FIG. 2.

Micrograph illustrating immunofluorescence labeling of Sifs in HeLa cells infected with wild-type SL1344 and porin-deficient mutants at 6 h postinvasion. Shown is a typical Sif (stained with anti-lgp monoclonal antibody) (A) induced by wild-type SL1344. Induction of Sif formation was defective for ompR mutants ARD3 (ompR::Mu dJ) (B) and CJD359 (ompR::Tn10) (D), a situation similar to what was previously shown for J1-3 (sifA::Tn10 dCm) (F) (33). Sif formation was restored to ARD3 (ompR::Mu dJ) (C) complemented in trans with the cloned ompB locus in pSWLOMP. Triple porin-deficient mutant BRD409 (ompC::Tn10, ompF::Mu d1-8, tppB::Mu dJ) induced Sifs similarly to wild-type SL1344 (E).