Catechin inhibits adhesion and migration of peripheral blood B cells by blocking CD11b

Context: Previously, we demonstrated that CD11b is expressed on peripheral blood memory B cells, and it plays an important role in the migration of B cells. And epigallocatechin gallate (EGCG), a bioactive component of green tea, by binding to CD11b, expressed on CD8(+) cytotoxic T cells, inhibited their migratory ability, one possible mechanism of the antiallergic activity of EGCG.

Objective: Here, we investigated whether EGCG also affected CD11b expressed on B cells, similar to cytotoxic T cells.

Materials and methods: Isolated peripheral blood CD19(+) B cells were treated with EGCG and the change in the expression of CD11b was analyzed using flow cytometry. The effects of EGCG on the ability of B cells to adhere to and to transmigrate through the endothelial cell layer were evaluated using the transwell assay.

Results: EGCG significantly suppressed the apparent expression of CD11b on B cells, in the flow-cytometric analysis, and this apparent suppression was speculated to be dependent on the competitive binding of EGCG to CD11b. EGCG also significantly suppressed CD11b-mediated migration and adhesion of B cells to endothelial cells.

Discussion and conclusion: EGCG has a strong suppressive activity on the adhesive and migratory abilities of peripheral blood B cells. This suppressive activity was mediated by the binding of EGCG to CD11b on B cells, and the consequent suppression of B-cell extravasation to the extravascular space. Because B cell plays an important role in the humoral immunity, EGCG could be a promising drug for the prevention and/or treatment of allergic and/or autoimmune diseases.     

Catechin inhibits adhesion and migration of peripheral blood B cells by blocking CD11b

Context: Previously, we demonstrated that CD11b is expressed on peripheral blood memory B cells, and it plays an important role in the migration of B cells. And epigallocatechin gallate (EGCG), a bioactive component of green tea, by binding to CD11b, expressed on CD8(+) cytotoxic T cells, inhibited their migratory ability, one possible mechanism of the antiallergic activity of EGCG. Objective: Here, we investigated whether EGCG also affected CD11b expressed on B cells, similar to cytotoxic T cells. Materials and methods: Isolated peripheral blood CD19(+) B cells were treated with EGCG and the change in the expression of CD11b was analyzed using flow cytometry. The effects of EGCG on the ability of B cells to adhere to and to transmigrate through the endothelial cell layer were evaluated using the transwell assay. Results: EGCG significantly suppressed the apparent expression of CD11b on B cells, in the flow-cytometric analysis, and this apparent suppression was speculated to be dependent on the competitive binding of EGCG to CD11b. EGCG also significantly suppressed CD11b-mediated migration and adhesion of B cells to endothelial cells. Discussion and conclusion: EGCG has a strong suppressive activity on the adhesive and migratory abilities of peripheral blood B cells. This suppressive activity was mediated by the binding of EGCG to CD11b on B cells, and the consequent suppression of B-cell extravasation to the extravascular space. Because B cell plays an important role in the humoral immunity, EGCG could be a promising drug for the prevention and/or treatment of allergic and/or autoimmune diseases.     

Disparate ability of murine CD8alpha- and CD8alpha+ dendritic cell subsets to traverse endothelium is not determined by differential CD11b expression

Upon Ag uptake and response to maturation stimuli, dendritic cells (DC) are directed through lymphatic or blood vessel endothelium to T cell areas of secondary lymphoid tissues by the constitutively expressed CC chemokines CCL19 and CCL21. We have shown that mature (m) murine CD8alpha+ DC exhibit poorer migratory ability to these chemokines than classic CD8alpha- DC by quantifying their in vitro chemotaxis through unmodified Transwell filters. We hypothesized that lower surface expression (compared to CD8alpha- mDC) of the adhesion molecule CD11b on CD8alpha+ DC might limit their ability to adhere to filter pores in vitro and/or endothelium in vitro/in vivo. To test the role of this and/or other adhesion molecules (CD11a, CD31, CD54 and CD62L) in regulating murine DC subset migration, we used specific mAbs to block their function and quantified their migration through resting or tumour necrosis factor (TNF)-alpha-activated endothelial cell (EC) layered-Transwell filters. Both CD8alpha+ and CD8alpha- subsets migrated through resting EC (albeit less than in the absence of EC) in response to CCL19 and CCL21, and migration through TNF-alpha-activated EC was enhanced. In contrast to reports concerning human DC, transendothelial migration of the murine DC subsets was not dependent on CD11b, CD31, or CD62L expression by these cells. CD54 and CD11a, however, were at least partly involved in DC/EC interactions. This is the first report to examine adhesion molecules involved in transendothelial migration of murine DC subsets.     

