Interferon-Inducible CXC Chemokines Directly Contribute to Host Defense against Inhalational Anthrax in a Murine Model of Infection
Figure 2
Chemokine-mediated antimicrobial activity against B. anthracis Ames strain spores and encapsulated bacilli.
Murine CXCL9 and human CXCL10 display direct antimicrobial activity against B. anthracis Ames strain (pXO1+ pXO2+) organisms. (A) Chemokine-mediated effects on Ames strain spore germination, viability, and primary outgrowth. CFU determination was performed 6 h post-treatment in the presence or absence of heat treatment. Data represent mean ± SEM; dotted line indicates initial inoculum. A representative data set is shown from three independent experiments. **p<0.01 ***p<0.001 compared to untreated control. (B) Direct antimicrobial effects of murine CXCL9 and human CXCL10 against encapsulated Ames strain bacilli. Bacterial cell viability was measured using CFU determination performed 6 h post-treatment. Data represent mean values ± SEM; initial inoculum (dotted line). Similar results were observed in three independent experiments. ***p<0.001 compared to untreated control. (C) Microscopic visualization of encapsulated Ames strain bacilli in India ink preparations. Capsules appear as defined clear zones around the bacterial cells. Representative fields from two independent experiments are shown at 200× magnification.