Table 2.
In trans complementation of a ΔpipB2 mutant increases LAMP-1 accumulation at the cell periphery and decreases Sif frequency in infected cells
| Strain | Peripheral LAMP-1-positive vesicles (%) | Sif-positive cells (%) | LAMP-1-positive bacteria (%) |
|---|---|---|---|
| SL1344 wild type | 7.0 ± 3.5 | 62 ± 3.9 | 90 ± 3.5 |
| ΔpipB2 | 5.7 ± 3.0 | 57 ± 6.2 | 91 ± 3.0 |
| ΔpipB2 PipB2-2HA | 46 ± 12* | 44 ± 5.7* | 94 ± 3.0 |
| ΔpipB2 PipB2(1-225)-2HA | 8.7 ± 3.8 | 60 ± 3.9 | |
| ΔpipB2 PipB2(Δ313-350)-2HA | 7.0 ± 4.7 | 60 ± 4.8 | |
| ΔpipB2 PipB2(Δ341-345)-2HA | 11 ± 1.2 | 62 ± 4.7 | 93 ± 5.2 |
| ΔpipB2 pACYC184 | 5.0 ± 3.7 | 62 ± 3.2 | 94 ± 3.1 |
| ΔpipB | 4.8 ± 1.2 | 63 ± 4.2 | 93 ± 4.1 |
| ΔpipB PipB-2HA | 9.9 ± 4.0 | 58 ± 3.2 | 92 ± 2.1 |
| ΔpipB PipB-PipB2(312-350)-2HA | 9.2 ± 3.4 | 60 ± 5.6 |
HeLa cells were seeded on coverslips in 24-well plates and infected with late-log phase bacteria as described in Materials and Methods. At 12 h postinfection, monolayers were fixed, permeabilized, and immunostained with anti-Salmonella LPS and anti-human LAMP-1 antibodies. Infected cells (>100 per experiment) were scored by fluorescent microscopy for LAMP-1 accumulation at the cell periphery, LAMP-1 accumulation around bacteria, and the presence of linear or punctate LAMP-1 staining extending from SCVs (a measure of Sif formation). Results are mean ± SD from at least three independent experiments.
Statistically different from wild type infection, p < 0.001, ANOVA.