Complement mediated solubilization: role of the complement in the clearance of circulating immune-complexes.

In 1975, Miller and Nussenzweig described a new function of the Complement (C'): the Capacity of this substance to solubilize "in vitro" antigen/antibody complexes previously formed. Subsequent studies of these authors and other researches (particularly Takahashi and his group) demonstrated that this process is mediated by activation of the alternative way of C', although it is faster when the classic way is involved. Basically, thanks to the Takahashi and group studies, it has been possible to know in detail the intimate mechanism of this phenomenon, usually known demonstrated that the key of all this process lies in the generation, through the C' alternative way, of numerous molecules of C3b that deposit over the antigen/antibody complexes (Ag/Ac), causing the breakage of the necessary mesh for such complexes to precipitate, which leads to formation of small immunocomplexes (IC) very rich in C3b which turn soluble again. ICs solubilized in this way suffer important physicochemical and biological changes, and transform into substances without inflammatory power that are not able to activate C' nor to interact with C3b receptors present in a great number of blood cells. However, they are captured by Kupffer cells in the hepatic sinusoids and quickly catabolized. CMS is closely related with another similar phenomenon, the Immuno-Precipitation inhibition (IPI), described by Schiferli and his group in the early 80's.(ABSTRACT TRUNCATED AT 250 WORDS)