This article was published as Journal of Immunology, 2008, 180, pp. 3313-3318. Copyright © American Association of Immunologists. It is available from http://www.jimmunol.org/.Properdin is a positive regulator of complement activation so far known to be instrumental in the survival of infections with certain serotypes of Neisseria meningitidis. We have generated a fully backcrossed properdin-deficient mouse line by conventional gene-specific targeting. In vitro, properdin-deficient serum is impaired in alternative pathway-dependent generation of complement fragment C3b when activated by Escherichia coli DH5α. Properdin-deficient mice and wild-type littermates compare in their levels of C3 and IgM. In an in vivo model of polymicrobial septic peritonitis induced by sublethal cecal ligation and puncture, properdin-deficient mice appear immunocompromised, because they are significantly impaired in their survival compared with wild-type littermates. We further show that properdin localizes to mast cells and that properdin has the ability to directly associate with E. coli DH5α. We conclude that properdin plays a significant role in the outcome of polymicrobial sepsis
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.