Glossary of terms
| B-cell aggregates | Rather diffuse accumulations of B- and T-cells without functional organisation, possibly preceding the development of lymphoid follicles |
| B-cell follicles | Part of functionally organised lymphoid tissue with segregated B- and T-cell areas, which may contain FDC networks with germinal centres |
| Bystander activation | Activation of B cells via soluble mediators present in the (inflammatory) micro-environment of the B-cell without the help of a cognate T-cell (i.e. a T-cell primed by the same antigen) |
| Dendritic cells (DCs) | Bone marrow-derived cells that take up antigen in peripheral tissues and present antigenic peptides to T-cells |
| Epitope spreading | The fact that antibody responses to auto-antigens tend to become more diverse as the response persists, due to responses being made to epitopes other than the original epitope (antigenic determinant) |
| Follicular dendritic cells (FDCs) | Highly specialised cells of mesenchymal origin which form networks in lymphoid follicles and present antigen to B-cells, mostly as immune complexes |
| Lymphoid neogenesis | The process that gives rise to tertiary lymphoid organs |
| Molecular mimicry | The induction of antibodies and T-cells that react against a pathogen but also cross-react with self antigens |
| Mucosa-associated lymphoid tissue (MALT) | Lymphoid tissue diffusely present in the different mucosae, including tonsils, Peyer's patches and (in some species) bronchus-associated lymphoid tissue |
| Primary lymphoid organ | The thymus and bone marrow, where lymphocytes are generated |
| Secondary lymphoid organs | The lymph nodes, spleen and MALT |
| Tertiary lymphoid organs | Ectopic lymphoid tissue with distinct B- and T-cell zones, which may contain FDCs, germinal centres and specialised high endothelial venules |