107 : Development of vaccination strategies for Yersinia Pestis that triggers T cell immune response
Introduction: Yersinia pestis , a Gram negative bacterium, is the etiological agent of pneumonic and bubonic plague. The current efforts are aimed at evaluating whether our vaccine protocol primes memory T cells that rapidly produce IFN- γ and/or perforin in response to peptide or conjugate stimulation. Method: In the present study, IFN- γ and IL-4 production was measured by ELISpot assay, parallel with the ELISA based measurements of total cytokine production in splenocytes, Lamina propria and peyer’s patches of mice, immunized by different constructs of B and T cell epitopes of F1 and V antigens entrapped in PLGA microspheres intranasally. The ratio of CD4+/CD8+ cell population expressing IFN- γ and perforin was also measured by intracellular staining. Result: We observed that three B–T constructs of F1 and seven B–T constructs of V antigens produced a high number of IFN- γ secreting cells as compared to native antigen and a low number of IL-4 secreting cells. B–T conjugates of F1 and V antigens showed significantly high ( p + IFN- γ + cells as compared to CD8 + IFN- γ + cells. Conclusion: Our study demonstrated that IFN- γ is an effector molecule of activated CD4 + and CD8 + T cells arisen from B–T constructs of F1 and V antigens for the antibacterial activity as an improved plague vaccine.