支气管哮喘患者记忆性T淋巴细胞对B淋巴细胞产生IgE作用的研究

目的 探讨记忆性（ＣＤ４＾＋ＣＤ４５ＲＯ＾＋）Ｔ淋巴细胞在支气管哮喘的发病中的作用。方法 分别分离出支气管哮喘病人及健康对照的ＣＤ４＾＋ＣＤ４５ＲＯ＾＋Ｔ淋巴细胞亚群,并将其与各自的Ｂ淋巴细胞共同培养,设定刺激组（美洲商陆有丝分裂原）及非刺激组,测定培养上清液中ＩｇＥ的含量。结果 哮喘病人自然状态的ＣＤ４＾＋ＣＤ４５ＲＯ＾＋Ｔ淋巴细胞对Ｂ淋巴细胞产生ＩｇＥ有正向促进作用,但有接受美洲商陆有丝分裂原     

Enhanced vascular production of superoxide in OLETF rat after the onset of hyperglycemia

This study was aimed to characterize the vascular production of superoxide in Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of type 2 diabetes. The nitroblue tetrazolium staining in the aorta from old (30 weeks) OLETF rat was more prominent than that of age-matched control (LETO) rat, which was significantly inhibited by diphenyleneiodonium (10 micromol/l), but not by inhibitors for other oxidases such as xanthine oxidase, mitochondrial oxidase, nitric oxide synthase, and cyclooxygenase. In the aorta from old OLETF rat with hyperglycemia, the enhanced NADH oxidase activity in association with upregulated expression of p22phox and gp91phox was observed, but not in both LETO and young (10 weeks) OLETF rats without hyperglycemia. Furthermore, there was a positive correlation (P<0.01) between elevation of blood glucose level and increase in vascular NADH oxidase activity. Based on these results, it was suggested that the enhanced NADH oxidase activity in the aorta from OLETF rat occurred after the onset of hyperglycemia, thereby resulting in the increased vascular production of superoxide.     

Enhanced interferon-gamma production by lymphocytes induced by a mitogen from mycoplasma arthritidis in patients with ankylosing spondylitis

Summary We have examined proliferation of and interferon-gamma (IFN-gamma) production by peripheral blood lymphocytes induced by a purified mitogen derived from mycoplasma arthritidis (MAS) in patients with seronegative spondyloarthropathies and healthy individuals. In all patients and healthy controls MAS exerted a potent nonspecific lymphoproliferation. In contrast, only patients with ankylosing spondylitis (ASp) showed a strong IFN-gamma production after stimulation with MAS. The maximal IFN-gamma response was observed in HLA-B27+/HLA-DQw3+ patients. However, healthy controls with the HLA-DQw3 haplotype with or without the presence of HLA-B27 exhibited also a slight but statistically not significant increase of IFN-gamma production. Moreover, in this study we have found an enhanced frequency of HLA-DQw3 in patients with ASp and reactive arthritis. This immunogenetic association explains the enhanced lymphocyte reactivity in these inflammatory rheumatic disorders to mycoplasmal antigens.     

Ontogeny of mouse B lymphocytes and inactivation by antigen of early B lymphocytes.

Taking advantage of recent findings about membrane fluidity, we have studied and compared the biosynthetic capacities of fetal or neonatal mouse B (bone-marrow derived) lymphocytes (until 10 days after birth) and adult B lymphocytes. Although both early and adult lymphocytes can synthesize surface immunoglobulins, they have a different physiological behavior after interaction with a ligand (anti-immunoglobulin sera or antigen), either in vivo or in vitro. Fetal and neonatal lymphocytes bearing surface immunoglobulins do not reexpress their membrane receptors after capping and endocytosis promoted by anti-immunoglobulin sera. On the other hand, adult lymphocytes resynthesize completely their receptors after the same treatment. Furthermore, intrafetal injections of hemocyanin in pregnant mice lead to a striking decrease in the number of hemocyanin-binding cells. It seems plausible that this non-reexpression of surface immunoglobulins could be the first step in tolerance establishment.     

Stimulation of gonadotropin secretion after castration in rainbow trout

The effects of bilateral castration on plasma gonadotropin (t-GtH), as measured by radioimmunoassay, were investigated in male rainbow trout at several stages in the reproductive cycle: at the start of spermatogenesis at the end of May, after its completion in September, and before and after the beginning of spermiation in October and December. Castration resulted in increased level of circulating immunoreactive t-GtH but the response varied with the season. The rise after castration was four times the initial value in May and September, and increased twofold in October and sevenfold in December. The duration of the response following castration was 4 months in May, 2 months in September, and less than 1 month in October and December.     

