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PubMed1999

Secretory IgA-mediated basophil activation. II. Roles of GTP-binding regulatory proteins and phosphatidylinositol 3-kinase.

Secretory IgA (sIgA) is the most abundant Ig isotype in mucous secretions in the upper and lower airways, where basophils exert effector functions during allergic inflammation. We recently demonstrated that immobilized sIgA on Sepharose beads is capable of inducing basophil degranulation ( approximately 15% of total histamine). To investigate the detailed mechanisms of this degranulation, we established in this study a new assay system for sIgA-mediated basophil activation. Immobilized sIgA on a plastic surface induced strong histamine release ( approximately 50% of total histamine) comparable to anti-IgE, and we analyzed the nature of basophil signal transduction by sIgA using various inhibitors. sIgA-induced basophil histamine release was inhibited completely by pertussis toxin, but anti-IgE-induced release was not affected. sIgA-mediated release was also inhibited by phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, wortmannin. These results strongly suggest that sIgA activates basophils via an IgE-independent novel mechanism involving both Gi protein and PI 3-kinase.

Basophils↗
PubMed1985

Ultrastructural cytochemistry of glycoconjugates in basophils from humans and animals.

The distribution of glycoconjugates in the basophil granules of humans, guinea pigs, and rabbits was compared. The observation of acid mucopolysaccharides using the dialyzed iron method and of sulfated glycoconjugates using the high iron diamine method revealed three types of reactions in the basophil granules of all three species: granules showing a strong overall reaction, granules showing reaction only at their periphery, and granules showing no reaction. With regard to the relationship between maturation and the types of basophil granules, it appeared that, in general, there were many type-1 granules among immature basophils, but that these granules decreased in mature basophils as type-3 granules increased. The reaction patterns of periodate-reactive neutral glycoconjugates, as shown by the periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method, were different from those of acid mucopolysaccharides: the reaction of basophil granules was diffusely positive, and localization at the periphery was rarely observed. Therefore, unlike the acid mucopolysaccharides, it was difficult to classify the glycoconjugates into three types. However, as with acid mucopolysaccharides, there was a tendency for periodate-reactive glycoconjugates to decrease as maturation progressed. In terms of different species of animals, the reaction of periodate-reactive glycoconjugates with PA-TCH-SP was stronger in humans and rabbits than in guinea pigs.

Animals↗
PubMed1982

Basophil activation in idiopathic mixed cryoglobulinemia.

We studied basophil activation in patients affected by idiopathic mixed cryoglobulinemia in order to investigate the role of the basophil cell in the pathogenesis of the vasculitis typical of this disease. We selected 13 patients and we performed the in vitro basophil degranulation test with cryoprecipitate; in 5 cases the test was positive when it was performed in whole blood, while it was negative when it was performed with cells washed and resuspended in Tyrode's buffer. In 6 subjects it was not possible to perform the test because of the very low number of circulating basophil cells. Finally, in 2 subjects the in vitro basophil degranulation test with cryoprecipitate was negative; this result may be related to the very low levels of complement factors in the sera of these subjects. These findings suggest that the pathogenetic mechanism of vasculitis in idiopathic mixed cryoglobulinemia could be started by basophil activation.

Adult↗
PubMed1992

Differential expression of cell surface integrins on human mast cells and human basophils.

Integrins are multifunctional recognition molecules and are expressed on various hematopoietic cells. In the present study expression of integrins on the cell surface of human mast cells and human basophils was investigated by using monoclonal antibodies (mAbs) and indirect immunofluorescence. Human mast cells were obtained from lung (n = 5), uterus (n = 5) and skin (n = 4). Human blood basophils were obtained from normal donors (n = 2). In addition, HMC-1 cells (human mast cell line) and KU-812 cells (a basophil cell line) were analyzed. Primary mast cells were found to react with mAbs directed against the common beta chain of beta 1 integrins (CD 29), the alpha chain of VLA-4 (CD 49 d) and VLA-5 (CD 49 e), the beta chain of beta 3 integrins (CD 61), and the alpha chain of the vitronectin receptor (VNR) (CD 51). Mast cells were not recognized by mAbs to beta 2 integrins (CD 18, CD 11 a, CD 11 b, CD 11 c), the alpha chain of VLA-2 (CD 49 b), and VLA-6 (CD 49 f). No differences in expression of integrins on human mast cells obtained from different organs were found. HMC-1 cells and primary mast cells expressed an almost identical pattern of integrins. Human basophils and KU-812 cells were found to react with mAbs directed against beta 1-integrins (CD 29, CD 49 b, CD 49 d, CD 49 e) and beta 2-integrins (CD 18, CD 11 a, CD 11 b, CD 11 c). Together, mast cells and blood basophils express a unique pattern of integrins. These cell surface structures may be involved in the distribution of basophils and tissue mast cells and their accumulation and function in inflammed tissues.

