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Macrophages are innate immune cells with multiple functions such as phagocytosis, cytokine production, and antigen presentation. Since macrophages play critical roles in some bacterial infectious diseases in cattle, including tuberculosis, paratuberculosis, and brucellosis, the in vitro culturing of bovine macrophages is useful for evaluating host–pathogen interactions at the cellular and molecular levels. We have previously reported the establishment of two immortalized bovine liver sinusoidal cell lines, endothelial B46 cells and myofibroblast‐like A26 cells (Cell Biology International, 40, 1372−1379, 2016). In this study, we investigated the use of these cell lines as feeder cells that support the proliferation of bovine blood‐derived macrophages (BBMs). Notably, the B46 cell line efficiently acts as feeder cells for the propagation of BBMs. Compared with primary cultured vascular endothelial cells, the infinite proliferation ability of B46 cells is more beneficial for preparing confluent feeder layers. In conclusion, this study provides a simple and efficient protocol for the isolation and propagation of BBMs using a primary mixed culture of bovine whole blood with B46 feeder cells. Isolated BBMs are expected to be useful for developing in vitro models for studying the interactions between bovine pathogens and host immune cells. [ABSTRACT FROM AUTHOR]

To the Editor: A definitive diagnosis of bovine spongiform encephalopathy (BSE) in cattle usually relies on Western blot and immunohistochemical testing of samples from the obex region of the brainstem. [...]

The global outbreak of bovine spongiform encephalopathy (BSE) has been attributed to the recycling of contaminated meat and bone meals (MBMs) as feed supplements. The use of MBMs has been prohibited in many countries; however, the development of a method for inactivating BSE prions could enable the efficient and safe use of these products as an organic resource. Subcritical water (SCW), which is water heated under pressure to maintain a liquid state at temperatures below the critical temperature (374°C), exhibits strong hydrolytic activity against organic compounds. In this study, we examined the residual in vitro seeding activity of protease-resistant prion protein (PrPSc) and the infectivity of BSE prions after SCW treatments. Spinal cord homogenates prepared from BSE-infected cows were treated with SCW at 230–280°C for 5–7.5 min and used to intracerebrally inoculate transgenic mice overexpressing bovine prion protein. Serial protein misfolding cyclic amplification (sPMCA) analysis detected no PrPSc in the SCW-treated homogenates, and the mice treated with these samples survived for more than 700 days without any signs of disease. However, sPMCA analyses detected PrPSc accumulation in the brains of all inoculated mice. Furthermore, secondary passage mice, which inoculated with brain homogenates derived from a western blotting (WB)-positive primary passage mouse, died after an average of 240 days, similar to mice inoculated with untreated BSE-infected spinal cord homogenates. The PrPSc accumulation and vacuolation typically observed in the brains of BSE-infected mice were confirmed in these secondary passage mice, suggesting that the BSE prions maintained their infectivity after SCW treatment. One late-onset case, as well as asymptomatic but sPMCA-positive cases, were also recognized in secondary passage mice inoculated with brain homogenates from WB-negative but sPMCA-positive primary passage mice. These results indicated that SCW-mediated hydrolysis was insufficient to eliminate the infectivity of BSE prions under the conditions tested. [ABSTRACT FROM AUTHOR]

Prions are the infectious agents responsible for transmissible spongiform encephalopathy, and are primarily composed of the pathogenic form (PrP) of the host-encoded prion protein (PrP). Recent studies have revealed that protein misfolding cyclic amplification (PMCA), a highly sensitive method for PrP detection, can overcome the species barrier in several xenogeneic combinations of PrP seed and PrP substrate. Although these findings provide valuable insight into the origin and diversity of prions, the differences between PrP generated by interspecies PMCA and by in vivo cross-species transmission have not been described. This study investigated the histopathological and biochemical properties of PrP in the brains of tga20 transgenic mice inoculated with Sc237 hamster scrapie prion and PrP from mice inoculated with Sc237-derived mouse PrP, which had been generated by interspecies PMCA using Sc237 as seed and normal mouse brain homogenate as substrate. Tga20 mice overexpressing mouse PrP were susceptible to Sc237 after primary transmission. PrP in the brains of mice inoculated with Sc237-derived mouse PrP and in the brains of mice inoculated with Sc237 differed in their lesion profiles and accumulation patterns, Western blot profiles, and denaturant resistance. In addition, these PrP exhibited distinctive virulence profiles upon secondary passage. These results suggest that different in vivo and in vitro environments result in propagation of PrP with different biological properties. [ABSTRACT FROM AUTHOR]

