Langerin, the "Catcher in the Rye": an important receptor for pathogens on Langerhans cells

Area of Science:

• Immunology
• Dermatology
• Virology

Background:

• Langerhans cells (LCs) are key antigen-presenting cells in the skin's epidermis.
• LCs utilize C-type lectin receptors, like Langerin/CD207, for pathogen uptake.
• Understanding LC interactions with viruses is vital for antiviral immunity and immunotherapy.

Purpose of the Study:

• To investigate the role of Langerin on human LCs in measles virus interaction.
• To determine if Langerin mediates measles virus capture, infection, and T-cell presentation.
• To elucidate the specific T-cell responses induced by measles virus-LC interactions.

Main Methods:

• Analysis of human Langerhans cells and measles virus.
• Assessment of virus binding, capture, and infection mediated by Langerin.
• Evaluation of T-cell activation, including CD4+ and CD8+ T cells, following virus exposure.

Main Results:

• Langerin facilitates the binding and capture of measles virus by human LCs.
• Measles virus does not productively infect LCs via Langerin.
• LCs present measles virus to CD4+ T cells in a Langerin-dependent manner, but not to CD8+ T cells (cross-presentation).

Conclusions:

• Langerin's primary role in LCs concerning measles virus is pathogen capture for CD4+ T-cell priming, not productive infection or cross-presentation.
• Cross-presentation of measles virus may be mediated by other skin dendritic cell subsets.
• These findings underscore the intricate nature of skin-initiated antiviral T-cell responses and highlight the potential of human skin dendritic cells in immunotherapy.