IL-23/IL-17/G-CSF pathway is associated with granulocyte recruitment to the lung during African swine fever.

The interleukin (IL)-23/IL-17 pathway plays a crucial role in various forms of inflammation but its function in acute African swine fever (ASF) is not well understood. Thus, in this study, we aimed to find out whether IL-23/IL-17/G-CSF is released in acute ASF and what function it may have. The present study revealed that the production of IL-17 and IL-23 were significantly increased in the sera of ASFV infected pigs. Using ELISA, we found that the serum levels of IL-23 and IL-17 have overexpressed in ASF virus infected pigs compared with healthy controls. The levels of IL-17 and IL-23 increase in the early stages and the levels of G-CSF and C - reactive protein in the later stages of ASF. Simultaneously, with the increase of the levels of IL-23/IL-17 extravasation of granular leukocytes in the tissue (diapedesis) is observed. Diapedesis can explain the neutropenia that we identified previously in the terminal stages of ASF. The increase in serum levels of IL-23/IL-17 is preceded by enhanced migration of neutrophils in tissues, and the last one is preceded by neutropenia. The increase in serum levels of G-CSF has compensatory nature, directed on stimulation of proliferation of granulocytes. Taken together, our results revealed an overexpression of the IL-23/IL-17 axis in the ASF virus infected pigs, suggesting that it may be a crucial pathway in the diapedesis at ASF.