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Biomedical subjects

P Kuna

Publications and source records attributed to P Kuna.

At least 73 records · Page 4Linked to original sources
PubMed1991

IL-8 inhibits histamine release from human basophils induced by histamine-releasing factors, connective tissue activating peptide III, and IL-3.

We have previously purified and partially characterized histamine releasing factors (HRF), which were derived from a mixture of human mononuclear cells and platelets. We now report the effect of IL-8 upon HRF-, connective tissue activating peptide III (CTAP III)-, and IL-3-induced histamine release from human basophils. We determined that IL-8 itself, at concentrations between 10(-7) to 10(-11) M, does not release histamine from basophils, although positive results are observed in two of 26 subjects at 10(-7) M. Unfractionated (crude) HRF released histamine in 25 of 26 donors, in the range of 6.7% to 100% of total basophil histamine stores. When basophils were preincubated with IL-8 (10(-7) to 10(-11) M) for 5 min, followed by a 40-min incubation with HRF, histamine release was significantly inhibited in 20 of 25 donors. Inhibition was observed at as little as 10(-11) M IL-8, with maximal inhibition being attained at 10(-9) M. HRF-containing supernatants contain a mixture of different histamine-releasing moieties. To better define which factor(s) may be inhibited by IL-8, fractionated supernatants, purified CTAP III, and IL-3 were studied. Histamine release produced by two different HRF-containing chromatographic fractions (HRFvoid and HRFpeak 2) and purified CTAP-III (5 micrograms/ml) was inhibited by IL-8 in 10 of 12 donors, three of three donors, and seven of 10 donors, respectively. IL-3 (5000 U/ml)-dependent histamine release was inhibited by IL-8 in all subjects tested. In contrast, histamine release by anti-IgE and FMLP was not affected by IL-8. Thus, IL-8 appears to be an inhibitor of cytokine-like molecules that induce histamine release and may represent the previously described 8-kDa histamine release inhibitory factor present in mononuclear cell supernatants.

Basophils↗
PubMed1991

Histamine-releasing factors.

Histamine-releasing factors (HRF) are cell-derived products which cause histamine release from basophils and/or mast cells. We have isolated HRF from human mononuclear cells and platelets and have purified 3 molecular species having molecular weights of 8-10, 15-17 and 35-41 kilodaltons (kDa). We prepared monoclonal antibodies to the 8- to 10-kDa form and have isolated it by affinity chromatography. A broad band was seen upon sodium dodecyl sulfate gel electrophoresis in 15% gels as well as immunoblotting, and the band was divided into an upper and a lower half. Amino acid sequence analysis of the upper half indicated that it is closely homologous to connective-tissue activating peptide III (CTAP III). The lower half also aligned with CTAP III beginning with amino acid 16; thus, proteolysis and occurred removing the N-terminal 15 amino acids. This corresponds to neutrophil-activating peptide 2. Both appear to be active on basophils with a dose-response between 250 ng up to 10 micrograms. Although interleukin-3 and granulocyte/macrophage-colony-stimulating factor have similar histamine-releasing capability at lower effective concentrations, they do not account for HRF activity in mononuclear cell/platelet supernatants, and the 15- to 17 and 40- to 41-kDa moieties appear to be unique gene products unrelated to previously described cytokines.

Amino Acid Sequence↗
PubMed1989

The effect of preseasonal immunotherapy on the production of histamine-releasing factor (HRF) by mononuclear cells from patients with seasonal asthma: results of a double-blind, placebo-controlled, randomized study.

The effect of immunotherapy on the production of histamine-releasing factor (HRF) by mononuclear cells (MNC) from patients with seasonal asthma was investigated in a double-blind, placebo-controlled, randomized study. Twenty-four patients with asthma were randomly divided into a placebo-treated group and a grass pollen-treated group. In vitro production of HRF by MNCs and the provocative concentration of histamine that causes 20% fall in FEV1 were measured before and after immunotherapy, and symptoms were monitored during the pollen season. MNCs from the patients were either cultured alone, spontaneous HRF production (spHRF), or in the presence of grass allergens (grass-stimulated HRF production), and the supernatants were assayed for HRF activity with basophils from a single donor after the study. We found that MNCs from patients with seasonal asthma to grass pollen spontaneously produce substantial amounts of HRF. The group of patients treated with placebo developed typical symptoms in the pollen season and also an increase in HRF production. In contrast, patients treated with grass pollen demonstrated reduced symptoms and no increase in spHRF production. A high degree of correlation between spHRF productions and symptom scores in both treated groups was noted. After 2 years of immunotherapy, allergen-stimulated HRF production decreased significantly, whereas spHRF production decreased significantly only in the patients who were clinically benefitted. The change in the provocative concentration of histamine that causes 20% fall in FEV1 during the pollen season highly correlated with the change in HRF production. The results of this study suggest that HRF might be involved in the pathogenesis of atopic asthma.