Regulation of human gut B lymphocytes by T lymphocytes

The aims of this study were first, to assess whether or not immunoglobulin secretion from human gut mucosal B lymphocytes can be modified by T lymphocytes, and second whether human gut mucosal T lymphocytes are capable of regulating mucosal B lymphocyte function. T and B lymphocyte enriched cell populations were isolated from gut mucosa and co-cultured in varying proportions. Addition of T lymphocytes to B enriched mucosal cell populations (ratio B:T = 2:1) showed that mucosal B lymphocytes were responsive to T cell 'help'. Addition of more T cells (ratio B:T = 2:10) suppressed immunoglobulin synthesis.     

Evidence that chronic lymphocytic leukemia B lymphocytes are frequently committed to production of natural autoantibodies

CD5+ B lymphocytes have been postulated to be primarily involved in autoantibody production. To investigate whether CD5 B lymphocytes from chronic lymphocytic leukemia (CLL) patients display the same function, we fused B lymphocytes from 23 CD5+ B-CLL with nonsecreting murine myeloma X-63 cells. Hybrids were derived from 18 of the 23 patients, but only hybrids from 13 patients were found to secrete immunoglobulin (Ig) (IgM kappa 4, IgM lambda 8, and only kappa light chain 1). Supernatants of these hybrids were tested against an extensive panel of antigens by enzyme-linked immunosorbent assay, indirect immunofluorescence, and hemagglutination. At the same time, peripheral blood mononuclear cells (PBMC) from 15 of these patients, including most patients from whom secreting hybrids had not been obtained, were stimulated with phorbol myristate acetate (PMA). Our results indicated that secreting heterohybrids from CLL B lymphocytes are frequently obtained; however, this is highly dependent on the light chain phenotype, since 8 of 9 lambda-expressing CLL produced hybrids secreting complete Igs, as compared with 4 of 12 kappa-expressing CLL. In addition, B lymphocytes of most patients from whom we failed to derive secreting hybrids also failed to secrete Ig on PMA stimulation. Secondly, CD5+ B-CLL lymphocytes were frequently committed to the production of natural autoantibodies, since in 8 of 15 cases (including hybrids and PMA stimulation) anti-Fc activity was found; three of these also displayed a multispecific binding pattern.     

Enhanced representation of HL-A antigens on human lymphocytes after mitogenesis induced by phytohemagglutinin or Epstein-Barr virus.

The amount of HL-A antigens present on the peripheral blood lymphocytes of a single human donor was increased about 11-fold after stimulation with phytohemagglutinin and 36-fold after transformation with Epstein-Barr virus. This increase applied to all four HL-A specificities of these cells. The response to phytohemagglutinin was dependent on dose and was first observed at 12 hr of incubation. Measurements of the amount of surface membranes by geometry, by radioiodinatable surface proteins, and by 5'-nucleotidase (5'-ribonucleotide phosphohydrolase, EC 3.1.3.5) assay all indicated that the enhanced representation of HL-A antigens after stimulation by phytohemagglutinin or transformation by Epstein-Barr virus must be due to an increase in the density of these antigens on the cell surface.     

Enhanced thromboxane B2 release from challenged guinea pig lung after oxygen exposure

The effects of exposure to 100% oxygen (O2) on the release of thromboxane B2 (TXB2) and prostaglandins (PG) from guinea pig lungs during anaphylaxis were studied. Lungs from sensitized guinea pigs were isolated, perfused, and challenged. Serologic examination of the perfusate showed that larger amounts of TXB2, 6-keto-PGF1 alpha, PGE2, and PGF2 alpha were released from the lungs of animals previously exposed to 100% O2 for 72 h. Conversely, these lungs released smaller amounts of 13, 14-dihydro-15-keto-PGF2 alpha. Histamine release, measured spectrofluorometrically, was unchanged. 15-hydroxyprostaglandin dehydrogenase (PGDH) was inhibited by 83% after O2 exposure, as measured by an in vitro enzyme assay. These results suggested that the reported enhancement of systemic anaphylaxis in the guinea pig in vivo after exposure to oxidant gases may be due in part to inhibition of pulmonary PGDH resulting in increased half-lives of primary PG and TX released from the lung.     

