Figure 7.
Lm antigenicity of MPs elicits protective immune response in vivo. (a) IFN-γ production by splenocytes in MPs-immunized mice. BALB/c mice were i.p. immunized with MPs mixed with rehydragel adjuvant for 7 days. Splenic cells were isolated and stimulated by MPs from Lm-infected or uninfected macrophages. Forty-eight hours later, the supernatants were harvested and assayed for IFN-γ by ELISA. (b) MPs by Lm-infected macrophages elicited protective immunity against Lm infection. MPs were isolated from the supernatants of the cultured macrophages in the presence or absence of Lm, and passed through 1.2 µm filter. The supernatants of sole Lm incubation were also experienced such processes and used as control. BALB/c mice (n=6) were immunized with MPs mixed with rehydragel adjuvants for 7 days and challenged with the i.v. injection of 1×105 viable Lm. The survival of mice was observed (P<0.001; Kaplan–Meier analysis). The data shown here were representative of three independent experiments. IFN, interferon; i.p., intraperitoneally; i.v., intravenous; Lm, Listeria monocytogenes; MP, microparticle.