Passive sensitization of guinea-pig skin in vitro for the antigen-induced release of anaphylactic mediators

Guinea-pig skin fragments were passively sensitized for the antigen-induced release of histamine, SRS-A and ECF-A. Skin histamine was chemically identified by fluorimetry; SRS-A gave a characteristic dose-dependent contraction of the guinea-pig ileum; and ECF-A selectively attracted eosinophils. The antibody mediating the release of these agents was shown to be IgG₁. Following antigen challenge different time courses of release were demonstrable for histamine, SRS-A and ECF-A. Skin SRS-A was resistant to treatment with the enzyme pronase and skin ECF-A had an estimated molecular size of between 500 and 1000. They were therefore comparable to similar agents released from the lung. Thus SRS-A and ECF-A join histamine as chemical mediators in cutaneous anaphylaxis.

Selective attraction of eosinophils and synergism between eosinophil chemotactic factor of anaphylaxis (ECF-A) and a fragment cleaved from the fifth component of complement (C5a)

ECF-A and C5a were chemotactic both for eosinophils and neutrophils. However, when eosinophils comprised approximately 10 per cent or more of a mixed leucocyte population, they were preferentially attracted by both of these agents.

Marked synergism was observed between ECF-A and C5a in their ability to attract eosinophil leucocytes.

Chemotaxis of human basophil leucocytes

Human peripheral blood basophils from two patients with unusually high basophil counts in association with chronic myelogenous leukaemia migrated in vitro toward various chemotactic agents of human origin. These included supernatants from sensitized lymphocytes challenged with specific antigen, diffusates from lung fragments challenged with pollen antigen E, the enzyme plasma kallikrein, and two complement derived agents, C5a and C[unk][unk][unk]. Thus, chemotaxis in vitro, a previously unreported property of human basophils, has been observed, although none of the agents tested produced a selective chemotactic response.

Antigen-antibody induced cutaneous eosinophilia in complement deficient guinea-pigs

Decomplementation with cobra venom factor had no effect on eosinophil accumulation into the site of IgG₁-mediated PCA reactions in the guinea-pig. Eosinophil and neutrophil accumulation also followed PCA reactions in animals partially or totally deficient in C4.

The effect of intradermal injections of pre-formed antigen–antibody complexes prepared from guinea-pig IgG₁ or IgG₂ were not affected by decomplementation with cobra venom. The lesions produced with either immunoglobulin complex were similar in appearance in decomplemented and normal animals and were followed by comparable tissue accumulation of eosinophils and neutrophils.

A prealbumin activator of prekallikrein. 3. Appearance of chemotactic activity for human neutrophils by the conversion of human prekallikrein to kallikrein

Human plasma kallikrein has been shown to directly and selectively attract human neutrophils from a mixed leukocyte population. The capacity of plasma kallikrein to be chemotactic and to generate the nonapeptide bradykinin was maintained during progressive purification. While neither highly purified prekallikrein nor the prealbumin Hageman factor fragments were chemotactic alone, their interaction so as to convert prekallikrein to kallikrein yielded both chemotactic and kinin-generating activity. Both functions of kallikrein were inhibited by treatment with diisopropyl fluorophosphate, indicating an essential role for the active site of the enzyme in the expression of its chemotactic activity.

The IgE-Mediated Release of an Eosinophil Leukocyte Chemotactic Factor from Human Lung

Following antigenic challenge of human lung passively sensitized with serum from a ragweed-sensitive donor, the anaphylactic diffusate contained, in addition to histamine and slow reacting substance of anaphylaxis (SRS-A), a factor selectively chemotactic for human eosinophils (ECF-A). ECF-A evoked the migration of eosinophils obtained from the blood of a number of donors with eosinophilia. ECF-A was distinguished from histamine, bradykinin, serotonin, the prostaglandins PGE1, PGE2 and PGF2α and from SRS-A. The immunoglobulin mediating the release of ECF-A was IgE. Heating or absorption of ragweed-sensitive serum with a rabbit antibody specific for IgE removed its ability to passively sensitize lung for mediator release, and anti-IgE released ECF-A from normal lung. ECF-A, a unique mediator of the anaphylactic reaction, has been identified in human lung tissue.

