Autoantibody-producing RP105(-) B cells, from patients with systemic lupus erythematosus, showed more preferential expression of BCMA compared with BAFF-R than normal subjects

OBJECTIVE

B cells lacking RP105 produce autoantibodies in patients with SLE. Expression of B-cell activating factor (BAFF) binding receptors (BBRs) and survival of RP105(-) B cells from SLE patients were examined.

METHODS

Detection of difference of gene expression between RP105(-) and RP105(+) B cells was done by DNA microarrays. Surface expression was confirmed by flow cytometry. The contribution of BAFF, a proliferation-inducing ligand (APRIL) and monomers/trimers of sCD40L to survival of RP105(-) and RP105(+) B cells was examined.

RESULTS

Gene expression of B-cell maturation antigen (BCMA) was different among BBRs in RP105(-) and RP105(+) B cells in SLE. Preferential expression of BCMA on RP105(-) B cells was confirmed compared with RP105(+) B cells by flow cytometry, although BAFF receptor (BAFF-R) expression on RP105(-) B cells was significantly lower. Additionally, relative ratios of BCMA/BAFF-R expression on RP105(-) B cells were increased significantly in SLE patients compared with normal subjects. Stimulation by sCD40L decreased the number of surviving RP105(-) and RP105(+) B cells in vitro. RP105(+) B cells were not rescued from sCD40L-induced cell death by BAFF and/or APRIL. In contrast, either BAFF or APRIL maintained the survival of RP105(-) B cells due to avoidance of cell death. Activated RP105(-) B cells reduced BAFF-R and increased BCMA levels.

CONCLUSIONS

RP105(-) B cells from SLE patients showed more preferential expression of BCMA compared with BAFF-R than normal subjects, and were possibly regulated by BAFF/APRIL. Our results provide a new insight of BCMA and their ligands in B cells from SLE patients.

High expression of Toll-like receptor 4 on CD14+ monocytes in acute infectious diseases

Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS) and other exogenous and endogenous molecules, and is thought to contribute to defense mechanisms against infections. Our objective was to elucidate the clinical significance of TLR4 in acute infectious diseases by analyzing its sequential expression on CD14+ monocytes. Peripheral blood samples were obtained from 36 patients with acute infectious diseases on admission and after treatment within certain intervals. The TLR4 expression on CD14+ monocytes was analyzed using flow cytometry and was presented as a mean fluorescence intensity (MFI). TLR4 expression during the acute phase of infection was highly enhanced compared to that of normal subjects (MFI: 22.1 vs 8.5). TLR4 expression was promptly reduced to normal levels in parallel with the disease improvement. In patients who died despite treatment, the enhancement of TLR4 expression during the acute phase was less prominent compared to those who survived (MFI: 14.6 vs 23.5) and its sequential change was also subtle. These results indicate that monocytes respond to acute infections by the induction of TLR4 expression and that a poor response may be associated with a poor prognosis.

Effect of disease activity and corticosteroids on serum levels of soluble endothelial cell protein C receptor in patients with systemic lupus erythematosus

To assess the effects of disease activity of systemic lupus erythematosus (SLE) and high-dose corticosteroids on endothelial injuries, the significance of soluble endothelial cell protein C receptor (sEPCR) and soluble thrombomodulin (sTM) was analyzed. Serum levels of sEPCR and sTM were measured by enzyme-linked immunosorbent assay (ELISA) cross-sectionally in 97 SLE patients, 49 patients with other rheumatic diseases and 22 normal subjects. The changes in these levels upon corticosteroid treatment were also analyzed in 41 patients. The levels of sEPCR and sTM were both higher in SLE and other rheumatic disease patients than in normal subjects. When low-dose corticosteroids were used, both the level of sEPCR and the ratio of positive tests for sEPCR were significantly higher in active SLE patients than in inactive patients [median 2.30 ng/ml (range 0.00-147.10 ng/ml) vs 0.00 ng/ml (0.00-58.90 ng/ml) and 53.5 vs 13.0%, respectively] (P < 0.005). Moreover, the ratio of positive tests for sEPCR was higher after corticosteroid treatment in 9 of 19 (47.3%) SLE patients compared to other rheumatic diseases (3/22; 13.6%). Although the mean level of sTM was significantly higher in active SLE patients than in inactive patients, the ratio of positive tests for sTM was not affected by disease activity or corticosteroids. In conclusion, the positive test for sEPCR is a more sensitive biomarker than that for sTM in reflecting endothelial injuries caused by active disease and often by corticosteroids in SLE.

