Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BASOPHILS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources
PubMed1984

Purification of human blood basophils by single step isopycnic banding on Percoll.

Human venous blood, anticoagulated with EDTA, was layered onto a discontinuous Percoll gradient, made from solutions of density 1.088, 1.079, and 1.070 gm/ml. After centrifugation at 700g for 15 min at 22 degrees C, the majority of the blood basophils was found in a narrow band at the density 1.070-1.079 interface (Percoll band 2). For 15 normal donors, mean total basophil number recovered from all locations in the gradient was 3.8 +/- 1.2 (SD) X 10(4) basophils per ml of blood applied. Thus, 95% of the values ranged from 1.5 to 6 X 10(4), which compares favorably with the reported range of 1 to 8 X 10(4) basophils per ml for normal subjects. In the basophil-rich Percoll band 2, 2.8 +/- 0.8 X 10(4) basophils were recovered per ml of blood applied. The mean percentage of basophils in Percoll band 2 was 19%, with a range of 5 to 53%. Monocytes and neutrophils were present in very small numbers; the majority of accompanying cells were small lymphocytes.

Basophils↗
PubMed1994

Increased numbers of circulating basophils with decreased releasability after administration of rhG-CSF to allergic patients.

Preliminary studies in hematological patients have indicated that treatment with rhG-CSF reduces basophil releasability ex vivo. We examined this phenomenon further, in allergic patients. Ten patients with grass pollen rhinoconjunctivitis were given rhG-CSF (5 micrograms/kg/day s.c.) for 5 days, and examined before and after treatment. Basophil counts increased from 5 to 19 x 10(9)/l (P < 0.01). Total blood histamine increased from 80 to 160 micrograms/l (P < 0.01), corresponding to a decrease in average basophil histamine content from 1.5 to 0.81 pg/cell (P < 0.01). Isolated mononuclear cells showed a significantly decreased histamine release (HR) when stimulated with A23187 and grass. Whole blood experiments showed a similar decreased HR to grass and anti-IgE (P < 0.01). However, we found an increase in total blood histamine. We conclude that treatment with rhG-CSF (1) increases the number of circulating blood basophils, (2) reduces the average histamine content per basophil, and (3) reduces the basophil releasability. These findings could be due to the mobilization of immature basophils from the bone marrow.

Adult↗
PubMed1998

Analysis of anti-IgE and allergen induced human basophil activation by flow cytometry. Comparison with histamine release.

OBJECTIVE AND DESIGN: On the basis of flow cytometric methods previously described for the analysis of human basophil activation, we present here a bi-color anti-IgE FITC, anti CD63 PE method and the correlation with histamine release. MATERIALS AND SUBJECTS: Subjects allergic to grass pollen were selected by their clinical history, skin tests and specific IgE. METHODS: Basophils gated in the lymphocyte region of the side scatter (SSC)/forward scatter (FSC) pattern were selected by their high IgE epitope density. Percentage of cells expressing CD63 marker, upregulated on activated basophil membrane, was calculated by the cytometer. Histamine released into the supernatants was measured by RIA. RESULTS: In these conditions, flow cytometric analysis of blood leukocytes showed that the selected cells had the phenotype CD14-, CD19-, CD45+, IgE++ and CD63- or + which is related to human basophil phenotype, the isotype controls being negative. The use of an anti-CD41 FITC antibody also showed the presence of aggregated platelets on the basophil membrane, CD63 antigen being, however, expressed by basophils themselves and not by platelets. Moreover, no statistical difference was observed between histamine release and flow cytometry after passive sensitization of blood donor leukocytes. CONCLUSION: Flow cytometry, as a popular method often used in the immunology and haematology departments of clinical laboratories may represent a new alternative for allergy diagnosis and basophil pharmacology.

Allergens↗
PubMed2006

L3L4ES antigen and secretagogues induce histamine release from porcine peripheral blood basophils after Ascaris suum infection.

