RAPID NORMALIZATION OF EPIDERMAL INTEGRIN EXPRESSION AFTER ALLOGRAFTING OF HUMAN KERATINOCYTES

Allogeneic keratinocyte grafts have beneficial effects on skin wounds, but the underlying interactions between graft and woundbed remain to be explored in detail. The epidermal integrins play a pivotal role in mediating cell-to-cell and cell-to-matrix interactions, In unwounded e pidermis, alpha(2) beta(1)-, alpha(3) beta(1)-, alpha(6) beta(4)-, alp ha(5) beta(1)-, and alpha(v) beta(5)-integrins are confined to basal c ells, During healing of incisional wounds, these integrins are also ex pressed in suprabasal cells, where they remain detectable even after e pidermal integrity is fully reestablished, We examined the integrin su bunits alpha(2), alpha(3), alpha(6), alpha(5) and alpha(v) in partial thickness burn wounds grafted with allogeneic keratinocytes and asked whether the effect of allogeneic keratinocyte grafts, i.e., fast reepi thelialization, is reflected by an accelerated reversion to a normal i ntegrin pattern, Biopsies were taken after wound debridement before gr afting and 10 d after transplantation. After 10 d, a stratified epider mis had developed in all cases and integrins were mainly restricted to the basal cell layer of the neo-epidermis, alpha(2)-, alpha(3)-, alph a(6)-, and alpha(v)-subunits were present at basal and/or lateral cell borders, duplicating the integrin pattern in normal epidermis, The fi ndings indicate that grafting accelerates the shift of the epidermis f rom an inflammatory to a regenerative state, as reflected by the rever sion of the integrin pattern from a ''spread-and-migrate'' to the ''st eady-state'' phenotype.