Induction by synthetic peptides of broadly reactive, type-specific neutralizing antibody to poliovirus type 3

A region of virus capsid protein VP1 located 89-100 amino acids from the N-terminus has been proposed to comprise a major antigenic site involved in the neutralization of poliovirus type 3. Synthetic peptides 10-18 amino acids in length, containing all or part of this sequence, were tested for their ability to induce antiviral antibodies. Rabbits, but not guinea pigs or mice, immunized with the most active peptide, developed hightitered, type-specific, neutralizing antibodies for a wide range of poliovirus type 3 strains. Consistent with the broad type specificity of the antibody response was the observation that amino acids 89-100 of VP1 are highly conserved among different poliovirus type 3 strains. This sequence thus appears to provide, at least in part, a molecular basis for serotype antigenic specificity. Individual amino acids from 93 to 98 within this sequence were shown to be important for the neutralization of virus by antipeptide sera by examination of the ability of the sera to neutralize laboratory-derived poliovirus type 3 mutants with known single amino acid substitutions in the proposed antigenic site.

Principal and subsidiary antigenic sites of VP1 involved in the neutralization of poliovirus type 3

The characterization of over 300 mutants, derived from two strains of poliovirus type 3 and selected for resistance to neutralization by monoclonal antibodies, has led to the further definition of the major antigenic site involved in neutralization. The site encompasses amino acids 89 to 100 of VP1. A subsidiary antigenic site near the C-terminus of VP1 has been identified for the Sabin vaccine strain of poliovirus type 3. Of 59 monoclonal antibodies to poliovirus type 3 examined, 27 had virus-neutralizing activity and 25 of these were identified as directed against the major site on VP1 (designated site 1), indicating the immunodominant role of this site. One of the six monoclonal antibodies that recognized the subsidiary antigenic site on VP1 (designated site 2) possessed virus-neutralizing activity. The identification of the principal antigenic site of the virus provides a rational basis for attempts at the development of synthetic oligopeptide vaccines against poliovirus type 3.

New poliovirus vaccines: a molecular approach

This article summarizes recent work on the determinants of antigenicity in poliovirus type 3 and reports on experiments in progress aimed at understanding the molecular basis of attenuation in Sabin's type 3 vaccines. Ways in which this new information might be used to produce alternative, safe, inexpensive, multivalent vaccines against polio and other enteroviruses are discussed.

A collaborative study on the use of single radial immunodiffusion for the assay of rabies virus glycoprotein

The single radial immunodiffusion (SRD) technique has been applied to the assay of the glycoprotein content of rabies vaccines produced in cell cultures. Fourteen laboratories in seven countries participated in a collaborative study to evaluate the reproducibility of the SRD technique; some laboratories also examined vaccines in the mouse protection (NIH) test and by enzyme immunoassay. Good agreement was found between potency estimates using the SRD technique: the geometric coefficients of variation for combined potency estimates of all laboratories were about 10%. SRD assays appear to have a role for the in vitro assay of antigen content of vaccine and could complement results obtained in in vivo assays which are subject to wide variability.

Antigenic characterization of poliovirus type 3 using monoclonal antibodies

Hybridoma cell lines secreting monoclonal antibodies to type 3 poliovirus were prepared, and their reactivity with infectious virus (D antigen), empty particles (C antigen), and isolated virion capsid proteins ( VPs ) were examined. Eight antibodies reacted with epitopes common to D and C antigens, and all of these possessed high titers of neutralizing activity. However, only 12 of 19 antibodies that reacted exclusively with D antigen neutralized virus infectivity, and some of these reacted only with strains of virus with T1-oligonucleotide maps identical or similar to that of Sabin vaccine polio virus. These antibodies will be of value in identifying strains of virus derived from Sabin vaccine. None of the 20 monoclonal antibodies that neutralized type 3 poliovirus strains reacted in immunoblot experiments with isolated virion capsid proteins. However, six of the 24 antibodies that reacted only with noninfectious C antigen bound to VP1 and VP3, and three of these antibodies also reacted with proteins of poliovirus types 1 or 2. The lack of reactivity of neutralizing monoclonal antibodies with isolated viral proteins suggests that the antigenic properties of proteins are determined by their arrangement in the virus and not simply by amino acid sequence.

