Figure 1

Morphological changes of THP-1 and A549 cells after Streptococcus pneumoniae (SP) infection. THP-1 and A549 cells began to die after infection at 4 to 8 h: (A) THP-1 at 0 h; (B) THP-1 (uninfected control) at 4 h; (C) THP-1 (uninfected control) at 8 h; (D) THP-1 with SP at 4 h; (E) THP-1 with SP at 8 h; (F) A549 at 0 h; (G) A549 (uninfected control) at 4 h; (H) A549 (uninfected control) at 8 h; (I) A549 with SP at 4 h; (J) A549 with SP at 8 h. (A-J: ×400). One strain of blood-derived SP was used except in the uninfected control. 0 h means before infection.