Cellular events in the IgE antibody response

Deficient concanavalin-A-induced suppressor-cell activity in patients with bronchial asthma, allergic rhinitis and atopic dermatitis

Concanavalin-A (Con-A)-induced suppressor activity against the proliferative response of autologous lymphocytes to phytohaemagglutinin (PHA) was examined in the peripheral-blood lymphocytes from fourteen patients with bronchial asthma, ten patients with allergic rhinitis and eleven patients with atopic dermatitis and compared with eleven simultaneously studied healthy normals. Eight of fourteen patients (57%) with bronchial asthma, eight of ten patients (80%) with allergic rhinitis and five of eleven patients (45%) with atopic dermatitis demonstrated deficient Con-A-induced suppressor function. Abnormal suppressor-cell functions could play an important role in the pathogenesis of atopic states.

The cellular IgE response of rodents to infection with Nippostrongylus brasiliensis, Trichinella spiralis and Schistosoma mansoni

The IgE response at the cellular level to helminthic infection was studied in BALB/c mice inoculated with the infective larvae of the nematodes Nippostrongylus brasiliensis (Nb) or Trichinella spiralis (Ts) or with the cercariae of the trematode Schistosoma mansoni (Sm). Changes in mesenteric lymph node (MLN) cell number, cell surface(s) IgD, IgM, IgE and Thy-1.2 and intracytoplasmic (c) IgE were recorded. In addition, a comparable study was conducted in rats infected with Nb. At 11 days after infection (DAI) of mice with Nb or Ts, or rats with Nb, there was a 3-fold increase in cell number in the MNL. There was a marked increase in cell number in the MLN of mice infected with Sm at 7 weeks after infection (WAI) and in the spleens of Sm-infected mice at 4 WAI. The percentage of cIgE+ cells increased from undetectable levels in uninfected mice and rats to as high as 0.5-1.3% in the MLN of helminth-infected mice and rats. Analysis of cell surface molecules with a fluorescence activated cell sorter (FACS) showed that Nb and Ts infection induced slight increases in the percentages of B cells and slight decreases in the percentage of T cells. More remarkably, the percentage of sIgE+ cells in the MLN of both Nb- and Ts-infected mice rose from undetectable levels in uninfected mice to 33 and 27%, respectively, at 15 DAI. This rise was stimulated in Ts-infected mice predominantly by adult Ts. In the MLN of Nb-infected rats, the percentage of cells that were sIgE+ was greater than 50% at 15 DAI. However, there was no detectable increase in sIgE+ cells in the spleen and MLN of Sm-infected mice until 5 WAI; peak levels of approximately 20% sIgE+ cells were reached at 8 WAI. Treatment of MLN cells from mice infected with Nb, Ts or Sm and rats infected with Nb, with pH 4.0 acetate buffer for 1 min (acid treatment) removed all detectable sIgE from greater than 90% of the sIgE+ cells, but did not remove sIgD or sIgM from cells with these surface isotypes. The effect of acid treatment on sIgE was similar even after a secondary infection of mice or rats with nematode larvae. These data show that helminthic infection, in general, is a potent stimulator of the IgE system at the cellular level and that almost all of the sIgE+ cells that arise have acquired cytophilic sIgE.

Suppression of IgE responses in inbred rats by repeated respiratory tract exposure to antigen: responder phenotype influences isotype specificity of induced tolerance

Repeated exposure of rats to an aerosol of ovalbumin (OVA) induced tolerance to subsequent parenteral challenge with the same antigen. In the low-IgE responder WAG strain, responses in both the IgE and IgG classes were affected, whereas rats of the moderate (Lou/M) and high-IgE responder BN strain developed high titers of anti-OVA IgG in serum during exposure with concomitant tolerance in the IgE class. Repeated parenteral challenge, however, failed to elicit significant secondary anti-OVA IgG responses in the Lou/M and BN strains, suggesting that the isotype specificity of induced tolerance in these strains was not absolute. Spleen and respiratory tract lymph node cells, but not serum from aerosol-exposed BN rats, were capable of transferring IgE isotype- and antigen-specific tolerance. Dose response experiments demonstrated that the low-IgE responder WAG strain was exquisitely sensitive to tolerance induction in response to antigen inhalation, being susceptible to dosages in the nanogram range; at least 1000 times more antigen was required in the high-IgE responder BN to induce comparable tolerance in the IgE class. It was also apparent that the IgE isotype was more readily suppressed than the IgG isotype in both high- and low-IgE responder strains.

