BC7 cblS does not express cable pilus similar to the BC7 cblA mutant. The BC7 cblS complemented strain which expresses cable pili stimulated IL8 response very similar to wild-type BC7, indicating that cable pili is required for this trait. Together, these results suggest both cable pili and the associated 22 kDa adhesin also contributes to BC7 stimulated IL-8 in CF and normal airway epithelial cells. To obtain persistent infection with B. cenocepacia, other investigators have adapted the agarose bead model that was originally developed for P. aeruginosa infection by Cash et al. Although this method is valuable in establishing chronic infection, it often facilitates infection of conducting airways, likely due to mechanical blocking of bronchioles by the beads. In LY294002 addition, this damage may mask the inflammation caused by bacteria. In contrast, we and others have shown that the alginate suspension alone does not cause lung inflammation in mice. Further, the mechanical entrapment of bacteria in beads may prevent spreading of bacteria to respiratory zone. This led us to examine the location of bacteria in the lungs of mice infected with BC7 suspended in alginate by immunolocalization. Lung sections immunostained with antibody to the bacteria showed BC7 in the airway lumen as well as in the respiratory zone associated with alveolar septa and inflammatory cells in these mice, suggesting that alginate does not restrict bacteria to conducting airways. This distribution was very similar to that observed in CFTR knockout mice infected with B. cenocepacia suspended in alginate as well as that observed in CF patients colonized with B. cenocepacia. Chemokines and cytokines play an important role in recruiting phagocytes to the site of infection and subsequent clearance of bacteria. To examine whether alginate increases persistence of bacteria by delaying the initial chemokine and cytokine responses in normal mice, we measured the levels of selected chemokines and cytokines in lung homogenates obtained from uninfected control mice, and mice infected with BC7/PBS or BC7/alginate. Mice mock-infected with PBS or alginate alone showed very low or undetectable levels of all the measured cytokines and chemokines at all the time points tested. In contrast, mice infected with either BC7/PBS or BC7/alginate showed a significant increase of all cytokines measured compared to the respective sham-infected groups, but with different kinetics. Mice infected with BC7/PBS showed peak induction of KC/CXCL1, MIP-2/CXCL2, IL-1b, TNF-a, as early as 6 h, correlating with the bacterial load in the lung. The levels of these chemokines and cytokines gradually decreased and returned to normal by 3 d post infection. In contrast, mice infected with BC7/alginate showed increased KC/CXCL1, MIP-2/CXCL2, IL-1b and TNF-a at 6 h post infection.