Neonatal T cells exhibit innate-like functions. This diagram shows how neonatal T cells express hardwired receptors and display functions that are more typically associated with innate and innate-like T cells. For example, naive neonatal T cells can express Toll-like receptors (TLRs), complement receptors, and natural killer (NK) cell receptors, as well as a more peptide-promiscuous T cell receptor (TCR). Following TCR stimulation, neonatal T cells also rapidly produce IL-8, which is consistent with their more broadly reactive nature. In contrast, adult T cells express a higher avidity TCR and produce more conventional cytokines (IFN-γ or IL-4 and IL-13) after clonal proliferation and differentiation.