Sidney Leskowitz

An hypothesis for the development of atopic allergy in man

Atopic allergy has long been recognized as a disease of immunologic origin. Most immunologists and allergists would now agree that the symptom complex seen in uncomplicated allergic rhinitis and bronchial asthma is in large part attributable to the activity of pharmacologic intermediates either released from mast cells or formed in vivo as a consequence of specific antigen-antibody interactions. These interactions involve a highly specialized and extraordinarily active antibody of a newly defined immunoglobulin class (IgE) (Ishizaka & Ishizaka, 1966,1968; W.H.O., 1968) which has the capacity to sensitize cells for long periods of time for the subsequent triggering action of antigens. Immunoglobulin E is a normal constituent of human serum which is present at 1/40,000th the concentration of immunoglobulin G (Johansson, 1967). Recent studies suggest that IgE may be significantly increased in patients with atopic allergy (Johansson, 1967; Berg & Johannson, 1969; Schwartz & Buckley, 1971a; Kumar, Newcomb & Hornbrook, 1971; Yunginer & Gleich, 1971; HogarthScott et al., 1971) and that IgE levels rise with seasonal allergen exposure. It may be elevated as well in many other diseases, among which are severe liver disease, hypersensitivity aspergillosis, coehac disease, visceral larva migrans, ascariasis, pulmonary haemosiderosis and rare forms of infectious disease (Buckley, Wray & Belmaker, 1971; Heiner & Rose, 1970; Johansson, Mellkin & Vahlquist, 1968). However, it has never been clearly understood why the specific antibodies of this class, which react with air-borne antigens and are responsible for the symptoms of hay fever and asthma, appear in only certain individuals exposed to these antigens. The present article advances a general hypothesis to explain one underlying basic abnormality leading to the development of IgE-mediated human atopic allergy.

Amino acid contribution to hapten specificity in delayed reaction to arsanilic acid conjugates

Abstract Guinea pigs immunized with azobenzenearsonate (ABA) conjugates of N-acetyltyrosine, and N-acetylhistidine develop a delayed sensitivity that can be elicited by ABA groups attached to tyrosine or histidine containing polymers or proteins. There is some suggestion of an increased reactivity when the homologous amino acid is the major component of the eliciting carrier suggesting a contribution by the amino acid residue to the overall reactivity. Comparable reactions elicited by conjugates of D - or L -tyrosine present in L -amino acid carriers is indicative of the minor contribution by the α-amino acid portion of the ligand to the immunochemical specificity of the reaction.

Structural requirements for in vivo and in vitro immunogenicity in hapten-specific delayed hypersensitivity

Abstract Structural changes in the α-amino acid portion of the azobenzenearsonate conjugate of tyrosine produced marked and parallel changes in immunogenicity measured in vivo by ability to immunize guinea pigs and in vitro by ability to stimulate sensitized lymphocytes. Progressive loss in immunogenicity was produced by removal of the carboxyl group, the amino group, or both. Studies with carrageenan indicate that reaction of sensitized lymphocytes with these small conjugates is macrophage-dependent and suggest that immunogenicity requires the presence of an amino or carboxyl function to serve as the handle for some essential processing event occurring on the macrophage.

A gene locus affecting tolerance to BGG in mice

Abstract A genetic analysis was made of the ease of tolerance induction to bovine γ-globulin (BGG) in DBA/2, BALB/c, F1 and backcross generation mice. Like parental DBA/2 mice, the F1 generation of BALB/c × DBA/2 becomes tolerant when treated with 2 mg BGG. A backcross of this F1 to DBA/2 parents produced mice that all became tolerant to this dose of BGG. A backcross of F1 mice to BALB/c parents produced 50% offspring tolerized by the same dose of BGG and 50% resistant to tolerance induction. The data suggest a single autosomal locus affecting tolerance induction. Data presented elsewhere suggest that the locus affects macrophage function. We propose that this locus be called tolerance (symbol Tol-l) and the two alleles be (Tol-la (DBA/2 type) and Tol-lb (BALB/c type) with Tol-la being dominant.

The Cutaneous Basophil Response to Particulate Antigens

Summary Cutaneous basophil hypersensitivity was elicited with particulate antigens consisting of egg albumin coupled to formalinized sheep red blood cells and sheep red blood cells themselves. By observation of these visible markers, it could be seen that basophils appeared predominantly in the superficial dermis while the antigen was engulfed by macrophages in the deeper dermis. The absence of contact between basophils and particulate antigen suggests that they are not primarily phagocytic in function and appear in response to chemotactic substances released from other cells.

