Fig. 5.

Defects in cell wall mannan but not glucan or chitin decrease the competitive uptake of yeast cells by both J774 and primary macrophages. Green fluorescent yeast strains containing mutations that affect protein mannosylation or glucan or chitin synthesis were mixed with an equal number of red fluorescent isogenic wild-type (WT) strains and coincubated with macrophages. After 40 min, CW was added and fluorescent yeast cells were visually scored as being in or out of macrophages to calculate the percent internalization ratio, as described in Materials and Methods. Data sets represent an average of three different experiments (n > 300 cells per experiment). The genotypes of the yeasts affected in N-linked mannan (och1, mnn10, hoc1), O-linked mannan (pmt1, pmt2, pmt4), β1,3-glucan (fks1), β1,6-glucan (kre1, kre6), or chitin (chs3) are listed in Table 2. Competition assays were performed using J744 cells (A) or primary bone marrow-derived macrophages (B) infected with yeast cells at an MOI of 5, as described in Materials and Methods.