Scholarly Works, Biomedical Sciences and Pathobiology
Permanent URI for this collection
Research articles, presentations, and other scholarship
Browse
Browsing Scholarly Works, Biomedical Sciences and Pathobiology by Subject "06 Biological Sciences"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- Adenovirus transduction to express human ACE2 causes obesity-specific morbidity in mice, impeding studies on the effect of host nutritional status on SARS-CoV-2 pathogenesisRai, Pallavi; Chuong, Christina; LeRoith, Tanya; Smyth, James W.; Panov, Julia; Levi, Moshe; Kehn-Hall, Kylene; Duggal, Nisha K.; Weger-Lucarelli, James (Elsevier, 2021-11-01)The COVID-19 pandemic has paralyzed the global economy and resulted in millions of deaths globally. People with co-morbidities like obesity, diabetes and hypertension are at an increased risk for severe COVID-19 illness. This is of overwhelming concern because 42% of Americans are obese, 30% are pre-diabetic and 9.4% have clinical diabetes. Here, we investigated the effect of obesity on disease severity following SARS-CoV-2 infection using a well-established mouse model of diet-induced obesity. Diet-induced obese and lean control C57BL/6 N mice, transduced for ACE2 expression using replication-defective adenovirus, were infected with SARS-CoV-2, and monitored for lung pathology, viral titers, and cytokine expression. No significant differences in tissue pathology or viral replication was observed between AdV transduced lean and obese groups, infected with SARS-CoV-2, but certain cytokines were expressed more significantly in infected obese mice compared to the lean ones. Notably, significant weight loss was observed in obese mice treated with the adenovirus vector, independent of SARS-CoV-2 infection, suggesting an obesity-dependent morbidity induced by the vector. These data indicate that the adenovirus-transduced mouse model of SARS-CoV-2 infection, as described here and elsewhere, may be inappropriate for nutrition studies.
- Immunogenicity of Potomac horse fever vaccine when simultaneously co-administered with rabies vaccine in a multivalent vaccine or as two monovalent vaccines at separate sitesMcKenzie, H. C.; Funk, Rebecca A.; Trager, L.; Werre, Stephen R.; Crisman, Mark V. (Wiley, 2019-11-01)Background: Potomac horse fever (PHF) is a potentially fatal enterocolitis of horses caused by Neorickettsia risticii. The disease was originally recognised almost 40 years ago in the state of Maryland in the US. It is now known to occur in many areas of North America, as well as having been described in South America and Europe. Monocomponent PHF vaccines are available, but clinical protection with vaccination has been reported to be inconsistent. Objectives: This study was designed to assess the immunogenicity of a commercially available Potomac Horse Fever (PHF) vaccine when administered as either a monovalent PHF vaccine simultaneously co-administered with a separate monovalent Rabies vaccine or as a multivalent PHF/Rabies vaccine in horses. Study design: Randomised parallel group trial. Methods: Ninety-one client or University owned horses participated in this open-label randomised study, with 45 horses receiving the monovalent vaccines at separate sites and 46 receiving the multivalent vaccine at a single site. Serum PHF IFA titres were determined twice prior to vaccination and at 1, 2 and 3 months after vaccination. Results: Both vaccination protocols exhibited poor immunogenicity, with only one-third of all the animals demonstrating seroconversion, defined as an increase in titre of greater than 400 over baseline, at any time point after vaccination. The monovalent PHF vaccine exhibited significantly greater immunogenicity in terms of the number of horses exhibiting seroconversion, as compared to the multivalent vaccine, at one (20 vs. 11, P = 0.03) and two (18 vs. 9, p = 0.02) months post vaccination. The monovalent PHF vaccine also exhibited significantly greater immunogenicity in terms of the median (interquartile range) IFA titres, as compared to the multivalent vaccine, at one (800 [200–1600] vs. 400 [200–800], P = 0.009) and 2 months (400 [200–1600] vs. 400 [100–800], P = 0.02) post vaccination. There was no significant difference between groups at 3 months in either seroconversion rate or median IFA titers. Main limitations: This study did not assess the actual protective effects of PHF vaccination but rather used the serologic response to vaccination as a surrogate biomarker of immunity. Conclusions: The multivalent PHF/Rabies vaccine exhibited lower immunogenicity as compared to the monovalent PHF vaccine co-administered with a separate Rabies vaccine.
- Improved plaque assay for human coronaviruses 229E and OC43Bracci, Nicole R.; Pan, Han-Chi; Lehman, Caitlin W.; Kehn-Hall, Kylene; Lin, Shih-Chao (PeerJ, 2020-12-21)In light of the COVID-19 pandemic, studies that work to understand SARS-CoV-2 are urgently needed. In turn, the less severe human coronaviruses such as HCoV-229E and OC43 are drawing newfound attention. These less severe coronaviruses can be used as a model to facilitate our understanding of the host immune response to coronavirus infection. SARS-CoV-2 must be handled under biosafety level 3 (BSL-3) conditions. Therefore, HCoV-229E and OC43, which can be handled at BSL-2 provide an alternative to SARS-CoV-2 for preclinical screening and designing of antivirals. However, to date, there is no published effective and efficient method to titrate HCoVs other than expensive indirect immunostaining. Here we present an improved approach using an agarose-based conventional plaque assay to titrate HCoV 229E and OC43 with mink lung epithelial cells, Mv1Lu. Our results indicate that titration of HCoV 229E and OC43 with Mv1Lu is consistent and reproducible. The titers produced are also comparable to those produced using human rhabdomyosarcoma (RD) cells. More importantly, Mv1Lu cells display a higher tolerance for cell-cell contact stress, decreased temperature sensitivity, and a faster growth rate. We believe that our improved low-cost plaque assay can serve as an easy tool for researchers conducting HCoV research.
