Mechanisms underlying binding of immune complexes to macrophages.

The mechanism of binding of immune complexes to macrophages was investigated using purified antibody and haptens of different valences. Antibody alone bound to macrophages; enhancement of binding occurred when polyvalent and divalent haptens were present at equivalence but did not occur in great antigen excess. Monovalent hapten did not increase the binding of antibody at any concentration ratio tried, though it inhibited the enhancement due to oligovalent hapten. Ultracentrifuged normal rabbit globulin also inhibited the binding of complexes indicating the presence of exposed binding sites on the uncomplexed molecules. Complexes bound more strongly than antibody alone as determined from elution studies. These results support the hypothesis that the enhancement of antibody binding to macrophages in the presence of antigen is due to increased energy of binding resulting from summation of individual binding sites already exposed on the antibody molecules. It was also possible, by saturating the macrophages with gamma globulin, to estimate the number of binding sites per cell; this was calculated to be approximately 2 million per alveolar macrophage.

H-2-linked genetic control of immune responsiveness to ovalbumin and ovomucoid.

Immune responsiveness of inbred mice to low doses of ovalbumin or ovomucoid is under control of single dominant genes closely linked to alleles of the H-2 locus. High responsiveness to ovomucoid is linked with the H-2(a) and H-2(k) alleles, and to ovalbumin with the H-2(b), H-2(d), and H-2(q) alleles.

Immune responses of inbred mice to repeated low doses of antigen: relationship to histocompatibility (H-2) type.

Immunization of inbred strains of mice with repeated minute doses (0.1 to 1.0 microgram) of hapten-protein conjugates demonstrated wide differences in the magnitude of their antibody responses, which were related to the histocompatibility (H-2) type of the strains. Immunization with a single high dose (100 micrograms) of antigen failed to demonstrate these differences.

Ragweed hay fever: genetic control and linkage to HL-A haplotypes.

Clinical ragweed pollenosis (hay fever) and IgE antibody production specific for antigen E (the major purified protein antigen from ragweed pollen extract) correlated closely with HL-A haplotypes in successive generations of seven families. HL-A associated IgE antibody responsiveness was antigen specific and extended also to IgE antibody production. These data indicate an immune response (Ir) gene specific for antigen E necessary but not sufficient for the development of hay fever. This appears to be the first documentation of an Ir gene in man.

The nature of the antigen-antibody complexes initiating the specific wheal-and-flare reaction in sensitized man.

To study the nature of the antigen-antibody complexes which initiate the specific wheal-and-flare (W & F) reaction in sensitized man, a homologous series of bivalent, oligovalent, and multivalent benzylpenicilloyl (BPO) haptens were quantitatively compared for their effectiveness in eliciting W & F in BPO-sensitized human subjects.A series of seven divalent haptens were capable of eliciting W & F, but these generally were not maximally effective elicitors. Of the divalent haptens, those with separation chains of 8 or 13 A were the most effective. Of the oligovalent haptens, maximal effectiveness was attained with BPO(6)-lysine(7), and not with BPO(2)-lysine(3) or BPO(4)-lysine(4), i.e., haptens which are 6- 3- and 4-valent, respectively, from a chemical point of view. However, evidence was obtained from quantitative precipitation experiments which indicated that BPO(6)-lysine(7) functions as a trivalent hapten immunologically, i.e., capable of binding three antibody molecules per mole hapten. Large molecularsized haptens with immunological valences of 7 or 12, but in which the haptenic groups were widely separated, were comparatively ineffective elicitors of W & F. In individual subjects, threshold W & F reactions were obtained with equimolar concentrations of the differently sized divalent, oligovalent, and multivalent haptens. The results demonstrate that for maximally effective elicitation of W & F by haptens, trivalency with optimal distances of separation of haptenic groups is necessary and sufficient. These results indicate the requirement for the formation of a high energy complex of two or three membrane-fixed skin-sensitizing antibody molecules closely bridged together by the elicitor hapten as the initiator of the W & F reaction.

The preparation and determination of structure of benzylpenicilloyl compounds used in skin-testing for penicillin allergy.

