Complement receptor 1 and 2 fusion proteins
Modulation of the complement system represents a therapeutic modality for numerous pathologic conditions associated with complement activation. In a strategy to prepare complement inhibitors that are targeted to sites of complement activation and disease, compositions comprising a complement inhibitor linked to complement receptor (CR) 2 are disclosed. The disclosed are compositions can be used in methods of treating pathogenic diseases and inflammatory conditions by modulating the complement system.
1. A composition comprising a construct, wherein the construct is a fusion protein consisting of:
(a) a complement receptor 2 (CR2) or a fragment thereof, wherein the fragment consists of at least the first two N-terminal short consensus repeat (SCR) domains of the CR2 protein;
(b) a modulator of complement activity, wherein the modulator consists of one or more active sites of CR1; and
(c) optionally, a linker linking (a) and (b).
2. The composition of claim 1 , wherein the sequence of the modulator consists of SEQ ID NO. 14.
3. The composition of claim 1 , wherein the modulator consists of murine CR1 or human CR1.
4. The composition of claim 1 , wherein the CR2 or fragment thereof is fused to the N-terminus of the modulator.
5. The composition of claim 1 , wherein the CR2 or fragment thereof is fused to the C-terminus of the modulator.
6. The composition of claim 1 , wherein the CR2 is a full-length CR 2 protein.
7. The composition of claim 1 , wherein the CR2 or fragment thereof consists of the four N-terminal SCR domains of the CR2 protein.
8. The composition of claim 1 , wherein the modulator consists of the entire extracellular region of CR1.
9. The composition of claim 1 , wherein at least one of the one or more active sites of CR1 consists of a leader peptide, wherein the sequence of the leader peptide consists of amino acids 6-46 of SEQ ID NO:14.
10. The composition of claim 1 , wherein said modulator consists of SCR1-4 of CR1.
11. The composition of claim 1 , wherein said modulator consists of SCR8-11 of CR1.
12. The composition of claim 1 , wherein said modulator consists of SCR15-18 of CR1.
13. The composition of claim 1 , wherein at least one of the one or more active sites of CR1 consists of the C1q binding site of CR1.