The aim of this paper was to investigate the role of porcine basophils in protective immunity. Experimental pigs were infected with 10(3) Ascaris suum eggs daily for 21 days. Control pigs were maintained helminth-free. Circulating porcine basophils were isolated from the anticoagulated whole blood of A. suum-infected and noninfected pigs by dextran (4.5%) sedimentation of erythrocytes or by the centrifugation of dextran-isolated leukocytes through discontinuous Percoll gradients. Results showed that 2.2% of the isolated leukocytes, stained with May-Grunwald Giemsa, were basophils. Each basophil from infected pigs contained 1.30 x 10(-2) to 1.20 x 10(-1) pg of histamine. Peripheral blood basophils (PBBs) from infected swine released 49% specific histamine when induced with A. suum-derived antigen (L3L4ES), 55% with anti-immunoglobulin G, and 62% with calcium ionophore A23l87. During A. suum infection, the number of isolated basophils and histamine levels peaked at 14 to 21 days postinfection and then showed a significant decrease. Percent-specific histamine released from PBBs by infected swine was significantly greater than that released by control pigs. The L3L4ES antigen and secretagogues effectively induced specific/nonspecific histamine release from PBBs and should facilitate future investigations of porcine basophils.

Animals↗
PubMed1987

Purified human basophils do not generate LTB4.

We investigated the release of the 5-lipoxygenase derivatives of arachidonic acid (AA) in purified human basophils and compared them with similar results obtained in the human lung mast cell. We have shown that purified basophils (average purity = 51 +/- 6%) challenged with 0.1 microgram/ml anti-IgE released histamine (35 +/- 9%), and LTC4 (32 +/- 10 ng/10(6) cells) but failed to release measurable quantities of immunoreactive LTB4. In contrast, the non-specific stimulus, A23187, caused the release of histamine and both LTC4 (279 +/- 95 ng/10(6) cells) and LTB4 (148 +/- 41 ng/10(6) cells). Closer analysis of the data revealed an inverse relationship between the levels of LTB4 released and the purity of the basophils, strongly suggesting that the contaminating monocytes were responsible for LTB4 synthesis. Purified human lung mast cells have been shown to release 6 ng of immunoreactive LTB4/10(6) cells, indicating that basophils release significantly less LTB4 following an IgE-mediated challenge. In a series of experiments using highly purified basophils prelabeled with [3H]AA, we demonstrated that exposure to 0.1 microgram/ml anti-IgE led to the release of [3H]LTC4, with no detectable [3H]LTB4, whereas exposure to 1.0 micrograms/ml A23187 caused the release of [3H]LTC4 and smaller quantities of [3H]LTB4, [3H]LTD4, and [3H]LTE4. We failed to detect any [3H]LTB4 in the cell pellet following challenge with either anti-IgE or A23187, indicating that LTB4 was not synthesized and retained within the cell pellet. Finally, we found that exogenously added [3H]LTB4 was not metabolized, either by basophils alone or by basophils stimulated with anti-IgE (0.1 microgram/ml).

Basophils↗
PubMed1989

A staphylococcal protein A rosetting assay for the demonstration of high affinity IgE receptors on rIL-3-dependent human basophil-like cells grown in mixed cell cultures.

Mature basophils can be differentiated from other blood born cells by their morphology, metachromatically staining granules, histamine content, and the presence on their surfaces of high-affinity IgE receptors. The identification of basophil-like cells arising in mixed human bone marrow cultures, however, is made more difficult because of their immaturity and the morphologic alterations due to in vitro culture. Identification of IgE receptors on individual cells in cell preparations which could simultaneously be examined for their histochemical properties would facilitate the study of basophil growth and differentiation. Because this was difficult using existing techniques, we developed an IgE staphylococcal protein A rosetting assay which allows the identification of cells bearing high-affinity IgE receptors and permits the same cells to be examined by a variety of staining techniques. We then examined the appearance of basophil-like cells bearing IgE receptors in cultures of human bone marrow and correlated this data with measurements of IgE receptor number and affinity. The percentage of total cells grown in the presence of human recombinant IL-3 (rIL-3) that rosetted with Staphylococcus aureus increased from 2 +/- 0.5% at 1 week of culture to 7 +/- 2% at 2 weeks, 14 +/- 5% at 3 weeks, and 18 +/- 5% at 4 weeks. Using 125I-labeled IgEPS, the number of IgE receptors per rosetting basophil-like cell was calculated to be 7.3 x 10(4) at 2 weeks, 6.8 x 10(4) at 3 weeks, and 3.9 x 10(4) receptors per rosette positive basophil-like cell at 4 weeks. Finally, the rate of dissociation of IgE from these cultured cells was found to be 4.0 +/- 1.3 x 10(-5) s-1, indicating that IgE bound to IgE receptors on cultured basophil-like cells with high affinity.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1990

Purification of human basophils using mouse monoclonal IgE.

