Investigations on allergogenic properties of Tolpa Peat Preparation.

The ability of Tolpa Peat Preparation (TPP) to induce or enhance an allergic sensitization was tested on mice and guinea pigs. The levels of IgE antibody in the mouse sera and IgG1 as well as IgE antibody levels in guinea pig sera were evaluated by PCA (Passive Cutaneous Anaphylaxis) tests. TPP adsorbed on aluminium hydroxide gel (alum) and introduced into BALB/c mice by several subcutaneous injections was unable to stimulate the noticeable anti-TPP IgE antibody response. TPP introduced together with ovalbumin (OA) into the mice in the course of immunization with OA did not enhance anti-OA IgE antibody response. TPP adsorbed on alum and injected subcutaneously into guinea pigs was unable to induce noticeable IgG1a, IgG1b and IgE antibody response, and mast cells obtained from lung and mesentery of these animals did not release histamine when challenged with TPP in vitro at 37 degrees C. In conclusion, our results show that under the experimental conditions used in the present experiments TPP was unable to induce or enhance an allergic sensitization of mice and guinea pigs.

The immunomodulating preparation Ukrain does not induce anaphylactic sensitization in mice and guinea pigs.

The ability of Chelidonium majus L. alkaloids derivative Ukrain to induce an anaphylactic sensitization was tested on mice and guinea pigs. The levels of IgE antibody in the mouse sera, and IgG1a, IgG1b as well as IgE antibody levels in guinea pig sera, were evaluated by passive cutaneous anaphylaxis (PCA) tests. Ukrain alone or adsorbed on aluminium hydroxide gel (alum) introduced into BALB/c mice in several subcutaneous injections was unable to stimulate measurable anti-Ukrain IgE antibody response. Moreover, Ukrain introduced together with ovalbumin (OA) into mice in the course of immunization with OA induced lower anti-OA antibody response as compared to the response induced by OA alone. Ukrain adsorbed on alum and injected subcutaneously into guinea pigs did not induce measurable IgG1a, IgG1b and IgE antibody response. The present results suggest that the immunomodulating preparation Ukrain could be therapeutically safe at least as far its inability to induce anaphylaxis is concerned.

Histamine release from human pulmonary mast cells induced by bacterial antigens.

Antigens of four bacteria (Staphylococcus aureus, Haemophilus influenzae, Streptococcus viridans, Branhamella catarrhalis) were tested for their ability to release histamine from human pulmonary mast cells recovered by means of bronchoalveolar lavages. For the sake of comparison the action of bacterial antigens on human mesenteric and adenoidal mast cells obtained by enzymatic dispersion of the tissues was studied. BAL mast cells released histamine in response to all studied bacterial antigens. Haemophilus influenzae antigens were the most effective histamine releasers. From among three populations of human mast cells pulmonary mast cells were the most sensitive to the challenge with bacterial antigens. Mesenteric mast cells were markedly more reactive than adenoidal cells. Adenoidal cells had low sensitivity to bacterial antigens.

Histamine release from human adenoidal and mesenteric mast cells induced by bacterial antigens.

The histamine-releasing capability of Staphylococcus aureus antigens was examined in human adenoidal and mesenteric mast cells obtained by enzymic dispersion of tissues from non-allergic patients. Both populations of mast cells released histamine after challenge with bacterial protein in concentrations between 5-500 micrograms/ml. The release was dependent on the dose, temperature and metabolic energy. The maximum release was observed at 15 min after challenge. The present results suggest that Staphylococcus aureus antigens release histamine from human adenoidal and mesenteric mast cells via a non-cytotoxic, active secretory process.

Histamine-releasing properties of guinea pig cardiac mast cells.

The immunization of guinea pigs with OA + Al(OH)3 induced substantial IgG1a and IgG1b antibody response and low, transient IgE response, as examined by PCA test. Cardiac mast cells obtained by enzymatic dispersion method from sensitized animals released histamine in vitro after the challenge with specific antigen (histamine release up to 21%). Cardiac mast cells obtained from nonsensitized guinea pigs were sensitive to the action of ionophore A23187 and polymyxin B only when the agents were used in high concentrations (histamine release up to 25.1% and 21. respectively) and were only slightly responsive to the challenge with Concanavalin A and compound 48/80.

Histamine release from mast cells of various species induced by histamine releasing factor from human lymphocytes.

