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.

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.