IgE class-restricted tolerance induced by neonatal administration of soluble or cell-bound IgE. Cellular mechanisms

Certain aspects of the phenomenon of IgE class-restricted tolerance induced in mice by neonatal treatment with monoclonal IgE, either in soluble form or coupled to syngeneic spleen cells, were examined. The present studies document that this tolerance results from exposure to IgE molecules, irrespective of their antigen specificity, and the resulting effects are polyclonal in nature since IgE responses directed against antigenic determinants unrelated to the tolerance-inducing IgE molecules are affected. Moreover, such findings indicate that the molecular subregion(s) responsible for inducing IgE class-restricted tolerance resides in the epsilon heavy chain constant region domain(s) of IgE. When soluble IgE is employed, tolerance induction results from neonatal treatment with doses as low as 2.5 micrograms per injection per mouse; cell-bound IgE is considerably more potent, in terms of total dose required, since tolerance results from treatment with as few as 1 X 10(6) cells per injection (per mouse), equivalent to an absolute quantity of 0.2 ng of IgE per injection. This long-term class-specific tolerance appears to be a unique feature of the IgE antibody system, since treatment of mice with monoclonal antibodies of the IgA, IgG1, or IgG2b isotypes, either in soluble or cell-bound form, does not perturb antibody responses of their corresponding isotypes or in the IgE class. By analyzing the lymphoid cells of IgE-tolerant mice after they reached adulthood, the following observations were made: (a) lymphoid cells from such tolerant mice fail to develop FcR epsilon + cells upon in vitro stimulation with IgE, as is characteristically observed with lymphoid cells from nontolerant mice; and (b) mice rendered tolerant by neonatal treatment with soluble IgE possess IgE class-restricted suppressor T cells, demonstrable in adoptive transfer experiments, whereas no such suppressor cells are evident in mice in which cell-bound IgE was used for neonatal treatment. The latter observations could mean that two different mechanisms underlie the IgE class-restricted tolerance, or both mechanisms operate coordinately to varying degrees depending upon which regimen is used for tolerance induction, as discussed herein.

Immunoglobulin isotype distribution of malaria-specific antibodies produced during infection with Plasmodium chabaudi adami and Plasmodium yoelii

The antibody response of mice to Plasmodium chabaudi adami and Plasmodium yoelii has been compared using a solid phase isotype-specific radioimmunoassay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Serological cross-reactivity between these parasites was substantial. Studies using a radioimmunoassay detecting all classes of malaria-specific antibody demonstrated that during the early part of infection it was not possible to distinguish between homologous and heterologous reactions. Immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that 50% or more of the protein antigens detected were apparently shared by both parasites although the intensity of bands was always greater with homologous reactions. However, the distribution of isotypes in the antibody (Ab) response differed in the two infections. P. chabaudi infections were characterized by a predominant and persistent IgM response, moderate IgG2 and IgG3 and little significant IgG1 response during a primary infection. By contrast, IgM antibodies were transient in P. yoelii infection, IgG2 was the predominant isotype, and both IgG1 and IgG3 antibodies were present during a primary infection. These differences in isotypes were also detected when sera were tested on the heterologous antigen extracts suggesting that antigens shared by P. chabaudi and P. yoelii do not necessarily induce similar antibody responses in the two infections.

Receptor-specific mediation by immunoglobulin E of antigen-induced contraction of tracheal and lung parenchymal strips isolated from the guinea pig

The guinea pig is much like humans in the cells and mediators involved in immediate hypersensitivity reactions. However, the major anaphylactic antibody in this species is IgG1, not IgE. Recently, we have been successful in producing IgE antibody in guinea pigs. The current study examined whether guinea pig IgE antibody could mediate pulmonary smooth muscle contraction. IgE antibody to picryl and oxazolone determinants was induced by immunizing Hartley strain guinea pigs pretreated with cyclophosphamide. Hyperimmune serum from these animals was passed through a heavy chain-specific anti-IgG1 affinity column. The presence of IgE anti-hapten antibody in the filtrate fraction was verified by passive cutaneous anaphylaxis (PCA) testing with a 7-d period of local passive sensitization and by heat lability (56 degrees C X 4 h) of PCA activity. This IgE-rich fraction, and purified IgG1 anti-hapten antibody were transferred to normal guinea pigs. Both fractions sensitized trachea and pulmonary parenchyma for antigen-induced smooth muscle contraction. The IgG1-mediated antigen-induced contractile response was not affected by heat (56 degrees C X 4 h) and was inhibited in a dose-dependent fashion by IgG1 blocking antibody (anti-OA). The IgE-mediated antigen-induced contractile response was significantly decreased by heat and was not affected by the anti-OA blocking antibody even at a concentration of 100 mg/kg. Thus, two antigen-specific factors in guinea pig serum can mediate antigen-induced pulmonary smooth muscle contraction: IgG1 and IgE antibodies. Our data also suggests that these antibodies mediate the contractile response through separate receptors. The finding that guinea pig IgE can mediate pulmonary smooth muscle contraction suggests this species can be a model for IgE-mediated events in the lung.

