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Abstract Background Bovine viral diarrhea virus (BVDV) is one of the main causes of infectious diseases in cattle and causes large financial losses to the cattle industry worldwide. In this study, Lactobacillus casei strain W56 (Lc W56) was used as antigen deliver carrier to construct a recombinant Lactobacillus vaccine pPG-E2-ctxB/Lc W56 constitutively expressing BVDV E2 protein fused with cholera toxin B subunit (ctxB) as an adjuvant, and its immunogenicity against BVDV infection in mice model by oral route was explored. Results Our results suggested that pPG-E2-ctxB/Lc W56 can effectively activate dendritic cells (DCs) in the Peyer’s patches, up-regulate the expression of Bcl-6, and promote T-follicular helper (Tfh) cells differentiation, as well as enhance B lymphocyte proliferation and promote them differentiate into specific IgA-secreting plasma cells, secreting anti-E2 mucosal sIgA antibody with BVDV-neutralizing activity. Moreover, significant levels (p

Background: Bovine viral diarrhea virus (BVDV) is one of the main causes of infectious diseases in cattle and causes large financial losses to the cattle industry worldwide. In this study, Lactobacillus casei strain W56 (Lc W56) was used as antigen deliver carrier to construct a recombinant Lactobacillus vaccine pPG-E2-ctxB/Lc W56 constitutively expressing BVDV E2 protein fused with cholera toxin B subunit (ctxB) as an adjuvant, and its immunogenicity against BVDV infection in mice model by oral route was explored. Results: Our results suggested that pPG-E2-ctxB/Lc W56 can effectively activate dendritic cells (DCs) in the Peyer's patches, up-regulate the expression of Bcl-6, and promote T-follicular helper (Tfh) cells differentiation, as well as enhance B lymphocyte proliferation and promote them differentiate into specific IgA-secreting plasma cells, secreting anti-E2 mucosal sIgA antibody with BVDV-neutralizing activity. Moreover, significant levels (p < 0.01) of BVDV-neutralizing antigen-specific serum antibodies were induced in the pPG-E2-ctxB/LC W56 group post-vaccination. The recombinant Lactobacillus vaccine can induce cellular immune responses, and significant levels (p < 0.01) of Th1-associated cytokines (IL-2, IL-12, and IFN-γ), Th2-associated cytokines (IL-4, IL-10) and Th17-associated cytokine (IL-17) were determined in the serum of vaccinated mice. Significantly, the recombinant Lactobacillus vaccine provides immune protection against BVDV infection, which can be cleared effectively by the vaccine post-challenge in orally vaccinated animals. Conclusions: The genetically engineered Lactobacillus vaccine constructed in this study is immunogenic in mice and can induce mucosal, humoral, and cellular immune responses, providing effective anti-BVDV immune protection. It thus represents a promising strategy for vaccine development against BVDV. [ABSTRACT FROM AUTHOR]

Doppel is the first identified homologue of the prion protein (PrPc) implicated in prion disease. Doppel is considered an N-truncated form of PrPc, and shares with PrPc several structural and biochemical features. When over expressed in the brain of some PrP knockout animals, it provokes cerebellar ataxia. As this phenotype is rescued by reintroducing the PrP gene, it has been suggested that Doppel and PrPc have antagonistic functions and may compete for a common ligand. However, a direct interaction between the two proteins has recently been observed.To investigate whether the neuronal environment is suitable for such possibility, human Doppel and PrPc were expressed separately, or together, in neuroblastoma cells, and then studied by biochemical and immunomicroscopic tools, as well as in intact cells expressing fluorescent fusion constructs.The results demonstrate that Doppel and PrPc co-patch extensively at the plasma membrane, and get internalized together after ganglioside cross-linking by cholera toxin or addition of an antibody against only one of the proteins. These processes no longer occur if the integrity of rafts is disrupted. We also show that, whereas each protein expressed alone occupies Triton X-100-insoluble membrane microdomains, co-transfected Doppel and PrPc redistribute together into a less ordered lipidic environment. All these features are consistent with interactions occurring between Doppel and PrPc in our neuronal cell model. [Copyright &y& Elsevier]

The hexose transporter family, which mediates a facilitated uptake in mammalian cells, consists of more than 10 members containing 12 membrane-spanning segments with a single N-glycosylation site. However, it remains unknown how these isoforms are functionally organized in the membrane domains. In this report, we describe a differential distribution of the glucose transporter isoforms GLUT1 and GLUT3 to detergent-resistant membrane domains (DRMs) in non-polarized mammalian cells. Whereas more than 80% of cellular proteins containing GLUT3 in HeLa cell lines was solubilized by a non-ionic detergent (either Triton X-100 or Lubrol WX) at 4 °C, GLUT1 remained insoluble together with the DRM-associated proteins, such as caveolin-1 and intestinal alkaline phosphatase (IAP). These DRM-associated proteins and the ganglioside GM1 were shown to float to the upper fractions when Triton X-100-solubilized cell extracts were centrifuged on a density gradient. In contrast, GLUT3 as well as most soluble proteins remained in the lower layers. Furthermore, perturbations of DRMs due to depletion of cholesterol by methyl-β-cyclodextrin (mβCD) rendered GLUT1 soluble in Triton X-100. Immunostaining patterns for these isoforms detected by confocal laser scanning microscopy in a living cell were also distinctive. These results suggest that in non-polarized mammalian cells, GLUT1 can be organized into a raft-like DRM domain but GLUT3 may distribute to fluid membrane domains. This differential distribution may occur irrespective of the N-glycosylation state or cell type. [Copyright &y& Elsevier]