TMT-based proteomic analysis reveals integrins involved in the synergistic infection of reticuloendotheliosis virus and avian leukosis virus subgroup J

Background Co-infection with the avian leukosis virus subgroup J (ALV-J) and the reticuloendotheliosis virus (REV) increases mutual viral replication, causing a more serious pathogenic effect by accelerating the progression of neoplasia and extending the tumor spectrum. However, the molecular mechanism underlying the synergistic replication of ALV-J and REV remains unclear. Results Here, we performed this study to compare the differentially expressed proteins among CEF cells infected with ALV-J, REV or both at the optimal synergistic infection time using TMT-based quantitative proteomics. We identified a total of 719 (292 upregulated and 427 downregulated) and 64 (35 upregulated and 29 downregulated) proteins by comparing co-infecting both viruses with monoinfecting ALV-J and REV, respectively. GO annotation and KEGG pathway analysis showed the differentially expressed proteins participated in virus-vector interaction, biological adhesion and immune response pathways in the synergistic actions of ALV-J and REV at the protein levels. Among the differentially expressed proteins, a large number of integrins were inhibited or increased in the co-infection group. Further, eight integrins, including ITG alpha 1, ITG alpha 3, ITG alpha 5, ITG alpha 6, ITG alpha 8, ITG alpha 9, ITG alpha 11 and ITG beta 3, were validated in CEF cells by qRT-PCR or western blot. Conclusions These findings proved that integrins may be key regulators in the mechanism of synergistic infection of REV and ALV-J, which will provide more insight into the pathogenesis of synergism of REV and ALV-J at protein level.

Automated summary

This study used TMT-based quantitative proteomics to investigate the molecular mechanism of synergistic replication of avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV). The results showed that integrins may be key regulators in the mechanism of synergistic infection of REV and ALV-J, providing more insight into the pathogenesis of this synergism at the protein level.