Article Figures & Data
Figures
- FIG 1
B. abortus is not lethal in complement-depleted mice. Groups of BALB/c mice were chronically depleted of complement by means of repeated injections of CVF. (A) Serum C3 detection by Western blotting was used to determine the depletion of complement (Cdepl) in CVF-injected mice. Arrows indicate the position of the C3 fraction and its fragments. (B) Percentage of leukocyte types in complement-depleted mice (n = 5) and PBS-injected control mice (n = 5). Lymph, lymphocytes; Mono, monocytes. (C) Survival percentage of PBS-injected control mice (n = 7) and complement-depleted mice (n = 7) after infection with S. enterica. (D) Survival percentage of PBS-injected control mice (n = 7) and complement-depleted mice (n = 7) after infection with B. abortus 2308W. Black and white bars represent the median ± interquartile range (IQR). The Mann-Whitney U test showed no significant differences. Data are representative of those from at least three independent experiments.
- FIG 2
The absence of complement favors the removal of B. abortus. (A) Groups of seven BALB/c mice were depleted of complement or injected with PBS and then infected with 0.1 ml of B. abortus 2308W at 106 CFU/ml by the i.p. route. At 7 days postinfection, the spleen weight and bacterial counts were determined for each group. (B) To ensure that CVF did not prime an adjuvant immune response, promoting bacterial clearance, groups of seven BALB/c mice were treated with repeated i.p. injections of 80 μg of aspercetin or with PBS and then infected with 0.1 ml of B. abortus 2308W at 106 CFU/ml by the i.p. route. (C and D) At 7 days postinfection the spleen weight (C) and bacterial counts (D) were determined for each group. The median is represented by a line. Statistical significance was calculated by the Mann-Whitney U test. *, P < 0.05. Data are representative of those from at least three independent experiments.
- FIG 3
Complement-depleted B. abortus-infected mice produce higher levels of proinflammatory cytokines. Cytokine levels in sera from complement-depleted (n = 7) and control (n = 7) mice were determined by ELISA after 7 days of infection with 0.1 ml of B. abortus 2308W (Ba 2308) at 106 CFU/ml by the i.p. route. A group of noninfected complement-depleted mice (n = 5) was used as a control. The mean is represented as a line. Asterisks above the bars indicate statistically significant differences relative to complement-depleted noninfected mice. Statistical significance was calculated by ANOVA and Tukey's multiple-comparison test. **, P < 0.01; ***, P < 0.001. Data are representative of those from at least three independent experiments.
- FIG 4
Complement-depleted B. abortus-infected mice show a histopathological profile similar to that of the control PBS-injected B. abortus-infected mice. (A) The semiquantitative pathological index was determined by histopathological observation of the spleen and liver from complement-depleted mice (n = 7) and control mice (n = 7) after 7 days of infection with 0.1 ml of 106 B. abortus bacteria or 3 days of infection with 103 S. enterica bacteria. (B) Histopathological examination of the liver and spleen of complement-depleted B. abortus-infected mice after 7 days of infection. The arrows indicate the characteristic granulomas induced by Brucella in the liver and spleen (35). Data are representative of those from at least three independent experiments.
- FIG 5
Protocol for depletion of complement with CVF in mice. CVF (0.8 μg/g body weight) was administered intraperitoneally at different times before and after bacterial infections (thin arrows). Bacteria were inoculated at time zero (broken arrow). Bacterial counts, cytokine estimation, and histopathological studies were performed at 7 days of infection (bent arrow). The end of the survival experiment is indicated with a thick arrow.
