Differential production of proinflammatory cytokines: in vitro PRRSV and Mycoplasma hyopneumoniae co-infection model

Increased Production of Proinflammatory Cytokines following Infection with Porcine Reproductive and Respiratory Syndrome Virus andMycoplasma hyopneumoniae

“…The increase in IL-1␣ and IL-1␤ levels was less consistent in vitro, and no increase in IL-6 levels was observed any time point, including 24 hpi, in the earlier study (32). However, IL-8 levels were increased in vitro in noninfected PAMs cultured with M. hyopneumoniae-inoculated tracheas at 15 hpi, and increased levels of IL-8 protein were present in the supernatant at 6 and 15 hpi.…”

“…In addition, the same proinflammatory cytokines produced by pulmonary alveolar macrophages (PAMs) infected or not infected with PRRSV and incubated with tracheal explants with or without M. hyopneumoniae infection were measured at 6 and 15 h postinfection (hpi) by an in vitro assay. Both the in vivo and the in vitro models described in this study have previously proven useful in investigating the proinflammatory cytokine responses by PAMs to infection with PRRSV and/or M. hyopneumoniae (31,32). In an earlier study that measured in vitro cytokine production by PAMs at 24 and 48 hpi in pigs infected with PRRSV and/or M. hyopneumoniae, the differences in various proinflammatory cytokine levels were observed at 24 hpi.…”

“…The experimental design is summarized in Table 1 and consisted of the same treatments described previously (32). Cells and tracheal explants from each of the donor pigs were subjected to all treatments.…”

“…Total RNA isolation, RT-PCR, and densitometric quantification of RT-PCR products. Total RNA isolation, the primers used, and reverse transcription-PCR (RT-PCR) procedures were performed with the PAMs collected by BAL in the in vivo study and the cultured PAMs from the in vitro study, as described previously (31,32). RT-PCRs for IL-1␣, IL-1␤, IL-6, IL-8, IL-10, IL-12 (p40), TNF-␣, and cyclophilin (a housekeeping gene) were performed with a Mastercycler instrument (Eppendorf, Westbury, N.Y.) and an Access RT-PCR system (Promega, Madison, Wis.).…”

The N-N non-covalent domain of the nucleocapsid protein of type 2 porcine reproductive and respiratory syndrome virus enhances induction of IL-10 expression

“…IL-10 induction was also observed in PRRSV-infected DCs (Chang et al, 2008). However, some conflicting results showed that IL-10 expression was not correlated with PRRSV infection (Klinge et al, 2009;Thanawongnuwech et al, 2001;Wang et al, 2007). Thus, further exploration of PRRSV proteins or even the aa residues of these proteins that are correlated with IL-10 expression is warranted.…”