Vaginal vaccination seems to be the best strategy for inducing specific immunoglobulin A (IgA) and IgG antibody responses in the female genital tract. The relative efficiencies of one, two, and three vaginal doses of recombinant cholera toxin B subunit (CTB) in generating mucosal and systemic immune responses in healthy women were evaluated, and the kinetics of the immune responses were monitor...

Toxin-antitoxin (TA) systems are essential for bacterial persistence under stressful conditions. In particular, Mycobacterium tuberculosis express VapBC TA genes that encode the stable VapC toxin and the labile VapB antitoxin. Under normal conditions, these proteins interact to form a non-toxic TA complex, but the toxin is activated by release from the antitoxin in response to unfavorable condi...

Toxin/antitoxin (TA) systems are nearly universal in prokaryotes; toxins are paired with antitoxins which inactivate them until the toxins are utilized. Here we explore whether toxins may function alone; i.e., whether a toxin which lacks a corresponding antitoxin (orphan toxin) is physiologically relevant. By focusing on a homologous protein of the membrane-damaging toxin GhoT of the Escherichi...

Bacteria have evolved mechanisms that allow them to survive in the face of a variety of stresses including nutrient deprivation, antibiotic challenge and engulfment by predator cells. A switch to dormancy represents one strategy that reduces energy utilization and can render cells resistant to compounds that kill growing bacteria. These persister cells pose a problem during treatment of infecti...

Toxin-antitoxin (TA) modules are pairs of genes essential for bacterial regulation upon environmental stresses. The mazEF module encodes the MazF toxin and its cognate MazE antitoxin. The highly dynamic MazE possesses an N-terminal DNA binding domain through which it can negatively regulate its own promoter. Despite being one of the first TA systems studied, transcriptional regulation of Escher...

Type I toxin-antitoxin systems encoded on bacterial chromosomes became the focus of research during the past years. However, little is known in terms of structural requirements, kinetics of interaction with their targets and regulatory mechanisms of the antitoxin RNAs. Here, we present a combined in vitro and in vivo analysis of the bsrG/SR4 type I toxin-antitoxin system from Bacillus subtilis....

Lecithin has been found to interfere with the combining reaction of Cl. welchii alpha toxin (lecithinase) and its antitoxin. If the lecithinase is first brought into contact with lecithin, and the antitoxin is then added, the antitoxin fails to stop the enzymatic reaction, but gradually decelerates it. If the lecithinase is brought into contact with both lecithin and antitoxin at the same insta...