Escherichia coli endotoxin and Bacillus anthracis lethal toxin (LPS and LT)

Escherichia coli endotoxin and Bacillus anthracis lethal toxin is a composite entry representing two distinct bacterial virulence factors. Escherichia coli endotoxin, or lipopolysaccharide (LPS), is a major component of the Gram-negative bacterial cell wall that triggers a robust inflammatory response by binding to the TLR4/MD-2 receptor complex, potentially leading to sepsis and septic shock (Beutler et al., 2003). Bacillus anthracis lethal toxin is a bipartite protein toxin consisting of protective antigen (PA) and lethal factor (LF); PA facilitates the entry of LF, a zinc-dependent metalloprotease, into the host cytosol where it cleaves mitogen-activated protein kinase kinases (MAPKKs), disrupting essential signaling pathways and causing cell death (Moayeri et al., 2015). Therapeutic strategies for LPS include neutralization by polymyxins or experimental TLR4 antagonists, while anthrax lethal toxin is targeted by monoclonal antibodies like raxibacumab and obiltoxaximab that block PA binding (Migone et al., 2009). Because these entities have different structures, host receptors, and pathological mechanisms, they are treated as separate therapeutic targets in clinical practice. LPS is primarily associated with Gram-negative bacteremia, while lethal toxin is specific to anthrax infections. Both toxins are of significant interest in the fields of immunology, infectious disease, and biodefense.

Other names

LipopolysaccharideLPSEndotoxinLethal ToxinLTPA+LFAnthrax lethal toxinLipid AProtective antigenLethal factor

Neutralization of bacterial toxins to prevent host cell damage and systemic inflammation. Polymyxin B binds to the lipid A portion of E. coli LPS (PubChem). Raxibacumab and obiltoxaximab bind to the PA component of B. anthracis toxin to prevent cellular entry (FDA).