The aim of our work was to investigate the effect of histamine releasing factor (HRF), produced in vitro by lymphocytes obtained from atopic and non-atopic asthmatics, on mast cells of various species (mouse - peritoneal mast cells, hamster and rat - peritoneal and pleural mast cells, guinea-pig - mesenteric and pulmonary mast cells). We found that human HRF is able to release histamine from the examined mast cell populations in a dose-dependent fashion. Mast cells from various species differed in their susceptibility to the action of HRF; rat pleural and guinea-pig mesenteric and pulmonary mast cells were the most susceptible, while mouse and hamster peritoneal mast cells - the least susceptible. The presence of 50% D2O in the medium significantly increased HRF-induced histamine release from rat mast cells, while the addition of phosphatidylserine did not change it. HRF-induced histamine release from guinea-pig mesenteric mast cells was not related to sensitization of these cells. We also compared histamine release from guinea-pig pulmonary and mesenteric mast cells induced by human HRF produced in vitro by lymphocytes obtained from atopic and non-atopic asthmatics. We have found that supernatant from atopic asthmatics lymphocyte cultures released significantly more histamine than supernatant from non-atopic asthmatics lymphocyte cultures. Our studies give evidence that human HRF acts across the species barrier and induces histamine release from mast cells of various species. The mechanism of HRF action on mast cells seems to be different from that of allergen.

Isolation and sensitivity of human mesenteric mast cells to immunological and nonimmunological histamine releasers.

Since recent studies have emphasized that mast cells from different tissues within a given species may exhibit marked differences in their functional properties, we have now examined the effect of some immunological and non-immunological histamine releasers on human mesenteric mast cells. The mesentery derived from the patients subjected to gall-bladder surgery was dispersed by collagenase (concentration of enzyme--1 mg/ml, time of incubation--90 min, 37 degrees C). The mesenteric cell suspension contained about 2% mast cells as identified by staining with toluidine blue. We observed that the mesenteric mast cells released histamine when challenged with anti-human IgE, but marked individual variations were observed. These cells had a low sensitivity to challenge with Concanavalin A and compound 48/80 (histamine release about 6%), but responded to ionophore A23187 and polymyxin B (histamine release up to 24% and 22% respectively).

Histamine- and serotonin-releasing activity of the supernatants from guinea pig spleen cell cultures.

The action of supernatants from cultivated in vitro guinea pig spleen cells on the mast cells of guinea pigs, rats and hamsters was studied. It was found that supernatants from guinea pig spleen cell cultures are potent to release histamine from mast cells of the examined populations in a dose-dependent fashion. Histamine release from heterologous mast cells (especially from rat pleural mast cells) was significantly higher than that from homologous mesenteric mast cells. It was also demonstrated (on rat mast cells) that guinea pig spleen cell supernatants possessed not only histamine but 5-hydroxytryptamine releasing activity as well. Rat pleural mast cells were more sensitive and released more serotonin after challenge with spleen cell supernatants than peritoneal cells.

The sensitivity of guinea pig mesenteric and pulmonary mast cells to some histamine releasers.

The mesenteric and pulmonary mast cells of guinea pigs were obtained by enzymatic dispersion of the tissues with the enzyme collagenase. The guinea pig mast cells obtained by this method were morphologically intact, as judged by light microscopy. The mast cells from lung and mesentery of actively sensitized guinea pigs released histamine in a dose-dependent fashion after challenge with specific antigen. Both pulmonary and mesenteric mast cells of nonsensitized animals were unresponsive to the action of compound 48/80 and concanavalin A. Both populations of mast cells responded to polymyxin B, but the magnitude of histamine release was low. These cells responded strongly to the ionophore A23187; the mesenteric mast cells were markedly more reactive than pulmonary mast cells.

Histamine-releasing activity of lymphocyte supernatants of guinea pig spleen cell cultures.

We demonstrated the production of a histamine releasing factor (HRF) by 24-h cultures of guinea pig spleen cells which were stimulated or not with specific antigen (ovalbumin, OA) or mitogen (phytohemagglutinins or concanavalin A). HRF induced the release of histamine from homologous mesenteric mast cells in a dose-dependent fashion. The HRF-induced histamine release was not high compared to the release induced by calcium ionophore A23187, but higher than that induced by compound 48/80, polymyxin B and con canavalin A. The mast cells from sensitized guinea pigs released histamine when challenged with OA. We found that HRF-induced histamine release was additive to that induced by antigen, when both agents were added simultaneously to sensitized mast cells. The phenomenon was most significant when a suboptimal dose of antigen was used. Moreover, we did not observe any differences in the magnitude of HRF-induced histamine release between the mast cells from nonsensitized and sensitized guinea pigs. The time course of histamine release induced by HRF was significantly slower than that with specific antigen (10 min and 45 sec, respectively). Our results may suggest that HRF acts on mast cells through a different not immunological mechanism.