CIRCULATING ALLERGEN-REACTIVE T-CELLS FROM PATIENTS WITH ATOPIC-DERMATITIS AND ALLERGIC CONTACT-DERMATITIS EXPRESS THE SKIN-SELECTIVE HOMING RECEPTOR, THE CUTANEOUS LYMPHOCYTE-ASSOCIATED ANTIGEN
Lfs. Babi et al., CIRCULATING ALLERGEN-REACTIVE T-CELLS FROM PATIENTS WITH ATOPIC-DERMATITIS AND ALLERGIC CONTACT-DERMATITIS EXPRESS THE SKIN-SELECTIVE HOMING RECEPTOR, THE CUTANEOUS LYMPHOCYTE-ASSOCIATED ANTIGEN, The Journal of experimental medicine, 181(5), 1995, pp. 1935-1940
The cutaneous lymphocyte-associated antigen (CLA) is the major T cell
ligand for the vascular adhesion molecule E-selectin, and it has been
proposed to be involved in the selective targeting of memory T cells r
eactive with skin-associated Ag to cutaneous inflammatory sites. To fu
rther investigate the relation of CLA and cutaneous T cell responses,
we analyzed the CLA phenotype of circulating memory T cells in patient
s with allergic contact dermatitis and atopic dermatitis (AD) alone vs
in patients manifesting bronchopulmonary atopy (asthma with or withou
t AD) and nonallergic individuals. Significant T cell proliferative re
sponses to Ni, a contact allergen, and to the house dust mite (HDM), a
n allergen to which sensitization is often observed in AD and/or asthm
a, was noted only in allergic and atopic individuals, respectively. Wh
en the minor circulating CLA(+)CD3(+)CD45RO(+) subset was separated fr
om the major CLA(-)CD3(+)CD45RO(+) subpopulation in Ni-sensitive subje
cts, the Ni-dependent memory T cell response was largely confined to t
he CLA(+) subset. A similar restriction of the T cell proliferative re
sponse to the CLA(+) memory subset was observed for HDM in patients wi
th AD alone. In HDM-sensitive patients with asthma with or without AD,
however, the CLA(-) subset exhibited a strong antigen-dependent proli
feration, in contrast to patients with AD alone, whose CLA(-) subset p
roliferated very weakly to HDM. In asthma with or without AD, the HDM-
dependent proliferation slightly predominated in the CLA(-) when compa
red to the CLA(+) subset. The functional linkage between CLA expressio
n and disease-associated T cell effector function in AD was also demon
strated by the finding that the circulating CLA(+) T cell subset in AD
patients, but not nonatopic controls, selectively showed both evidenc
e of prior activation (human histocompatibility antigen-DR expression)
and spontaneous production of interleukin 4 but not interferon-gamma.
Taken together, these observations demonstrate the correlation of CLA
expression on circulating memory T cells and disease-associated memor
y T cell responses in cutaneous hypersensitivity, and they suggest the
existence of mechanisms capable of sorting particular T cell Ag speci
ficities and lymphokine patterns into homing receptor-defined memory s
ubsets.