Antibodies, Monoclonal↗
PubMed1978

Electron microscope study of basophilic cells in allergic nasal secretions.

In order to elucidate whether basophilic cells in nasal secretion belong to blood basophil or tissue mast cell, basophilic cells in the blood, nasal secretion, and nasal mucous membrane were electron microscopically observed in patients with house dust nasal allergy. The majority of basophilic cells in the nasal secretion was identical with the blood basophil in structure. The blood basophils pass through the vessels and emigrate in the mucous blanket in allergy.

Adult↗
PubMed1987

Impaired basophil histamine release from allergic patients.

A few patients (6-7%) with a verified type I allergic reaction do not respond with histamine release after challenge of their basophils with specific antigen (non-responding basophils from allergic patients). Sera from these non-responding patients were used for passive sensitization of responding cells from healthy controls. When these sensitized cells were challenged with specific antigen, histamine release was observed indicating that the non-responding allergic patients have circulating antigen-specific IgE capable of binding to Fc-receptors on the basophils. These findings suggest the possibility that non-responding basophils have impaired cell functions. We therefore examined the influence of enhanced IgE receptor stimulation on histamine release in non-responding basophils. This was made by stimulating protein kinase C activity by a phorbol ester (phorbol 12-myristate 13-acetate). When the non-responding cells were incubated with the phorbol ester and challenged with either anti-IgE or specific antigen, the cells released histamine. These findings support the hypothesis that the unresponsiveness of basophils in some allergic patients is associated with impaired IgE receptor complex activation or subcellular functioning and not with a lack of cell-bound IgE.

Asthma↗
PubMed2004

Histamine dilutions modulate basophil activation.

BACKGROUND: In order to demonstrate that high dilutions of histamine are able to inhibit basophil activation in a reproducible fashion, several techniques were used in different research laboratories. OBJECTIVE: The aim of the study was to investigate the action of histamine dilutions on basophil activation. METHODS: Basophil activation was assessed by alcian blue staining, measurement of histamine release and CD63 expression. Study 1 used a blinded multi-centre approach in 4 centres. Study 2, related to the confirmation of the multi-centre study by flow cytometry, was performed independently in 3 laboratories. Study 3 examined the histamine release (one laboratory) and the activity of H(2) receptor antagonists and structural analogues (two laboratories). RESULTS: High dilutions of histamine (10(-30)-10(-38) M) influence the activation of human basophils measured by alcian blue staining. The degree of inhibition depends on the initial level of anti-IgE induced stimulation, with the greatest inhibitory effects seen at lower levels of stimulation. This multicentre study was confirmed in the three laboratories by using flow cytometry and in one laboratory by histamine release. Inhibition of CD63 expression by histamine high dilutions was reversed by cimetidine (effect observed in two laboratories) and not by ranitidine (one laboratory). Histidine tested in parallel with histamine showed no activity on this model. CONCLUSIONS: In 3 different types of experiment, it has been shown that high dilutions of histamine may indeed exert an effect on basophil activity. This activity observed by staining basophils with alcian blue was confirmed by flow cytometry. Inhibition by histamine was reversed by anti-H2 and was not observed with histidine these results being in favour of the specificity of this effect We are however unable to explain our findings and are reporting them to encourage others to investigate this phenomenon.

Alcian Blue↗
PubMed1995

[The role of basophilic leukocytes in inflammatory skin diseases].

