Initiation of nasopharyngeal-associated lymphoid tissue (NALT) development is independent of the programmed cytokine cascade necessary for the formation of Peyer's patches (PP) and peripheral lymph nodes (PLN), a cytokine cascade which consists of IL-7R, LTα1β2/LTβR, and NIK. However, the subsequent organization of NALT seems to be controlled by these cytokine signaling cascades since the maturation of NALT structure is generally incomplete in those cytokine cascade-deficient mice. NALT as well as PP and PLN are completely absent in Id2−/− mice. NALT organogenesis is initiated following the adoptive transfer of CD3−CD4+CD45+ cells into Id2−/− mice, constituting direct evidence that CD3−CD4+CD45+ inducer cells can provide an IL-7R-, LTα1β2/LTβR-, and NIK-independent tissue organogenesis pathway for secondary lymphoid tissue development.
