L-selectin

Abstract

L-selectin is apparently essential for normal DTH responses. It is also required for the generation of primary T-cell responses, but not necessarily for humoral or memory responses. This chapter presents a study in which L-selectin–/– mice were viable and fertile but demonstrated complete lack of lymphocyte migration across HEVs of peripheral lymph nodes (PLNs). Migration across mesenteric lymph node and Peyer's patch HEVs was also impaired. This migratory defect resulted in a 70–90% decrease in the number of lymphocytes within PLN and a 30–55% increase in spleen cellularity. Elevated serum IgM and IgG1 levels and augmented humoral immune responses to T-cell-independent and T-cell-dependent antigens following i.p. immunization were seen. In contrast, s.c. immunization with T-cell-dependent antigens resulted in a reduced IgM response and a severely delayed IgG response. However, secondary responses were normal or increased in L-selectin–/– mice regardless of the immunization route.