Adhesion molecule expression patterns indicate activation and recruitment of CD4+ T cells from the lymph node to the peripheral blood of early cutaneous leishmaniasis patients

Adhesion molecules play a crucial role in cell migration and recruitment. Expression of adhesion molecules that preferentially address cells to inflammatory sites is a critical event in the formation and maintenance of leishmaniasis lesions. In this work, we analyzed the expression of CD11a, CD11b and CD62L, adhesion molecules involved in cell activation and circulation, in CD4+ and CD8+ T cells from peripheral blood and lymph nodes of patients with early cutaneous leishmaniasis. The percentage of expression of CD62L, CD11a and CD11b in total lymphocytes was lower in lymph nodes as compared to peripheral blood. Moreover, differences in adhesion molecule expression between blood and lymph nodes were more striking in CD4+ than CD8+ T cells. Stimulation of PBMC from leishmaniasis patients with soluble Leishmania antigens (SLA) lead to the expansion of CD4+CD62Lhigh cells, CD4+CD11b+ cells and to an increase in the intensity of expression of CD11a in CD4+, but not CD8+ T cells. Our data suggest that early activation events that occur in the lymph nodes of patients recently infected with Leishmania lead to changes in T cell adhesion molecule expression, favoring migration to the periphery and increasing the likelihood of further recruitment to lesion sites.     

Epigallocatechin gallate, the main polyphenol in green tea, binds to the T-cell receptor, CD4: Potential for HIV-1 therapy

BACKGROUND: The green tea flavonoid, epigallocatechin gallate (EGCG), has been proposed to have an anti-HIV-1 effect by preventing the binding of HIV-1 glycoprotein (gp) 120 to the CD4 molecule on T cells. OBJECTIVE: To demonstrate that EGCG binds to the CD4 molecule at the gp120 attachment site and inhibits gp120 binding at physiologically relevant levels, thus establishing EGCG as a potential therapeutic treatment for HIV-1 infection. METHODS: Nuclear magnetic resonance spectroscopy was used to examine the binding of EGCG and control, (-)-catechin, to CD4-IgG2 (PRO 542). Gp120 binding to human CD4+ T cells was analyzed by flow cytometry. RESULTS: Addition of CD4 to EGCG produced a linear decrease in nuclear magnetic resonance signal intensity from EGCG but not from the control, (-)-catechin. In saturation transfer difference experiments, addition of 5.8 micromol/L CD4 to 310 micromol/L EGCG produced strong saturation at the aromatic rings of EGCG, but identical concentrations of (-)-catechin produced much smaller effects, implying EGCG/CD4 binding strong enough to reduce gp120/CD4 binding substantially. Molecular modeling studies suggested a binding site for EGCG in the D1 domain of CD4, the pocket that binds gp120. Physiologically relevant concentrations of EGCG (0.2 micromol/L) inhibited binding of gp120 to isolated human CD4+ T cells. CONCLUSION: We have demonstrated clear evidence of high-affinity binding of EGCG to the CD4 molecule with a Kd of approximately 10 nmol/L and inhibition of gp120 binding to human CD4+ T cells. CLINICAL IMPLICATIONS: Epigallocatechin gallate has potential use as adjunctive therapy in HIV-1 infection.     

Epigallocatechin gallate induces apoptosis of monocytes

BACKGROUND: Monocytes are the main effector cells of the immune system, and the regulation of their survival and apoptosis is essential for monocyte-involved immune responses. Green tea polyphenol catechin has been reported to have antiallergic and anti-inflammatory activities, but its effect on monocytes has not yet been explored. OBJECTIVE: To elucidate the mechanisms of the anti-inflammatory effect of catechin, we studied the effect of catechin, especially epigallocatechin gallate (EGCG), on the apoptosis of monocytes. METHODS: Isolated peripheral blood monocytes were incubated without or with catechin, and apoptosis was evaluated by annexin V and propidium iodide double-staining or terminal deoxynucleotidyl assay. The activation of caspases 3, 8, and 9 was also evaluated by flow cytometry. The influence of GM-CSF or LPS, the known monocyte survival factors, on the EGCG-induced apoptosis of monocytes was investigated. RESULTS: Among the 4 catechin derivatives tested, EGCG and epicatechin gallate induced apoptosis of monocytes. Caspases 3, 8, and 9, which play a central role in the apoptotic cascade, were dose-dependently activated by EGCG treatment. The EGCG-induced apoptosis of monocytes was not affected by GM-CSF or LPS. CONCLUSION: Catechin, especially EGCG, by promoting monocytic apoptosis, may be a new promising anti-inflammatory agent, and should be tested in clinical trials.     

