Yoshio Okubo

Regulation of Aged Humoral Immune Defense against Pneumococcal Bacteria by IgM Memory B Cell

Elderly persons have a high incidence of lethal infections by encapsulated bacteria. However, mechanisms involved in their poor defense and maintenance of immunological memory have been poorly understood. The present study characterized the population of B cells known as IgM memory B cell compartment and their response by pneumococcal vaccine in elderly people. CD27+ memory B cells, particularly IgD+IgM+CD27+ IgM memory B cells, had dramatically declined in the aged. Their Ig syntheses by B cells and the differentiation into plasma cells were diminished in vitro compared with those in adults. A rise of anti-pneumococcal IgM in sera of elderly persons was found with lower levels compared with those in adults after pneumococcal vaccination. Although diminished function itself of aged B cells surely exist, decline of the IgM memory B cell pool is expected to result in a poor humoral immunity against pneumococcal infection in elderly people.

Acetylcholine stimulates alveolar macrophages to release inflammatory cell chemotactic activity.

Neurological transmitters including ACh, substance P (SP), and calcitonin gene-related peptide (CGRP) play an important role in regulating airway tone, and increased bronchial reactivity to cholinergic stimulation is a well-recognized phenomenon in patients with bronchial asthma. We postulated that ACh, SP, and CGRP might stimulate alveolar macrophages (AMs) to release neutrophil, monocyte, and eosinophil chemotactic activities. To test this hypothesis, bovine AMs were isolated by bronchoalveolar lavage and cultured. AMs released chemotactic activities in response to ACh in a dose- and time-dependent manner ( P < 0.05). However, SP and CGRP did not stimulate bovine AMs. Checkerboard analysis revealed that these released activities were predominantly chemotactic. Partial characterization and molecular-sieve column chromatography revealed that low-molecular-weight lipid-soluble activity was predominant. Lipoxygenase inhibitors significantly blocked the release of chemotactic activities ( P < 0.05). Leukotriene B4- and platelet-activating factor-receptor antagonists blocked the chemotactic activities. Immunoreactive leukotriene B4 significantly increased in supernatant fluids in response to ACh ( P < 0.05), but platelet-activating factor did not. The receptor responsible for the release of the chemotactic activities was the muscarinic M3 receptor. These data demonstrate that ACh stimulates AMs to release lipoxygenase-derived chemotactic activities and plays a role in inflammatory cell recruitment into the airway.Neurological transmitters including ACh, substance P (SP), and calcitonin gene-related peptide (CGRP) play an important role in regulating airway tone, and increased bronchial reactivity to cholinergic stimulation is a well-recognized phenomenon in patients with bronchial asthma. We postulated that ACh, SP, and CGRP might stimulate alveolar macrophages (AMs) to release neutrophil, monocyte, and eosinophil chemotactic activities. To test this hypothesis, bovine AMs were isolated by bronchoalveolar lavage and cultured. AMs released chemotactic activities in response to ACh in a dose- and time-dependent manner (P < 0.05). However, SP and CGRP did not stimulate bovine AMs. Checkerboard analysis revealed that these released activities were predominantly chemotactic. Partial characterization and molecular-sieve column chromatography revealed that low-molecular-weight lipid-soluble activity was predominant. Lipoxygenase inhibitors significantly blocked the release of chemotactic activities (P < 0.05). Leukotriene B4- and platelet-activating factor-receptor antagonists blocked the chemotactic activities. Immunoreactive leukotriene B4 significantly increased in supernatant fluids in response to ACh (P < 0.05), but platelet-activating factor did not. The receptor responsible for the release of the chemotactic activities was the muscarinic M3 receptor. These data demonstrate that ACh stimulates AMs to release lipoxygenase-derived chemotactic activities and plays a role in inflammatory cell recruitment into the airway.

Eosinophil active cytokines and surface analysis of eosinophils in Churg-Strauss syndrome.

