Characterization of African swine fever virus antigenic proteins by immunoprecipitation

Abstract

African swine fever virus is a large, complex virion in which numerous proteins have been identified by biochemical techniques. Few of these proteins have been shown to react with antibodies from recovered swine, leading to speculation that the immunological unreactivity of some viral proteins might explain the inability of immune sera from surviving animals to neutralize the virus. We used immunoprecipitation of radiolabeled viral proteins to examine these sera in more detail. Gradient sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis of these immunoprecipitates revealed that at least 37 viral proteins participated in antigen-antibody reactions in this system. Differences in the molecular weights of some immunoprecipitable proteins were noted between different isolates of virus, between the same isolate grown in different cells, and between an isolate adapted to Vero cells and one not adapted to these cells.

Proteins specified by African Swine Fever virus: V.-Identification of immediate early, early and late proteins

“…The molecular weights of the IP in this study (their corresponding number in kilodaltons) are similar to those reported by other laboratoi~es (1,7,14,21). Slight differences may be produced by the different molecular weight standard proteins taken as references, for example myosin which was taken as 220K (17) (17) to p 220 and p 150 (1,14), respectively.…”

“…T h e e t e c t r o p h o r e t i c p a t t e r n o f p r o t e i n s in infected cells w a s similar in several cell t y p e s (MS, V E R O , B H K a n d pig l e u k o c y t e s ) a n d after infection with several virus strains (5), a l t h o u g h s o m e p r o t e i n s can c h a n g e in mobility (7). I n this work, viral s t r a i n 608 g r o w i n g in V E R O cells (608 V 55) s h o w e d a clear difference as c o m p a r e d to the 608 L 6, in t h a t the I P 10 d i s a p p e a r e d a n d a n e w p o l y p e p t i d e (IP 13.5) a p p e a r e d (Fig.…”

Purification and properties of African swine fever virus

“…Proteins larger than 150,000 molecular weight that have been found in intracellular ASF virus purified by sucrose sedimentation (44) were not detected in preparations of extracellular virus purified by Percoll sedimentation, but appeared as components of the vesicle fraction. The discrepancy between the number and the apparent molecular weights of the ASF virus protein bands described previously (6,27,44) and those described in this paper could arise from the degree of vesicle contamination in the purified virus fraction, the higher resolution of the electrophoresis system used here, and differences in the source of virus (strain, extra-or intracellular) and host cells.…”

African Swine Fever Virus Gene Expression in Infected Vero Cells

“…2a, b). Letchworth & Whyard (1984), by immunoprecipitation of infected cell proteins with hyperimmune pig serum, demonstrated the specificity of the reaction and identified 37 ASFV-induced polypeptides. In our case we have identified 33 polypeptides.…”