Correction of an in vitro immunoregulatory defect in atopic subjects by the immunostimulating drug fanetizole mesylate (CP-48,810)

The effect of Fanetizole mesylate or CP-48,810, a new immunostimulating drug, on suppressor cell function and IgE synthesis in vitro was evaluated in atopic patients with allergic rhinitis and/or asthma and eczema. In the absence of the drug, histamine (10(-3)M) stimulated blood mononuclear cells from 23 atopic patients suppressed concanavalin A-induced lymphocyte proliferation by a mean (+/- S.E.M.) of 9.3% +/- 3.5 (compared to 25.1% +/- 2.7 for histamine stimulated mononuclear cells from non-atopic controls). The addition of the drug (2.5 X 10(-4)M) in vitro significantly increased histamine suppressor cell activity of atopic patients to 26.6% +/- 3.9 (compared to 24.7% +/- 2.8 for control cells in the presence of the drug). In order to determine a possible mechanism through which CP-48,810 might enhance histamine-induced suppressor activity, we examined the effects of the drug on the production of histamine-induced suppressor factor (HSF) by lymphocytes and the production of prostaglandin E2 by blood monocytes in the presence of HSF. Supernatants generated from histamine (10(-4)M) stimulated patient lymphocytes caused a 9.0% +/- 1.8 suppression of concanavalin A-induced lymphocyte proliferation (compared to 25.0% +/- 3.1 caused by supernatants from normal subjects). If the drug (2.5 X 10(-4)M) was added at the beginning of culture, HSF activity in supernatants derived from atopic lymphocytes increased significantly to 20.2% +/- 1.8 (compared to 23.3% +/- 3.9 for drug treated control supernatants). Prostaglandin E2 production by atopic monocytes exposed to HSF was less than that of normal monocytes in the absence of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

The inheritance of immunoglobulin E: genetic linkage analysis

Linkage analyses between 21 genetic markers including HLA-A, B, and the postulated locus for determining total serum IgE levels were done to try to clarify the inheritance of total IgE levels and to map the locus. A total of 316 individuals from five Mormon kindreds were studied, and data from an additional 204 Amish individuals from 11 families were analyzed for possible HLA linkage. Segregation analyses of both data sets did not give clear definition of the mode of inheritance of total IgE levels, but purely environmental models were rejected. Linkage analyses gave significant evidence against HLA linkage with the codominant, recessive, or dominant model of inheritance for total IgE levels. No significant evidence for linkage with any of the genetic markers was obtained. Since total serum IgE levels are correlated with allergies, understanding the genetics of total IgE levels is important to understanding the genetics of allergic disease in man.

Penicillin-induced anaphylaxis in a patient under hypotensive anesthesia

Elective use of penicillin during hypotensive anesthesia for orthognathic surgery induced a nearly fatal anaphylactic reaction. The first symptom of anaphylaxis was increased inspiratory resistance to mechanical ventilation, followed by severe hypotension. The therapeutic management of anaphylaxis is discussed. Patients susceptible to reactions from the administration of B-lactam antibiotics can be identified through skin tests. Patients reactive to such antibiotics should be treated with alternate antibiotics or they should be desensitized prior to receiving penicillin.

IgE responses of malnourished mice: immunogenic and tolerogenic effects of low-grade antigenic stimulation

Mice maintained on protein-restricted diets after weaning manifested normal IgE (and IgG) responses following intraperitoneal immunization under conditions of maximal antigenic stimulation, i.e., antigen adsorbed to adjuvant. However, antigenic challenge at levels closer to the stimulation threshold, employing soluble antigen alone, revealed marked differences between the immune competence of normal and malnourished animals. Diminished IgE responsiveness to soluble antigen in the malnourished mice was accompanied by enhanced susceptibility to the induction of antigen-specific tolerance associated with the appearance of suppressor T cells in the spleen. It is argued that enhanced susceptibility to suppressor T-cell induction under conditions of minimal antigenic stimulation may underlie the diminished IgE responsiveness of the malnourished animals.

Evidence for a malignant proliferation of IgE-class specific helper T cells in a patient with Sézary syndrome exhibiting massive hyperimmunoglobulinemia E

Peripheral blood mononuclear cells (PBM) from a patient with Sézary syndrome exhibiting massive hyperimmunoglobulinemia E were examined in vitro. The patient's PBM and B cells (Bp) but not normal individuals' PBM and B cells (Bn) produced spontaneously large amounts of IgE. The addition of pokeweed mitogen (PWM) did not affect IgE production by both the patient's and normal individuals' PBM. The IgE production by PWM-stimulated Bp was depressed when cocultured with normal T cells but not depressed with the patient's T cells (Tp). When Tp were cocultured with Bn, significantly larger than expected quantities of IgE were produced. Ig assay of the same supernates showed that Tp had significantly less helper activities for IgG, IgA, and IgM production. Almost all Tp possessed the Leu3a and Leu3b antigens which are expressed on the helper/inducer T cell subset. These results indicate that the neoplastic cells in this patient originated from a subset of T cells programmed not for IgG, IgA, and IgM, but for IgE synthesis.

