Sodium hydroxide treatment effectively inhibits PrPCWD replication in farm soil.

Chronic wasting disease (CWD) agents are shed into biological samples, facilitating their horizontal transmission between cervid species. Once prions enter the environment, binding of PrPCWD by soil particles may maintain them near the soil surface, posing a challenge for decontamination. A 2 N sodium hydroxide (NaOH) or 2% sodium hypochlorite (NaClO) solution is traditionally recommended for prion decontamination of equipment and surfaces. Using protein misfolding cyclic amplification with beads and a bioassay with TgElk mice, we compared the effects of these disinfectants in CWD-contaminated soil for 1 or 16 h to those of controls of known infectious titres. Our results suggest that 2 N NaOH in a 1/5 farm soil volume provides a large decrease (>102-fold) in prion infectivity.

Application of the fragment molecular orbital method to discover novel natural products for prion disease.

Conformational conversion of the normal cellular isoform of the prion protein PrPC into an infectious isoform PrPSc causes pathogenesis in prion diseases. To date, numerous antiprion compounds have been developed to block this conversion and to detect the molecular mechanisms of prion inhibition using several computational studies. Thus far, no suitable drug has been identified for clinical use. For these reasons, more accurate and predictive approaches to identify novel compounds with antiprion effects are required. Here, we have applied an in silico approach that integrates our previously described pharmacophore model and fragment molecular orbital (FMO) calculations, enabling the ab initio calculation of protein-ligand complexes. The FMO-based virtual screening suggested that two natural products with antiprion activity exhibited good binding interactions, with hotspot residues within the PrPC binding site, and effectively reduced PrPSc levels in a standard scrapie cell assay. Overall, the outcome of this study will be used as a promising strategy to discover antiprion compounds. Furthermore, the SAR-by-FMO approach can provide extremely powerful tools in quickly establishing virtual SAR to prioritise compounds for synthesis in further studies.

Stability of orally administered immunoglobulin in the gastrointestinal tract.

Oral administration of immunoglobulin in the colostrum or egg yolk has been considered an effective tool for preventing enterobacterial infection via passive immunization. During this process, the transmission and residence of the active immunoglobulin are the most important conditions for successful protection. We investigated the stability of encapsulated colostrum and egg yolk immunoglobulin for the effective transmission of immunoglobulin in the gastrointestinal (GI) tract. First, we measured GI transit time. Contrast media passed through and reached the stomach within 10 min, the small intestine within 3.5 h, and the cecum within 5 h. Both the encapsulated colostrum containing anti-hepatitis A virus (HAV) antibody (IgG) and egg yolk with anti-rotavirus antibody (IgY) showed lower antibody activity than the non-encapsulated colostrum did in the stomach after administration; however, significantly higher antibody activities were observed in the encapsulated groups than in the non-encapsulated groups in the small intestine 3.5 h after the administration. In the large intestine, the antibody activities of the encapsulated groups were maintained or slightly increased in a time-dependent manner; however, the titers of each non-capsulated control were as low as the negative controls. Therefore, this encapsulation is considered a useful tool for the delivery of active antibody through the GI tract.

Immunomodulatory and antitumor effects in vivo by the cytoplasmic fraction of Lactobacillus casei and Bifidobacterium longum.

The immunomodulatory and antitumor effects of lactic acid bacteria (LABs) were investigated. Cytoplasmic fraction of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium longum were tested for the antiproliferative activity in vitro to SNUC2A, SNU1, NIH/3T3 and Jurkat cell lines by crystal violet assay. All cytoplasmic fraction suppressed proliferation of tumor cells, though L. casei and B. longum were more effective. From these results, cytoplasmic fraction of L. casei and B. longum with Y400 as a control were administered as dietary supplements to Balb/c mice for 2, and 4 consecutive wks. Administration for 4 wks enhanced the number of total T cells, NK cells and MHC class II+ cells, and CD4-CD8+ T cells in flow cytometry analysis. To determine of antitumor activity of LABs preparation in vivo, F9 teratocarcinoma cells were inoculated on mice at 14th day. Body weight was decreased with increased survival rate in all groups with the cytoplasm of LABs. Our results showed that cytoplasmic fraction of LABs had direct antiproliferative effects on tumor cell lines in vitro, effects on immune cells in vivo, and antitumor effects on tumor-bearing mice with prolonged survival periods.