatric patients, especially younger children, treatment options are limited. Remdesivir has demonstrated a positive safety and efficacy profile in adults, but little data is published regarding remdesivir use in pediatric patients. Additional data for SARS-CoV-2 treatments in pediatric patients is required to prevent further SARS-CoV-2–related morbidity and mortality. At a single pediatric academic medical center, the safety and efficacy of remdesivir was evaluated. Methods: A retrospective review of patients admitted to a pediatric academic medical center who received remdesivir over a 17-month period was completed. All pediatric patients who received at least 1 dose of remdesivir were included. Safety and efficacy were assessed using national organization’s definitions of clinical improvement, bradycardia, hypertension, acute kidney injury and drug-induced liver injury. Results: There were 48 pediatric patients included in this study with 29% of patients admitted to the pediatric intensive care unit. Less than one-third of patients received the full treatment course of remdesivir, with over half of patients not completing therapy due to symptomatic improvement or hospital discharge. Majority of patients required some level of supplemental oxygen support. The median World Health Organization score was consistent throughout all 5 days of therapy. No patients experienced significant bradycardia, hypertension, acute kidney injury, or drug-induced liver injury. Conclusions: Remdesivir may correlate with clinical stability or improvement and demonstrates safety when used in pediatric patients. A randomized controlled trial is needed to confirm these findings.