A method was developed to purify human blood basophils using monoclonal mouse IgE. Enriched suspensions of basophils were sensitized with IgE anti-trinitrophenol (TNP) hapten which was prepared from hybridoma culture supernatants. Rosettes were induced with TNP-coupled red cells and separated from contaminating cells on Percoll gradients. Basophils were dissociated from red cells using cold hypotonic lysis. Using this technique the percentage of basophils was increased from less than 1% to an average of 83.5 +/- 7.8% with a recovery of 58.0 +/- 12.7%. Final purities were highest when enriched sensitized suspensions contained greater than or equal to 10% basophils. Using a radioenzymatic assay, purified basophils were shown to contain an average of 1.3 +/- 0.3 pg histamine. Anti-human, but not anti-mouse IgE, released histamine at an optimal dilution. Using this technique, in 3-4 h, we are able to prepare highly purified suspensions of basophils for further study.

Animals↗
PubMed1994

Purification of human basophils by density and size alone.

Basophils typically account for approximately 1% of the white cells in peripheral blood. We have developed a unique method for purifying basophils from whole blood of normal subjects to at least 95% purity. Basophils are separated from other cell types by density-dependent sedimentation in Percoll and cell sorting, based solely on their size and granularity. The mean overall yield ranged from 5% to 28%. The procedure is typically completed within 4 h. The highly purified basophils obtained are functionally competent and morphologically intact. They release histamine in response to Fc epsilon RI-mediated stimulation, express Fc epsilon RI and BSP-1 ligand as analyzed by flow cytometry, and exhibit the known characteristic ultrastructural features of basophils by electron microscopy. This procedure avoids positive-selection antibodies that might perturb receptors on basophils or negative-selection antibodies that might activate other cell types, and can be used to obtain basophils for studies in vitro.

Basophils↗
PubMed1985

The effect of bacterial lipopolysaccharide (LPS) on histamine release from human basophils. I. Enhancement of immunologic release by LPS.

Preincubation of human basophils with bacterial lipopolysaccharide (LPS) purified from the heptose-deficient mutant Salmonella minnesota R595 enhanced by an average of sixfold the response of peripheral blood basophils obtained from allergic donors to several allergens in vitro as judged by release of histamine. Enhancement occurred at suboptimal, optimal, and supraoptimal concentrations of antigen. No effect was seen if basophils were from a nonallergic donor, and LPS by itself rarely caused histamine release from any preparation of basophils. However, histamine release in basophils from nonallergic donors induced by antibody directed against IgE (anti-IgE) also was enhanced by LPS. Potentiation of histamine release occurred if basophils were pretreated with LPS before addition of anti-IgE for as little as 5 min; there was no increase in release if anti-IgE and LPS were added simultaneously to cells. LPS enhanced the rate of release without altering duration of the release response. LPS potentiation of release of histamine by F(ab')2 fragments of anti-IgE was equivalent to its effect on release triggered by the intact antibody molecule, confirming that the effect of LPS is not due solely to its interaction with the Fc component of the anti-IgE. These data thus provide evidence for modulation of basophil response to IgE-mediated stimuli by LPS, resulting in a significant enhancement of response. Enhancement by LPS appears to be independent of the stimulus which triggers the IgE receptor. The contribution of this mechanism to allergic disease or asthma remains to be determined.

Adjuvants, Immunologic↗
PubMed1980

Dose-response studies of the suppression of whole blood histamine and basophil counts by prednisone.

If some clinical problems (e.g., radiographic contrast media reactions) arise from mediator release by circulating basophils, prednisone's capacity to prevent such is likely to be at least partly related to its suppressive effects on whole blood histamine and basophil levels. To establish an optimal dosage schedule, 15 healthy male volunteers entered a two-phased study to determine (1) the single dose of prednisone required to produce maximal suppression of histamine and basophil levels and (2) the effects of repeated prednisone doses. Parameters monitored were whole blood histamine, quantitative basophil counts, white blood cell (WBC) and differential counts, and plasma prednisone, prednisolone, and cortisol levels. Fifty milligrams prednisone suppressed whole blood histamine levels as much as a larger dose and also showed a marked effect on circulating basophils and other leukocytes. Three 50-mg prednisone doses given at 6-hr intervals had a greater effect on whole blood histamine and circulating leukocytes than fewer doses. Thus, the commonly used empirical prednisone dosage regimen is supported. One implication of the results of this study is that greater suppression of blood basophils and histamine levels might be obtained by administering the last prednisone dose about 6 hr before procedures in which a very rapid release of mediators from basophils is anticipated.