Impaired CD4 and CD8 T cell phenotype and reduced chemokine secretion in recent-onset type 1 diabetic children

Although the role of the T cell-mediated autoimmune reaction in type 1 diabetes (T1D) is conclusive, studies including data from human circulating CD4(+) and CD8(+) lymphocytes subsets during the disease onset and posterior development are scarce. Further, chemokines and chemokine receptors are key players in the migration of pathogenic T cells into the islets of non-obese diabetic mice developing T1D, but few studies have investigated these markers in human T1D patients. We studied the expression of T helper 1 (Th1)- and Th2-associated chemokine receptors, and the two isoforms of CD45 leucocyte antigen on CD4(+) and CD8(+) lymphocytes from T1D and healthy children, as well as the secretion of chemokines in cell supernatants in peripheral blood mononuclear cells. Our results showed increased expression of CCR7 and CD45RA and reduced CD45RO on CD8(+) cells among recent-onset T1D patients. The percentages of CD4(+) cells expressing CXC chemokine receptor 3 (CXCR3), CXCR6 and CCR5, and the secretion of interferon-gamma-induced protein-10, monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-1alpha and MIP-1beta was lower among diabetics. Low expression of Th1-associated receptors and secretion of chemokines, together with an increased amount of CD8(+) cells expressing CD45RA and CCR7 in T1D patients therefore might represent suboptimal Th function in T1D, leading to impaired T cytotoxic responses or alternatively reflect a selective recruitment of Th1 cells into the pancreas.     

Epigallocatechin gallate, the main component of tea polyphenol, binds to CD4 and interferes with gp120 binding

BACKGROUND: Epigallocatechin gallate (EGCG), the major component of tea polyphenol, has been reported to have various physiologic modulatory activities. Several reports also have shown that catechin has a protective effect against HIV infection, part of which is mediated by inhibiting virions to bind to the target cell surface. OBJECTIVE: We investigated the effect of EGCG on the expression of CD4 molecules and on its ability to bind gp120, an envelope protein of HIV-1. METHODS: Peripheral blood CD4+ T cells were incubated in the presence of EGCG, and the expression of CD4 was evaluated by means of flow cytometry. The effect of EGCG on the antibody binding to CD4 was investigated by using a sandwich ELISA, and the effect on the gp120 binding to CD4 was analyzed by means of flow cytometry. RESULTS: EGCG efficiently inhibited binding of anti-CD4 antibody to its corresponding antigen. This effect was mediated by the direct binding of EGCG to the CD4 molecule, with consequent inhibition of antibody binding, as well as gp120 binding. CONCLUSION: The present results suggest a potential preventive effect of EGCG on HIV-1 infection by modulating binding to CD4.     

Differential regulation of CD11b on gammadelta T cells and monocytes in response to unripe apple polyphenols

Leukocyte adhesion and migration are mediated partially by CD11b/CD18 (membrane-activated complex-1, CR3). Earlier studies have demonstrated a role for green tea polyphenols in down-regulating CD11b on CD8(+) T cells and monocytes. We have shown recently a stimulatory effect of unripe apple polyphenols (APP) on gammadelta T cells. Thus, we compared the effect of APP on bovine gammadelta T cell and monocyte CD11b expression. Purified bovine monocytes and monocyte-depleted PBLs were cultured with APP. CD11b levels decreased on monocytes in response to APP. In contrast, a gammadelta T cell subset responded to APP by up-regulating CD11b. The CD11b regulation was not seen on gammadelta T cells or monocytes treated with APP fractions depleted of tannins. The APP-induced down-regulation of CD11b on monocytes was inhibited by an anti-CD11b mAb, consistent with previous studies showing that polyphenols bind CD11b. As expected, the anti-CD11b mAb had no effect on the APP response in resting gammadelta T cells, as these cells lacked CD11b. Consistent with the changes in surface CD11b expression, APP-treated gammadelta T cells showed increased adherence to plastic, whereas monocyte adhesion was reduced. APP also induced cytokine gene expression in gammadelta T cells. Some polyphenols are thought of as anti-inflammatory agents; however, these data, as well as other ongoing studies, indicate they have a proinflammatory effect on gammadelta T cells. In vivo, plant polyphenols may enhance gammadelta T cell migration and function at sites of inflammation, where they could induce rapid, immune-regulatory and innate-like immune responses.     

