1. ¹INSERM Unit 659, Créteil, France
2. ²Department of Dermatology, Henri Mondor Hospital, Créteil, France
3. ³Department of Pathology, Henri Mondor Hospital, Créteil, France

Correspondence: Dr Sofia Abecassis, Unité INSERM 659. Faculté de médecine de Créteil, 8 rue Général Sarrail, 94010 Créteil Cedex, France. E-mail: sofia.abecassis@hmn.aphp.fr

Received 31 May 2006; Revised 23 August 2006; Accepted 9 September 2006; Published online 11 January 2007.

Abstract

CD160 is a glycosylphosphatidylinositol-anchored cell surface molecule expressed by human circulating cytotoxic lymphocytes that correspond to the majority of natural killer cell (NK) expressing CD56^dim, TCR lymphocytes, and to a minor CD8 T-cell subset. CD160 engagement by major histocompatibility complex class I molecules triggers by itself both cytotoxic function and cytokine production in NK lymphocytes, whereas it provides co-activating signals to TCR-induced proliferation in T CD8+ lymphocytes. In this study, we analyzed by immunohistochemistry the phenotype of lymphocytes infiltrating normal skin and inflammatory skin lesions of atopic dermatitis, contact dermatitis, and psoriasis. We identified a minor original subset of CD4⁺CD160⁺ T cells infiltrating inflammatory lesions. We found that this lymphocyte subset localization is not restricted to the skin, as we demonstrated that CD160 transcripts could be induced in IL-2 or IL-15-activated CD4⁺ peripheral blood lymphocytes. Finally, we report that CD160 acts as a co-activator receptor for CD3-induced proliferation of CD4⁺CD160⁺ T cells isolated from inflammatory skin lesions. Thus, we hypothesize that the unique CD4⁺CD160⁺ lymphocyte subset plays a role in the pathogenesis of skin inflammation.