|ZHANG, H - IOWA STATE UNIVERSITY|
|BAKER, RODNEY - IOWA STATE UNIVERSITY|
|OPRIESSNIG, TANJA - IOWA STATE UNIVERSITY|
Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2010
Publication Date: 3/15/2011
Citation: Zhang, H., Lunney, J.K., Baker, R.B., Opriessnig, T. 2011. Cytokine and chemokine mRNA expression profiles in tracheobronchial lymph nodes from pigs singularly infected or coinfected with porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHYO). Veterinary Immunology and Immunopathology. 140:152-8.
Interpretive Summary: Porcine circovirus type 2 (PCV2)-associated disease (PCVAD) is increasingly recognized as a serious threat to global swine production. To characterize the effect of Mycoplasma hyopneumoniae (MHYO) on PCV2 the objective of this work was to determine if there were changes in mRNA expression of cytokines and chemokines in local lung-associated lymphoid tissues (tracheobronchiolar lymph nodes; TBLN) from pigs singularly infected or coinfected with PCV2 or MHYO. Tests of cytokineand chemokine mRNA expression levels in TBLN obtained from IMHYO, IPCV2, or CoI pigs were elucidated for the first time in this study. MHYO potentiated PCV2 infection by increasing innate immune markers, IL1B and IL8, and IFNG and IL10 mRNA expression levels. PCV2 singular infection was characterized by significantly increasing IFNG, IL8, NOS2A, and chemokine CCL2, CCL5, CXCL10, slightly increasing IFNB and IL1B mRNA, and decreasing IL4 and IFNA mRNA expression levels. The increase in IFNG and chemokines, and decrease in IFNA was correlated with increases in severity of microscopic lesions and amount of PCV2 antigen. In summary, this work provided evidence that the increased severity of lesions in PCV2 and MHYO coinfected pigs was associated with alterations of cytokine mRNA expression profiles.
Technical Abstract: The objective of this study was to determine cytokine and chemokine mRNA expression profiles in tracheobronchial lymph nodes from pigs singularly infected with porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (MHYO), or coinfected with both. Twenty-eight pigs were randomly assigned to one of four groups: (1) negative controls (NEG), (2) inoculated with MHYO (IMHYO), (3) inoculated with MHYO and PCV2 (CoI), and (4) inoculated with PCV2 (IPCV2). MHYO infection significantly (P < 0.05) stimulated innate cytokines, IL1B and IL8. PCV2 infection significantly stimulated expression of IFNG, IL8, NOS2A and chemokines CCL2, CCL5, and CXCL10. IFNB, IL1B and IL12 were slightly increased with PCV2 infection and IFNA and IL4 significantly downregulated. Coinfection resulted in a significant increase in expression of IFNG, IL1B, IL8, CCL5, CXCL10, and weak stimulation of IFNB, IL6 and IL10; IL13 and IFNA were significantly downregulated. Overall MHYO potentiated PCV2 infection by increasing IL1B, IL8, IFNG and IL10 mRNA expression levels. The increase of IFNG and chemokines, and decrease of IFNA in IPCV2 and CoI pigs was correlated with increased severity of lymphoid lesions and increased amount of PCV2 antigen. In summary, this work provided evidence that the increased severity of lesions in PCV2 and MHYO coinfected pigs was associated with alterations of cytokine mRNA expression profiles.