- In vitro and in vivo activities of the carbonic anhydrase inhibitor, dorzolamide, against vancomycin-resistant enterococciAbutaleb, Nader S.; Elhassanny, Ahmed E. M.; Flaherty, Daniel P.; Seleem, Mohamed N. (PeerJ, 2021-03-30)Vancomycin-resistant enterococci (VRE) are a serious public health threat and a leading cause of healthcare-associated infections. Bacterial resistance to antibiotics recommended for the treatment of enterococcal infections complicates the management of these infections. Hence, there is a critical need for the discovery of new anti-VRE agents. We previously reported carbonic anhydrase inhibitors (CAIs) as new potent VRE inhibitors. In the present study, the activity of the CAI, dorzolamide was evaluated against VRE both in vitro and in vivo. Dorzolamide exhibited potent activity against a panel of clinical VRE isolates, with minimum inhibitory concentration (MIC) values ranging from 1 µg/mL to 8 µg/mL. A killing kinetics experiment determined that dorzolamide exhibited a bacteriostatic effect against VRE, which was similar to the drug of choice (linezolid). Dorzolamide interacted synergistically with gentamicin against four strains of VRE, and exhibited an additive interaction with gentamicin against six VRE strains, reducing gentamicin’s MIC by several folds. Moreover, dorzolamide outperformed linezolid in an in vivo VRE colonization reduction mouse model. Dorzolamide significantly reduced the VRE burden in fecal samples of mice by 2.9-log10 (99.9%) and 3.86-log10 (99.99%) after 3 and 5 days of treatment, respectively. Furthermore, dorzolamide reduced the VRE count in the cecal (1.74-log10 (98.2%) reduction) and ileal contents (1.5-log10 (96.3%)) of mice, which was superior to linezolid. Collectively, these results indicate that dorzolamide represents a promising treatment option that warrants consideration as a supplement to current therapeutics used for VRE infections.
- Pharmacokinetics and ex vivo anti-inflammatory effects of oral misoprostol in horsesMartin, E. M.; Schirmer, J. M.; Jones, S. L.; Davis, Jennifer L. (Wiley, 2019-05)Background: Misoprostol is an E prostanoid (EP) 2, 3 and 4 receptor agonist that is anecdotally used to treat and prevent NSAID-induced GI injury in horses. Misoprostol elicits anti-inflammatory effects in vivo in men and rodents, and inhibits TNFα production in equine leucocytes in vitro. Objective: Define the pharmacokinetic parameters of oral misoprostol in horses, and determine the inhibitory effect of oral misoprostol administration on equine leucocyte TNFα production in an ex vivo inflammation model. Study design: Pharmacokinetic study, ex vivo experimental study. Methods: Six healthy adult horses of mixed breeds were used. In phase one, horses were given 5 μg/kg misoprostol orally, and blood was collected at predetermined times for determination of misoprostol free acid (MFA) by UHPLC-MS/MS. Pharmacokinetic parameters were calculated. In phase two, horses were dosed as in phase one, and blood was collected at T0, 0.5, 1 and 4 h following misoprostol administration for leucocyte isolation. Leucocytes were stimulated with 100 ng/mL LPS, and TNFα mRNA concentrations were determined via quantitative real-time PCR. Results: About 5 μg/kg oral misoprostol produced a rapid time to maximum concentration (Tmax ) of 23.4 ± 2.4 min, with a maximum concentration (Cmax ) of 0.29 ± 0.07 ng/mL and area under the curve (AUC0-∞ ) of 0.4 ± 0.12 h ng/mL. LPS stimulation of equine leucocytes ex vivo significantly increased TNFα mRNA concentrations, and there was no significant effect of misoprostol even at the Tmax . Main limitations: Only a single dose was used, and sample size was small. Conclusions: Misoprostol is rapidly absorbed following oral administration in horses, and a single 5 μg/kg dose had no significant inhibitory effect on ex vivo LPS-stimulated TNFα mRNA production in leucocytes. Further studies analysing different dosing strategies, including repeat administration or combination with other anti-inflammatory drugs, are warranted.
- A selective sweep in the Spike gene has driven SARS-CoV-2 human adaptationKang, Lin; He, Guijuan; Sharp, Amanda K.; Wang, Xiaofeng; Brown, Anne M.; Michalak, Pawel; Weger-Lucarelli, James (Cell Press, 2021-08-19)The coronavirus disease 2019 (COVID-19) pandemic underscores the need to better understand animal-to-human transmission of coronaviruses and adaptive evolution within new hosts. We scanned more than 182,000 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes for selective sweep signatures and found a distinct footprint of positive selection located around a non-synonymous change (A1114G; T372A) within the spike protein receptor-binding domain (RBD), predicted to remove glycosylation and increase binding to human ACE2 (hACE2), the cellular receptor. This change is present in all human SARS-CoV-2 sequences but not in closely related viruses from bats and pangolins. As predicted, T372A RBD bound hACE2 with higher affinity in experimental binding assays. We engineered the reversion mutant (A372T) and found that A372 (wild-type [WT]-SARS-CoV-2) enhanced replication in human lung cells relative to its putative ancestral variant (T372), an effect that was 20 times greater than the well-known D614G mutation. Our findings suggest that this mutation likely contributed to SARS-CoV-2 emergence from animal reservoirs or enabled sustained human-to-human transmission.