African swine fever virus (ASFV) causes acute, febrile, and highly contagious diseases in swine. Early diagnosis is critically important for
African swine fever (ASF) prevention and control in the absence of an effective
vaccine. P30 is one of the most immunogenic
proteins that are produced during the early stage of an ASFV
infection. This makes P30 a good serological target for ASF detection and surveillance. In this study, two P30-reactive
monoclonal antibodies (mAbs), 2H2 and 5E8, were generated from mice immunized with recombinant P30
protein (rP30).
Epitope mapping was performed with overlapping
polypeptides,
alanine mutants, and synthetic
peptides. The mapping results revealed that 2H2 recognized a region located in the N-terminal, 16-48 aa. In contrast, 5E8 recognized a linear
epitope in the C-terminal, 122-128 aa. Further analysis indicated that the
epitope recognized by 2H2 was highly conserved in genotypes I and II, while the 5E8
epitope was conserved in most genotypes and the Ser to Pro change at position 128 in genotypes IV, V, and VI did not affect recognition. Overall, the results of this study provide valuable information on the antigenic regions of ASFV P30 and lay the foundation for the serological diagnosis of ASF and
vaccine research. KEY POINTS: • Two specific and reactive mAbs were prepared and their
epitopes were identified. • 2H2 recognized a novel
epitope highly conserved in genotypes I and II. • 5E8 recognized a seven-
amino acid linear
epitope highly conserved in most genotypes.