PT  - JOURNAL ARTICLE
AU  - Mold, C
AU  - Gewurz, H
TI  - Inhibitory effect of C-reactive protein on alternative C pathway activation by liposomes and Streptococcus pneumoniae.
DP  - 1981 Nov 01
TA  - The Journal of Immunology
PG  - 2089--2092
VI  - 127
IP  - 5
4099  - http://www.jimmunol.org/content/127/5/2089.short
4100  - http://www.jimmunol.org/content/127/5/2089.full
SO  - J. Immunol.1981 Nov 01; 127
AB  - C-reactive protein (CRP) is an acute phase serum protein found associated with damaged tissue at sites of inflammation. CRP bound to multivalent phosphocholine-containing or polycationic ligands activates C by the classical pathway. We have previously described liposomes of a particular lipid composition that are able both to activate the alternative pathway of C and to bind CRP. In addition many strains of Streptococcus pneumoniae activate the alternative pathway. We have shown CRP binding to these bacteria as well. Because antibody to an activating surface in many cases enhances alternative pathway activation, we tested CRP for a similar function in these systems. Our results indicate that, in contrast to antibody, CRP inhibits alternative pathway activation. This inhibition by CRP is apparently restricted to surfaces that bind CRP. Thus, CRP binding to membrane or bacterial surfaces can convert them from alternative pathway activation to classical pathway activation.