African Swine Fever Virus Infection and Cytokine Response In Vivo: An Update

African swine fever (ASF) is a hemorrhagic viral disease of domestic pigs and wild suids (all Sus scrofa) caused by the ASF virus (ASFV). The disease is spreading worldwide without control, threatening pig production due to the absence of licensed vaccine or commercially available treatments. A thorough understanding of the immunopathogenic mechanisms behind ASFV infection is required to better fight the disease. Cytokines are small, non-structural proteins, which play a crucial role in many aspects of the immune responses to viruses, including ASFV. Infection with virulent ASFV isolates often results in exacerbated immune responses, with increased levels of serum pro-inflammatory interleukins (IL-1 alpha, IL-1 beta, IL-6), TNF and chemokines (CCL2, CCL5, CXCL10). Increased levels of IL-1, IL-6 and TNF are often detected in several tissues during acute ASFV infections and associated with lymphoid depletion, hemorrhages and oedemas. IL-1Ra is frequently released during ASFV infection to block further IL-1 activity, with its implication in ASFV immunopathology having been suggested. Increased levels of IFN-alpha and of the anti-inflammatory IL-10 seem to be negatively correlated with animal survival, whereas some correlation between virus-specific IFN-gamma-producing cells and protection has been suggested in different studies where different vaccine candidates were tested, although future works should elucidate whether IFN-gamma release by specific cell types is related to protection or disease development.

Automated summary

African swine fever (ASF) is a viral disease caused by ASF virus (ASFV) that affects domestic pigs and wild suids worldwide. The absence of licensed vaccine or treatments poses a threat to pig production. Understanding the immunopathogenic mechanisms of ASFV infection is crucial in combating the disease. Cytokines, such as IL-1, IL-6, TNF, and chemokines, play a role in immune responses to ASFV. Increased levels of these cytokines are associated with tissue damage and disease severity, while increased levels of IFN-alpha and IL-10 may have negative effects on animal survival.