Langerhans cells cross-present antigen derived from skin.
Dendritic cells (DC) efficiently cross-present exogenous antigen on MHC class I molecules to CD8+ T cells. However, little is known about cross-presentation by Langerhans cells (LC), the DCs of the epidermis. Therefore, we investigated this issue in detail. Isolated murine LCs were able to cross-present soluble ovalbumin protein on MHC-class I molecules to antigen-specific CD8+ T cells, albeit less potently than the CD8+ DC subsets from spleen. Furthermore, LCs cross-presented cell-associated ovalbumin peptide and protein expressed by neighboring keratinocytes. Use of transporter associated with antigen processing (TAP-1)-deficient mice suggested a TAP-dependent pathway. Similar observations were made with migratory LC. Antigen expressed in the epidermis was ingested by LCs during migration from the epidermis and presented to antigen-specific T cells in vitro. Cross-presentation of ovalbumin protein by LCs induced IFN-gamma production and cytotoxicity in antigen-specific CD8+ T cells. Additionally, epicutaneous application of ovalbumin protein induced in vivo proliferation of OT-I T cells in the draining lymph nodes; this was markedly enhanced when antigen was applied to inflamed, barrier-disrupted skin. Thus, LCs cross-present exogenous antigen to CD8+ T cells and induce effector functions, like cytokine production and cytotoxicity, and may thereby critically contribute in epicutaneous vaccination approaches.
Stoitzner
Patrizia
P
Department of Dermatology, Innsbruck Medical University, 6020 Innsbruck, Austria.
Tripp
Christoph H
CH
Eberhart
Andreas
A
Price
Kylie M
KM
Jung
Jae Y
JY
Bursch
Laura
L
Ronchese
Franca
F
Romani
Nikolaus
N