Langerin-mediated internalization of a modified peptide routes antigens to early endosomes and enhances cross-presentation by human Langerhans cells

Cell Mol Immunol. 2017 Apr;14(4):360-370. doi: 10.1038/cmi.2015.87. Epub 2015 Oct 12.

Abstract

The potential of the skin immune system to generate immune responses is well established, and the skin is actively exploited as a vaccination site. Human skin contains several antigen-presenting cell subsets with specialized functions. In particular, the capacity to cross-present exogenous antigens to CD8+ T cells is of interest for the design of effective immunotherapies against viruses or cancer. Here, we show that primary human Langerhans cells (LCs) were able to cross-present a synthetic long peptide (SLP) to CD8+ T cells. In addition, modification of this SLP using antibodies against the receptor langerin, but not dectin-1, further enhanced the cross-presenting capacity of LCs through routing of internalized antigens to less proteolytic early endosome antigen 1+ early endosomes. The potency of LCs to enhance CD8+ T-cell responses could be further increased through activation of LCs with the toll-like receptor 3 ligand polyinosinic:polycytidylic acid (pI:C). Altogether, the data provide evidence that human LCs are able to cross-present antigens after langerin-mediated internalization. Furthermore, the potential for antigen modification to target LCs specifically provides a rationale for generating effective anti-tumor or anti-viral cytotoxic T lymphocyte responses.

MeSH terms

  • Antibodies / metabolism
  • Antigens / metabolism*
  • Antigens, CD / metabolism*
  • Cell Compartmentation
  • Cell Differentiation / drug effects
  • Cross-Priming / drug effects
  • Cross-Priming / immunology*
  • Endocytosis* / drug effects
  • Endosomes / drug effects
  • Endosomes / metabolism*
  • Humans
  • Langerhans Cells / cytology
  • Langerhans Cells / drug effects
  • Langerhans Cells / metabolism*
  • Lectins, C-Type / metabolism*
  • Ligands
  • Mannose-Binding Lectins / metabolism*
  • Peptides / metabolism*
  • Poly I-C / pharmacology
  • Skin / metabolism
  • Toll-Like Receptors / metabolism

Substances

  • Antibodies
  • Antigens
  • Antigens, CD
  • CD207 protein, human
  • Lectins, C-Type
  • Ligands
  • Mannose-Binding Lectins
  • Peptides
  • Toll-Like Receptors
  • dectin 1
  • Poly I-C