Specificity of fixation loci for homocytotropic antibodies

Induction of lung eosinophilia and neutrophilia in guinea pigs following injection of sephadex beads

We have developed a method of induction of airway eosinophilia and neutrophilia in guinea pigs by intravenous injection of various types of Sephadex beads. In the first series of experiments, we have shown that G-50 Sephadex beads (Superfine, 24 mg/kg in conscious animals) induced a large accumulation of inflammatory cells in alveolar walls. The bronchoalveolar lavage (BAL) fluid from animals treated with this dose of Sephadex beads contained about 85 x 10(6) cells as compared to 20 x 10(6) cells in control animals. The eosinophils corresponded to 41% of the BAL cell population as assessed with Wright-Giemsa staining. However, in the BAL fluid from these bead-treated animals, a significant increase of monocytes, lymphocytes, and neutrophils was also observed. We have also tested the potency of G-75, G-100, and G-200 Sephadex beads (Superfine) to induce eosinophilia in guinea pig. Nonlethal intravenous doses of G-75 (14.27 mg/kg), G-100 (8.0 mg/kg), and G-200 (10.71 mg/kg) Sephadex beads were selected and induced variable levels of airway eosinophilia and neutrophilia in conscious guinea pigs. The percentage of eosinophil recovered in the BAL fluid corresponded to 35, 61, and 44% of total cells for G-75, G-100, and G-200, respectively. The neutrophils corresponded to 24, 2, and 12% of the total BAL cells for G-75, G-100, and G-200, respectively. Since the size of the beads did not seem to correlate with the intensity of airway eosinophilia and neutrophilia, the effect of lower doses of the G-50 Sephadex beads (9.86-0.43 mg/kg) on the inflammatory cell infiltration was also tested. Results showed that there was a correlation between the neutrophil number and the number of beads (r = 0.996), whereas the number of eosinophils was less directly correlated to the bead number (r = 0.812). The alveolar eosinophils were purified from BAL fluid by centrifugation on a continuous Percoll gradient (65%) to separate eosinophils from neutrophils. Normodense eosinophils (density 1.087-1.100 g/ml) obtained from Sephadex-treated animals were found at the bottom of the continuous Percoll gradient (25 x 10(6); 98% purity). These highly purified eosinophils released thromboxane A2 (TxA2) following stimulation with 2 microM ionophore A23187. The method of accumulation and purification of guinea pig alveolar eosinophils is simple, rapid, and provides a large number of pure normodense cells for further biological studies.(ABSTRACT TRUNCATED AT 400 WORDS)

Dextran induces changes in immunological responses to unrelated antigenic and haptenic stimuli

Clinical grade, low molecular weight dextran administered intravenously to guinea-pigs altered the course of immunological events that follow unrelated antigenic and haptenic stimuli. Delayed hypersensitivity detectable by dermal responses was initially postponed and upon later retesting was greatly heightened. In addition, the synthesis of circulating antibody that mediates passive cutaneous anaphylaxis was depressed.

Infusion of dextran into guinea-pigs with established immunological responses did not alter either delayed hypersensitivity or PCA antibody synthesis.

Naturally occurring human antiglobulins with specificity for E

Human sera have been examined for antibodies with specific reactivity for gammaE using the tanned cell hemagglutination test. Cells tanned with three different gammaE myeloma proteins provided a reproducible test system. Inhibition of agglutination reactions by gammaE proteins, but not by gammaG, gammaA, gammaM, or gammaD confirmed the specificity of these reactions. 8.5% of 304 serial serum samples obtained from miscellaneous hospitalized patients showed clear-cut anti-gamma-globulins with specificity for gammaE. In most of these instances no definite clinical history of concomitant allergic disorders could be obtained. 53% of 73 patients with well-established allergic disorders (hay fever, extrinsic asthma) showed serum anti-gamma-globulins with reactivity for gammaE. Some patients studied before and after desensitization to Bermuda grass allergen showed an increase in titer or a conversion from negative to positive reactions for anti-gammaE antibodies following several month courses of progressive desensitization. Gradient and gel filtration studies indicated that anti-gammaE globulins were 19S gammaM in all instances. No clear correlation was noted between quantitative serum gammaE levels and titer of anti-gammaE antibodies.19S serum fractions with anti-gammaE antibody activity did not release histamine from normal human peripheral blood leukocytes, whereas specific rabbit anti-gammaE antisera consistently induced leukocytic histamine release. Moreover, macroglobulin fractions with anti-gammaE activity did not block allergen-specific leukocyte histamine release induced by in vitro leukocyte challenge with allergens such as Bermuda grass and leukocytes from allergic donors. In some instances 19S human serum fractions with anti-gammaE activity appeared to potentiate histamine release when incubated concomitantly with specific allergen and leukocytes from allergic individuals.