Adenoidal follicular T helper cells provide stronger B-cell help than those from tonsils

The tonsils and adenoids are secondary lymphoid organs, where antigen processing and immune cell development occur to control bacterial colonization and infection in the upper respiratory tract. Both organs are abundant in follicular T helper cells (TFH), a subset of T cells specialized for promoting B-cell development. There are no prior studies on differences between the immune cells of the tonsils and adenoids and whether the cells function differently.

In vitro assays to assess cell phenotype of tonsils and adenoids from young children (median age = 40 months).

Mononuclear cells from tonsils and adenoids were cultured with or without 1 µg/mL Staphylococcus enterotoxin B (SEB) for 4 days. Cell phenotype and function were assessed by flow cytometry and multiplex enzyme-linked immunosorbent assay.

We found that in resting adenoids, TFH expressed higher CXCR5 and inducible costimulator but lower PD-1 than those from the tonsils, and that adenoidal B cells expressed higher CD27. Upon polyclonal stimulation with SEB, both TFH and B cells from the adenoids proliferated to a greater extent, and culture supernatants contained higher levels of interleukin 21.

We conclude that the cells of the adenoid are disposed toward the provision of more robust B-cell help than the tonsils.

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