Basophilic leukocytes are effector cells of the peripheral blood. They have several morphological and functional characteristics in common with tissue mast cells, such as expression of the high-affinity IgE receptor (Fc epsilon RI) and a high content of histamine within their granules. Functional comparison of human basophils and human mast cells isolated from different tissues revealed marked heterogeneity of mediator release after incubation with different secretagogues. Owing to their wide range of surface receptors, their (pro)inflammatory mediators released after activation, their mobility, and their rapid turnover, basophils appear basically to be potent effector cells, which migrate transiently into the skin during IgE-mediated (and/or IgE-independent) inflammatory reactions. The present paper reviews recent findings on the possible role of basophils for different immune reactions of the skin. Inhibition of basophil (and/or mast cell) activity seems to be necessary for both effective prophylaxis and therapy of allergic and inflammatory skin diseases. To date, however, the pharmacological modulation of mediator release from basophils lacks potent clinically useful compounds that can suppress the cellular response, since mast cell stabilizers such as cromoglycate and nedocromil are not effective. With a view to the development of active compounds, further in vitro studies should focus on the mechanisms of cell activation.

Basophils↗
PubMed1998

Sulfated glycosaminoglycans in guinea pig basophils studied by means of cationic colloidal gold.

Bone marrow embedding in the hydrophilic resin, Lowicryl K4M, followed by cationic colloidal gold (CCG, pH 1.0) staining was used to study the sulfated glycosaminoglycans (GAGs) and their sites of sulfation ultrastructurally in various maturational stages of both basophil granulocytes and basophil granules in the guinea pig. CCG at pH 1.0 is specific for sulfated GAG staining. Basophil granulocytes and granules reacted positively to CCG with a variety of staining according to the stage of maturation. The formation of basophil granules takes place throughout the myelocyte stage. Early basophil myelocytes contain a large Golgi apparatus with active granulogenesis, while late myelocytes contain a small and less active Golgi apparatus as judged by CCG staining. All the immature granules and some of the granules with characteristic ultrastructure stained positively. However, some of the mature granules had lost their affinity for CCG upon maturation. Interestingly, strongly positive CCG staining was also observed in the trans to transmost Golgi apparatus. This indicates that sulfation of GAGs occurs in the trans to transmost Golgi apparatus in all maturational stages of basophil granulocytes. Treatment with chondroitinase ABC or heparinase I abolished the majority of CCG staining.

Animals↗
PubMed1998

A role for vesicles in human basophil secretion.

The evidence for vesicular transport as a mechanism for secretion by human basophils is reviewed. Initially, direct electron-microscopic inspection of experimentally produced and sequentially biopsied contact allergy skin lesions revealed a unique form of secretion termed piecemeal degranulation, characterized by the slow emptying of secretory granule contents (with retention of empty containers) in the absence of extrusion of entire granules. Budding of small vesicles to/from secretory granules was observed, and cytoplasmic vesicles were abundant. A generalized degranulation model was proposed to unify classical regulated secretion and this new form of secretion. Investigation of the mechanism(s) of secretion from human basophils required the development of numerous tools and resources. Chief among these were: (a) isolation and purification of circulating basophils; (b) identification of specific growth factors to increase the supply of this rare granulocyte; (c) understanding of secretogogue mechanisms and reliable analyses of secreted basophil products; and (d) development of ultrastructural preparations allowing imaging of small vesicles and quantifiable small electron-dense tags for granule materials in small vesicles. Applications of these tools to well-defined models of basophil secretion have established a role for vesicles as a mechanism for effecting secretion of histamine and the Charcot-Leyden crystal protein from activated human basophils.

Basophils↗
PubMed1983

Ornithodorus tartakovskyi: quantitation and ultrastructure of cutaneous basophil responses in the guinea pig.

Cutaneous lesions elicited in guinea pigs by primary and secondary feeding populations of the argasid tick, Ornithodorus tartakovskyi, were analyzed by light and electron microscopy. Small clusters of basophils appeared at primary bite sites within 24 hr of tick attachment, and by 72 hr constituted approximately 11% of the total leukocytes. Secondary feeding sites exhibited an augmented cellular infiltrate that was dominated by basophils at all times (48-56% of total cells). Eosinophil proliferation was minimal, however, and the remaining cells were of the mononuclear type. Despite mounting a strong cutaneous basophil response of the kind that mediates immune rejection of prolonged-feeding ixodid ticks, the guinea pigs showed no resistance to the fast-feeding Argasidae. It is suggested that argasid ticks probably complete their blood meal prior to basophil arrival at the bite site. Electron microscopy indicated that the number of epidermal Langerhans cells increased with time in both primary and secondary lesions; these cells were more numerous in challenge infections however, and seemed also to occur in the dermis. Basophils at secondary bite sites exhibited three kinds of structural alterations classified as: (1) piecemeal alterations--involving a vesicular degranulation mechanism; (2) an anaphylactic-type of alteration--involving single or compound exocytosis of whole granules; and (3) cytotoxic alterations culminating in complete disintegration. The majority of basophils in 72 hr secondary lesions exhibited cytotoxic alterations. It is suggested that such changes result from contact with tick-derived toxins or enzymes.

