Synthetic peptides that inhibit leukocyte superoxide anion production and/or attract leukocytes

Abstract

Methods of inhibiting leukocyte O 2 − production and attracting leuckocytes using specific peptides are disclosed. These peptides include the proline-arginine (PR)-rich antimicrobial peptide known as PR-39 and truncated analogs thereof. These peptides can be used as medicaments that fight infection by attracting leukocytes to a wound site, yet restrict tissue damage at the wound site caused by excessive oxygen radicals produced by these leukocytes.

1 . A method of inhibiting leukocyte O 2   −  production comprising the step of contacting a leukocyte with a peptide selected from the group consisting of SEQ ID NOS: 1 and 2 for a time and under conditions effective to inhibit leukocyte O 2   −  production, wherein the inhibition of O 2   −  production occurs as a consequence of binding between the peptide and p47 phox , wherein said p47 phox  is a 47 kD cytosolic protein of the phagocyte NADPH oxidase complex.  
     
     
         2 . The method of  claim 1 , wherein the peptide consists of SEQ ID NO: 1.  
     
     
         3 . The method of  claim 1 , wherein the peptide is synthesized.  
     
     
         4 . The method of  claim 1 , wherein the peptide inhibits the activity of NADPH oxidase.  
     
     
         5 . The method of  claim 1 , wherein the leukocyte is a mammalian leukocyte.  
     
     
         6 . The method of  claim 5 , wherein the leukocyte is a porcine leukocyte.  
     
     
         7 . The method of  claim 1 , wherein the leukocyte is a neutrophil.  
     
     
         8 . The method of  claim 1 , wherein said peptide binds to the SH3 domain of p47 phox , and wherein said SH3 domain refers to Src homology 3 domains in intact proteins in cytosolic components.  
     
     
         9 . A method of inhibiting leukocyte O 2   −  production comprising the step of contacting a leukocyte with an effective peptide selected from the group consisting of peptides having the sequence of Sequence ID No. 5 therein, the sum of the proline and arginine residues in said effective peptide being at least about 66% of the total number of amino acid residues therein, said effective peptide being capable of inhibiting leukocyte O 2   −  production by the effective peptide binding to p47 phox  in whole cells and thereby interfering with the binding of p47 phox  to p22 phox .  
     
     
         10 . The method of  claim 9 , wherein the sum of the proline and arginine residues in said effective peptide is 74% of the total number of amino acid residues therein.  
     
     
         11 . The method of  claim 9 , wherein at least about 14% of the amino acid residues in said effective peptide are arginine residues.  
     
     
         12 . The method of  claim 9 , wherein at least about 25% of the amino acid residues in said effective peptide are arginine residues.