FIGURE 3.

Independent actions of integrin βν and Draper in defense against S. aureus. A, adult flies of control (w¹¹¹⁸), integrin βν-deficient (betaInt-nu²), and Draper-deficient (drpr^Δ5) lines, and a double mutant for betaInt-nu and drpr (betaInt-nu²; drpr^Δ5) were injected with FITC-labeled wild-type S. aureus and analyzed for the level of phagocytosis in vivo. The data with betaInt-nu² and drpr^Δ5 fly lines are a duplicate of those shown in Fig. 2A. The micrographs at the bottom two rows are magnified views of the area with the squares in micrographs at the top two rows. The data are presented as in Fig. 2A. Scale bars, 0.5 mm. B, an assay for phagocytosis in vitro was conducted with FITC-labeled wild-type S. aureus as targets and larval hemocytes prepared from the indicated fly lines as phagocytes. C, an assay for phagocytosis in vitro was conducted with FITC-labeled wild-type (parent) or LtaS-deficient (ΔltaS) S. aureus as targets and larval hemocytes prepared from integrin βν-deficient fly lines as phagocytes. The level of phagocytosis is shown relative to that with wild-type bacteria taken as 100. Data from one of three independent experiments with similar results are presented. D, adult flies of betaInt-nu², drpr^Δ5, and betaInt-nu²; drpr^Δ5 lines were injected with wild-type S. aureus and analyzed for bacterial growth (left) and fly survival (right) at the indicated time points. In the left panel, cfu values at 24 h relative to those at 0 h were compared between the fly lines. Genotypes of the fly lines analyzed are w; +; drpr^Δ5 (drpr^Δ5) and w; betaInt-nu²; drpr^Δ5 (betaInt-nu²; drpr^Δ5).