Structural requirements for T-cell recognition of tyrosine-azobenzene-arsonate in the rat and mouse

The ability of various analogues of tyrosine-azobenzenearsonate (ABA-tyr) to elicit responses in CBA mice and Lewis rats was studied in order to determine the essential features for association with Ia molecules on accessory cells and T-cell recognition. Exquisite specificity for the AsO3H2 group was found in the rat while substantial cross-reactivity was seen in the mouse when other acidic but not neutral groups were substituted. The azo linkage was found to be essential for specificity as was the phenolic ring of tyrosine. Reaction was found to be less specific for changes in the COOH group than the NH2 group of the tyrosine moiety indicating the associations of this end with Ia molecules was dependant on both charge and hydrophilic interactions and differed also between rat and mouse cells. It was concluded that an antigens reaction with T-cells is affected by an epitope, determining specificity, an agretope, determining association with an appropriate Ia molecule, and an ability to be processed down to these minimal essential structures.

The azobenzenearsonate conjugate of poly-glutamic-lysine-tyrosine will induce tyrosine-azobenzenearsonate-specific T-cell responses and clones in nonresponder mice☆

Mice of the H-2b haplotype are low responders to ABA-tyr. However, when they were immunized with ABA coupled to poly-GLT15 for which they are nonresponders, they developed strong proliferative responses to ABA-tyr in draining lymph node cells. Clones derived from these cells were highly reactive to ABA-tyr although the original mice were not. No evidence was found to indicate that suppression played a role in the failure to respond to ABA-tyr. Characterization of two clones showed an absolute specificity for the arsonic acid group and the Azo linkage. Alterations in the terminal amino acid residues produced varying changes in reactivity which could not be ascribed unequivocally to an effect on epitope or agretope.

In vitro correlates of hapten-specific delayed hypersensitivity☆

Abstract Azobenzenearsonate conjugates of l and d -amino acid polymers were studied in respect to their ability to stimulate lymphocytes from guinea pigs sensitized to the hapten. Using the two in vitro techniques of thymidine incorporation and inhibition of macrophage migration, it was shown that only conjugates of the l -amino acid polymers were active. The results confirm previous in vivo studies and suggest as one possibility that a preliminary processing event by macrophages may be obligatory for all associated phenomena of hapten-specific delayed hypersensitivity.

Strain differences in tolerance induction to human γ-globulin subclasses: Dependence on macrophages

Abstract BALB/c and DBA/2 mice differ with respect to ease of tolerance induction with HGG, BALB/c mice being the resistant strain. When tested for susceptibility to tolerance induction with individual IgG subclasses, both strains were easily rendered unresponsive with IgG 1 and IgG 2 and less so with IgG 4 . A strain difference appeared with IgG 3 , where only BALB/c mice showed complete resistance to tolerance induction. Mixtures of the IgG subclasses Showed that IgG 1 and IgG 2 accounted for most of the tolerance to whole HGG seen in both strains, while addition of IgG 3 to the mixture made DBA/2 completely tolerant but reversed the trend toward tolerance in the BALB/c mice. By rosette assay it was found that BALB/c macrophages had receptors for IgG 3 (and to a lesser extent for IgG 4 ). These results are consistent with the hypothesis that resistance to tolerance induction with HGG is dependent on the presence of a receptor on the macrophage for a minor IgG subclass.

The ability of hapten-conjugated cells to induce cell-mediated cytotoxicity is affected by the mode of hapten linkage

Abstract Spleen cells from C57 B 1 6 mice were modified with varying concentrations of several haptens coupled in different ways, then assayed for their ability to induce a cytotoxic response against hapten-modified target cells when cocultured with syngeneic spleen cells. Haptens such as TNBS, DNBS, Fl-NCS, and AB-NCS which couple via the ϵ-amino groups of lysine were all capable of generating high levels of cytotoxicity when tested against hapten-coupled syngeneic tumor. One hapten, DNBM, which coupled via -COOH groups was effective in generating cell-mediated cytotoxicity. By contrast, similar haptens such as ABA and DNBA which couple as diazonium salts via tyrosine and histidine groups were not found to generate cytotoxic responses over wide ranges of concentrations. Possible explanations are discussed.