Extended Data Fig. 10: Proposed model for early-life thymic expansion of microbiota-specific T cells.

At weaning we propose that CX3CR1⁺ DCs take up intestinal commensal microorganisms (1) and migrate to the thymus (2), where they present bacterial antigens to CD4⁺ T cells. This induces the expansion of bacteria-specific CD4⁺T cells (3) that are later exported to peripheral organs (4).