There are few reports regarding the measurement of cytokines and surface analysis of eosinophils in Churg-Strauss syndrome (CSS). To examine the pathophysiology of CSS, concentrations of cytokines in serum and bronchoalveolar lavage fluid (BALF), and surface antigens on peripheral blood eosinophils were analyzed in five patients with CSS. Concentrations of cytokines (interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-3 (IL-3), interleukin-5 (IL-5) and granulocyte/macrophage colony stimulating factor (GM-CSF) were measured using ELISA. Surface antigens on eosinophils in peripheral blood were analyzed using flow cytometry. A concentration of interleukin-5 (IL-5) and TNF-alpha in serum was detected in five cases; however IL-1 beta, GM-CSF, and IL-3 were detected in 3 of 5, 2 of 5, and 1 of 5 patients, respectively. In BALF, TNF-alpha and IL-5 were detected in 2 of 3 and 1 of 3 patients, respectively; however, neither IL-1 beta, GM-CSF, nor IL-3 was detected in any. Newly expressed surface antigens such as CD25, CD4, and CD69 were observed on peripheral blood eosinophils in five cases. CD54 and HLA-DR were expressed in 4 of 5 and 3 of 5 patients, respectively. Eosinophils in peripheral blood are activated to various degrees, possibly depending on cytokine stimulation. This eosinophil activation may be related to the clinical stage of CSS.

Chromosomal aberrations in intravascular lymphomatosis.

Intravascular lymphomatosis (IVL) is a unique, disseminated type of malignant lymphoma. However, no detailed comparative study limited to the chromosomal aberrations of IVL has been reported, because IVL is extremely rare and difficult to diagnose while the patient is alive. We present here a case of IVL, and compare its karyotype with those of five cases of previously reported IVL. The accumulation of structural aberrations in chromosomes 1, 6, and 18, especially 1p (4 of 6 cases) and trisomy 18 (4 of 6 cases), were found in our comparative study of the B-cell lineage typical IVL. These chromosomal rearrangements must provide important information regarding the characteristics of cytogenetically associated with the cellular genetics of IVL.

Effects of intracellular cyclic AMP modulators on human eosinophil survival, degranulation and CD11b expression.

Background: Brochial asthma is characterized by infiltration of inflammatory cells such as lymphocytes and eosinophils. Theophylline is one of the most widely used drugs in the therapy of bronchial asthma, and phosphodiesterase (PDE) inhibition is thought to be an important mechanism of its anti–inflammatory actions. However, the detailed effects of PDE inhibition on eosinophils still remain unclear. Methods: Eosinophils in peripheral blood obtained from normal subjects and patients with mild off–season allergic rhinitis were purified using CD16 negative selection. The following effects of theophylline (nonselective PDE inhibitor), KF19514 (selective PDE IV inhibitor), mirlinone (selective PDE III inhibitor), procaterol (β2–adrenoceptor agonist) and N6, 2′–O–dibutyryladenosine 3′5′–cyclic monophosphate (dB–cAMP; AMP analogue) on eosinophils were examined: (1) survival in the presence of interleukin–5, (2) degranulation by granulocyte/macrophage colony–stimulating factor (GM–CSF) or platelet–activating factor (PAF), (3) CD11b expression under GM–CSF or PAF stimulation and (4) intracellular cAMP level. Results: Eosinophil survival was inhibited by theophilline, KF19514 or procaterol. GM–CSF– or PAF–induced degranulation was inhibited by theophylline, KF19514, procaterol or dB–cAMP. CD11b up–regulation by PAF was inhibited by theophylline, KF19514 or dB–cAMP, while GM–CSF–stimulated CD11b up–regulation was not significantly inhibited by any of the drugs tested. The levels of intracellular cAMP were increased by theophylline, KF19514 and procaterol. Conclusions: Intracellular cAMP is an important factor in the regulation of eosinophil biological functions. PDE IV inhibitors and β2–agonists are suggested to be useful for the treatment of bronchial asthma through inhibition of eosinophil effector function.

Eosinophilia associated with proliferation of CD3+4−8− αβ+ T cells with chromosome 16 anomalies

We describe a patient with eosinophilia and an abnormal CD3+4−8−αβ+ T‐cell population. Chromosomal analysis of sorted CD3+4−8− cells revealed abnormal karyotypes on chromosome 16. In the presence of IL‐2 the production of IL‐5 from CD3+4−8− cells was higher than that from CD3+4+/8+ cells. Eosinophil survival‐enhancing activity in the patient serum was inhibited by a combination of anti‐IL‐5 and anti‐GM‐CSF monoclonal antibodies. These data suggest that increased production of IL‐5 and GM‐CSF from the abnormal CD3+4−8− cells might cause eosinophilia.