Adult↗
PubMed1988

Effect of autogenic bacterial antigens on the production of histamine releasing factor by mononuclear cells from intrinsic asthmatic patients.

The production of histamine releasing factor (HRF) by mononuclear cells (MNC) from intrinsic asthmatic patients has previously been reported. In this study, we investigated the effect of preincubation of lymphocytes with autogenic killed bacteria upon the production of HRF. Bacteria were isolated from the sputum, and nasopharyngeal swab obtained from patients and control subjects. MNC from intrinsic asthmatics and healthy controls were preincubated with killed bacteria for 4 h, then washed and cultured for 18 h. HRF activity of the cell-free supernatants was assayed in the histamine release test using basophils from normal subjects. We found that MNC from the patients spontaneously produce significant amounts of HRF. Preincubation of the cells with autogenic bacterial antigens enhanced HRF production in 12 of 25 patients and only in one of 15 control subjects. No specific bacterial strain was identified as having the sole stimulatory property for HRF production; rather, individual susceptibility predisposes to the ability to produce HRF in response to some common bacteria. When MNC from healthy subjects were preincubated with bacterial antigens isolated from the patients, no enhancement in HRF production was observed. We concluded that MNC from some intrinsic asthmatics are specifically sensitized to certain bacterial antigens and release HRF upon contact with these antigens.

Adolescent↗
PubMed1987

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.

Animals↗
PubMed1987

The magnitude of the spontaneous production of histamine-releasing factor (HRF) by lymphocytes in vitro correlates with the state of bronchial hyperreactivity in patients with asthma.

In our previous studies we reported that lymphocytes from patients with asthma spontaneously produce histamine-releasing factor (HRF) in vitro. In an effort to examine whether spontaneous HRF production (SpHRF) by lymphocytes from patients with asthma is related to the state of bronchial hyperreactivity (BHR), 20 patients with mild to severe asthma were studied. Peripheral blood lymphocytes were cultured alone in a serum-free medium for 24 hours, and culture supernatant was assayed for HRF activity in two separate histamine-release tests with autologous basophils and normal basophils from known healthy donors. BHR was measured as bronchial reactivity to inhaled histamine and was expressed as a provocation concentration of histamine required to induce a 20% fall in FEV1 (PC20). The result of this study demonstrated that lymphocyte supernatant from all patients with asthma released significant amount of histamine from both autologous and normal basophils. Very high histamine release was usually induced by lymphocyte supernatant from severely ill patients who had PC20 less than 2 mg/ml. Statistical analysis demonstrated that the magnitude of the SpHRF significantly correlated (r = -0.86; p less than 0.001) with PC20. Since mast cell- and basophil-derived mediators have been implicated in the pathogenesis of BHR, high correlation between PC20 and SpHRF by lymphocytes suggests that the latter may contribute to the development of BHR. Further studies are required to disclose the exact relationship between SpHRF and BHR.

Adult↗
PubMed1987

Megakaryocytes in rabbit pulmonary blood vessels.

Semiserial sections of lung capillaries of seven rabbits were examined for megakaryocytes. Triads of serial sections of each lobe were examined, and megakaryocyte counts per cm2 were determined. Median megakaryocyte count was determined for each lobe. The lobal values were used to calculate the was determined for each lobe. The lobal values were used to calculate the median cell-counts for each experimental animal. Values of 0.16-0.64 megakaryocytes per cm2 were established as "normal".

Animals↗
PubMed1986

Bacterial antigens stimulate the production of histamine releasing factor (HRF) by lymphocytes from intrinsic asthmatic patients.

Lymphocyte from 12 intrinsic asthmatic patients and 10 healthy controls were studied for their capability to produce histamine releasing factor (HRF) in vitro. Spontaneous HRF production was measured by culturing the lymphocytes alone for 20 h. In another set of experiments lymphocytes were first preincubated separately with phytohaemagglutinin, antigens of Haemophilus influenzae, Streptococcus viridans, Staphylococcus sp. and Neisseria catarrhalis for 4 h then carefully washed three times and cultured alone for an additional 16 h. Cell-free supernatant was assayed for histamine releasing activity using basophils from healthy donors. It was observed that lymphocytes from intrinsic asthmatic patients spontaneously produced HRF. The production of this lymphokine was enhanced following preincubation of lymphocytes with phytohaemagglutinin or bacterial antigens. Results of skin test with bacterial antigens did not correlate with the magnitude of the production of HRF by lymphocytes. At gel chromatography over Sephadex G-75 bacterial antigen-stimulated lymphocyte supernatant revealed two peaks of HRF activity in the molecular weight ranges 35,000-50,000 and 3,000-7,000.

Adult↗