Autologous mixed lymphocyte reaction in man. VII. Autologous mixed lymphocyte reaction in patients with bronchial asthma, allergic rhinitis and atopic dermatitis

The proliferative response of T lymphocyte cultured with autologous non-T lymphocyte is known as the autologous mixed lymphocyte reaction (AMLR). In AMLR, both helper and suppressor functions are generated. In this investigation we have examined T cell proliferative responses in AMLR in 12 patients with bronchial asthma, 10 patients with allergic rhinitis, and 10 patients with atopic dermatitis and compared that with simultaneously studied healthy controls. Our data show that the T cell proliferation in AMLR in patients with bronchial asthma is significantly higher than that of healthy normals. However, AMLR response in patients with allergic rhinitis or atopic dermatitis is comparable to controls. Mechanisms for increased AMLR in patients with bronchial asthma are discussed.

IgE class-restricted tolerance induced by neonatal administration of soluble or cell-bound IgE

Induction of IgE class-restricted tolerance was studied in high IgE-responder (BALB/c X SJL)F1 mice, of which the parental BALB/c and SJL mice are high and low IgE-responder mice, respectively. 2,4-Dinitrophenyl (DNP)-specific monoclonal IgE was administered to (BALB/c X SJL)F1 mice neonatally in two forms: soluble IgE at 250 micrograms per injection, or 10-100 ng of IgE coupled to 25-50 X 10(6) syngeneic splenocytes by binding to the chemically reactive hapten trinitrobenzene sulfonate (TNBS) or directly conjugated via a heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). Polyclonal induction of IgE class-restricted tolerance was observed in (BALB/c X SJL)F1 mice, neonatally treated with soluble IgE or IgE-conjugated syngeneic splenocytes. Thus these mice failed to mount IgE antibody responses to either keyhole limpet hemocyanin or ovalbumin challenge, assessed by the passive cutaneous anaphylaxis reaction. The IgG antibody responses to these same antigens, however, were not affected by this treatment. The IgE class-restricted tolerance induced by both forms of IgE persisted up to at least 6 mo with repeated antigenic challenges. IgE coupled to syngeneic cells by TNBS or the SPDP method induced prolonged tolerance up to 9 mo. The induction of polyclonal IgE class-restricted tolerance was achieved only by monoclonal IgE, whereas DNP-specific monoclonal IgG1 plus IgG2b coupled to syngeneic splenocytes by the SPDP method failed to modulate either IgE or IgG antibody responses. In contrast, (BALB/c X A/J)F1 mice, of which both parental strains are high IgE responders, developed IgE class-restricted tolerance upon repeated neonatal injection of soluble IgE, but not IgE-conjugated syngeneic splenocytes, indicating that gene products of the low IgE-responder mice contributed to the effective presentation and/or recognition of epsilon heavy chain of the IgE molecules. Taken collectively, these results demonstrated that non-antigen-specific, isotype-restricted tolerance can be induced in the IgE antibody system. The differential induction of IgE class-restricted tolerance by different forms of tolerogen in the strains studied perhaps distinguishes two underlying cellular mechanisms for IgE class-restricted tolerance.

Regulation of immunoglobulin E antibody synthesis in man by antiidiotypic antibodies

The effect of rabbit antiidiotypic antibody raised against human IgG F(ab')2 anti-tetanus toxoid (TT) antibodies on the in vitro synthesis of TT-specific IgE antibody by peripheral blood lymphocytes (PBL) was examined in three subjects. Two of these subjects were allergic twins whose sera persistently contained IgE anti-TT antibodies. The third subject was a nonallergic individual who had a slightly elevated serum IgE (250 IU/ml) and who exhibited a transient serum IgE anti-TT response after booster immunization with TT. After appropriate absorptions rabbit anti-idiotype (Id) IgG reacted with anti-TT antibodies of both IgG and IgE isotypes in an idiotype- and antigen-specific fashion. PBL and B cells from the three subjects studied spontaneously synthesized TT-specific IgE in culture. In all three cases, adsorption of B cells over plastic plates coated with anti-Id before culture specifically decreased the synthesis of IgE antibodies to TT but did not affect the synthesis of IgE antibodies to ragweed antigen E by PBL from the twin allergic subjects. Addition of anti-Id to cultures of PBL from all three subjects specifically inhibited the synthesis of TT-specific IgE. This inhibition was shown to be exerted both at the level of the B cells and via the generation of antigen-specific suppressor T cells from radiosensitive precursors. The present results indicate that the synthesis of antigen-specific IgE in man is subject to regulation by idiotypic anti-idiotypic interactions that can involve both B and T lymphocytes.

