Label-Free Quantitative Proteomic Analysis of Differentially Expressed Membrane Proteins of Pulmonary Alveolar Macrophages Infected with Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and Its Attenuated Strain

Significant differences exist between the highly pathogenic (HP) porcine reproductive and respiratory syndrome virus (PRRSV) and its attenuated pathogenic (AP) strain in the ability to infect host cells. The mechanisms by which different virulent strains invade host cells remain relatively unknown. In this study, pulmonary alveolar macrophages (PAMs) were infected with HP-PRRSV (HuN4) and AP-PRRSV (HuN4-F112) for 24 h, then harvested and subjected to label-free quantitative mass spectrometry. A total of 2849 proteins were identified, including 95 that were differentially expressed. Among them, 26 proteins were located on the membrane. The most differentially expressed proteins were involved in response to stimulus, metabolic process and immune system process, which mainly had the function of binding and catalytic activity. CD163, Vimentin and nmII as well as detected proteins were assessed together by string analysis, which elucidated a potentially different infection mechanism. According to the function annotations, PRRSV with different virulence may mainly differ in immunology, inflammation, immune evasion as well as cell apoptosis. This is the first attempt to explore the differential characteristics between HP-PRRSV and its attenuated PRRSV infected PAMs focusing on membrane proteins which will be of great help to further understand the different infective mechanisms of HP-PRRSV and AP-PRRSV. This article is protected by copyright. All rights reserved