A Case of Pathophysiologic Study in Kimura's Disease: Measurement of Cytokines and Surface Analysis of Eosinophils

BACKGROUND Kimuras disease is a rare but distinctive eosinophilic inflammatory disorder of unknown etiology; few reported case studies have focused on the immunopathologic background of this unique disease. OBJECTIVE To define better the immunopathogenetic features of Kimuras disease, we attempted to quantitatively analyze values of cytokines and soluble interleukin-2 receptor (sIL-2R) in peripheral blood (PB), as well as perform surface immunophenotypic analysis of eosinophils from a Japanese patient with chronic relapsing Kimuras disease. RESULTS Granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF-alpha) and sIL-2R were elevated, and newly expressed antigens on eosinophils CD4, CD25, and HLA-DR were found to be involved in the pathophysiology of this disorder. CONCLUSIONS Kimuras disease may be a disease in which activated lymphocytes release cytokines, and these released cytokines, such as GM-CSF and TNF-alpha cause eosinophil activation. These processes may be related to the pathogenesis of this disorder.

Improvement of eosinophilic heart disease after steroid therapy: successful demonstration by endomyocardial biopsied specimens.

SummaryA 62-year-old man with acute eosinophilic endomyocarditis developed congestive heart failure. The biopsy specimens revealed degranulated eosinophils and eosinophil cationic protein (ECP) in the endocardium, and in activated eosinophils and the myocardial interstitium. On electronmicroscopy, a characteristic cardiac myocytolytic change showing disruption at the intercellular junctional site was observed. After steroid treatment, clinical symptoms, systolic dysfunction and laboratory data dramatically improved. In the subsequent biopsy specimens, eosinophilic infiltration and ECP disappeared. Steroid therapy provided a beneficial effect in preventing the progression of cardiac damage. This effect was clearly documented by histochemical studies of the serial endomyocardial biopsy samples.

Intercellular adhesion molecule-1 on eosinophils is involved in eosinophil protein X release induced by cytokines.

Recent evidence suggests that adhesion molecules play important roles in eosinophil functions such as degranulation and superoxide anion production. CD11b/CD18 (Mac‐1) and CD49d/CD29 (VLA‐4) are involved in eosinophil–endothelial adhesion through their counterligands, intercellular adhesion molecule‐1 (ICAM‐1; CD54) and vascular cell adhesion molecule‐1 (VCAM‐1), respectively. CD54 is also induced on eosinophils by cytokine stimulation. We hypothesized that CD54 on human eosinophils may participate in eosinophil degranulation. CD54 was induced on eosinophils by a combination of human recombinant granulocyte–macrophage colony‐stimulating factor (rGM‐CSF) and human recombinant tumour necrosis factor‐α (rTNF‐α) within 2 hr of incubation, as determined by flow cytometric analysis. Recombinant GM‐CSF alone induced a slight but significant CD54 expression on eosinophils. Release of eosinophil protein X, an indicator of eosinophil degranulation, was induced by rGM‐CSF and this effect was synergistically enhanced by adding rTNF‐α. To determine the role of newly expressed CD54 in eosinophil degranulation, a blocking assay was performed using monoclonal antibody (mAb) against CD54 and CD18. Anti‐CD18 mAb and anti‐CD54 mAb markedly inhibited eosinophil degranulation induced by rGM‐CSF or a combination of rGM‐CSF and rTNF‐α. On the other hand, anti‐CD54 mAb had little effect on rGM‐CSF‐ or rGM‐CSF/rTNF‐α‐induced adhesion of eosinophils, whereas anti‐CD18 mAb significantly inhibited eosinophil adhesion. These results indicate that CD54 on eosinophils plays an important role in the eosinophil degranulation and that eosinophils are capable of interacting with other β2 integrin‐positive cells.

Histamine and Serotonin Stimulate Eotaxin Production by a Human Lung Fibroblast Cell Line

Histamine and serotonin are important inflammatory mediators in the pathophysiology of asthma, and asthmatic patients have higher plasma histamine and serotonin levels than nonasthmatic control subjects. Eotaxin, a potent eosinophil-specific chemotactic factor, is increased in the lower respiratory tract of allergic patients. Recently, lung fibroblasts have been reported to produce eotaxin and are suggested to be the major cellular source of eotaxin. We postulated that lung fibroblasts might release eotaxin in response to histamine or serotonin. To test this hypothesis, we evaluated the potential of histamine or serotonin to induce the release of eotaxin by the human fetal lung fibroblast cell line, HFL-1. HFL-1 released eotaxin in response to histamine and serotonin in a dose- and time-dependent manner (p < 0.05). Histamine or serotonin treatment of HFL-1 augmented the expression of eotaxin mRNA. Eosinophil chemotactic activity by HFL-1 supernatant fluids was inhibited by anti-human eotaxin-neutralizing antibody. These findings lead to the hypothesis that lung-fibroblast-derived eotaxin may in part be responsible for the eosinophil infiltration observed in allergic disease of the airways.