Mlk. Tang et al., L-SELECTIN IS INVOLVED IN LYMPHOCYTE MIGRATION TO SITES OF INFLAMMATION IN THE SKIN - DELAYED REJECTION OF ALLOGRAFTS IN L-SELECTIN-DEFICIENT MICE, The Journal of immunology, 158(11), 1997, pp. 5191-5199
Adhesion of leukocytes to vascular endothelium is crucial for leukocyt
e migration into tissues. The contributions of L-selectin, P-selectin,
and ICAM-1 to interactions between lymphocytes and endothelium was ex
amined using allogeneic skin graft rejection as a model of cutaneous i
nflammation, L-selectin-deficient (L-selectin(-/-)) mice rejected both
primary and secondary allogeneic (BALB/c) skin grafts significantly m
ore slowly than L-selectin(+/+) littermates. Furthermore, skin graft r
ejection remained significantly delayed in L-selectin(-/-) mice, despi
te placement of grafts 7 days after i.p. immunization with allogeneic
cells, when CTL responses in L-selectin(-/-) mice and L-selectin(+/+)
littermates were confirmed to be equivalent. Indeed, specific CTL resp
onses to BALB/c splenocytes were normal or elevated in L-selectin(-/-)
mice following either skin grafts or immunization, However, the numbe
r of T lymphocytes within allogeneic grafts was lower in L-selectin(-/
-) mice as compared with L-selectin(+/+) littermates. Therefore, delay
ed rejection of skin grafts by L-selectin(-/-) mice reflects impaired
migration of effector cells into the graft rather than delayed or impa
ired generation of a CTL response. In contrast to L-selectin(-/-) mice
, P-selectin-deficient and ICAM-1-deficient mice rejected allogeneic s
kin grafts normally. These findings delineate an important role for L-
selectin in lymphocyte recruitment to cutaneous sites of inflammation.