Table 1.

Cytokine-binding bacterial proteins, their ligands and their virulence properties.

Protein	Type	Species	Cytokine ligands	Effect of cytokine binding	Virulence	PDBa	Ref
Caf1A	OM usher	Ypb	IL-1β	Potential IL-1β uptake	F1 antigen secreted by Caf1A inhibits adhesion to macrophages and airway epithelia, potential vaccine antigen	4BOE (N-terminal PapC domain)	2,17,23,5-27
PilQ	OM secretin	Nmc	IL-8, TNF-α	Cytokine uptake, increased virulence, complement resistance	Adherence to nasopharyngeal cells, inhibits phagocytosis by macrophages, initial binding to the blood-brain barrier	4AV2 (Domains N0 and N1)	6,31,33,34
OprF	OM porin	Pad	IFN-γ	Increased production of PA-I lectin and pyocyanin, activation of QS signaling	Adherence to gliad and intestine cells, cytotoxic, induction of other virulence factors, potential vaccine antigen	4RLC (N-terminal transmembrane domain) 5U1H (C-terminal domain)	5,35,37-40
IrmA	secreted	Ece	IL-2, IL-4, IL-10	Not determined	Immunogenic, potential vaccine candidate	5EK5	7,44
PilE	Pilus subunit	Nmc	IL-8, TNF-α	Cytokine uptake, increased virulence, complement resistance	Adheres to endothelial cells in the blood-brain barrier, induces host cell signaling	5JW8	6,45,45,47-49
BilRI	OM lipo-protein	Aaf	IL-1β, IL-8, IL-10, TNF-α, TGF-1β, IFN-γ	IL-1β uptake, decreased amount of extracellular DNA in biofilm	Not determined	N/A	4,13,42

Notes.

^aThe Protein Data Bank

^bYersinia pestis

^cNeisseria meningitidis

^dPseudomonas aeruginosa

^eEscherichia coli

^fAggregatibacter actinomycetemcomitans