Background: Prions, infectious agents associated with prion diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE) in cattle, and scrapie in sheep and goats, are primarily comprised of PrPSc, a proteaseresistant misfolded isoform of the cellular prion protein PrPC. Protein misfolding cyclic amplification (PMCA) is a highly sensitive technique used to detect minute amounts of scrapie PrPSc. However, the current PMCA technique has been unsuccessful in achieving good amplification in cattle. The detailed distribution of PrPSc in BSE-affected cattle therefore remains unknown. Methodology/Principal Findings: We report here that PrPSc derived from BSE-affected cattle can be amplified ultraefficiently by PMCA in the presence of sulfated dextran compounds. This method is capable of amplifying very small amounts of PrPSc from the saliva, palatine tonsils, lymph nodes, ileocecal region, and muscular tissues of BSE-affected cattle. Individual differences in the distribution of PrPSc in spleen and cerebrospinal fluid samples were observed in terminal-stage animals. However, the presence of PrPSc in blood was not substantiated in the BSE-affected cattle examined. Conclusions/Significance: The distribution of PrPSc is not restricted to the nervous system and can spread to peripheral tissues in the terminal disease stage. The finding that PrPSc could be amplified in the saliva of an asymptomatic animal suggests a potential usefulness of this technique for BSE diagnosis. This highly sensitive method also has other practical applications, including safety evaluation or safety assurance of products and byproducts manufactured from bovine source materials. [ABSTRACT FROM AUTHOR]

Background: Prions, infectious agents associated with prion diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE) in cattle, and scrapie in sheep and goats, are primarily comprised of PrPSc, a proteaseresistant misfolded isoform of the cellular prion protein PrPC. Protein misfolding cyclic amplification (PMCA) is a highly sensitive technique used to detect minute amounts of scrapie PrPSc. However, the current PMCA technique has been unsuccessful in achieving good amplification in cattle. The detailed distribution of PrPSc in BSE-affected cattle therefore remains unknown. Methodology/Principal Findings: We report here that PrPSc derived from BSE-affected cattle can be amplified ultraefficiently by PMCA in the presence of sulfated dextran compounds. This method is capable of amplifying very small amounts of PrPSc from the saliva, palatine tonsils, lymph nodes, ileocecal region, and muscular tissues of BSE-affected cattle. Individual differences in the distribution of PrPSc in spleen and cerebrospinal fluid samples were observed in terminal-stage animals. However, the presence of PrPSc in blood was not substantiated in the BSE-affected cattle examined. Conclusions/Significance: The distribution of PrPSc is not restricted to the nervous system and can spread to peripheral tissues in the terminal disease stage. The finding that PrPSc could be amplified in the saliva of an asymptomatic animal suggests a potential usefulness of this technique for BSE diagnosis. This highly sensitive method also has other practical applications, including safety evaluation or safety assurance of products and byproducts manufactured from bovine source materials. [ABSTRACT FROM AUTHOR]

The article examines the efficacy of the Bacillus-derived MSK103 protease and sodium dodecyl sulphate (SDS) in scrapie prion inactivation. According to the authors, MSK103 protease effectively inhibits infectivity and the level of misfolded isoform of the prion protein in scrapie-infected brain homogenates in the presence of SDS.

In this study, we evaluated the efficacy of a novel minipig strain, the Microminipig (MMPig), as an animal model for studying the pharmacokinetics of a mixture of 10 perfluoroalkyl acids (PFAAs). After a single oral dose was given, we found that the blood depuration of PFAAs (blood t1/2), which we calculated using first-order elimination curves, ranged from 1.6 to 86.6 days. Among the five body compartments analyzed, the liver was the greatest site of accumulation of perfluorooctanesulfonate and longer chain perfluorinated carboxylates such as perfluorodecanoic acid, perfluoroundecanoic acid and perfluorododecanoic acid. We observed an increasing accumulation trend of perfluorinated carboxylates in the organs associated with the fluorinated carbon chain length. The perfluorononanoic acid burden was the highest among the treated compounds 21 days after a single exposure, as 29% of the given perfluorononanoic acid dose was accumulated in the tissues. The persistence of PFAAs in edible pig tissues even after 21 days post-exposure raises concerns about the safety of swine products. This was the first study to use MMPigs to elucidate the pharmacokinetics of a group of environmental pollutants. We found that MMPigs could be excellent experimental animals for toxicological studies due to their easy handling, cost efficacy for target compounds and ease of waste treatment., (Copyright © 2015 John Wiley & Sons, Ltd.)