Lectin complement pathway assays and related compositions and methods
This invention is related, in part, to assays for analyzing the lectin complement pathway (LCP) as well as to compositions and methods related thereto.
1. A method of assessing lectin complement pathway (LCP) activation, comprising:
determining an amount of mannose binding lectin (MBL) in a biological sample,
removing non-covalently bound MBL/mannose binding lectin serine protease 2 (MASP-2) complexes,
determining an amount of another LCP component in the biological sample, and
assessing LCP activation in the biological sample based on the amounts of MBL and the another component.
2. The method of claim 1 , wherein the another LCP component is, C3, C3b, C4, C4b or C4b/2a.
3. The method of claim 2 , wherein the method further comprises:
measuring a further LCP component in the biological sample.
4. The method of claim 3 , wherein the further LCP component is MASP-2, C3, C3b, C4, C4b or C4b/2a.
5. The method of claim 4 , wherein the another LCP component is C4 and the further LCP component is C3.
6. The method of claim 4 , wherein still another LCP component is measured in the biological sample.
7. The method of claim 6 , wherein the still other LCP component is MASP-2.
8. The method of claim 1 , wherein the non-covalently bound MBL/MASP-2complexes are removed with the addition of a buffer that contains a calcium chelator.
9. The method of claim 8 , wherein the calcium chelator is EDTA or EGTA.
10. The method of claim 8 , wherein the buffer further contains a competitive inhibitor of MBL.
11. The method of claim 10 , wherein the competitive inhibitor is mannose, N-acetylglucosamine (GlcNAc), fucose, glucose or an anti-MBL antibody.
12. The method of claim 1 , wherein the biological sample is a serum, plasma or cerebrospinal fluid sample.
13. The method of claim 1 , wherein the biological sample is from a subject with or suspected of having LCP-mediated disease.
14. The method of claim 1 , wherein the measurements are performed in the same biological sample or portion thereof.
15. A method of assessing LCP activation, comprising:
contacting a substrate coated with a ligand of MBL with a biological sample,
contacting the sample with a detectably labeled agent that specifically binds MBL,
determining the amount of MBL present,
removing non-covalently bound MBL/MASP-2 complexes from the sample,
contacting the sample with a detectably labeled agent that specifically binds C4,
contacting the sample with a detectably labeled agent that specifically binds C3,
determining the amount of C4 and C3 present, and
assessing LCP activation in the sample based on the amounts of MBL, C4 and C3.
16. The method of claim 15 , wherein the ligand of MBL is mannan, mannose or GlcNAc.
17. The method of claim 15 , wherein the agent that specifically binds MBL is an anti-MBL antibody.
18. The method of claim 15 , wherein the agent that specifically binds C4 is an anti-C4 antibody.
19. The method of claim 15 , wherein the agent that specifically binds C3 is an anti-C3 antibody.
20. The method of claim 15 , wherein the method further comprises:
contacting the sample with a detectably labeled agent that specifically binds MASP-2, and determining the amount of MASP-2 present.
21. The method of claim 20 , wherein the agent that specifically binds MASP-2 is an anti-MASP-2 antibody.
22. The method of claim 15 , wherein the biological sample is a serum, plasma or cerebrospinal fluid sample.
23. The method of claim 15 , wherein the biological sample is from a subject with or suspected of having a LCP-mediated disease.
24. The method of claim 15 , wherein the measurements are performed in the same well of a well plate.