Adolescent↗
PubMed1986

Enhanced basophil histamine release to concanavalin A in allergic rhinitis.

It has been suggested that IgE-dependent basophil histamine release (HR) does not necessarily relate to the amount of cell-bound IgE and, therefore, basophil "releasability" must be considered an important factor in this secretory process. To compare an IgE-dependent basophil HR process in nonatopic subjects and patients with allergic rhinitis, concanavalin A (Con A) was used as a secretagogue to stimulate mediator secretion. In 1.0 mmol/L of calcium-containing buffer, basophil HR to Con A (3.0 mcg/ml) was 50.2 +/- 8.6% in patients with allergic rhinitis and only 10.1 +/- 3.9% in nonatopic subjects. To evaluate whether this enhanced HR might be related to increased membrane influx of calcium, the following strategy was followed. Strontium (3.0 and 10.0 mmol/L) enhances immunologic (IgE) release of basophil histamine. Although the mechanism for strontium enhancement is not established, strontium may pass through the membrane channel more easily than calcium to increase secretion. We reasoned that if the enhanced release of histamine to Con A was related to increased membrane permeability to calcium, stimulation of basophil histamine secretion in the presence of strontium would reduce this difference. In both nonatopic subjects and patients with allergic rhinitis, strontium (3.0 and 10.0 mmol/L) enhanced HR. Enhanced HR with strontium was greater with basophils from normal subjects than from subjects with allergic rhinitis. Whether our observations with strontium indicate that the enhanced histamine releasability to Con A in subjects with allergic rhinitis may, in part, be due to a greater influx of calcium after immunologic stimulation must await characterization of the strontium effect or direct measurements of calcium ion disposition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Measurement of histamine-releasing factor activity in individual nasal washings: relationship with atopy, basophil response, and membrane-bound IgE.

We collected individual pools of nasal washings (NWs) from 15 allergic and 15 nonallergic subjects to determine histamine-releasing factor (HRF) activity and to ascertain the relationship of these cytokines with atopic status, basophil releasability, and cell membrane-bound IgE. NWs were concentrated, dialyzed, and assayed with basophils from a single donor. Samples from 12 of 15 allergic subjects and from all the nonallergic subjects revealed greater than or equal to 15% histamine release (HR), 33.5% +/- 21.3% (mean +/- SD) and 38.6% +/- 19.6%, respectively (p greater than 0.05). When we assayed the same samples with autologous basophils, the allergic group demonstrated higher HR than the nonallergic group (31.9% +/- 19.7% versus 4.8% +/- 4.3%; p less than 0.001). A standard lot of mononuclear cell-derived HRFs was also screened with basophils from both groups. Means for HR from basophils of allergic and nonallergic subjects were 51.9% +/- 16.7% versus 26.3% +/- 8.2%, respectively (p less than 0.001). Pretreatment of basophils with lactic acid led to abrogation of sensitivity to HRF. Acid-stripped cells incubated with sera from patients with asthma regained their capacity to release histamine. We found that HRF activity can be detected in NWs of most donors, and there is no difference among allergic and nonallergic subjects. Our results suggest that the capacity of these cytokines to induce HR depends on several factors: atopic status, basophil releasability, and membrane-bound IgE.

Basophils↗
PubMed1984

Bovine resistance to Amblyomma americanum ticks: an acquired immune response characterized by cutaneous basophil infiltrates.

