Table 1 Comparison between secondary lymphoid organs and tertiary lymphoid structures

Examples

Spleen, regional lymph nodes, peyer’s patches, ILFs, tonsils and NALT

Chronic Infection, autoimmune diseases, transplant rejection, cancer

[29,30,31,32,33,34]

Origin

During embryogenesis

After birth

[29, 35, 36]

Induction and development

LTo (FAP + podoplanin+,

LTβR+), LTi, endothelial

cells, retinoic acid

LTo (FAP + podoplanin+, LTβR+),

ILC3/LTi, endothelial cells,

NKT, Th17,

chronic inflammation, cytokines

(LT, TNF, LIGHT, IL-17), chemokines

(CXCL13, CCL19, CCL21)

[10, 37,38,39,40]

Location

Defined-relatively immutable

Variable (non-lymphoid organ or tissue site)

[29, 35, 41, 42]

Structure

B and T cell compartments, HEVs, lymphatic vessels

Variable (from mixed T and B cells to T and B cell compartments), HEVs, lymphatic vessels

[2, 35, 36, 42, 43]

Capsule

Defined

Rare

[2, 36, 42]

Self-tolerance

Maintained

Disturbed (autoantibody production etc.)

[2, 10, 44, 45]

Durability

Permanent (but can collapse)

Transient

[39]