Abstract: Aspects of the present invention relate to the recombinant production of a mature complement system protein. Certain embodiments of the present invention relate to recombinant production of fully mature human complement Factor I protein (CFI). Included herein are details of an expression vector with which to recombinantly express fully mature human CFI from mammalian cells. Further disclosed are chromatography steps with which to purify recombinantly expressed CFI. Certain aspects of the present invention relate to the use of an expression system in gene therapy and the like. Certain embodiments of the present invention relate to use of said vector as a medicament, for example for use in the treatment of complement-mediated disorders.

Abstract: Certain embodiments of the present invention relate to regulation of the innate immune system and complement activation. In particular, but not exclusively certain embodiments relate to a complement regulator protein and pharmaceutical compositions thereof for use in the treatment of diseases associated with or mediated by the alternative complement pathway and methods of treating such diseases and other subject matter.

Abstract: The disclosure provides, in part, compositions comprising mature recombinant mature Complement Factor I (CFI) protein and methods of making and using those compositions.