Proteins involved in cytoadhesion of plasmodlum falciparum ring-stage-infected erythrocytes, antibodies which bind to the proteins, and methods for detecting infection, stage of infection and vaccines for protecting against infection

Abstract

The present invention provides the RSP-1 and RSP-2 proteins which are involved in the cytoadhesion of P. falciparum during ring-stage infection of erythrocytes, antibodies which bind to the proteins, methods of screening for a P. falciparum infection, methods of determining the infective stage of P. falciparum and vaccines for protecting individuals from Plasmodium sp. infections.

1 . An isolated protein which mediates  Plasmodium falciparum  ring-stage adhesion to endothelial cells and is approximately 200 kilodaltons in size as determined by SDS-polyacrylamide gel electrophoresis.  
     
     
         2 . An isolated protein which mediates  Plasmodium falciparum  ring-stage adhesion to endothelial cells and is approximately 40 kilodaltons in size as determined by SDS-polyacrylamide gel electrophoresis.  
     
     
         3 . An antibody which binds to the isolated protein of  claim 1  or  2 .  
     
     
         4 . The antibody of  claim 3  which is a monoclonal antibody.  
     
     
         5 . The antibody of  claim 4 , which is a polyclonal antibody.  
     
     
         6 . A method of detecting the presence of a Plasmodium species in a sample comprising: 
 contacting said sample with the antibody of claim  3 ; and    identifying an interaction between the antibody and the Plasmodium species in said sample, wherein said interaction indicates the presence of the Plasmodium species.    
     
     
         7 . The method of  claim 6 , wherein said Plasmodium species is  Plasmodium falciparum.    
     
     
         8 . The method of  claim 6 , wherein said antibody is coupled to a detectable moiety.  
     
     
         9 . The method of  claim 6 , wherein said sample is obtained from a human patient suspected of having malaria.  
     
     
         10 . A method of detecting the presence of a Plasmodium antibody in a sample comprising: 
 contacting said sample with the isolated protein of  claim 1  or  claim 2;  and    identifying an interaction between the protein and the Plasmodium antibody in said sample, wherein said interaction indicates the presence of the Plasmodium.    
     
     
         11 . The method of  claim 10 , wherein said Plasmodium is  Plasmodium falciparum.    
     
     
         12 . The method of  claim 10 , wherein said protein is coupled to a detectable moiety.  
     
     
         13 . The method of  claim 10 , wherein said sample is obtained from a human patient suspected of having malaria.  
     
     
         14 . A method of diagnosing the  Plasmodium falciparum  blood-stage cycle in an individual suspected of being infected with  Plasmodium falciparum  comprising: 
 obtaining a biological sample from said individual;    contacting said sample with the antibody of claim  3 ; and    identifying an interaction between the antibody and an antigen in said sample, wherein said interaction indicates a ring-stage infection.    
     
     
         15 . A method of diagnosing the  Plasmodium falciparum  blood-stage cycle in an individual suspected of being infected with  Plasmodium falciparum  comprising: 
 obtaining a biological sample from said individual;    contacting said sample with the protein of  claim 1  or  2 ; and    identifying an interaction between the protein and an antibody in said sample, wherein said interaction indicates a ring-stage infection.    
     
     
         16 . A composition comprising at least one of the isolated proteins RSP-1 and RSP-2 and a pharmaceutical acceptable carrier.  
     
     
         17 . The composition of  claim 16 , which is an immunogenic composition  
     
     
         18 . The composition of  claim 16 , which is a vaccine.  
     
     
         19 . A method of protecting an individual against a  Plasmodium falciparum  infection comprising: 
 administering the at least one of the isolated proteins RSP-1 and RSP-2 to said individual in an amount sufficient to induce an immune response in said individual.    
     
     
         20 . The method of  claim 19 , wherein said administering further comprises administering an adjuvant.  
     
     
         21 . The method of  claim 19 , wherein said administering is performed one or more times.  
     
     
         22 . Hybridoma Pf 26G1/B4 deposited at the C.N.C.M under the accession number I-2635.  
     
     
         23 . A method of diagnosing the  Plasmodium falciparum  blood-stage cycle in an individual suspected of being infected with  Plasmodium falciparum  comprising: 
 obtaining a biological sample from said individual;    contacting said sample with the antibody of claim  22 ; and    identifying an interaction between the antibody and an antigen in said sample, wherein said interaction indicates a ring-stage infection.