Howard M. Johnson

Interferon inhibition of the primary in vitro antibody response to a thymus-independent antigen

Abstract Partially purified and crude mouse L cell interferon preparations inhibited the in vitro plaque-forming cell (PFC) response of mouse C57B1/6 spleen cells to the T-cell independent lipopolysaccharide antigen of Escherichia coli 0127. PFC responses of 5-day cultures were inhibited approximately 70–90% by 100–200 NIH reference units of interferon/culture. A similar inhibitory effect was obtained with spleen cells from athymic (nude) mice homozygous for the nu/nu allele. Spleen cultures depleted of adherent cells were also inhibited in their anti-0127 PFC response by interferon. Interferon, then, appears capable of inhibiting the PFC response to E. coli 0127 via direct action on B cells. Heating experiments along with the use of interferon preparations of different specific activities suggest that the inhibition was due to the interferon in the preparations.

Inhibitory effect of synthetic polyribonucleotides on the primary in vitro immune response.

Summary The synthetic double-stranded polyribonucleotides, poly (rA):poly (rU) and poly (rl):poly (rC), were shown to be potent inhibitors of the in vitro plaque-forming cell (PFC) response to a thymus-dependent (SRBC) and thymus-independent (E. coli 0127 LPS) antigen in mouse C57BL/6 spleen cell cultures. The same polynucleotides had no effect on the PFC response of nude (athymic) mouse spleen cells to E. coli 0127 LPS, suggesting that functional T lymphocytes are necessary for the inhibitory effect. Enhancement effects were modest and inconsistent in the cultures. Poly (rA) and poly (rU) were ineffective as inhibitors. The data indirectly suggest that the inhibition may be due to the early production of interferon by functional T lymphocytes.

Inverse relationship between immune interferon induction and mitogen effects on the maturation of the primary antibody response

Staphylococcal enterotoxin A (SEA) is both a potent inducer of immune interferon (IFN-gamma) and suppressor of the murine primary in vitro plaque-forming cell (PFC) response to the thymus-dependent antigen sheep erythrocytes (SRBC). Staphylococcal enterotoxin D (SED), which is structurally related to but antigenically different from SEA, is, in contrast, a poor inducer of IFN-gamma but a potent accelerator of PFC response maturation. SED added to cultures from 0.01 to 1.0 microgram/ml induced profound enhancement of the PFC response on day 3 of culture. SEA caused no acceleration of PFC maturation and suppressed the day 5 PFC response over an equivalent dose range. At the same concentration, SED only poorly induced IFN-gamma, while SEA was a potent IFN-gamma inducer. SED induced DNA synthesis in C57Bl/6 spleen cell cultures but not athymic nude (Nu/Nu) spleen cells, suggesting that SED is a T-cell mitogen. SED was most effective in accelerating PFC maturation and increasing the magnitude of the PFC response when added to cultures at the time of SRBC addition. SED was an equally effective adjuvant for SRBC of both high and low immunogenicity. Thus, two mitogens that are structurally related have diametrically opposite effects on the primary in vitro thymus-dependent antibody response that maybe related to their relative abilities to induce IFN-gamma. These effects could be related to differential activation of T-cell subpopulations.

Tartrazine: Quantitative passive hemagglutination studies on a food-borne allergen of small molecular weight☆

Abstract The quantitative hemagglutination migration procedure was adapted for the measurement of the food-borne allergen, tartrazine (FD&C Yellow No. 5). Tartrazine and sulfanilic acid are structurally and haptenically related, so the migration system was developed with azo sulfanilate coupled to sheep red blood cells and with antisera to azo sulfanilate. Tartrazine was a more effective inhibitor of the system than was sulfanilic acid. The system was most appropriately represented by the empirical mathematical model Log 10 Y = β 0 + β 1 X + ϵ , where Y = mm cell migration, X = serum concentration, β 0 and β 1 = regression coefficients, and ϵ = the residual error.

Haptenic relationships of p-azobenzenesulfonate and some structurally-related food dyes.

Abstract Tartrazine, an FD&C approved azo dye, has been implicated in food and drug-borne allergic reactions. The dye was coupled to bovine serum albumin (BSA) by a water-soluble carbodiimide and by bis-diazotized benzidine. Both conjugates, as immunogens in rabbits, elicited the production of antibodies specific for tartrazine. The antibodies cross-reacted with other FD&C dyes, the extent of the reaction depending on the structural relationship of these dyes to tartrazine. Tartrazine is structurally and haptenically related to p -azobenzenesulfonate. Antibodies to tartrazine, however, are serologically unique. The tartrazine-BSA conjugates should be useful in skin-test studies for tartrazine allergies and in immunoassays for the dye.

Serological Specificity of Types A and B Botulinal Toxins and Antitoxins

Summary Rabbit, National Communicable Disease Center (NCDC) equine, and International Standard antitoxins to types A and B botulinal toxins were compared by passive hemagglutination (HA), hemagglutination inhibition (HI), and gel-diffusion. The HA reactions in general were quite specific, although cross-reactions were observed. The extent of cross-reaction was greater with B antitoxins and A botulinal toxoid-sensitized red blood cells. The different antitoxins behaved similarly in HI and gel-diffusions, though the reactions of the NCDC and International antitoxins were weaker than those of rabbit antitoxins in gel-diffusions. Hemagglutination inhibition and gel-diffusion reactions with toxic cultures suggested that the in vitro specificity of the A toxin-antitoxin did not involve neutralizing antibodies. Hemagglutination inhibitions and gel-diffusions with B toxins did not resolve the question of the involvement of neutralizing antibodies in in vitro specificity, since fairly toxic cultures inhibited HA and formed bands believed to be associated with type specificity, whereas a virtually non-toxic B culture neither inhibited HA nor formed a line of identity with the type specific systems in gel-diffusion.

Tartrazine: Solid-Phase Radioimmunoassay Studies of an Azo Dye Implicated in Allergic Reactions (Azo Dyes and Allergy)

Summary A solid-phase radioimmunoassay procedure was adapted for the haptenic study of tartrazine, an azo dye implicated in various forms of allergy. Further, the haptenic relationship of tartrazine and aspirin was investigated, since sensitivity of individuals to the two substances is often clinically associated. The specificity of antibody to tartrazine was directed strongly toward a pyrazolone intermediate of the molecule, 1-(4-sulfophenyl)-3-carboxy-5-hydroxy-pyrazole. Aspirin did not cross-react with anti-tartrazine, suggesting that the clinical association of aspirin and tartrazine sensitivity in patients is a nonimmunological phenomenon.

Antibody Response and Ribonuclease Activity in the Sera of Calves Passively Immunized to Bovine Pancreatic Ribonuclease

Calves passively immunized with rabbit anti-bovine pancreatic ribonuclease serum were examined for their antibody response to egg albumin, rabbit γ-globulin, and rabbit serum albumin. An enhanced immu

Serological Specificity of Type E Botulinal Toxin

Summary A purified preparation of type E botulinal toxin possessed serological properties distinct from those of crude preparations. In vitro studies suggested that the specific toxicity of a toxin is not necessarily a true reflection of its relative concentration, and that some type E botulinal toxin molecules exist in a nontoxic or less toxic form than others. Although specific toxicities may be misleading in predicting the relative in vitro behavior of E toxins, it would be expected that purified Sakaguchi toxin would be a better inhibitor in HI than partially purified toxins on a weight basis with purified Sakaguchi SRBC antigen. The purified Sakaguchi toxin appears to be suitable for in vitro investigations and immunoassays.