Streptococcus pneumoniae is a respiratory tract pathogen that can cause mucosal and respiratory diseases such as sinusitis, otitis media and pneumonia, but also life-threatening diseases such as sepsis and meningitis. This Gram-positive bacterium has evolved several sophisticated mechanisms to evade the human innate immune system. One strategy is to bind human complement regulators to inhibit the complement system directly on the surface of the pathogen. The surface exposed protein Hic2 binds the complement inhibitor vitronectin and thereby uses its function to block the complement attack.

protein – protein interaction | complement evasion | MO-P-047