Expression of Toll-like receptor mRNA and cytokines in pigs infected with porcine reproductive and respiratory syndrome virus

• Published in: Veterinary microbiology Vol. 136; no. 3; pp. 266 - 276
• Main Authors: Liu, Ching-Hsing, Chaung, Hso-Chi, Chang, Hsiu-luan, Peng, Yu-Tang, Chung, Wen-Bin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 12.05.2009; Amsterdam; New York: Elsevier; Elsevier
• Subjects: Animals; biochemical pathways; Biological and medical sciences; complications; Cytokines; Cytokines - biosynthesis; Cytokines - immunology; disease resistance; Enzyme-Linked Immunosorbent Assay - veterinary; Fundamental and applied biological sciences. Psychology; gene expression; immune response; immunosuppression (physiological); infectious diseases; interleukin-6; interleukin-8; Leukocytes, Mononuclear - immunology; lymphatic system; Lymphoid Tissue - immunology; Macrophages, Alveolar - immunology; messenger RNA; Microbiology; Miscellaneous; pathogenesis; porcine reproductive and respiratory syndrome; Porcine Reproductive and Respiratory Syndrome - genetics; Porcine Reproductive and Respiratory Syndrome - immunology; Porcine Reproductive and Respiratory Syndrome - pathology; Porcine Reproductive and Respiratory Syndrome - virology; Porcine reproductive and respiratory syndrome virus; Porcine respiratory and reproductive syndrome virus - immunology; Random Allocation; receptors; Reverse Transcriptase Polymerase Chain Reaction - veterinary; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Swine; Toll-like receptors; Toll-Like Receptors - biosynthesis; Toll-Like Receptors - genetics; Toll-Like Receptors - immunology; Virology; Cytokines; Toll-like receptors; Porcine reproductive and respiratory syndrome virus; Microbiology; Arterivirus; Cytokine; Toll like receptor; Virus; Infection; Vertebrata; Mammalia; Messenger RNA; Swine; Arteriviridae; Swine infertility respiratory syndrome virus; Artiodactyla; Veterinary; Nidovirales; Ungulata
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2008.11.016

Field observations have suggested that porcine reproductive and respiratory syndrome virus (PRRSV) predispose pigs to secondary infections. The interaction between PRRSV and the secondary invaders has not yet been well elucidated. In this study, we investigated the mRNA expression of Toll-like receptors (TLR) in lymphoid organs and cells, and cytokine secretions by alveolar macrophages (AMs) and peripheral blood mononuclear cells (PBMCs) in response to pathogen-associated molecular patterns (PAMPs) in PRRSV-challenged pigs. TLR mRNA expressions were measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and cytokine concentrations were determined using commercially available ELISA kits. PRRSV infection led to significantly increased secretions of IL-1β and IL-6 by AMs of PRRSV-infected pigs. Infection of pigs with PRRSV also resulted in an increased secretion of IL-1β by AMs in response to lipoteichoic acid (LTA) stimulation, and IL-6 by PBMCs in response to lipopolysaccharide (LPS) and LTA stimulation. Infection of pigs with PRRSV tended to up-regulate the mRNA expression of TLR2, 3, 4, 7 and 8 in at least one of the lymphoid tissues and cells. Further research is required to demonstrate the association between the enhanced expressions of the specific TLRs and the increased susceptibility to secondary agents with more severe clinical outcomes in PRRSV-infected pigs.