Fig. 3. The ability of T. gondii to prevent the nuclear accumulation of NF-B does not depend on IB family members. Indirect immunofluorescence analysis of T. gondii-infected 3T3 cells doubly deficient in IBß and IB demonstrates lack of nuclear accumulation of NF-B. Anti-p65 (red) staining reveals cytoplasmic localization in uninfected cells and nuclear accumulation in cells stimulated with TNF- for 1 hour. `DAPI' indicates staining of host cell and parasite nuclei (blue). Yellow triangles indicate parasite-containing vacuoles, and infection times are indicated in the top left corner of each panel. Similarly, nuclear accumulation was not observed following infection of IB/IBß or IB/IB dKO cells (data not shown). Yellow triangles indicate parasite-containing vacuoles, and infection times are indicated in the top left corner of each panel.