Antigen-presenting cells, including Langerhans cells, veiled cells and interdigitating cells

Area of Science:

• Immunology
• Cell Biology

Background:

• Macrophages possess accessory functions like antigen presentation.
• Specialized marrow-derived cells, distinct from phagocytic macrophages, perform these roles.

Purpose of the Study:

• To elucidate the origin and function of specialized antigen-presenting cells.
• To describe the differentiation pathway of these cells from epidermis to lymph node.

Main Methods:

• Observation of cell morphology and location in epidermis, dermis, lymph, and lymph nodes.
• Tracking of cell movement and differentiation.

Main Results:

• Langerhans cells in the epidermis, characterized by Ia antigen, engulf fluid and migrate to afferent lymph as veiled cells.
• Veiled cells, originating from both epidermis and dermis, enter lymph nodes and differentiate into interdigitating cells.
• These cells are found in the T-cell rich paracortex of lymph nodes.

Conclusions:

• A distinct cell lineage, including Langerhans and veiled cells, is responsible for antigen transport to lymph nodes.
• The arrival of antigen-bearing veiled cells in the paracortex is proposed to trigger T-cell activation.