Identification of an antigenic site in the neutralization of type 3 poliovirus

Antigenic mutants of type 3 poliovirus were obtained by picking plaques formed in the presence of neutralizing monoclonal antibodies. All the mutants were clustered into a single operationally defined antigenic site based on their reactions with a panel of antibodies. Most of the mutations were shown to be located in the virion protein VP1 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and oligonucleotide mapping, and 15 of 16 mutants had single-point mutations in a region of VP1 encompassing only eight amino acids, a finding suggesting that this is a major target for the neutralization of the virus. Whereas other areas may also be required, it is likely that this region is a necessary component of a vaccine of any kind.

Neutralization epitopes on poliovirus type 3 particles: an analysis using monoclonal antibodies

Monoclonal antibodies to poliovirus type 3 secreted by 51 hybridoma cell clones have been characterized in terms of (i) virus-neutralizing properties, (ii) reactivity in antigen-blocking tests with infectious, 155S ('D' antigen) and empty 80S ('C' antigen) poliovirus particles and (iii) reactivity in immunoblot tests with the isolated protein components of the poliovirus capsid. The antibodies could be separated into three groups on the basis of their reactivities with 'D' and 'C' antigens. All antibodies that reacted with both 'D' and 'C' antigen had potent neutralizing activity. Only a proportion of antibodies that reacted uniquely with 'D' antigen possessed neutralizing activity. Unexpectedly, one of 24 'C' antigen-specific antibodies inhibited virus growth. None of the antibodies that possessed virus-neutralizing activity reacted with isolated poliovirus capsid proteins, although the majority of these have been shown in previous studies to be specific for VP1 on intact virus particles. These findings suggest that antigenic determinants involved in virus neutralization do not survive the denaturing conditions required for the isolation of poliovirus capsid proteins and consequently are likely to be specified by the structural conformation of VP1 rather than by amino acid sequence alone. However, several of the antibodies which bound uniquely to 'C' antigen reacted in immunoblot tests, five with VP1 and one with VP3. Some of these antibodies also possessed heterotypic reactivity with the corresponding capsid proteins separated from other poliovirus types.

Short course netilmicin prophylaxis in renal stone surgery

Following surgery for the removal of intrarenal calculi 30% of patients will develop severe wound complications. This study assesses the role of a short course of netilmicin given over the operative period, in 20 consecutive patients. Preoperative studies demonstrated that whilst 20% of patients had bacterial growth in the urine, culture of the removed calculus demonstrated that 50% of the stones exhibited a significant bacterial growth. Of the 20 patients, only one developed a wound complication. Following the preoperative dose, satisfactory netilmicin levels were obtained and no patient had levels greater than 1 microgram ml-1 by 7 h. Despite some degree of renal impairment, serum urea and creatinine values were unaffected.

Location and primary structure of a major antigenic site for poliovirus neutralization

We have determined a major antigenic site for virus neutralization on the capsid protein VP1 of poliovirus type 3. Antigenic mutant viruses selected for resistance to individual monoclonal antibodies had point mutations concentrated in a region 277-294 bases downstream from the start of the region of viral RNA coding for VP1. These findings provide the basis for an improved understanding of the molecular basis of virus neutralization.

Genetic and antigenic variation in type 3 polioviruses: characterization of strains by monoclonal antibodies and T1 oligonucleotide mapping

Considerable genetic and antigenic heterogeneity was detected among a collection of 17 poliovirus type 3 strains isolated between 1939 and 1958 in studies using monoclonal antibodies and by T1 oligonucleotide mapping. Heterogeneity was detected even amongst a collection of nine viruses designated Saukett and assumed to originate from the same prototype virus. The monoclonal antibodies were found to differ in their strain specificities for poliovirus type 3 strains in virus neutralization or single-radial-immunodiffusion tests. Relationships between strains detected in this way were in general consistent with those detected by oligonucleotide mapping. One of the monoclonal antibodies (NIBp 56) was able to distinguish between certain Saukett virus strains which differed by as little as a single specific oligonucleotide. The heterogeneity detected amongst Saukett viruses is of potential practical importance since these strains are used widely in the manufacture of inactivated poliovirus vaccine.

