An ELISA for hCAP-18, the cathelicidin present in human neutrophils and plasma.
hCAP-18 is a newly described protein of human neutrophilic granulocytes which belongs to the cathelicidin family of antimicrobial proteins. Members of this protein family share a common N-terminal sequence followed by a highly diverse antimicrobial, cationic C-terminus. The present work describes the production of recombinant hCAP-18, the generation of antibodies to the protein and the development of an accurate, sensitive and specific ELISA for the detection of hCAP-18 in cells, plasma and urine with a detection limit of 0.084 ng/ml. The amount of hCAP-18 in neutrophils is 0.627 microgram protein per 10(6) cells. The plasma level is 1.18 micrograms/ml which is several fold higher than for other neutrophil specific granule proteins. hCAP-18 is present in plasma as high molecular weight complexes. In accordance with this, hCAP-18 is barely excreted in the urine. The bone marrow appears to be the major source of plasma hCAP-18. The high level of hCAP-18 in plasma may provide an important defense against microorganisms and endotoxins.
Sørensen
O
O
Department of Hematology, Finsen Center, Rigshospitalet, Copenhagen, Denmark.
Cowland
J B
JB
Askaa
J
J
Borregaard
N
N
D000818:Animals; D000890:Anti-Infective Agents / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D000906:Antibodies / Q000737:chemistry; D023181:Antimicrobial Cationic Peptides; D002352:Carrier Proteins / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D054804:Cathelicidins; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D009504:Neutrophils / Q000737:chemistry*; D010949:Plasma / Q000737:chemistry*; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000890:Anti-Infective Agents; D000906:Antibodies; D023181:Antimicrobial Cationic Peptides; D002352:Carrier Proteins; D054804:Cathelicidins