Total serum IgE in uremia and after renal transplantation

Uremic patients on maintenance hemodialysis, but without clinical evidence of atopy or diabetes mellitus, had serum levels of total IgE significantly lower than in healthy controls matched for age and sex. Patients with uremia due to diabetic nephropathy had higher IgE levels than the reference group. No correlation was found between total IgE levels and length of dialysis treatment. After renal transplantation, the IgE levels decreased on average to 31% of the pretransplant values over a 60-day observation period. Bacterial or viral infections or episodes of kidney rejection had no apparent influence on the IgE synthesis in the patients with transplant. No correlation was detectable between pretransplant IgE levels and six-month survival of the kidney graft. The low IgE concentrations in uremia are suggested to reflect altered T-cell regulation of the IgE production. The raised IgE levels in diabetic patients could not be explained by specific reagins against insulin, but may have reflected an influence of abnormal carbohydrate metabolism on IgE synthesis. The fall in IgE levels following transplantation is proposed to be attributable to the combined corticosteroid-azathioprine treatment.

T cell-derived B cell differentiation factor(s). Effect on the isotype switch of murine B cells

Culturing BALB/c B cells for 6 d at low cell density in the presence of lipopolysaccharide (LPS) results in the appearance of a small number of IgG plaque-forming cells (PFC). The addition of supernatants from concanavalin A (Con A)-induced alloreactive (AKR anti-B6) long-term T cell lines (PK 7.1.1a and 7.1.2) or a T cell hybridoma (FS7-6.18) to LPS-treated B cells resulted in a marked increase in IgG PFC (3--10-fold higher than in cultures treated with LPS alone. The number of induced IgG PFC was not affected by removing IgG-bearing cells on the fluorescence-activated cell sorter, indicating that T cell-derived B cell differentiation factor enhances isotype switching of sIgG- cells, rather than selecting and expanding pre-existing subpopulations of sIgG+ cells. We also investigated the subclass of IgG produced in the absence or presence of T cell factors and found that PK 7.1.1a, PK 7.1.2, and FS7-6.18 supernatants selectively increased IgG1 production. Several other T cell supernatants containing a variety of lymphokines had no effect, suggesting that PK 7.1.1a, PK 7.1.2, and FS7-6.18 lines produce factor(s) that can specifically enhance the recovery of IgG secreting cells in culture in the presence of LPS. These factors, which we have termed B cell differentiation factors, are different from interleukin 1, interleukin 2, T cell-replacing factor, colony-stimulating factor, macrophage-activating factor, and immune interferon. Our results suggest that soluble factors produced by T cell lines and hybridomas can markedly influence both the class and subclass of Ig produced by B cells.

Abnormal histamine-induced suppressor-cell function in atopic subjects

To detect a potential defect in immunoregulatory function in atopic subjects, we studied histamine-induced suppressor-T-cell activity and histamine Type 1 and Type 2 receptors on T cells. Peripheral-blood mononuclear cells from 16 atopic subjects generated less histamine-induced suppressor activity than did those from 20 nonatopic normal controls (P less than 0.005). The percentage of T lymphocytes bearing histamine Type 2 receptors was lower in the atopic group than in the control group (P less than 0.001), but the percentage of cells with Type 1 receptors was the same in both groups. In the atopic subjects, the functional suppressor-cell abnormality positively correlated with the decreased phenotypic expression of histamine Type 2 receptors. No abnormality in concanavalin A-induced suppressor activity was detected in these subjects. Nonatopic control subjects with systemic mastocytosis had normal functional and phenotypic data, suggesting that chronic activation of atopic T cells in vivo by circulating histamine does not explain the abnormal histamine-induced suppressor response.

Nonspecific suppression of initiation of memory cells in Toxoplasma gondii-infected mice

The effect of Toxoplasma infection on initiation and expression of memory cells to dinitrophenol (DNP)-conjugated protein antigens in humoral immune responses was studied in mice. Marked suppression in the initiation of memory cells to DNP-conjugated keyhole limpet hemocyanin occurred in the acute phase of infection. However, once the memory cells were induced before infection, expression of the memory cells was not affected. Moreover, the suppression of priming occurred on both T and B cells. The suppressive effect was observed in all immunoglobulin classes tested, i.e., immunoglobulin M (IgM), IgG1, IgG2, and IgE, regardless of the four kinds of DNP-conjugated protein antigens. This nonspecific suppression could be induced only by living toxoplasmas, by either the peroral or parenteral route, but not by lysed organisms. A transfer of normal spleen cells could not restore the ability of infected mice to initiate memory cells. Furthermore, the suppressive effect of the infected mice was not removed by 400 R of gamma-irradiation. These results suggested that irradiation-resistant suppressor cells cause nonspecific suppression of the initiation of memory cells in Toxoplasma-infected mice.

