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Biomedical subjects

B BENACERRAF

Publications and source records attributed to B BENACERRAF.

At least 37 records · Page 2Linked to original sources
PubMed1963

Properties of guinea pig 7S antibodies. I. Electrophoretic separation of two types of guinea pig 7S antibodies.

Guinea pigs hyperimmunized with single protein antigens or hapten conjugates emulsified in complete adjuvants produced two types of precipitating antibodies with different electrophoretic mobilities. "Slow" migrating antibody generally appeared earlier and "fast" migrating antibody later in the course of immunization. Animals initially immunized by the intraperitoneal route with hapten conjugates without adjuvants produced primarily fast migrating antibody. Purified guinea pig antibodies were also separable into slow and fast migrating components by electrophoresis in supporting media. Using suitable antisera prepared in rabbits hyperimmunized with guinea pig serum, it was demonstrated that slow and fast antibodies have both common and distinct antigenic determinants. Analytical ultracentrifugation disclosed that both antibodies have sedimentation coefficients of approximately 7S. These antibodies have been designated guinea pig 7Sgamma(1) and 7Sgamma(2).

Animals↗
PubMed1963

Properties of guinea pig 7S antibodies. II. Identification of antibodies involved in passive cutaneous and systemic anaphylaxis.

Guinea pig 7Sgamma(1) antibodies were demonstrated to mediate passive systemic or cutaneous anaphylaxis; guinea pig 7Sgamma(2) antibodies were unable to mediate these reactions. Gamma-2 antibodies specifically inhibited passive cutaneous anaphylactic reactions provoked by gamma-1 antibodies by competing for antigen. However, gamma-2 antibodies were unable to inhibit passive cutaneous sensitization of guinea pigs by a heterologous antibody system. Guinea pig 7Sgamma(2) antibodies appear to lack receptors for fixation to guinea pig tissues and do not compete with sensitizing antibody for receptor sites.

Anaphylaxis↗
PubMed1963

Properties of guinea pig 7S antibodies. III. Identification of antibodies involved in complement fixation and hemolysis.

Guinea pig 7Sgamma(2) antibodies were demonstrated to fix complement in the presence of antigen and to sensitize antigen-coated, tanned erythrocytes for lysis in the presence of complement; guinea pig 7Sgamma(1) antibodies did not participate in these reactions. Gamma-2 antibodies were more efficient in provoking hemorrhagic necrosis in reverse passive Arthus reactions than equal amounts of non-complement-fixing gamma-1 antibodies. Unlike anaphylaxis in the guinea pig, both guinea pig 7Sgamma(1) and 7Sgamma(2) antibodies provoked passive cutaneous anaphylactic reactions in the rat. Efficient hemolytic activity attributable to 7S guinea pig anti-sheep erythrocyte antibodies migrated faster than the peak of complement-fixing activity, but slower than the peak of PCA activity in starch block electrophoresis. It is uncertain whether this activity is a function of a third type of antibody produced in response to the particulate property of the antigen or whether it is due to the antigenic heterogeneity of the erythrocyte cell membrane.

Anaphylaxis↗
PubMed1962

Immunological specificity of delayed and immediate hypersensitivity reactions.

The effects of the following parameters on the immunologic specificity of delayed and immediate hypersensitivity reactions were investigated in the guinea pig using the picryl and p-toluenesulfonyl systems: (a) the contribution of the carrier protein, (b) the effect of the number of hapten groups per molecule of the immunizing and challenging antigens, and (c) the effect of interposing a 6 carbon chain (epsilon-aminocaproic acid) between the hapten and its usual attachment to the lysine epsilon-NH(2) groups of the carrier protein. It was found that induction of delayed hypersensitivity was accomplished equally well with both lightly and heavily coupled conjugates. Sensitized animals which gave strong delayed reactions to the immunizing conjugate cross-reacted poorly or not at all to (a) conjugates of the same hapten with a different carrier protein, or (b) conjugates differing from the immunizing conjugate by having an epsilon-aminocaproyl chain interposed between hapten and its attachment onto the carrier protein. Animals sensitized with either lightly or heavily substituted conjugates exhibited strong delayed reactions to both conjugates, but more intense reactions to the immunizing conjugate were always observed. In contrast to the marker carrier specificity exhibited by the delayed hypersensitivity reactions, immediate hypersensitivity reactions, (specific precipitation, Arthus, and PCA reactions) could be elicited equally well with hapten conjugates of all carrier proteins, as well as with conjugates containing epsilon-aminocaproyl chains interposed between hapten and the carrier protein, provided the number of hapten groups per molecule conjugate was sufficiently high. Both in inducing antibody response and in provoking immediate hypersensitivity reactions, heavily substituted conjugates were considerably more effective than were lightly substituted conjugates. Alternative explanations for these observed differences in specificity between immediate and delayed hypersensitivity reactions are discussed.

Animals↗