IL-8 and IL-6 levels were measured by ELISA, and adherence was measured by flow cytometry. Left, six East Asian strains and five Western strains were used. After natural transformation, we picked eight clones of each ΔalpAB mutant. Three independent co-cultures were performed for each clone and WT strain, and each was measured in duplicate. Data are expressed as mean of each clone or WT strain. Right, strains TN and 43504 and their mutants were used. Three or four independent co-cultures were performed, and each was measured in duplicate. Data are expressed as mean ± S.E.*,p < 0.01 decreased compared with WT strains; †, p < 0.01 increased compared with WT strains.