Regulation of complement activation by C-reactive protein: targeting the complement inhibitory activity of factor H by an interaction with short consensus repeat domains 7 and 8-11.

Haemophilus influenzae interacts with the human complement inhibitor factor H.

Pathogenic microbes acquire human complement inhibitors to circumvent the innate immune system. In this study, we identify two novel host-pathogen interactions, factor H (FH) and factor H-like protein 1 (FHL-1), the inhibitors of the alternative pathway that binds to Hib. A collection of clinical Haemophilus influenzae isolates was tested and the majority of encapsulated and unencapsulated boun...

Improvement of anticomplementary activity assay for the quality control of immunoglobulin product: an Iranian pilot scale study

Abstract Background and Objectives One of the side effects of immunoglobulin administration is the activation of the complement system related to the high concentration of aggregates/large polymers in the production process. Measuring anticomplementary activity (ACA) is important in pharmaceutical quality control and is a criterion of spontaneous activation of complement system in immunoglobuli...

Streptococcus pneumoniae evades complement attack and opsonophagocytosis by expressing the pspC locus-encoded Hic protein that binds to short consensus repeats 8-11 of factor H.

Streptococcus pneumoniae is an important cause of upper and lower respiratory tract infections, meningitis, peritonitis, bacterial arthritis, and sepsis. Here we have studied a novel immune evasion mechanism of serotype 3 pneumococci, which are particularly resistant to phagocytosis. On their surfaces the bacteria express the factor H-binding inhibitor of complement (Hic), a protein of the pneu...

Inhibitory Activity of C4b-Binding Protein C-Reactive Protein: Targeting of the Regulation of Complement Activation by

Regulation of complement activation by C-reactive protein: targeting of the inhibitory activity of C4b-binding protein.

C-reactive protein (CRP) is the major acute phase protein in humans. It has been shown that CRP interacts with factor H, an inhibitor of the alternative pathway of complement, and now we demonstrate binding of CRP to the fluid-phase inhibitor of the classical pathway, C4b-binding protein (C4BP). C4BP bound to directly immobilized recombinant CRP as well as CRP attached to phosphorylcholine. The...