Abstracts (complete list) - Wissenschaft Online

Stefan A. Kaden, Juergen Schmitz, Gregor Winkels
Dendritic Cell immuno-activating receptor 1 –
Characterization of a novel member of the C-type Lectin family
C-type lectins (CLECs) are involved in a variety of immune interactions, in which they
have been shown to act as both, pathogen recognition as well as adhesion receptors.
The recently described murine dendritic cell (DC) immuno-receptor (DCIR)/DC immunoactivating
receptor (DCAR) family consists of six type II CLECs clustered on
chromosome 6. Beside the already characterised mDCIR, mDCIR2 (33D1) and mDCAR,
little is known about mDCAR1, mDCIR3 and mDCIR4.
To study phenotype and function of these gene products, we generated monoclonal
antibodies (mAbs) against mDCAR1. In contrast to the previously published gene
expression profile of DCIR/DCAR family genes, in which mDCAR1 was found to be
restricted to NK cells (NK), we identify the receptor in bone marrow on subsets of F4/80
+ macrophages and Ly6G + granulocytes, but not on NK or DC. Noteworthy, in thymus,
expression of mDCAR1 is restricted to CD11c high DC. mDCAR1 + thymocytes comprise a
typical myeloid DC phenotype characterised by the expression of CD8α and CD205, as
well as the absence of CD11b. These mature DC express high amounts of MHCII and
the costimulatory molecules CD40, CD80, CD86. mDCAR1 + thymic DC are positive for
CD54, CD90, the stem cell and progenitor markers Sca-1 and c-kit (CD117), as well as
the thymic specific DC marker BP-1.
The successful generation of mAbs allowed us to identify the expression of mDCAR1,
being the first step to uncover a presumably interesting function of this representative
of the CLEC receptor family in the immune system.