Split-Dose Administration Enhances Immune Responses Elicited by a mRNA/Lipid Nanoparticle Vaccine Expressing Respiratory Syncytial Virus F Protein.

mRNA vaccines have recently received significant attention due to their role in combating the SARS-CoV-2 pandemic. As a platform, mRNA vaccines have been shown to elicit strong humoral and cellular immune responses with acceptable safety profiles for prophylactic use. Despite their potential, industrial challenges have limited realization of the vaccine platform on a global scale. Critical among these challenges are supply chain considerations, including mRNA production, cost of goods, and vaccine frozen-chain distribution. Here, we assess the delivery of lipid nanoparticle-encapsulated mRNA (mRNA/LNP) vaccines using a split-dose immunization regimen as an approach to develop mRNA dose-sparing vaccine regimens with potential to mitigate mRNA supply chain challenges. Our data demonstrate that immunization by a mRNA/LNP vaccine encoding respiratory syncytial virus pre-F (RSV pre-F) over a 9 day period elicits comparable or superior magnitude of antibodies when compared to traditional bolus immunization of the vaccine. The split-dose immunization regimens evaluated in our studies were designed to mimic reported drug or antigen release profiles from microneedle patches, highlighting the potential benefit of pairing mRNA vaccines with patch-based delivery technologies to enable sustained release and solid-state stabilization. Overall, our findings provide a proof of concept to support further investigations into the development of sustained delivery approaches for mRNA/LNP vaccines.

ß-Adrenergic receptor-mediated transactivation of epidermal growth factor receptor decreases cardiomyocyte apoptosis through differential subcellular activation of ERK1/2 and Akt.

ß-Adrenergic receptor (ßAR)-mediated transactivation of epidermal growth factor receptor (EGFR) has been shown to relay pro-survival effects via unknown mechanisms. We hypothesized that acute ßAR-mediated EGFR transactivation in the heart promotes differential subcellular activation of ERK1/2 and Akt, promoting cell survival through modulation of apoptosis. C57BL/6 mice underwent acute i.p. injection with isoproterenol (ISO)±AG 1478 (EGFR antagonist) to assess the impact of ßAR-mediated EGFR transactivation on the phosphorylation of ERK1/2 (P-ERK1/2) and Akt (P-Akt) in distinct cardiac subcellular fractions. Increased P-ERK1/2 and P-Akt were observed in cytosolic, plasma membrane and nuclear fractions following ISO stimulation. Whereas the P-ERK1/2 response was EGFR-sensitive in all fractions, the P-Akt response was EGFR-sensitive only in the plasma membrane and nucleus, results confirmed in primary rat neonatal cardiomyocytes (RNCM). ßAR-mediated EGFR-transactivation also decreased apoptosis in serum-depleted RNCM, as measured via TUNEL as well as caspase 3 activity/cleavage, which were sensitive to the inhibition of either ERK1/2 (PD184352) or Akt (LY-294002) signaling. Caspase 3 activity/cleavage was also sensitive to the inhibition of transcription, which, with an increase in nuclear P-ERK1/2 and P-Akt in response to ISO, suggested that ßAR-mediated EGFR transactivation may regulate apoptotic gene transcription. An Apoptosis PCR Array identified tnfsf10 (TRAIL) to be altered by ISO in an EGFR-sensitive manner, results confirmed via RT-PCR and ELISA measurement of both membrane-bound and soluble cardiomyocyte TRAIL levels. ßAR-mediated EGFR transactivation induces differential subcellular activation of ERK1/2 and Akt leading to increased cell survival through the modulation of caspase 3 activity and apoptotic gene expression in cardiomyocytes.

Validation of the AgraStrip® gluten G12 test kit.

Romer Labs , Inc. developed an immunochromatographic lateral flow assay for the qualitative detection of gluten in raw ingredients, processed foods, finished food products, and environmental surfaces, using the G12 antibody developed by Belén Morón. The G12 antibody targets a 33-mer peptide which is resistant to enzymatic digestion and heat denatiuration, as well as being the fragment of the gliadin protein.to which celiac disease sufferers react, making it a reliable analytical marker. This study was performed to validate the AgraStrip® GlutenG12 assay method under the guidance of the AOAC Peiformance Tested MethodsSM (PTM) program against AOAC Official Method of AnalysisSM 2012.01 in rice flour, bread, cookie, ice cream, and chocolate matrixes spiked with either purified gliadin or wheat gluten standard at 0, 3, 8, 15, and 25 ppm concentrations and tested at the 5, 10, and 20 ppm assay thresholds, as well as on, environmental surfaces. Stability, robustness, variation, and lot consistency studies were performed by spiking wheat gluten into a rice flour matrix at 0 and 15 ppm concentrations. The AgraStrip Gluten G12 assay was rigorously evaluated during this study and demonstrates its suitability as an AOAC PTM-certified gluten detection method.

A review of the application of active learning pedagogies in undergraduate animal science curricula.

