NONSPECIFIC T-CELL HOMING DURING INFLAMMATION IN ATOPIC-DERMATITIS - EXPRESSION OF CUTANEOUS LYMPHOCYTE-ASSOCIATED ANTIGEN AND INTEGRIN ALPHA-E-BETA-7 ON SKIN-INFILTRATING T-CELLS
Ijm. Devries et al., NONSPECIFIC T-CELL HOMING DURING INFLAMMATION IN ATOPIC-DERMATITIS - EXPRESSION OF CUTANEOUS LYMPHOCYTE-ASSOCIATED ANTIGEN AND INTEGRIN ALPHA-E-BETA-7 ON SKIN-INFILTRATING T-CELLS, Journal of allergy and clinical immunology, 100(5), 1997, pp. 694-701
Atopic dermatitis (AD) is a chronic skin disorder, characterized by in
filtration of activated memory CD4(+) T cells into skin. A model to st
udy the onset of allergic inflammation in a patient with AD is the ato
py patch test (APT), in which, by epicutaneous application of aeroalle
rgen, an eczematous reaction is induced in 50% of sensitized patients
with AD. Extravasation of T cells into skin is thought to be criticall
y dependent on expression of the surface molecule cutaneous lymphocyte
-associated antigen (CLA), which recognizes and binds its ligand E-sel
ectin on endothelium. We studied the dynamics of expression of CLA and
the gut homing receptor alpha E beta 7 (HML-1) on T cells in the skin
of patients with AD and in APT reactions and nickel and sodium lauryl
sulfate patch test reactions by means of immunohistochemical double s
taining of skin biopsy specimens. The results show an increase in the
number of CD3(+) T cells in the lesional skin of patients with AD, APT
reactions, and nickel and sodium lauryl sulfate patch test reactions
as compared with nonlesional skin of the same patients and nonatopic i
ndividuals. In contrast, the percentages of CLA(+) T cells in the lesi
onal skin of patients with AD, in the APT reactions, and in sodium lau
ryl sulfate and nickel patch test reactions were decreased. In additio
n, we found a marked expression of alpha E beta 7 by T cells present i
n skin, indicating a nonspecific influx of T cells during allergic ski
n inflammation. We propose that during allergic skin inflammation CLA
expression is not a prerequisite for cutaneous T-cell infiltration. CL
A expression may be important for T cells to extravasate from blood in
to skin during immune surveillance or for retention of allergen-specif
ic T cells in skin.