Purebred Holstein calves acquired resistance to Amblyomma americanum adult ticks after 1 infestation and expressed resistance during a challenge infestation 26 days later. Tick yields from resistant animals were normal, but mean tick weight and egg-mass weight were reduced significantly (31 and 32%, respectively). Cutaneous cellular responses at tick feeding sites in primary (naive) hosts consisted almost exclusively of mononuclear cells, until 24-h post-infestation when granulocytes appeared. At 48 h, basophils were the most abundant granulocyte and comprised 19% of the total cellular response. Secondary and tertiary hosts expressed significant cutaneous basophil responses as early as 6 h post-tick infestation, indicative of an anamnestic response. Cutaneous basophil levels in tertiary hosts (16-34% of the infiltrate) were increased by 2-fold over secondary hosts (12-16% of the infiltrate). Neutrophils and eosinophils were fairly abundant in secondary hosts (22-33%, and 3-13%, respectively), but decreased significantly in tertiary hosts corresponding to increased basophil levels. Mast cells comprised less than 10% of the cells found in primary hosts, and less than 5% in secondary and tertiary hosts representing a consistent, but insignificant component of the total cells. Basophils were not observed in the blood of hosts during any tick infestation, but a peripheral blood basophilia (0.1-1.1%) marked the end of each tick feeding period. A neutropenia was observed in the blood of tertiary hosts corresponding to a decreased tissue neutrophil response. Blood eosinophil, lymphocyte and monocyte levels remained unchanged during each tick infestation compared to controls. In summary, calves acquired immunity to A. americanum ticks, resulting in significant decreases in feeding and ovipositional success associated with a local cutaneous basophil response and peripheral blood basophilia. These findings suggest that basophils are involved in bovine immunity to ticks as has been established in the guinea pig model.

Animals↗
PubMed2004

Expression of alpha-tryptase and beta-tryptase by human basophils.

BACKGROUND: Alpha and beta-tryptase levels in serum are clinical tools for the evaluation of systemic anaphylaxis and systemic mastocytosis. Basophils and mast cells are known to produce these proteins. OBJECTIVE: The current study examines the effect of the alpha,beta-tryptase genotype on basophil tryptase levels and the type of tryptase stored in these cells. METHODS: Tryptase extracted from purified peripheral blood basophils from 20 subjects was examined by using ELISAs measuring mature and total tryptase and by using an enzymatic assay with tosyl-Gly-Pro-Lys-p-nitroanilide. Tryptase genotypes (4:0, 3:1, and 2:2 beta/alpha ratios) were assessed by using a hot-stop PCR technique with alpha,beta-tryptase-specific primers. Total alpha,beta-tryptase mRNA was measured by means of competitive RT-PCR, and ratios of alpha to beta-tryptase mRNA were measured by means of hot-stop RT-PCR. RESULTS: Tryptase in all but one of the basophil preparations was mature and enzymatically active. Tryptase quantities in basophils were less than 1% of those in tissue mast cells. Tryptase genotypes (beta/alpha) among the 20 donors were 4:0 in 7, 3:1 in 7, and 2:2 in 6. Tryptase protein and mRNA levels per basophil were not affected by the tryptase genotype. CONCLUSION: Basophils from healthy subjects contain modest amounts of mature and enzymatically active tryptase unaffected by the tryptase genotype.

Basophils↗
PubMed2005

Detection of basophil-activating IgG autoantibodies in chronic idiopathic urticaria by induction of CD 63.

BACKGROUND: Approximately 40% to 50% of patients with chronic idiopathic urticaria (CIU) have functional IgG autoantibodies against FcepsilonRIalpha or IgE, which induce histamine release from basophils and cutaneous mast cells. A positive autologous serum skin test response is believed to reflect the presence of these autoantibodies. OBJECTIVE: We sought to further define the functional properties of and develop a sensitive functional assay for detection of autoantibodies in patients with CIU. METHODS: Sera from patients with CIU (n=61) and sera from healthy control subjects (n=23) were incubated with donor basophils. Activation of basophils was determined on the basis of CD 63 surface expression, as analyzed on a FACScan flow cytometer. RESULTS: A positive basophil activation test result was found in 51% of patients with CIU, and basophil-activating properties were present in the IgG fractions of sera. When both the in vitro test and the autologous serum skin test were considered, basophil/mast cell-activating autoantibodies were present in 62% of the patients. Patients with a positive basophil activation test result had a significantly higher prevalence of other autoantibodies, had more severe urticaria, and were more likely to have angioedema. CONCLUSION: The results demonstrate the presence of basophil-activating autoantibodies in about 50% of patients with CIU. The data support the autoimmune cause of the disease and provide a simple test for detection of these autoantibodies.

