The protective immune response to African swine fever virus (ASFV) includes both cellular and serological components. In this study, the role of
antibodies in the pathogenicity and diagnosis of
African swine fever (ASF) was explored. Accordingly, total and
Ig isotype antibody responses against the 12
viral proteins previously demonstrated to be the main targets of serological immunity were evaluated in longitudinally collected sera from pigs infected experimentally with the non-pathogenic ASFV/NH/P68 isolate. Strong total
IgG antibody responses were observed against
viral proteins E183L/p54, K205R/'unassigned', A104R/
histone-like and B602L/'unassigned'; therefore,
IgM,
IgG1 and
IgG2 responses to these
proteins were also determined. One
protein stimulating
IgM (K205R) may have practical potential for the detection of recently infected animals. There was a clear trend towards an
IgG1 response to all of the
proteins. This may reflect a dominant Th2-controlled immune response. In order to identify possible correlations between these serological responses and the pathogenesis of ASF, total
IgG responses to the 12
recombinant proteins were compared in asymptomatic and chronically infected animals. For the
proteins NP419L/
DNA ligase, CP312R, B646L/p73, K196R/
thymidine kinase and K205R, the antibody titres were significantly higher in animals developing lesions. One exception was the antibody response to the A104R/
histone-like
protein, which was higher in asymptomatic than in chronically infected pigs, suggesting that
antibodies against this
protein might be an
indicator of an effective immune response or that this response is somehow involved in protection.