Display of porcine epidemic diarrhea virus spike protein B-cell linear epitope on Lactobacillus mucosae G01 S-layer surface induce a robust immunogenicity in mice.

The Porcine epidemic diarrhea virus (PEDV) presents a substantial risk to the domestic pig industry, resulting in extensive and fatal viral diarrhea among piglets. Recognizing the mucosal stimulation triggered by PEDV and harnessing the regulatory impact of lactobacilli on intestinal function, we have developed a lactobacillus-based vaccine that is carefully designed to elicit a strong mucosal immune response. Through bioinformatics analysis, we examined PEDV S proteins to identify B-cell linear epitopes that meet the criteria of being non-toxic, soluble, antigenic, and capable of neutralizing the virus. In this study, a genetically modified strain of Lactobacillus mucosae G01 (L.mucosae G01) was created by utilizing the S layer protein (SLP) as a scaffold for surface presentation. Chimeric immunodominant epitopes with neutralizing activity were incorporated at various sites on SLP. The successful expression of SLP chimeric immunodominant epitope 1 on the surface of L.mucosae G01 was confirmed through indirect immunofluorescence and transmission electron microscopy, revealing the formation of a transparent membrane. The findings demonstrate that the oral administration of L.mucosae G01, which expresses the SLP chimeric immunodominant gene epitope1, induces the production of secreted IgA in the intestine and feces of mice. Additionally, there is an elevation in IgG levels in the serum. Moreover, the levels of cytokines IL-2, IL-4, IFN-γ, and IL-17 are significantly increased compared to the negative control group. These results suggest that L. mucosae G01 has the ability to deliver exogenous antigens and elicit a specific mucosal immune response against PEDV. This investigation presents new possibilities for immunoprophylaxis against PEDV-induced diarrhea.

Isolation of Limosilactobacillus mucosae G01 with inhibitory effects on porcine epidemic diarrhea virus in vitro from Bama pig gastroenteritis.

Porcine epidemic diarrhea virus (PEDV) is responsible for causing fatal watery diarrhea in piglets, resulting in significant economic losses within the pig farming industry. Although vaccination is currently employed as a preventive measure, certain vaccines do not provide complete protection against PEDV field strains. Probiotics present a promising alternative due to their ability to regulate intestinal flora, enhance host immunity, and improve resistance against pathogenic microorganisms. We isolated six lactic acid bacteria (LAB) from the fecal microorganisms of Bama pigs, compared to Limosilactobacillus mucosae DSM13345 of the same genus in which Limosilactobacillus mucosae G01 (L. mucosae G01) proved to have a potent anti-PEDV effect. In a comprehensive manner, L. mucosae G01 significantly augmented the phosphorylation of IRF3 in IPEC-J2 cells, resulting in the induction of interferons (IFN α, IFN ß, IFN λ1, and IFN λ3) and subsequent upregulation of interferon-stimulated genes (ISGs) (MX1, MX2, OAS1, and ZAP) in a dose-dependent fashion, consequently leading to the mitigation of PEDV replication. These findings underscore the promising prospects of L. mucosae G01 as a naturally derived substitute for combating PEDV and other enteric coronavirus infections.

Effects of the Aidi Dripping Pills on immune functions of the tumor-bearing mouse.

OBJECTIVE: To study the effects of Aidi Dripping Pills on immune functions of the tumor-bearing mouse on the basis of the previous experimental studies on its tumor-inhibiting and life-prolonging effects. METHODS: By using the transplantation tumor mouse models, the effects of Aidi Dripping Pills on the lymphocyte transformation rate and the hemolysin formation in the S180 tumor-bearing mice, and on the phagocytic function of macrophages in the abdominal cavity of H22 tumor-bearing mice were investigated. RESULTS: In the 2.25 g/kg and 1.125 g/kg Aidi Dripping Pills groups, the lymphocyte transformation rates in the S180 tumor-bearing mice were significantly higher than that of the control group (P<0.01). In all the Aidi Dripping Pills groups, HC50 significantly increased (P<0.01 or P<0.05), carbon granular clearance significantly raised, and both the phagocytic index and phagocytic coefficient were significantly higher than those in the control group (P<0.01 or P<0.05). CONCLUSION: The Aidi Dripping Pills can significantly increase the cellular immune function, the humoral immune function and the phagocytic function of the mononuclear-macrophages, so it may show anti-tumor effects by enhancing the function of the reticuloendothelial system.