Methods of modulating immune coagulation

Abstract

Methods for mediating immune coagulation using novel antibodies and compounds are described. A protein Fgl2 having direct prothrombinase activity has been identified. Inhibitors of Fgl2 are useful in preventing and treating diseases which require a reduction in immune coagulation including bacterial and viral infections, allograft and xenograft rejection, glomerulonephritis, cancer, a number of gastrointestinal diseases and fetal loss.

I claim:  
     
         1 . A method of preventing or treating a condition requiring a reduction in immune coagulation comprising administering an effective amount of an inhibitor of Fgl2 to an animal in need thereof.  
     
     
         2 . A method according to  claim 1  wherein said inhibitor is an antibody that binds to Fgl2.  
     
     
         3 . A method according to  claim 2  wherein the antibody is a monoclonal antibody that binds to a human Fgl2 having the amino acid sequence as shown in FIG. 5.  
     
     
         4 . A method according to  claim 3  wherein the antibody binds an epitope of human Fgl2 comprising the amino acids at positions 364-378 (DRYPSGNCGLYYSSG) in FIG. 5.  
     
     
         5 . A method according to any one of  claims 1  to  4  wherein the condition is graft rejection.  
     
     
         6 . A method according to any one of  claims 1  to  4  wherein the condition is fetal loss.  
     
     
         7 . A method for diagnosing or monitoring a condition involving increased immune coagulation in an animal comprising detecting a Fgl2 protein or a Fgl2 nucleic acid in a biological sample from the animal.  
     
     
         8 . A method according to  claim 7  comprising detecting (a) a nucleic acid molecule having a sequence shown in FIG. 2 or  3  or SEQ.ID.NO.:1 or 3, or a fragment thereof, or (b) a protein having an amino acid sequence as shown in FIG. 5 or SEQ.ID.NO.:2 or 4, or a fragment thereof.  
     
     
         9 . A method for detecting a Fgl2 protein according to  claim 7  or  8  comprising contacting the sample with an antibody that binds to Fgl2 which is capable of being detected after it becomes bound to the Fgl2 in the sample.  
     
     
         10 . A method for detecting a nucleic acid molecule encoding Fgl2 according to  claim 7  or  8  comprising contacting the sample with a nucleotide probe capable of hybridizing with the nucleic acid molecule to form a hybridization product, under conditions which permit the formation of the hybridization product, and assaying for the hybridization product.  
     
     
         11 . A method according to  claim 10  further comprising treating the sample with primers which are capable of amplifying the nucleic acid molecule in a polymerase chain reaction to form amplified sequences under conditions which permit the formation of amplified sequences, and assaying for amplified sequences.  
     
     
         12 . A method according to any one of  claims 7  to  11  wherein the condition is graft rejection.  
     
     
         13 . A method according to any one of  claims 7  to  11  wherein the condition is fetal loss.  
     
     
         14 . A method of inducing immune coagulation comprising administering a nucleic acid sequence encoding Fgl2 or an Fgl2 protein to an animal in need thereof.  
     
     
         15 . A method according to  claim 14  comprising administering (a) a nucleic acid molecule having a sequence shown in FIG. 2 or  3  or SEQ.ID.NO.:1 or 3 or (b) a protein having a sequence shown in FIG. 5 or SEQ.ID.NO.:2 or 4.  
     
     
         16 . A method for assaying for a substance that affects the prothrombinase activity of a Fgl2 protein comprising reacting a Fgl2 protein, a substrate which is capable of being cleaved by the protein to produce a product, and a test substance, under conditions which permit cleavage of the substrate to produce the product, assaying for product, and comparing to the product obtained in the absence of the substance to determine the effect of the substance on the prothrombinase activity of the protein.  
     
     
         17 . A composition for use in inhibiting procoagulant activity in an animal comprising (a) an antibody specific for a Fgl2 protein; (b) an antisense oligonucleotide to Fgl2; or (c) a substance identified using the method as claimed in  claim 16  in admixture with a suitable diluent or carrier.  
     
     
         18 . A method for preventing or treating a condition requiring a reduction in procoagulant activity in an animal comprising administering a therapeutically effective amount of a composition as claimed in  claim 17 .  
     
     
         19 . A vaccine for preventing graft rejection comprising an effective amount of an Fgl2 protein or peptide in admixture with a suitable diluent or carrier.  
     
     
         20 . A vaccine for preventing fetal loss comprising an effective amount of an Fgl2 protein or peptide in admixture with a suitable diluent or carrier.  
     
     
         21 . An isolated nucleic acid molecule comprising (a) the sequence shown in FIG. 8, where T can also be U; (b) nucleic acid sequences which have substantial sequence identity with (a); and (c) a fragment of (a) or (b).  
     
     
         22 . An isolated nucleic acid molecule comprising (a) the sequence shown in FIG. 4, where T can also be U; (b) nucleic acid sequences which have substantial sequence identity with (a); and (c) a fragment of (a) or (b).