Nonspecific suppression of primary antibody responses and presence of plastic-adherent suppressor cells in Toxoplasma gondii-infected mice

The effect of Toxoplasma infection on primary antibody responses to both T-dependent and T-independent antigens was examined in mice. Drastic suppression of primary responses to sheep erythrocytes (SRBC) occurred when mice were immunized 7 days after infection. The suppression was observed in both 2-mercaptoethanol-sensitive and -resistant hemagglutinin responses. Anti-dinitrophenol (DNP) immunoglobulin E and G1 responses to DNP-conjugated keyhole limpet hemocyanin were also suppressed by infection. It was suggested that the suppressive effect is nonspecific for the antigens and immunoglobulin classes produced. Anti-DNP responses to DNP-Ficoll, a T-independent antigen, were suppressed by infection, but the suppressive effect was weaker than that on the responses to SRBC. This suggests that both T and B cells are suppressed by infection. In vitro responses of infected mouse spleen cells to SRBC and DNP-Ficoll confirmed the results of in vivo experiments. In addition, the presence of plastic-adherent suppressor cells was demonstrated in the spleen cells of infected mice, which suppressed the ability of normal mouse spleen cells to mount an SRBC-specific plaque-forming cell response. These plastic-adherent suppressor cells appeared to be a major cause of nonspecific suppression of primary antibody responses in Toxoplasma-infected mice.

Biological activities of crystalline pertussigen from Bordetella pertussis

We studied various biological activities of crystalline pertussigen and found that in mice as little as 0.5 ng of pertussigen induced hypersensitivity to histamine, 8 to 40 ng induced leukocytosis, 2 ng increased production of insulin, 0.1 ng increased production of immunoglobulin E and immunoglobulin G1 antibodies to hen egg albumin, 9.5 ng increased susceptibility to anaphylactic shock, and 0.5 ng increased the vascular permeability of striated muscle. We also found that in Lewis rats 20 ng of pertussigen promoted the induction of hyperacute experimental allergic encephalomyelitis. Pertussigen given intraperitoneally was toxic to mice at a dose of 546 ng. Treatment of pertussigen with glutaraldehyde eliminated this toxicity. Mice immunized with 1,700 ng of detoxified pertussigen were protected against intracerebral challenge with 3 x 10(4) viable Bordetella pertussis cells. When as little as 0.5 ng of pertussigen was given intravenously to mice, the increased susceptibility of the animals to histamine could still be detected 84 days later. The biological properties of crystalline pertussigen indicate its similarity to leukocytosis-promoting factor, Islet-activating protein, late-appearing toxic factor, and mouse-protective antigen of B. pertussis.

The immunological status of children with atopic dermatitis

We studied 16 children during the quiescent phase of atopic dermatitis with a broad range of in vitro immunological tests. Subnormal levels of IgA were present in 2 children, and subnormal IgG in 1. IgE levels were elevated in 6 children. T cell percentages were significantly but slightly reduced. Normal results were obtained for lymphocyte transformation to 3 mitogens, neutrophil chemotaxis, quantitative iodination and microbicidal activity, and for the serum levels of CH50, C3 and C4. Thus most of the abnormal immunological findings in atopic dermatitis nay be secondary to the disease process itself.

Stimulation of primary in vitro IgE antibody responses in culture of human peripheral mononuclear cells

Experiments are presented herein that demonstrate the capacity to stimulate human peripheral mononuclear cells to synthesize and secrete significant quantities of IgE molecules in vitro by exposure to appropriate concentrations of 2,4-dinitrophenyl (DNP)-protein conjugates, pokeweed mitogen (PWM), or a combination of DNP-proteins and PWM. Cultures stimulated in this fashion synthesize increased quantities of both total IgE and DNP-specific IgE antibody molecules. This in vitro human IgE antibody system should provide a useful tool for further exploration of regulatory control of IgE responses in both normal humans and those manifesting various forms of IgE-mediated allergic disorders.

The enumeration of mouse IgE-secreting cells using plaque-forming cell assays

With the aid of a specific rabbit antibody preparation to purified monoclonal murine IgE, two plaque-forming cell (PFC) assays have been developed for the detection and enumeration of mouse IgE-secreting cells. The first assay, utilizing protein A-coated sheep red cells (protein A-SRC), detected antibody-secreting cells on the basis of the class of the secreted Ig irrespective of antigen specificity. With this assay, 30% of the class of the viable cells of two distinct IgE-secreting hybridoma cell lines were scored as PFC. Under these conditions, plaques were not obtained with IgG1 or IgG2a-secreting hybridoma cells. The second PFC assay, which utilized SRC coated with ovalbumin (OA-SRC), enumerated cells secreting anti-OA IgE antibodies. Similar kinetic patterns were observed for the cellular (IgE PFC/spleen) and humoral (IgE serum levels) responses of (C57BL/6 x DBA/2)F1 mice following immunization with 10 micrograms of OA adsorbed to 1 mg of A1(OH)3. Thus, it is concluded that the reverse plaque assay detecting all IgE-secreting cells, as well as the antigen-specific IgE PFC assay, can be used for the quantitation of IgE responses at the cellular level.

