H. Control proteins of the complement cascade Eight host proteins which prevent activation on host cells. Complement evasion 1. Serum sensitive in the lab, but clearly resistant in vivo. Important concept that serum resistance only manifested in vivo . The S. pneumoniae capsule is essential for pathogenesis.
Immunity is mediated by anti-capsular antibody which fixes complement.
M-protein of S. pyogenes binds factor H which promotes degradation of C3b. 5. Synthesis of a protein that fixes Complement, but does not kill. Surface exclusion protein of F-plasmid. TnPhoA analysis of lysogens revealed two proteins expressed in the host cell membrane, Lom and Bor. C. Summation Complement is extremely effective at maintaining the sterility of blood.