ELISA for quantitation of L-selectin shed from leukocytes in vivo.
L-selectin is a cell surface receptor on granulocytes, lymphocytes and monocytes that is responsible for the initial attachment of leukocytes to endothelium. The extracellular domain of L-selectin is proteolytically shed from leukocytes following cellular activation in vitro. The shed form of L-selectin (SL-selectin) is functionally active and at high concentrations can inhibit leukocyte attachment to endothelium. Therefore, an ELISA was developed to quantitate the levels of SL-selectin in biological fluids, biopsy specimens and during recombinant protein production. This simple, quantitative sandwich ELISA uses two monoclonal antibodies directed against the extracellular domain of SL-selectin. The assay has a detection range of 5-1300 ng/ml, is precise and sensitive. The ability of this assay to detect SL-selectin in serum, plasma, and culture supernatant fluid was demonstrated and it was used to quantitate circulating SL-selectin in normal and patient sera. Patients with sepsis and HIV infection showed markedly elevated SL-selectin levels in serum. Thus, the ELISA should prove useful both for laboratory purposes as well as in the diagnostic evaluation of patients with inflammatory diseases.
Spertini
O
O
Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, MA 02115-6084.
Schleiffenbaum
B
B
White-Owen
C
C
Ruiz
P
P
Tedder
T F
TF
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000097:blood*; D002478:Cells, Cultured; D003470:Culture Media / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005615:Freezing; D006801:Humans; D066298:In Vitro Techniques; D019041:L-Selectin; D007962:Leukocytes / Q000378:metabolism*; D013552:Swine
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D003470:Culture Media; D019041:L-Selectin