Reprogramming the unfolded protein response for replication by porcine reproductive and respiratory syndrome virus
(A and B) MARC-145 cells or porcine alveolar macrophages (PAMs) were infected with PRRSV strain JXwn06 at an MOI of 0.1. At the indicated times post infection, the cells were collected and subject to western blot analysis with antibodies against the indicated proteins. Nucleocapsid protein N and β-actin served as the indicator for infection and the loading control, respectively. (C and D) Detection of XBP1 mRNA splicing. PRRSV-infected cells were harvested at the indicated times post infection. The XBP1 mRNA sequence was amplified by RT-PCR followed by digestion with Pst I and the products were analyzed by electrophoresis on a 1.5% agarose gel. (E and F) Quantification of the proteins or mRNAs during PRRSV infections. The abundance of pPERK, peIF2a, ATF4, XBP1s, ATF6, and PDI were expressed as fold changes compared to mock-infected control after being normalized against β-actin. (G and H) Kinetics of virus production in MARC-145 cells and PAMs at an MOI of 0.1. The results represent the averages of at least three independent experiments. Data information: Error bars indicate means ± standard deviations (SD).