An eosinophil leukocyte chemotactic factor of anaphylaxis

The capacity of actively or passively sensitized guinea pig lung to react with antigen to release a factor specifically chemotactic for eosinophil leukocytes (ECF-A) has been demonstrated. The release of ECF-A was also accompanied by the elaboration of both histamine and SRS-A and the appearance of all these mediators exhibited a similar response in terms of the time course of passve sensitization, the effect of antigen dose, the time course of release, divalent cation dependence and enhancement by the presence of succinate or maleate. Decomplementation by the administration of purified cobra venom factor had no effect on the antigen-induced release of ECF-A from actively or passively sensitized lung fragments. When fragments of guinea pig lung were passively sensitized with fractions of guinea pig 7S IgG, only the IgG(1)-containing fractions prepared tissue for the antigen-induced release of ECF-A. Histamine, SRS-A, bradykinin, serotonin, and the prostaglandins PGE(1), PGE(2), and PGF(2alpha) were not eosinophilotactic per se; neither was ECF-A detected following the incubation of these agents with sensitized lung in the absence of antigen. Both eosinophilotactic activity and SRS-A survived extraction in 80% ethanol and evaporation to dryness. SRS-A, however, withstood boiling in alkaline solution for 20 min, whereas ECF-A activity was abolished by this procedure. SRS-A and ECF-A could also be separated by gel filtration. ECF-A activity was completely recovered following its passage through a column of Sephadex G-25 and had an estimated molecular weight of between 500 and 1000. On the basis of size and a formation mechanism independent of the complement system, ECF-A is distinguishable from a previously described complement-dependent eosinophilotactic factor (ECF-C). Thus, ECF-A represents a hitherto undescribed agent which selectively attracts eosinophil leukocytes.

The chemotactic activity for neutrophil and eosinophil leucocytes of the trimolecular complex of the fifth, sixth and seventh components of human complement (C567) prepared in free solution by the 'reactive lysis' procedure

C[unk]567, prepared by the interaction of purified C[unk]56 with purified C7 in solution, has been shown to be chemotactic for neutrophils and eosinophils. This activity was not significantly affected by the presence of C8 and C9, even in substantial excess. However, if the interaction of C[unk]56 with C7 took place in the presence of an excess of erythrocytes, these cells bound the C[unk]567 and were converted to EC567; and no chemotactic factor was found.

Studies on eosinophil leucocyte migration. II. Factors specifically chemotactic for eosinophils and neutrophils generated from guinea-pig serum by antigen-antibody complexes

Chemotactic activity for eosinophils and neutrophils has been studied using guinea-pig serum activated by preformed antigen–antibody complexes.

Rabbit complexes or complexes prepared either with guinea-pig IgG₂ or IgG₁ were equally capable of generating a heat stable activity from guinea-pig serum that was chemotactic for guinea-pig eosinophils and for neutrophils of both the guinea-pig and the rabbit. This was distinguished from a relatively heat-labile chemotactic activity present in untreated guinea-pig serum.

The heat-stable complex-mediated chemotactic activity was thought to be complement dependent since chemotaxis for eosinophils or neutrophils could not be generated from heated serum, ammonia treated serum or from serum treated with complexes in the presence of 0·01 M EDTA.

Guinea-pig sera, activated either with rabbit, guinea-pig IgG₁ or IgG₂ complexes, was fractionated by sucrose-density gradient ultracentrifugation and by Sephadex chromatography. In all experiments two peaks of cell specific chemotactic activity could be separated. The peak of activity for guinea-pig neutrophils was approximately 4·5S and in the fractionation range of proteins having a molecular weight of between 65,000 and 85,000. The peak of guinea-pig eosinophil chemotactic activity was 1·5S–2S and in the molecular weight range of between 15,000 and 20,000. Those fractions which were chemotactic for guinea-pig neutrophils did not attract rabbit neutrophils. Rabbit neutrophils migrated towards those fractions of guinea-pig serum chemotactic for guinea-pig eosinophils; therefore, the properties associated with guinea-pig eosinophil chemotactic activity were similar to previously published data for a fragment cleaved from the 5th component of complement.

Studies on eosinophil leucocyte migration. I. Eosinophil and neutrophil accumulation following antigen-antibody reactions in guinea-pig skin

Eosinophil leucocytes migrated into the site of PCA reactions mediated by those fractions of 7S guinea-pig IgG containing IgG₁; neutrophils were associated with IgG₁ and IgG₂. Maximal eosinophil infiltration is seen at 12 hr and was associated with degranulation.

Intradermal histamine was not eosinophilotactic in guinea-pigs.

Preformed antigen–antibody complexes of IgG₁ and IgG₂ both promoted eosinophil and neutrophil migration in guinea-pig skin but slightly more eosinophils were seen following injections of complexes containing IgG₁. Local eosinophilia and PCA activity were mediated by a relatively heat-stable element since these effects were demonstrable even after prolonged heating of fractions containing IgG₁. Eosinophils were seen following injections of Compound 48/80 and this was accompanied by low mast cell counts; however, there was also some associated tissue destruction.