Peripheral antigen display by lymph node stroma promotes T cell tolerance to intestinal self

Area of Science:

• Immunology
• Cell Biology
• Gastroenterology

Background:

• The intestinal epithelium requires T cell tolerance to prevent autoimmune responses.
• Medullary thymic epithelial cells (mTECs) induce central T cell tolerance by presenting self-antigens.
• Current models suggest dendritic cells induce peripheral tolerance via antigen cross-presentation.

Purpose of the Study:

• To investigate the role of lymph node stromal cells in T cell tolerance.
• To determine if lymph node stromal cells can present peripheral-tissue antigens (PTAs).
• To assess the capacity of lymph node stromal cells to induce T cell activation and tolerance.

Main Methods:

• Analysis of antigen presentation by lymph node stromal cells.
• Assessment of T cell activation and tolerance induction in vivo.
• Comparison of lymph node stromal cell function to mTECs.

Main Results:

• Lymph node stromal cells present endogenously expressed PTAs to T cells.
• Antigen presentation by lymph node stroma is sufficient for primary CD8(+) T cell activation.
• This presentation induces subsequent tolerance in CD8(+) T cells.

Conclusions:

• Lymph node stromal cells function similarly to mTECs in establishing T cell tolerance.
• Lymph node stromal cells offer a direct mechanism for purging self-reactive T cells from the peripheral repertoire.
• This discovery provides a novel strategy for immune tolerance induction.