Limited reliability of E-cadherin as a specific marker for in vitro-generated Langerhans cells

Langerhans cells (LC) are a unique population of dendritic cells (DC) found in the epidermis where they can be identified by the expression of CD1a, E-cadherin and cytoplasmic Birbeck granules (BG) as their hallmark. Over the past years many techniques have been described to generate LC in vitro from either monocytes or CD34(+) hematopoietic cell progenitors. Antibodies against Lag and Langerin (two epitopes associated with BG) and E-cadherin (a Ca(2+)-dependent homophilic adhesion molecule) have been used to detect in vitro-generated LC. In this study we investigated whether the expression of E-cadherin on in vitro-generated CD1a(+) from either CD34(+) cells or monocytes is able to discriminate LC from other DC. Our results demonstrate that E-cadherin alone is not a reliable marker to specifically identify in vitro-generated LC.