Mouse CD146/MCAM is a marker of natural killer cell maturation

CD146/melanoma cell adhesion molecule is an adhesion molecule expressed by endothelial cells and by a small fraction of activated T and B lymphocytes in humans. In order to analyze the pattern of CD146 expression in mouse leukocytes at steady-state conditions, we generated a set of novel rat anti-mouse CD146 monoclonal antibodies. CD146 expression was undetectable on monocytes, dendritic cells, T cells or B cells, but was expressed on about 30% of neutrophils and 60% of NK cells. Within murine lymphocytes, CD146 was defined as a novel NK-specific surface molecule. An increased percentage of CD146+ cells was found in the most mature CD27(-)CD11b+ NK cell subpopulation, which also displays higher expression of Ly49C/I, Ly49D and KLRG1 and lower expression of NKG2A/C/E molecules. CD146+ NK cells were found to be less cytotoxic and produce less IFN-gamma than CD146(-) NK cells upon stimulation with target cells or activating antibodies. These findings define CD146 as a marker of mouse NK cell maturation that may be used as an alternative to the combined use of CD27 and CD11b staining to detect final stages of NK cell maturation.     

Differential expression of beta1 and beta2 integrins and L-selectin on CD4+ and CD8+ T lymphocytes in human blood: comparative analysis between isolated cells, whole blood samples and cryopreserved preparations

Flow cytometric analysis was used to compare the expression of adhesion molecules on human CD4+ and CD8+ T lymphocytes in isolated blood mononuclear cells (MNCs) in whole blood samples and in cryopreserved MNC preparations. Examination of MNCs revealed that the CD11b and CD11c components of the beta2 integrins were preferentially expressed on CD8+ T cells, whereas CD62L was present on more CD4+ T cells. All CD4+ and CD8+ T lymphocytes were positive for CD11a but the CD8+ population had a higher intensity of expression of CD11a and also CD11b. Virtually identical results were obtained with T cells in whole blood samples. In relation to the beta1 integrins, the only difference between isolated CD4+ and CD8+ T cells was that the latter subset had a greater proportion of cells bearing CD49d. The naive cell marker CD45RA was present on the majority of CD8+ T cells whereas CD45RA and the memory marker CD45RO were evenly distributed within the CD4+ T cell subset. Although cryopreservation of lymphocytes did not modify the expression of beta1 and beta2 integrins it produced a marked reduction in the percentage of CD4+ and CD8+ T cells bearing CD62L. With regard to endothelial interactions, it appears that cryopreserved lymphocytes are suitable for inclusion in studies of integrin-mediated adhesion but not for those relating to tethering or recognition of addressins on high endothelial venules. Differences in adhesion molecule expression between CD4+ and CD8+ T lymphocytes could underlie the selective extravasation of these subsets into sites of infection and inflammation.     

Chemokines,chemokine receptors and CD4+CD25+ regulatory T cells

The fields of regulatory T (Treg) cells and chemokines/chemokine receptors have progressed rapidly in the last few years. Treg cells, especially CD4⁺CD25⁺ Treg cells, play a critical role in maintaining self-tolerance and immune homeostasis. Chemokines and chemokine receptors are crucial for lymphoid development, homing and immunological regulation. This review will discuss the biological effects of chemokines and chemokine receptors on regulating the migration and development of CD4⁺CD25⁺ Treg cells, and the potential clinical implications of these findings when considering chemokine receptors as therapeutic targets.     

Expression of CD23 antigen and its ligands in children with intrinsic and extrinsic asthma

