Interferon gamma, lipopolysaccharide, and modified-live viral vaccines stimulation alter the mRNA expression of tumor necrosis factor α, inducible nitric oxide synthase, and interferon β in bovine alveolar macrophages

Abstract

To understand the pathogenesis of bovine respiratory disease (BRD), it is necessary to elucidate the mechanisms of alveolar macrophage regulation by cytokines and pathogen-associated molecular patterns (PAMPs). Moreover, "non-specific effects (NSEs)" an innate immune regulatory mechanism in response to vaccines containing PAMPs, has recently attracted attention. It may be applied to BRD control, but there is limited knowledge in bovine. To investigate this, we stimulated alveolar macrophages in vitro with lipopolysaccharide (LPS), polyinosinic-polycytidylic acid sodium salt (Poly I:C), interferon gamma (IFN-γ), and modified-live viral (MLV) vaccines, respectively, and analyzed changes in tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS), and interferon beta (IFN-β) mRNA expression levels. mRNA expression levels of TNF-α, iNOS, and IFN-β were significantly increased in bovine alveolar macrophages stimulated by IFN-γ and MLV vaccine; LPS, IFN-γ, and MLV vaccine; and MLV vaccine only, respectively. Additionally, all MLV vaccine-stimulated mRNA expression increases were observed in a concentration-dependent manner. These results revealed in part, the mechanism of bovine alveolar macrophage regulation by cytokines and PAMPs. Understanding the regulatory mechanisms of alveolar macrophages will contribute to understanding the pathogenesis of BRD and preventive and therapeutic BRD management based on NSEs.

Keywords: Alveolar macrophage; Bovine; Cytokines; Innate immunity; Modified-live viral vaccine; PAMPs.