Mouse Anti-Human Langerin monoclonal antibody, clone JID724

Langerhans cells (LCs) are specialized dendritic cells (DCs) that play a defense role in recognizing foreign antigens, in tissue where antigenic exposures occur, as in the skin and mucous membranes. LCs are able to continuously move within the tissues thanks to dendritic contraction and distension performing their surveillance and/or phagocytosis role. These cells are characterized by the presence of Birbeck granules in their cytoplasm, involved in endocytosis. LCs have been characterized in several classes of vertebrates, from fish to mammals using different histological and molecular techniques. The aim of the present review is to define the state of art and the need of information about immunohistochemical markers of LCs in different classes of vertebrates. The most used immunohistochemical (IHC) markers are Langerin/CD207, CD1a, S-100 and TLR. These IHC markers are described in relation to their finding in different vertebrate classes with phylogenetical considerations. Among the four markers, Langerin/CD207 and TLR have the widest spectrum of cross reactivity in LCs.

Overexpression of transforming growth factor beta-1 (TGF beta 1) in mouse epidermis causes cutaneous inflammation and keratinocyte hyperproliferation. Here we examined acute effects of TGF beta 1 overproduction by keratinocytes on skin dendritic cells (DCs). TGF beta 1 induction for 2 and 4 days increased the numbers and CD86 expression of B220(+) plasmacytoid DCs (pDCs) and CD207(+)CD103(+), CD207(-)CD103(-)CD111D(+), and CD207(-)CD103(-)CD11b(-) dermal DCs (dDCs) in skin-draining lymph nodes (SDLNs). The dermis of TGF beta 1-overexpressing mice had significantly more pDCs, CD207(+)CD103(+) dDCs, and CD207(-)CD11b(+) dDCs in the absence of increased dermal proliferation. Application of dye, tetramethyl rhodamine iso-thiocyanate (TRITC), in dibutylpthalate (DBP) solution after TGF beta 1 induction increased the numbers of TRITC(+)CD207(-) dDCs in SDLNs, and augmented TRITC/DBP-induced Langerhans cell (LC) migration 72 hours post TRITC treatment. Consistent with this, LC migration was increased in vitro by TGF beta 1 overexpression in skin explants and by exogenous TGF beta 1 in culture media. Transient TGF beta 1 induction during DNFB sensitization increased contact hypersensitivity responses by 1.5-fold. Thus, elevated epidermal TGF beta 1 alone is sufficient to alter homeostasis of multiple cutaneous DC subsets, and enhance DC migration and immune responses to contact sensitizers. These results highlight a role for keratinocyte-derived TGF beta 1 in DC trafficking and in the initiation of skin inflammation. Journal of Investigative Dermatology (2013) 133, 135-143; doi:10.1038/jid.2012.241; published online 26 July 2012