Proinflammatory Cytokines in Antilipopolysaccharide Immunity AgainstKlebsiellaInfections

Abstract

This study was undertaken in order to determine whether proinflammatory cytokines are involved in a previously described protection againstKlebsiellainfection mediated by antilipopolysaccharide antibodies. BALB/c mice were infected intraperitoneally with a lethal challenge ofKlebsiella pneumoniaeCaroli. One group of mice was protected with monoclonal antibodies against lipopolysaccharide prior to infection and the second was not. We determined the number of colony-forming units at different time points in the blood of infected animals and paralleled them with plasma levels of five proinflammatory cytokines measured by enzyme immunoassays. Our results show that the two groups of animals tested expressed different plasma concentrations for all cytokines. The greatest difference was detected 24 hours after infection, with a higher production in the unprotected group. We concluded that a reduced cytokine production is partially responsible for the survival of protected animals.