Animals↗
PubMed1993

New flow cytometric method for surface phenotyping basophils from peripheral blood.

To clarify the role of basophils in the pathogenesis of allergic disease, we developed a new method for performing surface phenotyping of these cells in centrifugation-enriched mononuclear cell fraction. This method identified basophils on the basic of a negative reactivity with mixed FITC-conjugated monoclonal anti-bodies (mAbs) (anti-CD2, -CD14, -CD16, and -CD19) with analysis performed by flow cytometry. The validity of this approach was confirmed by sorting experiments. Various PE-conjugated mAbs were also used to examine binding to FITC-negative basophils. Basophils from asthmatic patients (n = 14) as well as from normal subjects (n = 6) were shown to express CDw32 (Fc gamma RII), CD25 (IL-2R), but not CD64 (Fc gamma RI). We also detected binding of IgG1 and IgG4 to basophils. This method of phenotyping was very rapid and simple. It thus appears to be useful in the study of allergic disease, as well as of the biology of the basophil.

Antibodies, Monoclonal↗
PubMed1979

Early effects of corticosteroids on basophils, leukocyte histamine, and tissue histamine.

The comparative effect in 11 atopic subjects of a single intravenous injection of methylprednisolone on sequential studies of blood eosinophils, basophils, leukocyte sensitivity to antigen for histamine release, leukocyte histamine content, and skin histamine was examined. No significant changes occurred in any parameter after placebo treatment. In contrast, 4 hr after intravenous treatment with steroid there were significant decreases in mean eosinophil counts (-95%), basophil counts (-72%), and histamine content of 1 X 10(7) leukocyte samples (-62%). Temporal changes in the latter paralleled alterations in circulating basophil levels. No significant changes occured in the antigen histamine release sensitivity, or the total skin histamine. Studies over a longer period after steroids in 4 subjects showed eosinophil and basophil levels at a nadir at 8 hr, remaining suppressed for 24 hr, and returned to pretreatment levels by 72 hr. Results suggest that corticosteroids induce a prominent decrease in leukocyte histamine due to a depletion of basophils without a decrease in histamine content per basophil, and that skin tissue histamine stores remain unchanged by such treatment.

Basophils↗
PubMed1986

Conjunctival basophil hypersensitivity in the guinea pig.

We have induced a basophil hypersensitivity reaction in the upper tarsal conjunctiva of the guinea pig by methods that induce a comparable basophil hypersensitivity reaction in the flank. The inflammatory cell infiltrate in this reaction contained large numbers of basophils and eosinophils with accompanying neutrophils and monocytes. Ocular tissue can serve as a priming site for systemic immunization and also for elicitation of a secondary flare after challenge with antigen. Very few inflammatory cells were observed in the cutaneous epithelium of either primary or secondary flares. In contrast, the mucosal stroma and epithelium contained large numbers of inflammatory cells (basophils, eosinophils, and neutrophils), suggesting directed cellular movement onto the ocular surface. The lesion of ocular basophil hypersensitivity in the guinea pig has features in common with two human eye diseases, vernal conjunctivitis and contact lens-associated giant papillary conjunctivitis. We hypothesize that the acute basophil hypersensitivity reactions of the conjunctiva are transformed into chronic inflammatory and proliferative states in vernal conjunctivitis and giant papillary conjunctivitis.

Animals↗
PubMed1987

Effects of sex hormones on basophil histamine release in recurrent idiopathic anaphylaxis.

A subset of patients with recurrent anaphylaxis experience ovarian hormone-related exacerbations. Symptoms in several of these women may be provoked by gonadotropins or progesterone (P) and improved by ovarian suppression, with long-term remissions noted in several patients after oophorectomy. Since adverse reactions to P might explain this association, the effects of P and estrogen on basophil histamine release from these patients were studied. Eight patients and 10 control subjects were examined. Neither estrogen nor P caused histamine release from the basophils of patients or control subjects. Moreover, anti-IgE-induced histamine release was not influenced by P or estrogen. Attempts to culture basophils for 24 hours revealed that basophil preparations from eight of 10 normal subjects but only three of eight patients retained the capacity to respond to anti-IgE after 24 hours (p = 0.088). Culture with dexamethasone reduced anti-IgE-induced histamine release in all subjects, and the possibility that P might interfere with the effect of dexamethasone was also studied. P failed to affect dexamethasone-induced reduction of basophil histamine release. Therefore, P and estradiol appear to have no effect on basophils from either patients with hormone-related exacerbations of anaphylaxis or from control subjects.