Antibody suppression in mice infected with Nippostrongylus brasiliensis

A/SN mice infected with N. Brasiliensis showed depressed anti-DNP antibody responses following immunization with DNP-Asc in alum. The immunosuppression was only observed when infection preceded immunization by between 2 and 7 days, and was not achieved when the interval was extended to 10 days. The suppression lasted at least 50 days, and affected IgE levels more than IgG1 or IgG agglutinating anti-DNP antibodies. A high dose of infective larvae (500-1000 per mouse) was necessary to induce suppression. Use of low dose irradiation indicated a parasite-induced radiosensitive component of the mouse immune system which negatively regulated the anti-DNP IgE response. These results suggested that the parasite could induce suppression in an analogous manner to sequential antigen-induced suppression (AIS).

Immunological tolerance of the mouse IgE system: dissociation between T cell tolerance and suppressor cell activity

Immunological tolerance was induced in CBA mice with respect to both anti-hapten and anti-carrier IgE antibody production, following pretreatment of the animals with deaggregated ovalbumin. IgG antibody production was also affected. The tolerance was antigen-specific, was stable upon adoptive transfer to irradiated syngeneic recipients, but was reversed following booster. The extent and duration of the tolerant state depended on the dosage and number of tolerogen injections. Tolerogen administered after the initiation of the primary response was without effect. The pattern and duration of this tolerance suggested that T suppressor cells were not involved. The adoptive transfer of spleen cells from tolerogen-treated donors while being themselves unresponsive, failed to interfere with the induction of an immune response in the recipient. Evidence of T suppressor cell function was found in adoptive transfers, only after prolonged pretreatment of donors with a combination of tolerogenic and immunogenic forms of the carrier. These results suggested that T cell-dependent tolerance of the IgE antibody response operates via two distinct mechanisms, of which only one is provided by suppressor cell function.

Subpopulations of circulating B cells and regulatory T cells involved in in vitro immunoglobulin E production in atopic patients with elevted serum immunoglobulin E

The B lymphocyte subpopulations producing immunoglobulin (Ig)E and the regulatory T cells modulating this IgE production in normals, and in atopic patients with respiratory allergy, atopic dermatitis, and markedly elevated serum IgE levels (>5,000 ng/ml), were investigated. Peripheral blood lymphocytes (PBL) were separated into T and B cell fractions and the ability of B cells to produce IgE in the presence or absence of pokeweed mitogen (PWM) and/or T cells ws determined. The patients had a circulating population of cells which spontaneously produced up to 6 ng of IgE in vitro (per 4 X 10(5) non-E-rosetting cells) in the absence of T lymphocytes and PWM. PBL from normals did not possess such cells. This IgE synthesis occurred primarily (>75%) over the first 72 h of culture. There was a wide range in their activity between patients and from the same patient studied on repeated occasions (from <300 to 6,000 pg per culture). This spontaneous IgE production was inhibited by PWM (mean inhibition, 37%) or normal T lymphocytes (mean inhibition, 42%). The patients lacked T lymphocytes capable of inhibiting this spontaneous IgE synthesis in 7 of 13 experiments. Functionally distinct B cells were identified in the patients and normals that responded to PWM with IgE production in vitro and required T-helper cell activity. Patients had normal PWM-responsive B cell IgE biosynthetic activity and T-helper function for these B cells. Suppressor T cell activity for PWM-driven IgE synthesis was also evaluated. Both the normals' and the patients' T lymphocytes provided similar levels of T cell suppressor function for PWM-driven IgE production. Patients with elevated serum IgE possessed these inhibitory T cells at times when the T lymphocytes which suppressed spontaneous igE production were absent from their PBL.

Antigen-induced bronchial anaphylaxis in actively sensitized guinea-pigs. Pattern of response in relation to immunization regimen

This work studies the temporal development of the acute anaphylactic bronchoconstriction in guinea-pigs sensitized to ovalbumin by different regimens, including IgE-antibody promoting ones. The results show that guinea-pigs sensitized with low amounts (1-10 micrograms) of ovalbumin together with alum produce the most pronounced bronchospasm when challenged with an intravenous injection of a low dose of antigen. Examination of the antibody classes by PCA technique shows that guinea-pigs sensitized with small amounts of antigen together with alum produced IgE and IgG1 antibodies. However, in sera from animals immunized with large amounts of antigen, only IgG1 antibodies could be detected.