With most of the student attrition occurring early in undergraduate educational programs (Braunstein et al., 1997) it is necessary to interest and motivate students early on. The demographics of animal science students have shifted to students with minimal background in food producing animals. This presents a unique challenge as the current student population represents a diverse array of backgrounds and prior experiences. As a result, students enroll in undergraduate animal science programs with various expectations for their undergraduate degree and a focus primarily on careers in veterinary medicine. To engage all students, interest and motivation need to be generated. This review will use motivational frameworks as outlined by the self-determination theory, expectancy value theory, and interest, to explain the impact of the proposed solutions. Active learning classroom strategies are linked to increased knowledge compared with traditional, passive classrooms (Wells et al., 2019). Active learning shifts from a traditional teaching model to a student-centered model, which transitions instructors to facilitators of learning. This review summarizes current proposed pedagogies that have been researched in animal science classrooms such as experiential learning, flipped classrooms, hands-on animal experience, undergraduate research experiences, mentorship opportunities, capstone experiences, service-learning experiences, team-based learning, and cooperative learning. The limitations of these proposed pedagogies and the future research needed are also discussed.

Animal science undergraduate curricula face the issue of motivating and interesting students from diversified backgrounds to meet the growing job market (Benson et al., 2020; Lugar & Stewart, 2019). Students are entering animal science majors with different expectations and values as explained by the expectancy-value theory, so higher education systems face the struggle of meeting diverse student interests while fulfilling required course content. One solution to this challenge is to generate interest and motivation through engaging students in student-centered spaces and creating autonomy, competence and relatedness as outlined by the self-determination theory (Ryan & Deci, 2020). This review examines current research available on different teaching pedagogies in animal science classroom and summarizes their impact. The reviewed pedagogies are possible strategies that institutions can utilize to meet this challenge and motivate students.

A Novel Rotavirus Reverse Genetics Platform Supports Flexible Insertion of Exogenous Genes and Enables Rapid Development of a High-Throughput Neutralization Assay.

Despite the success of rotavirus vaccines, rotaviruses remain one of the leading causes of diarrheal diseases, resulting in significant childhood morbidity and mortality, especially in low- and middle-income countries. The reverse genetics system enables the manipulation of the rotavirus genome and opens the possibility of using rotavirus as an expression vector for heterologous proteins, such as vaccine antigens and therapeutic payloads. Here, we demonstrate that three positions in rotavirus genome-the C terminus of NSP1, NSP3 and NSP5-can tolerate the insertion of reporter genes. By using rotavirus expressing GFP, we develop a high-throughput neutralization assay and reveal the pre-existing immunity against rotavirus in humans and other animal species. Our work shows the plasticity of the rotavirus genome and establishes a high-throughput assay for interrogating humoral immune responses, benefiting the design of next-generation rotavirus vaccines and the development of rotavirus-based expression platforms.

Predominance of a bacteriocin-producing Lactobacillus salivarius component of a five-strain probiotic in the porcine ileum and effects on host immune phenotype.

Relative predominance of each of five probiotic strains was investigated in the ileum of weaned pigs, compared with that in feces, when administered in combination at c. 5 x 10(9) CFU day(-1) for 28 days. Probiotic was excreted at 10(6)-10(9) CFU g(-1) feces, while ileal survival ranged from 10(2) to 10(6) CFU g(-1) digesta. In contrast to the feces, where Lactobacillus murinus DPC6002 predominated, the bacteriocin-producing Lactobacillus salivarus DPC6005 dominated over coadministered strains both in the ileum digesta and in mucosa. Probiotic administration did not alter counts of culturable fecal Lactobacillus or Enterobacteriaceae but higher ileal Enterobacteriaceae were observed in the ileal digesta of probiotic-fed pigs (P<0.05). We observed decreased CD25 induction on T cells and monocytes (P<0.01) and decreased CTLA-4 induction (P<0.05) by the mitogen phytohemagglutinin on CD4 T cells from the probiotic group. Probiotic treatment also increased the proportion of CD4+ CD8+ T cells within the peripheral T-cell population and increased ileal IL-8 mRNA expression (P<0.05). In conclusion, superior ileal survival of L. salivarius compared with the other coadministered probiotics may be due to a competitive advantage conferred by its bacteriocin. The findings also suggest that the five-strain combination may function as a probiotic, at least in part, via immunomodulation.

Comparison of Vocalization Patterns in Piglets Which Were Crushed to Those Which Underwent Human Restraint.

Though many studies focused on piglet crushing utilizing piglet vocalizations to test sow response, none have verified the properties of test vocalizations against actual crushing events. Ten sows were observed 48 h after parturition, and crushing events were recorded from all sows. When a crushing event occurred, a second piglet within the same litter was used to solicit a vocalization through manual restraint to compare restrained piglets' call properties to those of crushed piglets'. A total of 659 Restrained calls and 631 Crushed calls were collected. Variables were gathered at the loudest point in a call, and as an average across the entire call. Crushed piglets had a lower fundamental frequency (p < 0.01; Crushed: 523.57 ± 210.6 Hz; Restrained: 1214.86 ± 203.2 Hz) and narrower bandwidth (p < 0.01; Crushed: 4897.01 ± 587.3 Hz; Restrained: 6674.99 ± 574.0 Hz) when analyzed at the loudest portion of a call. Overall, piglets which were crushed had a lower mean peak frequency than those which were restrained (p = 0.01; 1497.08 ± 239.4 Hz and 2566.12 ± 235.0 Hz, respectively). Future research should focus on measuring sow reactivity to Crushed and Restrained piglets to continue to improve research practices.