Toll-like receptor homolog RP105 modulates the antigen-presenting cell function and regulates the development of collagen-induced arthritis

Introduction

RP105 is a Toll-like receptor homolog expressed on B cells, dendritic cells (DCs), and macrophages. We investigated the role of RP105 in the development of collagen-induced arthritis (CIA).

Methods

CIA was induced in RP105-deficient DBA/1 mice and the incidence and arthritis index were analyzed. The cytokine production by spleen cells was determined. The functions of the DCs and regulatory T cells (Tregs) from RP105-deficient or control mice were determined by adding these cells to the lymph node cell culture. Arthritis was also induced by incomplete Freund's adjuvant (IFA) plus collagen or by injecting anti-collagen antibody and lipopolysaccharide.

Results

RP105-deficient mice showed accelerated onset of arthritis and increased severity. Interferon-gamma (IFN-γ) and tumor necrosis factor-alpha production by spleen cells from RP105-deficient mice was increased in comparison with that from wild-type mice. The DCs from RP105-deficient mice induced more IFN-γ production, whereas Tregs from those mice showed less inhibitory effect against IFN-γ production. RP105-deficient mice also showed more severe arthritis induced by collagen with IFA.

Conclusions

These results indicate that RP105 regulates the antigen-presenting cell function and Treg development, which induced the attenuation of the cell-mediated immune responses and, as a result, suppressed the development of CIA.

Depositional records of plutonium and (137)Cs released from Nagasaki atomic bomb in sediment of Nishiyama reservoir at Nagasaki

In a sediment core of Nishiyama reservoir at Nagasaki city, depth profiles of (240)Pu/(239)Pu isotopic ratio, (239+240)Pu and (137)Cs activities were determined. Sediments containing plutonium and (137)Cs, which were deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout of the Nagasaki atomic bomb. This is the first entire depositional records of plutonium and (137)Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.

A Case of Visceral Larva Migrans Due toToxocara canisShowing Varied Manifestations

A 21-year-old woman admitted for a low-grade fever, dry cough, polyarthralgia, and general fatigue was found to have elevateal accustomed to eating raw meat and cattle liver peripheral blood eosinophil counts and serum IgE. Chest X-ray imaging and computed tomography (CT) showed multiple small nodules in both lung fields. A multiple dot-ELISA assay of her serum showed that she had visceral larva migrans caused by Ascaris suum or Toxocara canis. Following treatment with albendazole, she developed myelopathy and was again admitted. A cerebrospinal fluid examination showed increased eosionophils and significant antibody elevation against T. canis. Her disease was considered to have entered the central nervous system, one of the target organs of visceral larva migrans. She was successfully treated with dietylcarbamazine and has shown no reccurrence. This case showed the different manifestations of visceral larva migrans and the rising incidence of this disease in Japan raises concerns about associated of diet.

Antifibrotic effects of hepatocyte growth factor on scleroderma fibroblasts and analysis of its mechanism

We investigated the effect of hepatocyte growth factor (HGF) on collagen metabolism in cultured fibroblasts from scleroderma (SSc) patients and discussed the possible mechanism of its effect. Synthesis of matrix metalloproteinase-1 (MMP-1) and collagen and mRNA levels of various cytokines were examined by enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively. Hepatocyte growth factor enhanced MMP-1 production and mRNA levels of MMP-1 and Ets-1 (a transcriptional factor of MMPs). In addition, HGF suppressed collagen synthesis and mRNA levels of procollagenalpha1(I) and connective tissue growth factor (CTGF) in SSc fibroblasts. Expression of transforming growth factor (TGF)-beta1 was not inhibited significantly in SSc or control fibroblasts. Hepatocyte growth factor also increased interferon (IFN)-gamma mRNA significantly in SSc and control fibroblasts. Addition of anti-HGF antibody neutralized these effects of HGF on MMP-1 and collagen synthesis. The results suggest that HGF can suppress collagen accumulation in SSc fibroblasts by increasing MMP-1 levels possibly via activation of Ets-1 and also by decreasing collagen synthesis, which may be partly related to inhibition of CTGF, and increasing IFN-gamma levels rather than the effect on TGF-beta1. The present study indicates that HGF may be a promising therapeutic agent for this intractable disease.

