The SPI2 effectors SseL and SteA do not contribute to formation of the LGP+ aggregate. (A) Confocal microscopy images showing LGP+ aggregates in CD63-GFP expressing NRK-49F fibroblasts infected with sseLΔ and steAΔ mutant strains expressing DsRed. Images obtained at 8 hpi. Insets show groups of bacteria with their associated LGP+ aggregates. Bacteria: Salmo, red; CD63: green; DAPI: blue. Scale bars: 5 μm (original images), 2.5 μm (insets). (B) Quantitative data of parameters such as: surface of the LGP+ (CD63)-aggregate, distance between the LGP+ aggregate and the nucleus centroid, and number of LGP+ aggregates per cell. At least 100 LGP+ aggregates or fibroblasts containing LGP+ aggregates were counted in 2 independent experiments. (C) The lack of SseL does not result in ubiquitin accumulation around the SCV or the LGP+ aggregate. CD63-GFP expressing NRK-49F fibroblasts were infected with the sseLΔ mutant expressing DsRed. Cell were fixed at 8 hpi and processed for immunofluorescence microscopy using anti-ubiquitin (UBI) antibody. Bacteria: Salmo, red; CD63: green; Ubiquitin: UBI, magenta; DAPI: blue. Scale bars: 5 μm. Arrows indicate positioning of bacteria and LGP+ aggregates. Note as positive control for the anti-ubiquitin antibody the labeling of ubiquitin in the midbody of 2 dividing cells in last stages of cytokinesis (arrowhead, UBI).