Toll-like receptors 3 and 5 are expressed by a subset of T cells, but expression is not always sufficient for activation by TLR ligands.

<p>(A) Whole PBMCs were isolated from healthy donors and expression of TLRs 2, 3, and 5 were evaluated by flow cytometry on gated CD3+ T cells. (B) Whole PBMCs, purified T cells (>95% CD3⁺), or purified T cells separated from whole PBMCs by a transwell, were cultured in medium alone, or in medium supplemented with plate bound anti-CD3, poly I:C or flagellin A. Expression of CD38 on memory (CD45RO⁺CD45RA⁻) CD4⁺ T cells was assessed by flow cytometry following overnight culture. Dotplots shown are representative of 8 separate experiments.