After stimulation with LPS/IFN-γ (TLR4) (Fig. 4b) and 3p-hpRNA/LyoVec (RIG-I) or G10 (cGAS-STING)-specific agonists at 24 h (Fig. 4b–d), the subsequent phosphorylation of TBK-1 was impaired in cDC1, and cDC2 dendritic cells and CD14dimCD16+ monocytes in older participants when compared with adult controls (Fig. 4b–d), suggesting a potential for impaired cross-presentation and activation of CD8+ T cells or polarization of CD4+ T cells through the secretion of IL-12 during a viral infection [11, 34]. Here, TLR4 is linked to viral infectious disease.