Inhibitory effect of various transfer factors on avian reticuloendotheliosis virus: A proteomic analysis

To investigate the variances in inhibitory effects and potential immunological mechanisms of transfer factors (TFs) from different origins against avian reticuloendotheliosis virus (REV) infection in chickens, this study firstly compared the protein expression profiles of spleens from REV-infected chickens, Newcastle disease (ND) vaccine-immunized chickens, and specific pathogen-free (SPF) chickens. TFs were subsequently extracted from the spleens of these groups, and the alterations in splenic proteomics were monitored post-administration of these TFs to chickens. Furthermore, the CD4⁺/CD8⁺ T cell subsets and the levels of cytokines such as IFN-γ and IL-2 were determined, followed by REV challenge experiments. The results demonstrated that TFs sourced from REV-infected spleens, which enriched virus-specific immune-related proteins such as STAT1 and OASL, significantly boosted cellular immune responses by activating the NOD-like receptor signaling pathway and establishing an efficient STAT1-OASL-PARP9-IRF7 protein-protein interaction network, consequently inhibiting REV replication efficiently. TFs obtained from vaccine-immunized spleens only amplified humoral immunity with restricted anti-REV effects, while TFs derived from SPF spleens had no substantial immunomodulatory activity. Notably, TFs extracted from REV-infected spleens exhibited superior anti-REV efficacy. This study furnishes crucial evidence for the selection of sources and molecular mechanism analysis of high-efficiency TF preparations.