Adolescent↗
PubMed1987

Two populations of human blood basophils: effect of prednisone on circulating numbers.

In a previous study, human blood basophils were separated by centrifugation on Percoll gradients into two fractions, band 1 and band 2, that differed in density and histamine content. In this study, the change in circulating numbers of band 1 and band 2 basophils, as well as other leukocytes, was measured after a single oral dose of prednisone. Three hours after ingestion of 50 mg of prednisone, the circulating number of band 1 basophils was 19 +/- 4% of the preprednisone value, whereas the band 2 level was 87 +/- 18% (SEM for five subjects). At 6 hours, values were 10 +/- 1% and 41 +/- 7% for band 1 and band 2, respectively. Circulating numbers of both basophil populations returned to near normal at 24 hours. The 3-hour response to a 10 mg oral dose in seven subjects was 28 +/- 5% and 89 +/- 10% of preprednisone levels for band 1 and band 2; the 6-hour responses were 28 +/- 7% and 84 +/- 7%. The 3-hour responses of other leukocytes in four of these subjects, expressed as a percentage of preprednisone counts were neutrophils, 171 +/- 27%; lymphocytes, 47 +/- 6%; monocytes, 36 +/- 9%; and eosinophils, 26 +/- 11%. The results demonstrate that band 2 basophils have a lower sensitivity to glucocorticoid action than do band 1 basophils or other types of circulating leukocytes.

Administration, Oral↗
PubMed1993

Antigen avoidance in a mountain environment: influence on basophil releasability in children with allergic asthma.

BACKGROUND: The influence of natural antigen avoidance in an environment free of relevant allergens (Istituto Pio XII, Misurina, Italian Alps, 1756 m) and of antigen exposure (sea level) on basophil releasability, as well as on bronchial hyperreactivity (BHR) and specific IgE serum level, were investigated in a group of children with asthma who were allergic to Dermatophagoides pteronyssinus. METHODS: Twenty allergic children with asthma participated in the study. Spontaneous and antigen-induced histamine release, BHR, and serum IgE were investigated at the time of admission, after 40 and 80 days of antigen avoidance, and after 15 days of exposure at sea level. RESULTS: Significant drops in antigen-induced basophil histamine release, BHR, and specific IgE serum level but not in spontaneous basophil histamine release were observed after 40 days of antigen avoidance and were confirmed at a further evaluation after 40 more days. After 15 days of antigen exposure at sea level, specific antigen-induced basophil histamine release, BHR, and serum IgE but not spontaneous basophil histamine release increased promptly, even if not significantly. CONCLUSION: In children with allergic asthma, antigen-induced basophil releasability, BHR, and specific IgE serum levels appear to be modifiable by periods of antigen avoidance or exposure.

Altitude↗
PubMed1985

A new leukemia cell line with Philadelphia chromosome characterized as basophil precursors.

A new myeloid cell line (KU812) was established from a patient with blastic crisis of chronic myelogenous leukemia. His blasts were morphologically characteristic of immature basophils and basophil colonies were grown in agar culture of the blood mononuclear cells. Suspension culture of his blood cells was continued for more than 2.5 years. The KU812 cells morphologically showed a fine reticular nuclei with nucleoli, and some of them contained metachromatic granules with toluidine blue (TB) staining. These granules were positive for astra blue (AB) staining. Immunological marker studies revealed that there were no lymphoid characters except Fc receptors. The KU812 cells grew colonies in in vitro agar cultures, which were proved to be composed of basophils by TB staining and AB staining. Cytogenetical analysis showed marked aneuploidy and was positive for the Philadelphia chromosome (Ph1). The cell lysate was proved to contain histamine. These data suggest that KU812 is a cell line from leukemic basophil precursors. This is the first human basophil cell line, and KU812 will be useful in clarifying the mechanism of basophilic differentiation of the stem cells.

Basophils↗