Lamin B is rapidly phosphorylated in lymphocytes after activation of protein kinase C.

Lamin B was shown to be a major substrate of cellular phosphorylation in the response of lymphocytes to phorbol esters. Lamins A and C, which were not observed in lymphocytes, were also substrates of phorbol-stimulated phosphorylation in those cell types that express them. Lamin B phosphopeptides labeled with 32P in intact cells treated with phorbol 12-myristate 13-acetate were compared to those produced by in vitro phosphorylation with protein kinase M, cAMP-dependent protein kinase, and Ca2+/calmodulin-dependent protein kinase II. The phosphopeptides labeled by in vivo stimulation with phorbol esters are very similar to those phosphorylated in vitro by protein kinase M, a catalytic domain of protein kinase C. Phorbol treatment of interphase cells significantly reduces the amount of detergent-insoluble lamin B, suggesting that phosphorylation of lamin may alter the architecture of the nuclear lamina. In addition, we have shown that treatment of a B-cell line with antibodies to IgM induces a modest increase in lamin B phosphorylation. These results strongly suggest that ligands that are known to activate protein kinase C at the cell surface or in the cytosol also lead to the activation of a nuclear kinase activity with a protein kinase C-type specificity.     

B lymphocytes and systemic sclerosis

PURPOSE OF REVIEW: Systemic sclerosis is characterized by fibrosis and autoimmunity. Systemic sclerosis displays a variety of abnormal immune activations, including the production of disease-specific autoantibodies, although the pathogenic relation between systemic autoimmunity and the clinical manifestations of systemic sclerosis remains unknown. Recent studies have rediscovered that B cells play critical roles in systemic autoimmunity and disease expression through various functions more than autoantibody production, such as antigen presentation and cytokine production. This review focuses on recent advances in understanding the B cell's role in systemic sclerosis. RECENT FINDINGS: Patients with systemic sclerosis have altered B-cell homeostasis characterized by expanded naive B cells and diminished memory B cells. Although memory B cells are decreased in number, they are chronically activated, possibly because of CD19 over-expression in B cells from patients with systemic sclerosis. CD19 over-expression can be genetically explained in part by a polymorphism of CD19 promoter region. Similarly, B cells from a tight-skin mouse, a genetic model of systemic sclerosis, show augmented CD19 signaling and chronic hyper-reactivity. CD19 hyper-phosphorylation in tight-skin B cells is caused by impaired function of CD22, a negative response regulator expressed on B cells. Classic roles of autoantibody secretion may also be important in systemic sclerosis because autoantibodies to matrix metalloproteinases can be pathogenic in vivo. SUMMARY: B cells may have more pathogenic roles in systemic sclerosis than had been appreciated. Further studies are required to clarify the precise molecular basis that links B cells and fibrosis. Collectively, B cells and B-cell-specific response regulators such as CD19/CD22 appear to be potential therapeutic targets of the disease.     

Enhanced trafficking to the pancreatic lymph nodes and auto-antigen presentation capacity distinguishes peritoneal B lymphocytes in non-obese diabetic mice

Aims/hypothesis  

NOD.Igμ ^null mice lacking mature B cells are highly resistant to diabetes and display poor CD4 T cell responses to autoantigens. Nevertheless, the degree to which different B cell subsets contribute to diabetes in NOD mice remains unresolved. Due to their role in the recognition of microbial and autoantigens, peritoneal B cell characteristics were examined in NOD mice to see if they differ developmentally, phenotypically or functionally in aspects relevant to diabetogenesis.     

B lymphocytes enhance interferon‐α production by plasmacytoid dendritic cells

Objective

The type I interferon (IFN) system and B cells are activated in many autoimmune diseases, such as systemic lupus erythematosus (SLE). The IFNα produced by plasmacytoid dendritic cells (PDCs) stimulates several B cell functions, including autoantibody production. However, not much is known about how B cells influence PDC function. The aim of this study was to investigate the regulatory effect of B cells on IFNα production by PDCs.

Methods

PDCs and B cells isolated from peripheral blood mononuclear cells from healthy blood donors were stimulated with RNA‐containing immune complexes (ICs) consisting of U1 small nuclear RNP and SLE IgG, herpes simplex virus, or oligonucleotide (ODN) 2216, alone or in cocultures. IFNα, several other cytokines, and PDC‐ or B cell–associated surface molecules were analyzed using immunoassays or flow cytometry.