The preparation of alpha-D-benzylpenicilloyl-n-propylamine and octa-epsilon-(alpha-D-benzylpenicilloyl)-octa-alpha-L-lysine are described. Their structures were established by chemical and spectroscopic evidence. Proton and carbon-13 nuclear magnetic resonance spectra of these two penicillin derivatives and some related compounds are provided. These compounds are useful in skin testing for penicillin allergy.

Providing service--or aiding and abetting discrimination?

Even though federal antidiscrimination laws do not include third-party liability, a number of states now have statutes containing aiding-and-abetting provisions that may provide a basis for causes of action. For instance, in a recent decision, the Colorado Supreme Court held that a third-party insurance company will be held liable along with the employer for providing health insurance coverage that does not cover normal pregnancy expenses. Similarly, cases involving newspapers have shown that newspaper classifieds may occasion liability solely to the newspaper, and not the advertiser, even absent intent. The author provides a full discussion of such issues as standard of proof and exactly who is liable and offers solutions to these new liability problems.

Effect of multiple injections of antigen on prolonged IgE antibody production in hypersensitive mice.

Multiple injections of ovomucoid were given to mice with ongoing prolonged IgE antibody production to that antigen. Two inbred strains and antigen doses ranging from 0.05 to 5 mug each injection, given intradermally and subcutaneously, were used. Mice treated in this manner showed a marked diminution of the Ig E antibody booster response as compared to controls. This decrease in booster response was antigen-specific. In addition, a protective effect from anaphylaxis was indicated. The mouse model continues to be a valuable tool for studies of certain IgE-mediated diseases.

Unique serum requirement for histamine release from human basophils.

Basophil histamine release in a patient with an IgE-mediated seminal plasma allergy had a requirement for serum. Washed leukocytes, in the absence of serum, released little histamine on challenge with seminal plasma antigen. The addition of serum markedly enhanced the release. However, serum had only a mild effect on ragweed antigen induced histamine release from the same cells of this individual. Serum from normal donors was equally effective as autologous serum. Heating the serum and treating it with mercaptoethanol did not destroy this activity. The serum effect was unique in that another patient with seminal plasma allergy did not demonstrate this phenomenon. It is postulated that the effect of the serum is to stabilize the antibody-antigen step at the basophil surface.

Desensitization of anaphylactic hypersensitivity specific for the penicilloate minor determinant of penicillin and carbenicillin.

A 68-yr-old man with a history of a morbilliform rash caused by intravenous penicillin required carbenicillin (CB) therapy for refractory Serratia marcescens septicemia. Skin testing showed a positive immediate skin test to the penicilloate minor determinant in the presence of negative tests to benzylpenicilloylpolylysine (BPL) and penicillin G (PG), as well as cross-reactivity between the penicilloate derivatives of PG and CB. True densensitization was accomplished by gradual administration of CB intravenously and was accompanied by a diffuse flush reaction. There was specific loss of wheal-and-flare reactivity as well as of specific serum reaginic antibody activity during the procedure, and there was no evidence of activation of serum complement. This case illustrates the usefulness of skin tests in the prediction and management of penicillin allergy and presents data pertaining to immunologic mechanisms involved in true desensitization.

Effects of iodoacetate and fluoride on islate respiration and insulin biosynthesis.

Fluoride and iodoacetate inhibited the oxidation of glucose by islets of Langerhans isolated from the rat pancreas. Fifty % inhibition occurred with either 17 mM fluoride or 0.5 mM iodoacetate. The rate of insulin biosynthesis was more strongly inhibited by these inhibitors, especially fluoride. Fifty % inhibition occurred with approximately 1.5 mM fluoride. At high concentrations of iodoacetate and fluoride, the inhibitory effect on insulin synthesis was not reversed to a significant degree by the addition of pyruvate in the incubation medium. In addition to inhibiting the glycolysis and depriving islets of energy essential for the biosynthesis of insulin, fluoride probably exerts a direct inhibitory influence on the biosynthetic mechanism. A separate experiment with [6-14C]glucose indicated that 0.2 mM iodoacetate does not inhibit glycolysis completely.