FIG. 4.

Adherence, invasiveness, hemolysis, and membrane insertion of ipaB mutants. (A to C) Adherence (A) and invasiveness (B) to HeLa cells and the hemolysis percentage of sheep RBC (C) were obtained, as described in Materials and Methods. The values are averages of results from 3 independent experiments performed in duplicate (or triplicate), and the errors given are standard deviations. “*” indicates the fold increase of mutants’ adhesion to HeLa cells compared with that of the wild type (WT). (D, E) Insertion of IpaB and IpaC into sheep RBC membranes after contact hemolysis (D) and further stripping (E) with PBS (−) or 5 M NaCl (+). The antibodies used for the Western blots are indicated on the right. The blots shown are representative of 2 independent assays giving similar results.