Peptides that block leukocyte recruitment and methods of use

Abstract

Disclosed are novel peptides comprising SEQ ID NO: 1 and modifications thereof, which are effective in blocking leukocyte recruitment. The disclosed peptides are useful for treating diseases associated with leukocyte recruitment for example inhibiting metastasis of a solid tumor to the liver and lungs and for treating sepsis. Also disclosed are methods of screening for compounds having the ability to block leukocyte recruitment.

1 - 12 . (canceled) 
     
     
         13 . A method of inhibiting leukocyte-recruitment-mediated disease in a patient by administering to the patient a pharmaceutically effective amount of an isolated peptide containing the sequence LSALTPSPSWLKYKAL, identified as SEQ ID NO: 1. 
     
     
         14 . The method of  claim 13  wherein the isolated peptide further comprises 1, 2, 3, 4, or 5 amino acid residues at the N-terminus and C-terminus of the LSALTPSPSWLKYKAL sequence. 
     
     
         15 . The method of  claim 13  wherein the isolated peptide further comprises 1, 2, 3, 4, or 5 amino acid residues at the N-terminus or C-terminus of the LSALTPSPSWLKYKAL sequence. 
     
     
         16 - 18 . (canceled) 
     
     
         19 . The method of  claim 13  wherein the amino acid analogs are selected from β-alanine, norvaline, norleucine, 4-aminobutyric acid, orithine, hydroxyproline, sarcosine, citrulline, cysteic acid, cyclohexylalanine, 2-aminoisobutyric acid, 6-aminohexanoic acid, t-butylglycine, phenylglycine, o-phosphoserine, N-acetyl serine, N-formylmethionine, 3-methylhistidine. 
     
     
         20 . The method of  claim 13  wherein the isolated peptide or variant thereof is administered at a dosage is between about 0.01 mg/kg to 100 mg/kg. 
     
     
         21 . The method of  claim 13  wherein the leukocyte-recruitment-mediated disease is tumor metastasis. 
     
     
         22 . The method of  claim 13  wherein the isolated peptide reduces tumor metastasis compared to tumor metastasis in the absence of treatment. 
     
     
         23 . The method of  claim 13  wherein administration of the isolated peptide inhibits tumor metastasis to the liver or lungs in the patient. 
     
     
         24 . The method of  claim 13  wherein the isolated peptide or variant thereof is administered at a dosage is between about 0.01 mg/kg to 100 mg/kg. 
     
     
         25 . The method of  claim 13  wherein the leukocyte-recruitment-mediated disease is sepsis. 
     
     
         26 . The method of  claim 13  wherein the sepsis caused by bacterial, viral, fungal or parasite infection. 
     
     
         27 . The method of  claim 13  wherein the sepsis is bacterial sepsis. 
     
     
         28 . The method of  claim 13  wherein administration of the isolated peptide treats at least one symptom of bacterial sepsis in the patient. 
     
     
         29 . The method of  claim 13  wherein the isolated peptide or variant thereof is administered at a dosage is between about 0.01 mg/kg to 100 mg/kg. 
     
     
         30 . The method of  claim 13  wherein the isolated peptide or variant thereof is administered until symptoms of bacterial sepsis are reduced or ameliorated. 
     
     
         31 . A method of identifying a compound effective to block leukocyte recruitment in the vasculature of a patient comprising:
 (a) screening a library of test compounds for their ability to bind to a target peptide having a sequence selected from the group consisting of SEQ ID NOS: 2-16;   (b) selecting compounds that show selective binding affinity;   (c) testing the compounds for leukocyte recruitment inhibiting activity, and   (d) selecting a compound if it inhibits leukocyte recruitment.   
     
     
         32 . The method of  claim 31  wherein the vasculature is lung vasculature or liver vasculature. 
     
     
         33 . The method of  claim 31  further comprising the steps of:
 (e) further testing the compound for its ability to inhibit tumor metastasis in an animal bearing a solid tumor; and 
 (f) selecting the compound if it inhibits tumor metastasis in step (e). 
 
     
     
         34 . The method of  claim 31  further comprising the steps of:
 (e) further testing the compound for its ability to inhibit tumor metastasis to the lungs and liver in an animal bearing a solid tumor known to metastasize the lungs or liver; and 
 (f) selecting the compound if it inhibits tumor metastasis in step (e). 
 
     
     
         35 . The method of  claim 31  further comprising the steps of:
 (e) further testing the compound for its ability to treat bacterial sepsis in a patient; and 
 (f) selecting the compound if it treats sepsis in step (e).