Monoclonal antibodies specific for the Sabin vaccine strain of poliovirus 3

Monoclonal antibodies to poliovirus type 3 secreted by nine mouse hybridoma cell lines were tested for virus-strain specificity with a collection of wild and vaccine-like type 3 viruses, the genetic characteristics of which had been determined by T1-oligonucleotide mapping. Four of the monoclonal antibodies had both virus-neutralising and antigen-blocking activity, and five had antigen-blocking activity only. Of the four virus-neutralising antibodies, two (NIBp138, NIBp165) reacted only with Sabin vaccine virus and other poliovirus type 3 strains with Sabin-like T1-oligonucleotide maps. Two antibodies (NIBp132, NIBp134) neutralised a broad range of type 3 viruses. Of five monoclonal antibodies with antigen-blocking activity only, four (NIBp135, NIBp136, NIBp140, and NIBp141) reacted exclusively with Sabin virus and strains with Sabin-like maps, and one (NIBp139) reacted with all type 3 strains tested. The vaccine-specific monoclonal antibodies, particularly NIBp138 and NIBp165, have considerable potential value in distinguishing wild type 3 viruses from those of Sabin vaccine origin. This conclusion was strongly supported by the finding that certain viruses which showed genetic evidence of being related to Sabin virus reacted well with vaccine-specific monoclonal antibodies despite having undergone genetic drift away from vaccine virus as indicated by changes in up to 30% of their oligonucleotides.

A single-radial-immunodiffusion technique for the assay of rabies glycoprotein antigen: application for potency tests of vaccines against rabies

An assay for rabies glycoprotein antigen based on single-radial-immunodiffusion (SRD) is described. Rabies glycoprotein antigen at concentrations of 0.7 microgram/ml or greater (approx. 1 international unit, IU) produced well-defined SRD reactions zones in immunoplates containing antibody to purified glycoprotein. Plots of zone area against relative antigen concentration were linear. The method was found to be of suitable sensitivity fo in vitro potency assays of inactivated cell culture rabies vaccines. Qualitative differences were detected between rabies vaccines prepared by two different methods when these were analysed in sucrose gradients for glycoprotein antigen associated with intact virions or in 'soluble' form associated with subviral structures. In vaccines prepared by zonal ultracentrifugation the glycoprotein was totally associated with intact virus, whilst in those prepared by ultrafiltration comparable quantities of subviral antigen were also detected. The SRD test appears to have considerable potential for assays of the antigenic content of rabies vaccines and has the advantage of reducing reliance on conventional in vivo tests for immunogenicity which employ infectious virus.

A hybridoma cell line secreting antibody to poliovirus type 3 D-antigen: detection in virus harvest of two D-antigen populations

A mouse hybridoma cell line (Mo56) secreting IgG antibody to poliovirus type 3 D-antigen was obtained by fusion of a mouse myeloma cell line with spleen cells from mice immunized with Saukett virus. The monoclonal antibody was specific for Saukett virus strains in virus-neutralization and single-radial-diffusion tests. In immunoprecipitation tests the monoclonal antibody reacted with intact infectious virus particles (155S) and with a previously undescribed 70S poliovirus particle with D-antigenic reactivity.

Chemical Species in Fly Ash from Coal-Burning Power Plants

Fly ash specimens from four power plants in the Tennessee Valley Authority system have been separated into three matrices: glass, mullite-quartz, and magnetic spinel. Chemical species of trace elements are defined to a large extent by the matrices that contain them. The magnetic component of fly ash is ferrite. The mullite-quartz phase is relatively pure and can be recovered as a resource.