The association of Behçet's disease with myelodysplastic syndrome in Japan: a review of the literature

OBJECTIVE

[corrected] To determine the clinical characteristics of patients with myelodysplastic syndrome (MDS)-associated Behçet's disease (BD) in Japan.

METHODS

54 Japanese cases of MDS-associated BD obtained from the literature and from our own clinical experience were reviewed. The clinical features of MDS-associated BD were compared with those of the 1991 nationwide BD survey in Japan.

RESULTS

In MDS-associated BD, the average age at onset was 42.6 years, which was 6.9 years later than for all BD patients; females developed disease more frequently than males (male: female ratio = 0.80). In MDS-associated BD cases, the occurrence of eye lesions was significantly lower, the frequency of intestinal lesions was markedly higher, and the rate of HLA-B51 positivity was lower than that in all BD. BD and MDS developed nearly simultaneously in 49.0% of cases; BD preceded MDS in 31.4% of the cases. The distribution of the age at BD onset showed two peaks, one in the 3rd decade and the other in the 6th decade. Females were more likely to develop younger-onset disease, while men were more likely to develop older-onset MDS-associated BD. Furthermore, in the older-onset group, BD was diagnosed together with or after the diagnosis of MDS, while half of the younger-onset group developed BD earlier than MDS.

CONCLUSION

MDS-associated BD patients form a distinct subset of patients. There may, in fact, be two major groups of MDS-associated BD patients based on age, gender, and temporal relationship of the two diseases.

Role of inducible costimulator in the development of lupus in MRL/lpr mice

Inducible costimulator (ICOS) is a costimulatory molecule expressed in activated T cells and plays an important role in T-cell-dependent immune responses. We investigated the role of ICOS in the development of autoimmune diseases in MRL/Mpj-lpr/lpr (MRL/lpr) mice. ICOS was expressed on CD4(+) T cells from adult MRL/lpr mice. ICOS-deficient MRL/lpr mice showed mild lymphoadenopathy and a decreased memory type CD4(+) T cells in the spleen. The anti-dsDNA antibody levels were decreased. CD4(+) T cells from ICOS-deficient MRL/lpr mice showed less of a bias to Th1 and an enhanced production of IL-4 in response to anti-CD3 antibody in comparison to those from wild-type MRL/lpr mice. Although ICOS-deficiency abrogated renal vasculitis completely, the severity of glomerulonephritis was not altered. ICOS is considered to play a role in CD4(+) T cell activation, autoantibody production, and renal vasculitis. However, it is not essentially required in the development of glomerulonephritis.

Ex vivo CD(+) T-cell cytokine expression from patients with Sjögren's syndrome following in vitro stimulation to induce proliferation

OBJECTIVE

To assess ex vivo CD4(+) T-cell cytokine expression from patients with primary Sjögren's syndrome (SS) following in vitro stimulation to induce proliferation, as proliferation is closely related to differentiation of cytokine-producing cells.

METHODS

Peripheral blood mononuclear cells (PBMCs) separated from primary SS patients (n = 28) and controls (n = 25) were analysed. PBMCs were stimulated with concanavalin A followed by phorbol 12-myristate 13-acetate and ionomycin. Intracellular interferon-gamma (IFN-gamma) and interleukin-4 (IL)-4 in proliferating CD4(+) T cells were assessed by flow cytometry. The proportion of cytokine-producing cells and proliferating cells in each division cycle was assessed using [5(and 6)-carboxyfluorescein diacetate, succinimidyl ester]-labelled CD4(+/-) T cells.