New concepts concerning the clinical control of IgE synthesis

Prospects for new therapeutic approaches to IgE-mediated allergic diseases have arisen from (1) recent experimental observations that have suggested new concepts concerning the pathogenesis of the allergic phenotype, and (2) adaptation of previously described methods for induction of specific immunological tolerance to problems to allergy. The bases for these new approaches to allergic diseases are summarized herein.

Allergenicity and lymphocyte-stimulating property of rice protein

Two protein fractions of rice, grain, glutelin and globulin, were prepared by dilute alkali and salt extraction, respectively. The globulin fraction was separated into G1-1, G1-2, and G1-3 fractions by Sephadex G-200 column chromatography. The allergenic activities and lymphocyte-stimulating properties of these fractions were investigated by the radioallergosorbent test (RAST) with sera from 6 individuals who showed immediate skin reaction to soluble rice extract and by 3H-thymidine incorporation tests with 5 subjects with indurated skin reaction of delayed onset. All fractions were found to be reactive with specific IgE antibody, and G1-1 and G-2 revealed lymphocyte-stimulating activity. RAST inhibition revealed considerable cross-reactivity of IgE antibody with the glutelin and globulin fractions. When the glutelin and globulin fractions were heated at 60 degrees C for 1 hr, 100 degrees C for 2 min, or 100 degrees C for 10 min, RAST activities were reduced to 40%-70% of native. On the other hand, lymphocyte-stimulating activities of the globulin fraction heated at 60 degrees C for 1 hr or 100 degrees C for 2 min were enhanced up to 6 times of native activities, while those of identically treated glutelin fractions remained unchanged.

Association between HLA-A1,B8 in children with extrinsic asthma and IgA deficiency

The tissue types, immunoglobulin levels, and the presence of circulating autoantibodies were investigated in 57 children. Fifteen of these children suffered from bronchial asthma and, in addition, had no or very little IgA in their serum and saliva (Group 1 patients). Another fifteen children with asthma but normal immunoglobulin levels in serum and saliva (Group 2 patients), seven patients with selective IgA deficiency but without allergic diseases (Group 3 patients), and twenty healthy children served as controls. Sixty per cent of the Group 1 patients had the phenotype HLA-A1,B8, whereas this tissue type was found only in 27, 14 and 15 per cent, respectively, of the Group 2 and Group 3 patients and the healthy children. Furthermore, high IgM- and IgE levels were observed in most Group 1 patients, and in five of these patients (33 per cent) autoantibodies were present in the serum. In addition, eczema and glomerulonephritis occurred rather frequently in this group of patients. Conversely, normal immunoglobulin levels and absence of circulating autoantibodies were found in the remaining three groups of children. The results emphasize the heterogeneity of the IgA deficiency syndrome, and the question is raised as to whether the tissue type HLA-A1,B8 observed in most Group 1 patients reflects the abnormal immune reactivity of these patients.

The enumeration of rat IgE-secreting cells using a reverse plaque-forming cell assay

A reverse hemolytic plaque assay utilizing protein A-coated sheep red cells and a specific rabbit anti-rat IgE preparation has been adapted for the enumeration of rat IgE-secreting cells derived from the IR-162 rat plasmacytoma and from rats infected with Nippostrongylus brasiliensis. Under optimal conditions, approximately 10-15% of the viable plasmacytoma cells were scored as plaque-forming cells. In rats infected with 5000 Nippostrongylus brasiliensis larvae, a maximum of 2 x 10(6) IgE-secreting cells were found in the mesenteric lymph nodes, and no IgE plaque-forming cells in their spleens. The kinetics of the mesenteric lymph node plaque-forming cell responses closely coincided with total serum IgE levels, with maximum responses occurring 15-16 days after infection. There was a high degree of correlation between the mesenteric lymph node IgE plaque-forming cell responses and total serum IgE levels of individuals rats. It was concluded that the IgE-secreting cells in the mesenteric lymph nodes contributed, in a large way, to the elevated levels of IgE found in the circulation of these rats.

Screening for specific calf thymus inhibitors (chalones) of T-lymphocyte proliferation

Using agar colony assays with truly proliferating stimulated human T-lymphocytes and mouse granulocytes, two ultrafiltrate fractions were obtained from calf thymus which preferentially inhibited lymphocyte colony growth: Fraction I in the molecular range 1000-10,000 proved to be stable upon heating, prolonged storage and lyophilization, whereas Fraction II in the molecular range 10,000-30,000, was found to be unstable. Fraction I was also extracted with Tween 80 and cetyltrimethylammonium bromide. Chromatography of Fraction I on Biogel P6 and DEAE-cellulose further increased its specificity of inhibition for lymphocyte colony growth and revealed an estimated molecular weight of below 1400. Its inhibitory activity was found to be reversible and unlikely to result from spermine. Thus the properties of fraction I meet the requirements of a T-lymphocyte chalone as an endogenous non-cytotoxic and reversible inhibitor of T-lymphocyte proliferation.