Table 1.

Signals and biological functions involved in crosstalk between bacteria and mammalian hosts

Prokaryotic signals	Eukaryotic cell	Eukaryotic function	References	Eukaryotic signals	Prokaryotic function	References
3O-C12-HSL	Skin cells	Stimulates the expression of cytokines including IL-1α and IL-6	[29]	α-Defensin	Controls bacterial localization	[48]
3O-C12-HSL	Macrophage, B cells, T cells, spleen cells	Modulates cell activities and antibody responses	[40]	Bile acid	Affects AI activity	[49]
3O-C12-HSL	Lymphocytes	Inhibits cytokine production and lymphocyte proliferation	[41, 42]	Paraoxonases	Degrading AIs	[50, 51]
3O-C12-HSL	BM-DCs	Decreases the ability of BM-DCs to induce T-cell proliferation and activation	[43, 44]	AI-2 mimics	Affect gene expression of bacteria	[26]
3O-C12-HSL	Macrophages, neutrophils	Cytotoxicity	[38]	Noradrenaline	Promotes bacterial growth	[54]
3O-C12-HSL	BM-DMs	Disruption of NF-kB signaling	[45]	Epinephrine	Mimic the activity of AI-3	[56]
AI-2	Colon cancer cells	Regulates Interleukin-8 expression	[28]	Dynorphin	Activates QS signaling and enhanced bacterial virulence	[57]
AI-2	Pneumocytes	Cellular damage	[31]
DPD	Gingival epithelial cells	Enhances cell proliferation	[27]
AI peptides	Colon cancer cells	Tumor metastasis	[46]
AI-3	HeLa cells	Produces AE lesions	[56]

AE attaching and effacing, AI autoinducer, BM-DCs bone marrow-derived dendritic cells, BM-DMs bone marrow-derived macrophages, DPD dihydroxy-2,3-pentanedione (precursor of AI-2), QS quorum sensing