RESULTS

The proportion of IFN-gamma+ proliferating CD4(+) T cells in each cell division cycle from extraglandular SS was increased in glandular SS patients compared glandular SS patients with controls (P<0.05 approximately 0.01). The percentage of IFN-gamma single positive proliferating CD4(+) T cells was greater in extraglandular SS patients (26.7+/-14.1%) compared with glandular SS (9.9 +/- 9.1%) (P<0.01) and controls (9.4 +/- 5.8%) (P<0.001). There was no significant difference in the percentages of IL-4(+) proliferating CD4(+) T cells among the groups. However, the proliferating response of CD4(+) T cells was significantly decreased in extraglandular SS patients (percentage of proliferating cells 38.4 +/- 18.6%) compared with that in glandular SS patients (64.2 +/- 17.2%) (P<0.05) and controls (63.1+/-10.6%) (P<0.01).

CONCLUSIONS

CD4(+) T cells from extraglandular SS patients may have a predisposition for entry into the IFN-gamma-producing effector pathway as a result of the stimulations. These results are helpful for understanding the immunological difference between glandular and extraglandular SS and the mechanisms of disease progression.

Casein kinase II inhibitors isolated from two Brazilian plants Hymenaea parvifolia and Wulffia baccata

Two dihydroflavonol rhamnosides (1 and 2) isolated from the bark of Hymenaea parvifolia and two pentacyclic triterpenoids (3 and 6) obtained from the leaves of Wulffia baccata have been found to exhibit inhibitory effects of casein kinase II (CK-II) dose-dependently, suggesting that at higher doses more than 10 microM, these four compounds may act as potent CK-II suppressors of the CK-II-mediated activation of 60S acidic ribosomal P proteins in vitro.

Anti-inflammatory effect of 22-oxa-1 alpha,25-dihydroxyvitamin D3 on carrageenin-induced inflammation in rats

The anti-inflammatory effect of 22-oxa-1 alpha,25-dihydroxyvitamin D3 [22-oxa-1 alpha,25(OH)2D3], an analogue of the active form of vitamin D3, was studied regarding carrageenin-induced inflammation in rats. In the early phase of the inflammation, the formation of granulation tissue and the weight of exudate were significantly suppressed by both oral and local administrations of 22-oxa-1 alpha,25(OH)2D3 daily for 4 d (day 0-3) after carrageenin injection, though the local injection of 22-oxa-1 alpha,25(OH)2D3 (7 and 10 micrograms/kg) into the carrageenin-air-pouch was much more effective than the oral administration of the compound (20 micrograms/kg). Similarly, oral and local administrations of 22-oxa-1 alpha,25(OH)2D3 from day 4 to 7 significantly suppressed the increase in exudate and the proliferation of granulation tissue in the late phase of carrageenin-induced inflammation in rats. The results suggest that 22-oxa-1 alpha,25(OH)2D3 has an anti-inflammatory activity on both the acute and proliferative phases of inflammation in rats.

Changes in the levels of rat interleukin 8/CINC and gelatinase in the exudate of carrageenin-induced inflammation in rats

A sensitive enzyme-linked immunosorbent assay (ELISA) for rat interleukin 8/cytokine-induced neutrophil chemoattractant (CINC) has been established by using biotin-conjugated anti-CINC rabbit IgG. The biotin-streptavidin sandwich ELISA detected CINC at concentrations from 3 pg/ml up to 30 ng/ml. The concentration of CINC in the pouch fluid (exudate) of rat carrageenin-induced inflammation was measured by the ELISA. After a time lag of about 2 h, neutrophils steadily accumulated in the carrageenin/air-pouch until 8 h. Similarly, the CINC level of exudate increased after about a 2-h lag, and reached a maximum (134 ng/ml) at 8 h, and thereafter decreased to a negligible concentration at 24 h after carrageenin injection. In association with the rise in CINC level, the concentration of exudate 96-kDa gelatinase corresponding to neutrophil gelatinase/type IV collagenase increased with time. The results suggest that CINC contributes, at least in part, to the neutrophil migration into the inflammatory lesion of the carrageenin-induced inflammation in rats.