Figure 3. Distinct SLO niches provide distinct combinations of output signals resulting from primary perception tasks.

Epitopes presented in the context of MHC molecules are the output signals resulting from the primary perception of antigens. In SLOs, multiple epitopes derived from an immune object are recognized by multiple epitope-specific T cells in distinct niches. These niches are formed by stromal cells (endothelial cells and fibroblastic reticular cells) and by partially overlapping combinations of immune cells performing the primary perception antigens, temporo-contextual signals and localization signals. Three examples of distinct SLO niches are depicted.