P-SELECTIN AND E-SELECTIN ARE REQUIRED FOR THE LEUKOCYTE RECRUITMENT,BUT NOT THE TISSUE SWELLING, ASSOCIATED WITH IGE-DEPENDENT AND MAST CELL-DEPENDENT INFLAMMATION IN MOUSE SKIN

Many studies, in both experimental animal and human systems, have indi cated that P- and/or E-selectins may contribute importantly to the leu kocyte recruitment that occurs in association with mast cell-dependent inflammatory responses. We used mice that genetically lack P-selectin (P -/-), E-selectin (E -/-), or both selectins (P/E -/-) to investiga te the possible roles of these selectins in the IgE- and mast cell-dep endent recruitment of neutrophils to the skin of mice. We found that a lack of either or both selectins had little or no effect on the exten t of mast cell degranulation or the tissue swelling associated with th ese reactions. Moreover, a lack of either P-or E-selectin alone did no t reduce the neutrophil infiltration at the reaction sites. However, m ice lacking both P-and E-selectins exhibited an almost complete ablati on of IgE- and mast cell-dependent neutrophil recruitment. These findi ngs show that P-and E-selectins can express overlapping functions in l eukocyte recruitment associated with IgE- and mast cell-dependent cuta neous tale-phase reactions in mouse skin, and that a lack of both sele ctins results in a virtual elimination of IgE-dependent leukocyte recr uitment.