Heterologously type IV pilus expressed protein of Burkholderia pseudomallei is immunogenic but fails to induce protective immunity in mice.
Burkholderia pseudomallei is the causative agent of melioidosis, a severe disease of humans and animals. At present, no effective vaccine against melioidosis exists. Bacterial type IV pilin proteins have been used successfully as subunit vaccines. In this study, we evaluated a heterologously expressed and purified type IV pilus protein (PilV) of B. pseudomallei strain K96243 as a candidate subunit vaccine. PilV protein was assessed for its ability to protect BALB/c mice against B. pseudomallei strain G207 infection. Mice subcutaneously immunized with purified PilV protein produced high titers of IgG antibodies, which were strongly biased towards IgG1, with lower levels of IgG2a. Even though the PilV protein was highly immunogenic, it could not induce protection against a lethal B. pseudomallei challenge. Possible mechanisms of this non-protection phenomenon are discussed.
Department of Clinical Immunology, Center for Research and Development in Medical Diagnostic Laboratory (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Kusavadee
K
Sangdee
Srivilai
S
Waropastrakul
Surasak
S
Wongratanachewin
Preecha
P
Homchampa
D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D016957:Burkholderia pseudomallei / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D036781:Fimbriae Proteins / Q000235:genetics / Q000276:immunology*; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000276:immunology*; D008554:Melioidosis / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C
D001428:Bacterial Vaccines; D036781:Fimbriae Proteins