Nasal-associated lymphoid tissue

[3][4] Formation of NALT starts early after birth, it is not present during embrygenesis or in newborn mice.

In contrast to Peyer's patches and lymph nodes, NALT formation is independent of IL-7R, LT-βR and ROR-γ signalling.

NALT is inductive site of MALT similarly to Peyer's patches in a small intestine.

After intranasal immunization or pathogen recognition, lymphocytes in NALT proliferate and differentiate.

They start to produce cytokines, such as IFN-γ, type I interferons, IL-2, IL-4, IL-5, IL-6 or IL-10 (amount depend on used immunizating agent or adjuvans).

Activated B cells can migrate through body to respiratory and genito-uritary tract, because they express chemokine receptors CCR10 and α4β1-integrin.

In 1997, nasal-spray vaccine containing inactivated influenza virus with nLT (heat-labile enterotoxin) as adjuvants was used in Switzerland, but it had to be withdrawn from the market, because it caused Bell's palsy in some patients.