Two-dimensional immunoelectrophoresis, indirect immunofluorescence, and radioimmunoassay were used to demonstrate that antisera from rabbits immunized with some strains of Streptococcus mutans contain antibodies that crossreact with human cardiac tissue. These rabbits were sensitized to a shocking dose of human heart antigen, and anaphylactic deaths were sometimes produced. Myocarditis was also a result of the immunization procedure. Data obtained with all five techniques were comparable. Cross-reactivity could be associated with three antigens designated ID, IF, and HL. Antigens ID and IF were major immunogens of S. mutans Ingbritt, but HL antibodies were produced only after hyperimmunization. Cross-reactivity was of an immunological nature and not the result of nonspecific factors such as bacterial Fc reactive components or antibody elicited to growth medium constituents. These findings support the hypothesis that immunization with S. mutans can induce autoimmune reactions and indicate that antigens must be selected with caution before formulating any dental caries vaccine.

Monoclonal antibodies against tetanus toxin were produced to obtain highly specific antisera. Ten hybridoma cell lines producing monoclonal antibodies were derived from the fusion of rat myeloma cells and spleen cells from rats immunized with tetanus toxoid. Eight produced monoclonal antibodies specific for determinants on toxin and toxoid, whereas two were specific only for determinants on the toxoid. The antibodies produced by hybridomas were characterized by determination of the class of light and heavy chain components, epitope specificity, toxin neutralization, and subunit specificity. All of the antibodies contained kappa light chain, eight contained the yl heavy chain, and the remaining two contained the y2a heavy chain. Five distinct epitopes were indicated by competition assay of paired monoclonal antibodies, and 4 of the 10 monoclonal antibodies neutralized the in vivo activity of tetanus toxin. The four neutralizing monoclonal antibodies and one other were specific for the C fragment of the heavy chain of the toxin molecule.

The preparation, characterisation and testing of stable non-porous coated perfluorocarbon supports functionalised with the metal chelate, iminodiacetic acid (IDA) is described. Polyvinyl alcohol (PVA), a neutral hydrophilic polymer was esterified with perfluorooctanoyl chloride and anchored to the surface of solid perfluorocarbon particles through multiple fluorophilic interactions. The PVA-coated particles were then activated by epoxidation and coupled with IDA. The presence of surface-attached chelates was clearly demonstrated by the binding and selective desorption of Zn2+ ions. Three particulate perfluorocarbons were selected as potential starting materials and the conditions for preparation of metal chelating adsorbents optimised with respect to ease of manufacture, ligand density and binding capacity towards a monoclonal antibody known to bind to commercial Zn(2+)-IDA supports. The choice of base particle strongly influenced the ligand densities and specific binding capacities towards the monoclonal antibody that could be achieved under optimal preparative conditions. Possible ways in which these metal chelating adsorbents may be employed to recover the monoclonal antibody directly from culture vessels are discussed.

Tetanus toxin has been immunopurified on immunoadsorbent columns derived from equine polyclonal antitoxin coupled to cyanogen bromide-activated Sepharose CL4B. Desorption of bound toxin in active form was achieved only when the immunoadsorbent was mixed with Sephadex G15 and this mixture overlaid on a further volume of Sephadex G15. With equine antibody, 64% of adsorbed toxin was recovered with a specific activity of 2400 limiting flocculation units (Lf)/mg protein N (1.2 X 10(8) minimum lethal doses (MLD)/mg protein N). Similarly prepared immunoadsorbent derived from murine monoclonal antitoxin of low affinity had improved desorption with less acidic desorbents, without the requirement for Sephadex G15; greater than 80% of adsorbed toxin was recovered with a specific activity of 3000 Lf/mg protein N (1.6 X 10(8) MLD/mg protein N).

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