Novel genes expressed selectively by long-term dendritic cell (DC) lines
(XS series) from murine epidermis which retain important features of
resident epidermal Langerhans cells (LC) are provided. These genes encode
distinct type II membrane-integrated polypeptides, each consisting of a
cytoplasmic domain, a transmembrane domain, an extracellular connecting
domain, and a C-terminal extracellular domain that exhibits significant
homology to the carbohydrate recognition domains (CRD) of C-type lectins.
Expression of both genes is highly restricted to cells of DC lineage
(including epidermal LC). Thus, these genes encode new, DC-specific
members of the C-type lectin family, now termed "DC-associated C-type
lectin-1 and -2" (dectin-1 and dectin-2). Two isoforms of the dectin-1
molecule and five isoforms of the dectin-2 molecule have also been
identified. The invention further provides His-tagged fusion proteins
comprising 6.times. histidine and the extracellular domain of dectin-1 or
dectin-2. Also provided are antibodies raised to synthetic peptides
designed from the dectin-1 sequence or to the His-tagged fusion proteins
described.