Results

B cells enhanced IFNα production by PDCs up to 47‐fold, and the effect was most pronounced for PDCs stimulated with RNA‐containing ICs. Anti‐CD31 antibody reduced RNA‐containing IC–induced IFNα production by 80% but had no effect on IFNα production when ODN 2216 was used as an inducer. Supernatants from ODN 2216–stimulated B cells promoted IFNα production by PDCs, while supernatants from RNA‐containing IC–stimulated B cells did not.

Conclusion

Our results showed that a novel function of B cells is enhancement of type I IFN production by PDCs. Because B cells are activated by type I IFN, this PDC–B cell cross‐talk might be of fundamental importance in the etiopathogenesis of SLE and contribute to long‐term immune activation in SLE and other systemic rheumatic diseases.

     

HBcAg-pulsed dendritic cell vaccine induces Th1 polarization and production of hepatitis B virus-specific cytotoxic T lymphocytes

Aim:  Dendritic cells (DCs) pulsed with HBsAg efficiently reverse the immune tolerance to hepatitis B virus (HBV) and induce HBV-specific cytotoxic T lymphocyte (CTL) responses in transgenic mice and healthy volunteers. However, it is not clear whether HBV core antigen (HBcAg)-pulsed DCs can effectively induce CD4⁺ helper T cells polarization into Th1, which contribute to the induction and maintenance of HBV-specific CD8⁺ T cells in chronic hepatitis B (CHB) patients. To address this issue, we conducted this study and investigated whether HBcAg-pulsed DCs could polarize Th1 cells and induce an HBcAg-specific CTL response.
Methods:  HBcAg-pulsed DCs were generated from 21 CHB patients. The capacity of the HBcAg-pulsed DC vaccine to stimulate CD4⁺ and CD8⁺ T cells to produce IFN-γ and IL-4 was estimated by intercellular cytokine staining, and the HBcAg-pulsed DCs derived from 10 humam leucocyte antigen (HLA)-A2⁺ CHB patients were tested for the induction of HBV-specific CTLs from autologous T cells by pentamer staining. The cytotoxicity of these CTLs was evaluated in vitro by flow cytometry.
Results:  The HBcAg-pulsed DCs derived from CHB patients exhibited a stronger capacity to stimulate autologous CD4⁺ and CD8⁺ T cells to release IFN-γ rather than IL-4, which could induce HBV core 18-27 specific CTLs, suggesting a specific cytotoxicity against T2 cells that had been loaded with the HBV core 18-27 peptide in vitro .
Conclusion:  HBcAg-pulsed DC vaccine derived from CHB patients efficiently induced autologous T cell polarization to Th1 and generation of HBV core 18-27 specific CTLs.     

Persistent intraprostatic androgen concentrations after medical castration in healthy men

CONTEXT: The impact of serum androgen manipulation on prostate tissue hormone levels in normal men is unknown. Studies of men with prostate cancer have suggested that prostatic androgens are preserved in the setting of castration. Tissue androgens might stimulate prostate growth, producing adverse clinical consequences. OBJECTIVE: The objective of the study was to determine the effect of serum androgen manipulation on intraprostatic androgens in normal men. DESIGN: Thirteen male volunteers ages 35-55 yr (prostate-specific antigen < 2.0 ng/ml; normal transrectal ultrasound) were randomly assigned to: 1) a long-acting GnRH-antagonist, acyline, every 2 wk; 2) acyline plus testosterone (T) gel (10 mg/d); or 3) placebo for 28 d. Serum hormones were assessed weekly. Prostate biopsies were obtained on d 28. Extracted androgens were measured by RIA, and immunohistochemistry for androgen-regulated proteins was performed. RESULTS: The mean decrease in serum T was 94%, whereas prostatic T and dihydrotestosterone levels were 70 and 80% lower, respectively, in subjects receiving acyline alone compared with controls (P < 0.05). Despite this decrease in prostate androgens, there were no detectable differences in prostate epithelial proliferation, apoptosis, prostate-specific antigen, and androgen receptor expression. CONCLUSION: In this small study of healthy subjects, despite a 94% decrease in serum T with medical castration, intraprostatic T and dihydrotestosterone levels remained 20-30% of control values, and prostate cell proliferation, apoptosis, and androgen-regulated protein expression were unaffected. Our data highlight the importance of assessing tissue hormone levels. The source of persistent prostate androgens associated with medical castration and their potential role in supporting prostate metabolism deserves further study.