1. Solubilization of immune precipitates by complement in the absence of properdin or factor D
- Author
-
U.B. Schaad, J. A. Schifferli, P. J. Spath, M. Pascual, and Liselotte Meyer-Hänni
- Subjects
Erythrocytes ,Complement Activating Enzymes ,Biophysics ,Complement ,Antigen-Antibody Complex ,Biochemistry ,Antibodies ,Classical complement pathway ,Structural Biology ,Tetanus Toxoid ,Genetics ,Solubilization ,Humans ,Factor D ,Bovine serum albumin ,Complement Activation ,Molecular Biology ,Chromatography ,Immune complex ,biology ,Properdin ,Chemistry ,Toxoid ,Serum Albumin, Bovine ,Complement C3 ,Cell Biology ,In vitro ,Receptors, Complement ,Solubility ,Complement C3b ,Receptors, Complement 3b ,biology.protein ,Alternative complement pathway ,Complement Factor D - Abstract
Various experiments have demonstrated that immune precipitates (IPs) are not solubilized by complement in the absence of alternative pathway function. To determine whether the characteristics of the IPs were responsible for these observations, we studied the solubilization (Sol) of IPs formed by bovine serum albumin (BSA)-rabbit antiBSA and tetanus toxoid (TT)-human antiTT. Sera deficient in properdin solubilized a fraction of BSA-antiBSA precipitates, although only when the IPs were formed in antibody excess. The same sera solubilized TT-antiTT precipitates with some delay but almost as efficiently as normal serum. Factor D-depleted serum solubilized a fraction of TT-antiTT precipitates too, indicating that Sol may proceed through activation of the classical pathway only. Thus, the requirements for complement-mediated Sol depend on the characteristics of the IPs and do not necessarily include alternative pathway function.
- Full Text
- View/download PDF