Promoting Immune Efficacy of the Oral Helicobacter pylori Vaccine by HP55/PBCA Nanoparticles against the Gastrointestinal Environment.

The immunogenicity of oral subunit vaccines is poor partly as a result of the harsh milieu of the gastrointestinal (GI) tract. For some pathogens that restrictedly inhabit the GI tract, a vaccine that works in situ may provide more potent protection than vaccines that operate parenterally. Yet, no appropriate delivery system is available for oral subunit vaccines. In this study, we designed HP55/poly( n-butylcyanoacrylate) (PBCA) nanoparticles (NPs) to carry Helicobacter pylori ( H. pylori) subunit vaccine CCF for oral administration in a prophylactic mice model. These NPs, which are synthesized using an interfacial polymerization method, protected the CCF antigen not only from the acidic pH in simulated gastric fluid (SGF, pH 1.2) but also from the proteolysis in simulated intestinal fluid (SIF, pH 7.4). Oral vaccination of mice with HP55/PBCA-CCF NPs promoted the production of serum antigen-specific antibodies, mucosal secretory IgA, and proinflammatory cytokines. Moreover, a Th1/Th17 response and augmented lymphocytes were found in the gastric tissue of HP55/PBCA-CCF NP-immunized mice, which might eventually limit H. pylori colonization. Collectively, these results indicate that HP55/PBCA NPs are promising carriers against the severe situation of the GI tract and thereby may be further utilized for other orally administrated vaccines or drugs.

Nongenetically modified Lactococcus lactis-adjuvanted vaccination enhanced innate immunity against Helicobacter pylori.

BACKGROUND: Gram-positive enhancer matrix particles (GEM) produced by Lactococcus lactis can enhance vaccine-induced immune response. However, the mechanism under which this adjuvant mounts the efficacy of orally administered vaccines remains unexplored. MATERIALS AND METHODS: We used a prophylactic mice model to investigate the mechanism of GEM-adjuvanted vaccination. Helicobacter pylori urease-specific antibody response was monitored and detected in murine serum by ELISA. Urease-specific splenic cytokine profile was examined. Gastric inflammatory responses were measured on day 43 or 71 by quantitative real-time PCR, flow cytometry and histology. RESULTS: We found that GEM enhanced the efficiency of oral H. pylori vaccine by promoting innate immunity. The vaccine CUE-GEM composed of GEM particles and recombinant antigen CTB-UE provided protection of immunized mice against H. pylori insult. The protective response was associated with induction of postimmunization gastritis and local Th1/Th17 cell-medicated immune response. We showed that innate inflammatory responses including neutrophil chemokines CXCL1-2, neutrophils, and antimicrobial proteins S100A8 and MUC1 were significantly elevated. Within all infected mice, S100A8 and MUC1 levels were negatively correlated with H. pylori burden. Strikingly, mice receiving GEM also show reduction of colonization, possibly through natural host response pathways to recruit CD4+ T cells and promote S100A8 expression. CONCLUSIONS: These findings suggest that GEM-based vaccine may impact Th1/Th17 immunity to orchestrate innate immune response against H. pylori infection.

MiR-9 enhances the sensitivity of A549 cells to cisplatin by inhibiting autophagy.

OBJECTIVES: To demonstrate that miR-9 inhibits autophagy by down-regulating Beclin1 and thus enhances the sensitivity of A549 cells to cisplatin. RESULTS: MiR-9 inhibited Beclin1 expression by binding to its 3'UTR. The inhibition decreased the cisplatin-induced autophagy in A549 cells, evidenced by the decreased expression of LC3II and GFP-LC3 puncta and the increased expression of P62. Upregulation of miR-9 level enhanced the sensibility of A549 cells to cisplatin and increased the cisplatin-induced apoptosis. Overexpression of Beclin1 reversed above effects of miR-9 mimics, cisplatin-induced autophagy was increased and apoptosis was decreased. CONCLUSIONS: MiR-9 inhibits autophagy via targeting Beclin1 3'UTR and thus enhances cisplatin sensitivity in A549 cells.

The competing endogenous RNA network of CYP4Z1 and pseudogene CYP4Z2P exerts an anti-apoptotic function in breast cancer.

The competing endogenous RNA network (ceRNET) is involved in tumorigenesis and has become a hot spot of research. The ceRNET between CYP4Z1 and the pseudogene CYP4Z2P promotes angiogenesis and mediates tamoxifen resistance in breast cancer. Nevertheless, the effects of this ceRNET on cell apoptosis and related mechanisms remain unclear. In the present study, we found that downregulation of CYP4Z1 or the CYP4Z2P 3'-UTR promotes cell apoptosis, mirroring the functions of human telomerase reverse transcriptase (hTERT). Furthermore, the ceRNET between CYP4Z1 and pseudogene CYP4Z2P modulates hTERT expression by operating as a sub-ceRNET for hTERT. Our data demonstrate that the ceRNET between CYP4Z1 and pseudogene CYP4Z2P acts as a sub-ceRNET for hTERT and, thus, inhibits breast cancer apoptosis.

Oral Helicobacter pylori vaccine-encapsulated acid-resistant HP55/PLGA nanoparticles promote immune protection.

Oral vaccination, is notoriously weak or nonimmunogenic. One of the major reasons is the inefficient antigen uptake caused by enzymolysis and hydrolysis in the gastrointestinal tract. In this study, acid-resistant HP55/PLGA nanoparticle was developed as an oral delivery system to protect H. pylori recombinant antigen CCF against the complex gastrointestinal environment. These ∼200nm particles controlled the release of antigen in the acidic environment (pH⩽5.5). Immunized mice with HP55/PLGA-CCF nanoparticles induced high levels of urease-specific antibodies and memory T cell responses. A month after H. pylori challenge, 43% of mice were completely protected. The protection was highly associated with the Th1/Th17-bias immune response, which had been recognized as an optimal immunity against H. pylori infection. In addition, a mass of T-cells were observed in the lamina propria of mice immunized with CCF, especially in the HP55/PLGA-CCF nanoparticles administered recipients, and contributed to the development of postimmunization gastritis. These results indicate that oral immunization with acid-resistant HP55/PLGA nanoparticles encapsulating vaccine antigens represent a promising strategy for antigen protection, slow-release and targeting, and thus prevented gastrointestinal infection.

Therapeutic efficacy of oral immunization with a non-genetically modified Lactococcus lactis-based vaccine CUE-GEM induces local immunity against Helicobacter pylori infection.

The gastric bacterial pathogen Helicobacter pylori persistently colonizes the gastric mucosa of humans and plays a critical role in the development of gastritis, peptic ulceration and gastric adenocarcinoma. Consequently, the eradication of H. pylori might contribute to the prevention of H. pylori-associated gastric diseases. In this study, a multi-epitope vaccine CTB-UE (CUE) was displayed on the surface of non-genetically modified Lactococcus lactis particles (GEM) to enhance immunogenicity. This particulate vaccine CUE-GEM induced serum and mucosal specific antibody responses against native H. pylori urease and provided potent protection to eliminate H. pylori colonization and relieve gastritis in an H. pylori-infected BALB/c mouse model. The immuno-protective mechanisms are highly associated with CD4(+) Th cell-mediated and humoral immunity, especially local immunity. There might be two main aspects of this association. One aspect is related to the suppression of urease activity by promotion of the production of specific mucosal neutralizing antibody. The other aspect is correlated with alleviating gastritis by regulating the gastric pro-inflammatory cytokine profile, especially IFN-γ and IL-17. These results demonstrated that conjugating antigen vaccines with GEM particles could lead to promising oral therapeutic vaccine formulations against H. pylori infection.