Figure 3.

C. burnetii secretes proteins during growth in mammalian host cells. Vero cells were infected for 5 days with C. burnetii transformants expressing the FLAG-tagged proteins CBU0110, CBU1135 or CBU1984, then protein expression was induced for 18 h. Host cells were lysed and lysates centrifuged to pellet intact bacteria and cell debris. Proteins present in the pellet and supernatant were separated by SDS-PAGE, transferred to nitrocellulose and analyzed by immunoblotting with antibodies directed against the FLAG-tag and EF-Ts. Uninfected Vero cells were employed as a negative control.