Bacillus collagen-like protein A (BclA)

Bacillus collagen-like protein A (BclA) is the predominant glycoprotein found on the exosporium, the outermost layer of Bacillus anthracis spores. It forms a characteristic hair-like nap on the spore surface and serves as the primary interface between the pathogen and the host immune system during the initial stages of infection. BclA plays a dual role in pathogenesis: it facilitates the uptake of spores by host macrophages and mediates the binding of complement factor H, which inhibits complement activation and promotes spore persistence within the host. Due to its immunodominant nature and critical role in the infection cycle, BclA is a major target for the development of next-generation anthrax vaccines and therapeutic antibodies designed to enhance spore opsonization and clearance. Experimental studies have shown that targeting BclA can significantly augment the protective efficacy of vaccines primarily based on the protective antigen (PA).

Other names

Bacillus collagen-like antigenExosporium protein BclACollagen-like protein ABclA protein

Induction of opsonizing antibodies that facilitate spore clearance by phagocytes and neutralization of spore-host interactions, including the blocking of complement factor H binding to prevent immune evasion.