Adolescent↗
PubMed2005

5-Oxo-6,8,11,14-eicosatetraenoic acid is a potent chemoattractant for human basophils.

BACKGROUND: 5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is a chemoattractant for eosinophils and neutrophils, and the messenger RNA for its receptor, the oxo-eicosatetraenoic acid receptor (OXE), has been detected in several tissues. OBJECTIVES: This study aimed at clarifying the role of 5-oxo-ETE in the regulation of basophil function. METHODS: Basophil responses were determined in assays of flow-cytometric shape change, Ca(2+) flux, chemotaxis, and histamine release. Messenger RNA for OXE was detected by real-time PCR. RESULTS: We observed that human eosinophils were 3 to 10 times more sensitive to 5-oxo-ETE than neutrophils in flow-cytometric shape change and Ca(2+) flux assays, as estimated from the half-maximal responses of the cells. Basophils responded to 5-oxo-ETE in the shape change assay with a sensitivity similar to that of eosinophils. 5-Oxo-ETE was a weak inducer of Ca(2+) flux in basophils and did not cause histamine release but was a highly effective chemoattractant for basophils in the low nanomolar concentration range in a pertussis toxin-sensitive manner. In agreement with these functional studies, the messenger RNA for the 5-oxo-ETE receptor, OXE, was detectable in basophils as in monocytes, eosinophils, and neutrophils, but not in fibroblasts. Specimens from sinus mucosa, tonsils, and adenoids also contained detectable levels of messenger RNA for OXE. CONCLUSION: Our data suggest that 5-oxo-ETE is potentially involved in the regulation of basophil recruitment and might hence be a useful therapeutic target in atopic disease.

Arachidonic Acids↗
PubMed2004

Transient transfection of human peripheral blood basophils.

The human basophil has resisted previous attempts at transient transfection. Basophils were transfected by nucleoporation and to test whether there was sufficient expression to modify cell function, the cells were transfected with a syk kinase tandem SH2 construct linked to GFP. This approach was taken because in RBL cells and murine mast cells syk kinase is known to play a very early role in signal transduction and previous studies in RBL cells demonstrated that expression of the tandem SH2 domains of syk would inhibit signaling, presumably by competition with endogenous syk for binding to ITAMs. Results from basophil transfections with SH2syk were compared to an empty construct. Basophils were stimulated with anti-IgE antibody and analyzed for single cell changes in cytosolic calcium levels. Basophils expressing the empty GFP construct showed a cytosolic calcium response similar to non-expressing cells. In contrast, basophils expressing the GFP-tandem SH2syk construct, on average, showed an anti-IgE-induced calcium response that was completely ablated. The transfection frequency was 8% (median), with an average viable recovery of 12% (n=18). While the procedure is not benign and is not always successful, these studies indicate that with gating techniques, the human basophil, a non-dividing primary leukocyte, can be transiently transfected to express high enough levels of an inhibitory protein to alter an IgE-mediated response.

Antibodies, Anti-Idiotypic↗
PubMed2003

Immunoglobulin E (IgE) containing complexes induce IL-4 production in human basophils: effect on Th1-Th2 balance in malaria.

Human basophils are potent producers of IL-4 following cross-linking of the high affinity receptor for IgE (Fc epsilon R1). Elevated levels of both total- and malaria-specific IgE have been demonstrated in sera from people living in malaria-endemic regions. Whether or not these IgE antibodies are pathogenic is unclear. Serum containing high IgE levels obtained from malaria individuals was used to establish whether IgE-immune complexes could induce IL-4 production in human basophils. The basophils, obtained from healthy donors, were primed with 10 ng/ml of IL-3 before being transferred to wells containing goat anti-human IgE or human antimalarial IgE-immune complexes. IL-4 was induced upon stimulation of human basophils by plate bound IgE-containing immune complexes. Basophils treated similarly but with goat anti-IgG/human antimalarial- IgG-immune complexes did not secrete IL-4. Similarly mononuclear cells depleted of basophils in parallel culture did not secrete IL-4. Thus, human basophils may contribute to the polarization of T-helper type 2 in the (Th2) responses in malaria hosts via IgE-induced IL-4 production.

Antigen-Antibody Complex↗