Epithelial dendritic cells vs. Langerhans cells: Implications for mucosal vaccines

Area of Science:

• Immunology
• Dermatology
• Vaccinology

Background:

• Stratified squamous epithelium (SSE), comprising skin and certain mucosa, is a key site for next-generation vaccine delivery.
• Langerhans cells (LCs) were historically considered the primary antigen-presenting cells (APCs) within the SSE.
• Recent findings reveal the presence and distinct functions of dendritic cells (DCs) alongside LCs in the SSE.

Purpose of the Study:

• To provide a historical overview of the evolving understanding of APCs in the SSE.
• To critically review the literature on the functional differences between LCs and DCs in pathogen uptake, processing, and T-cell activation.
• To emphasize the importance of characterizing SSE APCs for advancing vaccine development and preventing pathogen transmission.

Main Methods:

• Literature review and historical perspective.
• Analysis of recent scientific publications on SSE immunology.
• Comparative analysis of LC and DC functions.

Main Results:

• The SSE harbors both Langerhans cells (LCs) and dendritic cells (DCs) as key APCs.
• LCs and DCs exhibit functional heterogeneity in antigen handling and T-cell polarization.
• The precise role of DCs in SSE neuroimmune interactions remains an area for further investigation.

Conclusions:

• Accurate identification and functional characterization of SSE APCs, including LCs and DCs, are crucial for rational vaccine design.
• Understanding the distinct roles of LCs and DCs can lead to more effective strategies for blocking pathogen transmission.
• Further research into DC functions within the SSE, particularly in neuroimmune contexts, is warranted.