TABLE 3.
Effects of opsonization on 1-h uptake and 48-h growth of 16M in nonactivated and IFN-γ-activated mouse peritoneal macrophagesa
| Opsonin | No. of brucellae ingested by macrophages after 1-h exposure (103 CFU/well)b | Intracellular brucellae after 48-h incubation (103 CFU/well)bc
|
IFN-γ-mediated macrophage anti-Brucella activity (%)d | |
|---|---|---|---|---|
| Without IFN-γ | With IFN-γ | |||
| None | 3.56±0.45 | 11.17±3.10 (3.13) | 5.21±2.62 (1.46) | 53 |
| 2% HCS | 7.68±0.73 | 872.50±26.81 (113.60) | 275.00±66.41 (35.81) | 68 |
| 0.01% aLPS | 10.90±1.56 | 1,170.00±182.35 (107.34) | 130.00±18.71 (11.93) | 89 |
| 0.01% aLPS + 2% HCS | 22.5±5.44 | 2,512.00±253.96 (111.64) | 312.00±53.63 (13.86) | 88 |
a
Macrophage monolayers were incubated with 8 bacteria per macrophage with or without 0.01% aLPS and HCS or with a combination of 0.01% aLPS and 2% HCS. Controls received DME-FBS-MCSF medium but without opsonin. The number of intracellular bacteria was determined by lysis of monolayers after 1 and 48 h, followed by serial dilution and plating on agar.
b
Mean ± SEM CFU per well from five replicate wells in one of four similar experiments.
c
Numbers in parentheses represent the ratio of CFU at 48 h to CFU at 1 h.
d
[CFU (minus IFN-γ) − CFU (plus IFN-γ)]/[CFU (minus IFN-γ)] × 100.