Cytotoxicity and cytokine production by bovine alveolar macrophages challenged with wild type and leukotoxin-deficient Mannheimia haemolytica

K. Singh, A.W. Confer, J.C. Hope, T. Rizzi, III Wyckoff J.H., H.-Y. Weng, J.W. Ritchey

Research output: Contribution to journalArticlepeer-review

Abstract

Leukotoxin (LKT) is a virulence factor for Mannheimia haemolytica. In this study, bovine alveolar macrophages (BAMs) were challenged with wild type (wt) and LKT deficient (lkt(-)) M. haemolytica at a concentration of 1 bacterium/BAM and the cytokine response was quantified by ELISA and real-time reverse transcriptase-PCR. Significant increases in protein concentrations of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 were observed in supernatants obtained from BAMs challenged with the lkt(-) strain of M. haemolytica compared with wt challenged BAMs. There were no significant differences in mRNA expression of TNF alpha IL-1 beta, IL-6, IL-8 or IL-10 between BAMs challenged with the lkt(-) strain of M. haemolytica compared with wt challenged BAMs. BAMs challenged with the wt strain exhibited, on average, 43% more cytotoxicity than lkt(-) challenged BAMs (P <0.01). Published by Elsevier Ltd.
Original languageUndefined/Unknown
Pages (from-to)221-227
Number of pages7
JournalVeterinary Journal
Volume188
Issue number2
DOIs
Publication statusPublished - 2011

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