Properties of monoclonal antibodies against glycoproteins of western equine encephalitis virus

Abstract

To analyze the biological activities of the alphavirus glycoproteins, eight different monoclonal antibodies against the two glycoproteins of western equine encephalitis virus were isolated. Five of the eight monoclonal antibodies were shown to be specific for El and three for E2 protein by an enzyme-linked immunosorbent assay and by radioimmunoprecipitation. Three of the five anti-El and all of the anti-E2 monoclonal antibodies inhibited hemagglutination by purified virions. One anti-El and two anti-E2 monoclonal antibodies possessed high virus-neutralizing activity.

Properties of Monospecific Antibodies to the Glycoprotein of Western Equine Encephalitis Virus

“…Before any experiments were conducted, the specificity of the two MSp-Abs (anti-E 1 and anti-E2) was determined by immune precipitation with a 14C-WEE virion lysate as previously described (14). As shown in Fig.…”

“…1, the specificity of the anti-El and anti-E2 antibodies confirmed that they were highly pure. A faint band corresponding to the core protein is known to be nonspecifically precipitated by the fixed bacteria used as absorbent (14).…”

“…With respect to HI activity, only anti-E 1 MSp-Ab shows HI activity (4). Recent studies with monoclonal antibodies (McAbs) revealed that not only anti-E 1 but also anti-E2 McAb possesses HI activity (2,10,14). However, there is sometimes an increase in production of McAbs against rare antigenic determinant sites which are not usually recognized in conventional immunization such as vaccination or during convalescence from viral infection.…”

“…Enzyme-linked immunosorbent assay (ELISA). The antibodies were tested for virus-binding activity by ELISA as described previously (14). The values represent the reciprocal of the highest tenfold dilutions giving an optical density reading of more than 0.1 at 410 nm.…”

“…Blocking NT test. For this experiment, two McAbs were selected from the collection of McAb previously published (14). The immune ascitic fluids of Clone 8 (anti-El ; NT titer =800) and Clone 5 (anti-E2 ;NT titer =7,200) were diluted 1: 350 and 1: 4,000, respectively in Eagle's MEM.…”