Plasmid encoded protein (Pet), a product of E. coli, infiltrates leukocyte in experimental models and acts on
macrophages as a chemokine. As an immune response orchestrator, macrophages play an important role in inducing proinflammatory
cytokines. In this work, we tested whether in macrophages Pet stimulates the expression of IL1, TNFα, MIF
and the antagonist IL1Ra. We also sought the IKKαβ/NFκB pathway as a possible mediator. We found that indeed Pet
increases the mRNA of inflammatory cytokines and the antagonist IL1Ra with different rates and kinetics through the
IKKαβ/NFκB pathway, which could be consistent as a factor in chronic inflammation.