Classical swine fever virus (CSFV), a plus-sense RNA virus, utilizes host intracellular membrane organelles for its replication. Our previous studies have shown that disruption of the intracellular membrane-trafficking events can inhibit CSFV replication. However, the underlying mechanism of this process in CSFV
infection has not been elucidated. To determine the role of Golgi-associated anterograde and retrograde trafficking in CSFV replication, we revealed the effect of vesicular transport between Golgi and ER inhibitors
Brefeldin A (BFA) and 2,2-methyl-N-(2,4,6,-trimethoxyphenyl) dodecanamide (CI-976), the GBF1 inhibitor
golgicide A (GCA) on virus production. Our results showed that disruption of vesicular trafficking by BFA,
CI-976, and GCA significantly inhibited CSFV
infection. Subsequent experiments revealed that knockdown of Rab1b by lentiviruses and negative-mutant Rab1b-N121I transfection inhibited CSFV
infection. Furthermore, we showed that the Rab1b downstream vesicular component effectors GBF1, and class I and class II
ADP-ribosylation factors (ARFs) were also involved in virus replication. In addition, confocal microscopy assay showed that CSFV
infection disrupted the Golgi apparatus resulting in extended Golgi distribution around the nucleus. We also showed that cell secretory pathway, measured using Gaussia
luciferase flash assay, was blocked in CSFV infected cells. Taken together, these findings demonstrate that CSFV utilizes Rab1b-GBF1-ARFs mediated trafficking to promote its own replication. These findings also provide new insights into the intracellular trafficking pathways utilized for CSFV life cycle.