Recombinant Polypeptides for Diagnosing Infection with Trypanosoma Cruzi

Abstract

Recombinant polypeptides are disclosed that are useful for diagnosing American trypanosomiasis, or Chagas disease, a disease caused by the infectious agent Trypanosoma cruzi. Preferably, DNA sequences encoding the recombinant proteins are placed in plasmid vectors to be expressed in an organism.

1 . A recombinant plasmid vector comprising a DNA sequence which codes for a recombinant polypeptide corresponding to a polypeptide selected from the group consisting of FP3 [SEQ ID NO 22], FP4 [SEQ ID NO 8], FP5 [SEQ ID NO 10], FP6 [SEQ ID NO 14], FP7 [SEQ ID NO 12], FP8 [SEQ ID NO 16], FP9 [SEQ ID NO 18] and FP 10 [SEQ ID NO 20]. 
     
     
         2 . The plasmid vector of  claim 1 , wherein the plasmid vector is selected from the group consisting of pGEX and pET plasmid vectors. 
     
     
         3 . The plasmid vector of  claim 2 , wherein the plasmid vector is pET-32a. 
     
     
         4 . The plasmid vector of  claim 1 , wherein the DNA sequence comprises one selected from the group consisting of SEQ lD NO 21, SEQ ID NO 7, SEQ ID NO 9, SEQ ID NO 13, SEQ ID NO 11, SEQ ID NO 15, SEQ ID NO 17, and SEQ ID NO 19. 
     
     
         4 . An organism transfected with the plasmid vector of  claim 1 . 
     
     
         5 . The organism of  claim 4 , wherein the organism is  Escherichia coli.    
     
     
         6 . A recombinant polypeptide comprising a sequence corresponding to one of FP3, FP4, FP6, FP7, FP8 and FP10. 
     
     
         7 . A kit comprising:
 a first recombinant polypeptide wherein the first recombinant polypeptide is the recombinant polypeptide of  claim 6 , and   a second recombinant polypeptide.   
     
     
         8 . The kit of  claim 7 , wherein the second polypeptide comprises a sequence corresponding to one selected from the group consisting of Ag15 [SEQ ID NO 2], FP3, FP4, FP5, FP6, FP7 FP8, FP9 and FP10, wherein the first recombinant polypeptide is different from the second recombinant polypeptide. 
     
     
         9 . The kit of  claim 7 , wherein the first recombinant polypeptide is FP4 and the second recombinant polypeptide is FP6. 
     
     
         10 . The kit of  claim 7 , further comprising a third recombinant polypeptide selected from the group consisting of Ag15, FP3, FP4, FP5, FP6, FP7 FP8, FP9 and FP10, wherein the first recombinant polypeptide, the second recombinant polypeptide and the third recombinant polypeptide are different. 
     
     
         11 . The kit of  claim 10 , wherein the first recombinant polypeptide corresponds to FP4, the second recombinant polypeptide corresponds to FP6 and the third polypeptide corresponds to FP10. 
     
     
         12 . A method of detecting the presence of anti- Trypanosoma cruzi  antibodies in a sample from a subject, comprising:
 (A) contacting the sample with a polypeptide comprising an amino acid sequence selected from the group consisting of FP3, FP4, FP6, FP7, FP8 and FP10 or an immunoreactive fragment thereof, and   (B) detecting a specific binding interaction with an antibody in said sample, wherein the binding interaction comprises a specific binding between antibody in the sample and an epitope contained within the amino acid sequence set forth in FP3, FP4, FP6, FP7, FP8 and FP10 and wherein said specific binding interaction indicates past or present infection with  Trypanosoma cruzi.      
     
     
         13 . The method of  claim 12 , wherein the polypeptide of step A is immobilized on a carrier molecule or a solid phase. 
     
     
         14 . The method of  claim 12 , wherein the polypeptide of step A has a sequence obtained from a strain or clone of  Trypanosoma cruzi.    
     
     
         15 . The method of  claim 12 , wherein the polypeptide has had one or more amino acids truncated. 
     
     
         16 . The method of  claim 12 , wherein the step of detecting anti- Trypanosoma cruzi  antibodies bound to the immobilized polypeptide is carried out by adding at least one compound that detects the antibodies. 
     
     
         17 . The method of  claim 16 , wherein the at least one compound that enables detection of the anti- Trypanosoma cruzi  antibodies is selected from the group consisting of a colorimetric agent, a fluorescent agent, a chemiluminescent agent and a radionucleotide.