The role of the low-affinity IgE receptor CD23 in immune reactions has been further emphasized by recent discoveries of novel surface ligands for CD23: CD21, CD11b, and CD11c. We previously observed the difference between the expression of CD23 and CD21 antigens in children suffering from extrinsic asthma when compared to healthy controls. In the present study, we investigated the expression of CD23 and its ligand CD21 on CD20⁺B cells in 44 asthmatic children (23 allergic and 21 nonallergic) using three-color immunofluorescence analysis. In addition, the expression of two other ligands for CD23, CD11b, and CD11c, on T cells (CD3⁺), a subpopulation of T cells (CD4⁺ and CD8⁺), natural killer cells (CD56⁺), and monocytes (CD14⁺) was tested by two-color immunofluorescence analysis in 12 allergic and 14 nonallergic children. We found that children with extrinsic asthma had higher levels of CD23⁺ B cells than those with intrinsic asthma. No difference was observed in the percentage of either CD23⁺CD21⁺ or CD23^- CD21⁺ B cells. The CD11b antigen was expressed on each tested population, but only on CD4⁺ T cells was CD11b significantly increased in children with extrinsic asthma. CD11c was expressed mainly on monocytes, and no difference was observed between tested groups. The increased percentage of CD11b antigen on CD4⁺ T cells and the increased percentage of CD23 antigen on B cells in children with extrinsic asthma provide further evidence of the immunologic differences between intrinsic and extrinsic asthma.     

Level of major histocompatibility complex class I expression on endothelium in non-obese diabetic mice influences CD8 T cell adhesion and migration

An important prerequisite for development of insulitis and β-cell destruction in type 1 diabetes is successful transmigration of autoreactive T cells across the islet endothelium. Previous work suggests that antigen presentation to T cells by endothelium, which requires endothelial cell expression of major histocompatibility complex (MHC) molecules, promotes tissue-specific T cell migration. We therefore tested the hypothesis that the level of endothelial MHC class I molecule expression in diabetes-prone mice directly influences autoreactive CD8 T cell migration. We investigated the immune phenotype of endothelial cells, focusing on endothelial MHC class I molecule expression in a range of different tissues and mouse strains, including non-obese diabetic (NOD) mice. In addition, we examined whether the level of expression of MHC class I molecules influences autoantigen-driven CD8 T cell transmigration. Using endothelial cell lines that expressed ‘high’ (NOD mouse), medium (NOD × C3H/HeJ F₁ generation mice) and no (C3H/HeJ) H-2K^d, we demonstrated in vitro that MHC levels have a profound effect on the activation, adhesion and transmigration of pathogenic, islet autoreactive CD8 T cells. The expression level of MHC class I molecules on endothelial tissues has a direct impact upon the efficiency of migration of autoreactive T cells. The immune phenotype of microvascular endothelium in NOD mice may be an additional contributory factor in disease predisposition or development, and similar phenotypes should be sought in human type 1 diabetes.     

Altered expression of CD11/CD18 on the peripheral blood phagocytes of patients with tuberculosis.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is characterized by granulomatous lesions made up of epithelioid cells, giant cells and mononuclear leucocytes. Cell-cell adhesion is important in granuloma formation and in the leucocyte migration which accompanies it. We have recently shown increased expression of the adhesion molecules CD11/CD18 (LeuCAMs, beta 2 integrins) on peripheral blood leucocytes from patients with sarcoidosis (Shakoor & Hamblin, 1992). Here we have studied the expression of CD11/CD18 and CD29 (VLA beta 1 integrin) on the peripheral blood leucocytes of 10 TB patients by flow cytometry. The density (expressed as mean fluorescence intensity) of CD11b on monocytes and polymorphs was increased (P < 0.005), as was CD11c (P < 0.005) and CD18 (P < 0.05) on polymorphs. CD11a expression was significantly reduced on polymorphs (P < 0.05). No differences were found in the expression of CD29, the percentages of cells expressing any molecule and, in contrast to sarcoidosis, the density of any molecule on lymphocytes. Although the cytokine tumour necrosis factor (TNF) has been implicated in the process of up-regulation, an ELISA for TNF failed to detect significant levels in plasma. The results suggest increased peripheral phagocyte CD11/CD18 expression is a feature of TB, which may contribute to the pathological processes involved.     

CD5 plays an inhibitory role in the suppressive function of murine CD4(+) CD25(+) T(reg) cells

