International archives of allergy and applied immunology最新文献

The effects of prednisolone, theophylline or salbutamol treatment were studied on leukocyte numbers in bronchoalveolar lavage (BAL) fluid taken 72 h after ovalbumin challenge in sensitized guinea pigs. Ovalbumin challenge resulted in an approximate 3-fold increase in the number of eosinophils in BAL fluid. This increase was significantly reduced by oral administration of prednisolone (59% inhibition with 10 mg/kg x 2) theophylline (56% with 50 mg/kg x 2) but not by salbutamol (10 mg/kg x 2). A comparison with the bronchodilator potency of the above drugs indicated that in guinea pigs salbutamol appears relatively selective as a bronchodilator, prednisolone is selective as an inhibitor of eosinophilia whilst theophylline displays a balance of both activities.

Proteins of rat peritoneal mast cells (PMC), rat intestinal mast cells (IMMC) and human skin mast cells (SMC) were compared by two-dimensional electrophoresis. PMC and IMMC had many similarities in distribution of their neutral/acidic proteins but marked differences in the more abundant, granule-associated basic proteins. SMC proteins showed a unique distribution. Distributions of the products of in vitro translation of PMC and IMMC RNA were different from those of proteins isolated directly from these cells which, together with results of pulse-chase labelling experiments, shows evidence for processing of certain mast cell proteins including rat mast cell proteases I and II.

Interleukin-4 (IL-4) gene expression by stimulation with concanavalin A (Con A) in murine spleen cells was examined. The amount of IL-4 mRNA induced by Con A was greatest in spleen cells obtained from IgE high responder strains of mice. A trace amount of IL-4 mRNA was induced in spleen cells from IgE low responder (SJL) mice. The amount of IL-4 mRNA induced in spleen cells from an IgE intermediate responder (C57BL/6) was smaller than that from high responders, but significantly greater than that from low responders. Spleen cells from IgE nonresponders (SJA/9) developed only a negligible amount of IL-4 mRNA. IL-4 mRNA was detected in human peripheral blood mononuclear cells (PBMC) stimulated with Con A. The IL-4 gene expression seemed to be greater in PBMC obtained from highly atopic patients and was decreased in PBMC from individuals showing hypo-IgE immunoglobulinemia (less than 10 IU/ml). The results obtained in the present study may indicate that high and low IgE responder traits are determined depending on their levels of IL-4 mRNA expression.

The role of the cytokines interleukin-4 and interferon-gamma in the regulation of IgE responses in the mouse and man have focused on the role of CD4 T cells. In the rat, antigen-specific CD8 T cells, generated following inhalation of antigen, have been shown to be capable of suppressing IgE responses. Repeated intraperitoneal injections of 1 ng ricin and 1 microgram antigen established a long-lived IgE response in both low- and high-IgE responder rat strains (Wistar and Brown Norway). The duration of the IgE antibody response was 204 and 248 days, respectively. Total IgE levels rose from 30 +/- 20 to 39,000 +/- 7,500 ng/ml in the Wistar rat and from 120 +/- 100 to 47,000 +/- 8,000 ng/ml in the Brown Norway rat. An even greater (10(4)-fold) increase was seen in antigen-specific IgE antibody levels. Ricin alone had no effect and concomitant or prior stimulation with antigen was required. The proportion of CD4+ and CD8+ cells present in the spleen at the peak of the IgE response was markedly increased compared with animals given ricin or antigen alone. Furthermore, CD8 T cells were approximately 100 times more sensitive to ricin than CD4 T cells. These data suggest that enhancement of IgE responses in ricin-treated animals results from the selective deletion of T cells which suppress IgE and are of the CD8 phenotype.

Prophylactic administration of Piroxicam (Feldene), a reversible inhibitor of prostaglandin biosynthesis, significantly reduced the occurrence of paralytic signs and the amount of antibodies against myelin basic protein in the model of mild acute experimental allergic encephalomyelitis in the Lewis rat. Mononuclear infiltration of the central nervous system remained unaffected. A therapeutic intervention with piroxicam, however, increased paresis and CNS pathology. Immunohistochemical studies revealed an increased proportion of ED1-positive macrophages and monocytes in the infiltrates of the spinal cord in animals treated with piroxicam. Possible reasons for the different effects of the prophylactic and therapeutic treatment are discussed in the study.

A continuous ambulatory peritoneal dialysis patient developed eosinophilic peritonitis and was followed for 7 months. After 1 month, the peritonitis resolved, with a concomitant drop in percentage of hypodense eosinophils (Eos) recovered from peritoneal dialysate (PD) as well as a drop in fluid major basic protein levels. Blood eosinophil differential percentages were low, but the percentage of hypodense Eos in the blood tended to be relatively increased. Stool samples showed no evidence of parasitic infection, and epicutaneous skin tests were negative. Leukotriene C4 levels remained relatively constant as did white blood cell counts. Flow cytometric analysis of lymphocytes and granulocytes from PD and blood revealed high levels of CD23-positive lymphocytes.

The release of inflammatory mediators from mast cells occurs by a regulated exocytotic process. We have been able to study the intracellular events in this pathway by permeabilizing the plasma membrane of rat peritoneal mast cells and stimulating exocytosis by providing both Ca2+ and a guanine nucleotide. By this approach we have obtained evidence for the participation of at least two guanine nucleotide binding proteins in the control of exocytosis. We have also shown that ATP is unnecessary for the final events, but that it does have a number of modulatory functions, for instance in the control of the effective affinity of the proteins that bind Ca2+ and GTP. There is also evidence for a protein dephosphorylation in the later stages of the control pathway.

Cellular responses in bee venom (BV) allergy is a controversial issue. Previous studies could not reach an agreement whether this mechanism is activated as a result of allergic sensitization to bee venom. All previous works have used lymphocyte proliferation as their method to analyze cell-mediated immunity. In the present work, we tried to explore whether the production of macrophage migration inhibition factor (MIF), which is another in vitro correlate with cellular responses, is increased in these patients. We also examined which of the major antigenic components of BV played a significant role in the cellular response. Peripheral blood lymphocytes from 10 patients with systemic allergic reactions to bee sting and 9 healthy volunteers were examined for their ability to induce positive MIF responses. Macrophage inhibition was significantly increased in allergic patients when tested with BV, phospholipase A2 (PLA2) and with melittin. Positive MIF responses to other components were also more common in allergic patients than in the control group. Our results indicate that cellular response to BV is expressed in patients with systemic allergic reaction to BV. When major antigenic components of BV are examined, PLA2 seems to play the major role in inducing this response.

Hemagglutinating antibodies and cell-mediated immunity are increased when antigens are injected intraperitoneally (i.p.) into rats during the healing phase of a chemical peritonitis. In the present work, the anaphylactogenic effects of either sensitization or challenge were increased when any of three different antigens were injected i.p. in the postinflammatory state. The postinflammatory state made it possible to sensitize rats for anaphylaxis without any adjuvants at all. Lymph nodes draining the peritoneal cavity had evidence of enhanced absorption of inoculum in the postinflammatory state.