Outer Membrane Vesicles Displaying a Heterologous PcrV-HitA Fusion Antigen Promote Protection against Pulmonary Pseudomonas aeruginosa Infection

Hospital- and community-acquired infections with Pseudomonas aeruginosa cause a high rate of morbidity and mortality in patients who have underlying medical conditions. The spread of multidrug-resistant P. aeruginosa strains is becoming a great challenge for treatment using antibiotics. Thus, a vaccine as one of the alternative strategies is urgently required to prevent P. aeruginosa infection.

Self-assembled particulate vaccine elicits strong immune responses and reduces Mycobacterium avium subsp. paratuberculosis infection in mice

Mycobacterium avium subspecies paratuberculosis (MAP) causes chronic progressive granulomatous enteritis leading to diarrhoea, weight loss, and eventual death in ruminants. Commercially available vaccines provide only partial protection against MAP infection and can compromise the use of bovine tuberculosis diagnostic tests. Here, we report the development of a protein-particle-based vaccine containing MAP antigens Ag85A202–347-SOD1–72-Ag85B173–330-74F1–148+669–786 as a fusion (‘MAP fusion protein particle’). The fusion antigen displayed on protein particles was identified using mass spectrometry. Surface exposure and accessibility of the fusion antigen was confirmed by flow cytometry and ELISA. The MAP fusion protein particle vaccine induced strong antigen-specific T-cell immune responses in mice, as indicated by increased cytokine (IFN-γ and IL-17A) and costimulatory signals (CD40 and CD86) in these animals. Following MAP-challenge, a significant reduction in bacterial burden was observed in multiple organs of the mice vaccinated with the MAP fusion protein particle vaccine compared with the PBS group. The reduction in severity of MAP infection conferred by the MAP fusion protein particle vaccine was similar to that of Silirum and recombinant protein vaccines. Overall, the results provide evidence that MAP antigens can be engineered as a protein particulate vaccine capable of inducing immunity against MAP infection. This utility offers an attractive platform for production of low-cost particulate vaccines against other intracellular pathogens.

IFN-Gamma and IL-2 Secretion after ESAT-6-CFP-10 (EC-610) Fusion Antigen Stimulation from Patients with Active Lung Tuberculosis and Latent Lung Tuberculosis

The Secretion of IFN-Gamma and IL-2 After ESAT-6-CFP-10 Fusion Antigen Stimulation in Active and Latent TB Patients. This study held to discover how immune responses work and to know the pathogenesis of active TB and latent TB patients. This study used PBMC to stimulate T Cells with ESAT-6 and CFP-10 antigen fusion, and measure the level of IFN-gamma and IL-2 with ELISA antibody sandwich (U-Cytech). 16 ml of blood were drawn to 5 tubes. ESAT-6 CFP-20 inducted one tube with QuantiFERON for IFN-gamma assay. The other four tubes were PBMC isolated using Ficoll-Paque, and pre-incubated with stimulation of ESAT-6 CFP-10 fusion antigen for 24-72 hours at 370 C and measured using T-Spot and ELISA reader. We got from this study that there are no significant differences in IFN-gamma levels for both groups with active TB and latent TB. Measurement of IL-2 levels showed significant differences between the two group.