A subset of CD4(+) T cells, the CD4(+) CD25(+) regulatory T (T(reg)) cells in the lymphoid organs and peripheral blood are known to possess suppressive function. Previous in vitro and in vivo studies have indicated that T cell receptor (TCR) signal is required for development of such 'natural regulatory (T(reg)) cells' and for activation of the effector function of CD4(+) CD25(+) regulatory T cells. CD5 is a cell surface molecule present on all T cells and a subtype of B lymphocytes, the B-1 cells, primarily localized to coelomic cavities, Peyer's patches, tonsils and spleen. CD5 acts as a negative regulator of T cell and B cell signaling via recruitment of SHP-1. Here, we demonstrate that T(reg) cells obtained from CD5(-/-) mice are more potent than those from wild type mice in suppressing the in vitro cell proliferation of anti-CD3 stimulated CD4(+) CD25(-) responder T cells. This phenomenon was cell contact and GITR dependent. Lack of CD5 expression on T(reg) cells (from spleen, lymph node and thymus) did not affect the intracellular levels of Foxp3. However, CD5(-/-) T(reg) thymocytes were able to elicit a higher Ca(2+) response to TCR + co-stimulatory signals than the wild type cells. CD5(-/-) mice expressed more Foxp3 mRNA in the colon than wild type mice, and additionally, the severity of the dextran sulfate sodium (DSS)-induced colitis in CD5(-/-) mice was less than the wild type strain. We suggest that manipulation of CD5 expression or the downstream signaling components of CD4(+) CD25(+) T(reg) cells as a potential strategy for therapeutic intervention in cases of auto-immune disorders.     

Increased cytolytic T lymphocyte activity and decreased B7 responsiveness are associated with CD28 down-regulation on CD8+ T cells from HIV-infected subjects.

The CD28 receptor on CD4+ and CD8+ T cells interacts with B7 molecules on antigen-presenting cells (APC) to generate essential costimulatory signals. The cytolytic potential of CD8+ T cells could be linked to CD28 expression. Since HIV induces dysfunction of both CD4+ and CD8+ T cells, we evaluated CD28 expression and function in both subsets during HIV infection. CD28 expression on CD8+ T cells from HIV+ subjects was strongly reduced in a disease stage-related fashion. CD28- CD8+ T cells preferentially expressed CD57 and CD11b, but lacked CD26 and IL-2R alpha. The CD8+ T cells from the patients showed a significantly reduced proliferative response to co-stimulation with cell-bound anti-CD3 and B7. Nevertheless, when stimulated with plate-fixed anti-CD3, CD8+ T cells from HIV-infected subjects proliferated normally, and normal levels of IL-2R alpha and transferrin-receptor could be induced on CD28- CD8+ T cells from the patients. In addition, stimulation with plate-fixed anti-CD3 induced proliferative responses in highly purified CD28- CD8+ T cells from both HIV- and HIV+ persons. Furthermore, the increased cytotoxic activity of peripheral blood mononuclear cells (PBMC) from HIV+ subjects, measured in an anti-CD3 redirected assay, was predominantly exerted by CD28- CD57+ T cells. CD4+ T cells from the patients showed a slight but significant CD28 down-regulation and were slightly hyporesponsive to B7 co-stimulation. Decrease of CD28 on CD8+ T cells from HIV+ subjects is associated with an impaired response to co-stimulation via B7. CD28- CD8+ T cells from seropositives, however, are not completely inert, since they contain in vivo activated CTL and they can be additionally activated through a B7-independent stimulation.     

Increased CD11b expression on polymorphonuclear leucocytes and cytokine profiles in patients with Kawasaki disease

Clinical evidence implicates polymorphonuclear leucocytes in the pathogenesis of vasculitis in Kawasaki disease. We examined modulation of expression of adhesion molecules (CD11b and CD62L) on polymorphonuclear leucocytes and how this expression is related to serum cytokine concentrations. In 18 patients with Kawasaki disease and 15 control subjects, adhesion molecule expression was determined by two-colour immunofluorescence staining of blood leucocytes and flow cytometry. Eight cytokines and chemokines were also measured. In patients with Kawasaki disease, mean fluorescence intensity for CD11b before giving intravenous immunoglobulin was significantly higher than in normal subjects (P<0 x 005). After intravenous immunoglobulin, mean fluorescence intensity for CD11b decreased significantly. With coronary artery lesions present, mean CD11b fluorescence intensity was significantly higher than without coronary artery lesions (P=0 x 005 before intravenous immunoglobulin; P=0 x 024 after intravenous immunoglobulin). No differences were seen in CD62L expression on polymorphonuclear leucocytes between patients with Kawasaki disease and normal subjects. CD11b expression on polymorphonuclear leucocytes correlated positively with serum interleukin (IL)-6, IL-10, granulocyte colony-stimulating factor, percentage of neutrophils among white cells and C-reactive protein. Polymorphonuclear leucocytes from patients with Kawasaki disease showed increased CD11b expression, which was associated with increased serum cytokines and appeared to be related to coronary artery lesions.