NU 1997-026

Inventors

Geoffrey Kansas*

Karen Snapp

Short Description

KPL-1 has proven to be an excellent reagent for FACS staining, Western blotting, immunoprecipitation, and appears to be a reporter epitope for tyrosine sulfated PSGL-1.

Abstract

This invention describes a novel mAb, KPL1, that completely blocks the interaction of PSGL-1 with either L-selectin or P-selectin leukocyte adhesion molecules. KPL-1 is therefore useful in studying interactions between leukocytes and either platelets, endothelium or other leukocytes.

Interactions between P-selectin and P-selectin glycoprotein ligand-1 (PSGL-1) mediate the earliest "rolling" of leukocytes on the lumenal surface of endothelial cells at sites of inflammation. To date, the primary role of PSGL-1 in mediating the interaction between neutrophils and P-selectin has been well documented. A new mouse IgG mAb, named KPL1, has been produced. KPL1 completely blocks recognition of PSGL-1 by either P-selectin or by L-selectin, but does not affect leukocyte recognition of E-selectin. The KPL-1 epitope was mapped to a site within a consensus tyrosine sulfation motif of PSGL-1, previously shown to be essential for interaction with P-selectin (and now shown to be essential for recognition of PSGL-1 by L-selectin). The KPL1 epitope is distinct from the epitope identified by the PL1 function blocking anti-PSGL-1 mAb, published earlier in the literature. Two color flow cytometry of normal leukocytes immunostained with the KPL1 mAb demonstrated that PSGL-1 is expressed on essentially all circulating leukocytes, including neutrophils, NK cells, all subsets of T cells, and monocytes, however KPL1 stained B cells at significantly lower levels than these other cell types. Variation in tyrosine sulfation of PSGL-1 during B cell differentiation may affect the stability of B cells to interact with P- and L-selectin.