Binding of Flavivirus Nonstructural Protein NS1 to C4b Binding Protein Modulates Complement Activation

Complement Activation NS1 to C4b Binding Protein Modulates Binding of Flavivirus Nonstructural Protein

Complement Inhibitor C4b-Binding Protein

West Nile virus nonstructural protein NS1 inhibits complement activation by binding the regulatory protein factor H.

The complement system, by virtue of its dual effector and priming functions, is a major host defense against pathogens. Flavivirus nonstructural protein (NS)-1 has been speculated to have immune evasion activity, because it is a secreted glycoprotein, binds back to cell surfaces, and accumulates to high levels in the serum of infected patients. Herein, we demonstrate an immunomodulatory functio...

Binding of C4b-Binding Protein to Porin

We screened 29 strains of Neisseria gonorrhoeae and found 16/21 strains that resisted killing by normal human serum and 0/8 serum sensitive strains that bound the complement regulator, C4b-binding protein (C4bp). Microbial surface-bound C4bp demonstrated cofactor activity. We constructed gonococcal strains with hybrid porin (Por) molecules derived from each of the major serogroups (Por1A and Po...

Antagonism of the complement component C4 by flavivirus nonstructural protein NS1

The complement system plays an essential protective role in the initial defense against many microorganisms. Flavivirus NS1 is a secreted nonstructural glycoprotein that accumulates in blood, is displayed on the surface of infected cells, and has been hypothesized to have immune evasion functions. Herein, we demonstrate that dengue virus (DENV), West Nile virus (WNV), and yellow fever virus (YF...