bluuebunny/crossref_metadata_2025 huggingface dataset:
CD95 expression and function on lymphocyte subpopulations in common variable immunodeficiency (CVID); related to increased apoptosis
Authors: IGLESIAS J , MATAMOROS N , RAGA S , FERRER J M , MILA J
Published: March 2003

Apoptosis is now recognized as a central process of development and disease, and it has been proposed as one of the mechanisms that may account for the lymphopenia seen in some diseases. In this study we measured spontaneous apoptosis and CD95 expression on different cell subpopulations from CVID patients, using flow cytometric techniques. We divided our patients into two groups according to their CD4+ and CD4+CD45RA+ cell counts. Our results clearly show increased spontaneous apoptosis and CD95 expression on the CD4+ and CD4+CD45RA+ subsets from lymphopenic CVID patients compared with normal subjects and disease controls. Interestingly, our lymphopenic CVID patients presented a profound reduction in absolute counts, mainly affecting the CD4+CD45RA+ subpopulation. We also found a statistically significant direct correlation between absolute numbers of CD4+CD45RA+ T cells and spontaneous apoptosis on the same subset in CVID patients, but attempts to induce CD95-mediated apoptosis were unsuccessful despite increased CD95 expression on CD4+ T cells. These findings suggest that apoptosis could be one of the mechanisms implicated in the significant lymphopenia present in these patients.
Peripheral blood mononuclear cells from patients with rheumatoid arthritis spontaneously secrete vascular endothelial growth factor (VEGF): specific up-regulation by tumour necrosis factor-alpha (TNF-α) in synovial fluid
Authors: BOTTOMLEY M J , WEBB N J A , WATSON C J , HOLT P J L , FREEMONT A J , BRENCHLEY P E C
Published: March 2003

This study was designed to investigate VEGF production from peripheral blood mononuclear cells (PBMC) from patients with rheumatoid arthritis (RA) compared with healthy controls and to identify the predominant cellular source in PBMC isolated from RA patients. The regulation of PBMC VEGF production by cytokines and synovial fluid (SF) was studied. PBMC were isolated from RA patients and healthy controls and stimulated with lipopolysaccharide (LPS), IL-1β, IL-4, IL-6, IL-8, IL-10, TNF-α and transforming growth factor-beta (TGF-β) isoforms for varying time points up to 72 h at 37°C/5% CO2. The effect of SF on VEGF secretion by PBMC was also studied. Supernatant VEGF levels were measured using a flt-1 receptor capture ELISA. RA patients had significantly higher spontaneous production of VEGF compared with controls, and monocytes were identified as the predominant cellular source. RA PBMC VEGF production was up-regulated by TGF-β isoforms and TNF-α and down-regulated by IL-4 and IL-10, with no effect observed with IL-1β, IL-6 and IL-8. Antibody blocking experiments confirmed that TNF-α and not TGF-β isoforms in SF increased VEGF secretion by RA PBMC. These results emphasize the importance of monocytes as a source of VEGF in the pathophysiology of RA. Several cytokines known to be present in SF can modulate the level of VEGF secretion, but the predominant effect of SF in VEGF up-regulation is shown to be dependent on TNF-α.
Transcriptional activation of HIV byMycobacterium tuberculosisin human monocytes
Authors: Toossi Z , Xia L , Wu M , Salvekar A
Published: March 2003

Recently it has been shown that infection with Mycobacterium tuberculosis increases the replication of HIV in mononuclear cells. The objective of this study was to investigate the mechanism(s) of up-regulation of HIV in primary human monocytes. Monocytes from healthy subjects were infected with HIV in vitro and then cultured with purified protein derivative (PPD) of M. tuberculosis. Culture supernatants were assessed for HIV p24 and cytokines. HIV expression was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). PPD induced HIV-infected monocytes to increased expression of HIV RNA and production of HIV p24. This effect correlated with production of tumour necrosis factor-alpha (TNF-α) in monocyte cultures. However, neutralizing antibody to TNF-α only partly abrogated the PPD-induced HIV p24 in these cultures. Also, PPD and culture filtrate of M. tuberculosis induced HIV mRNA expression. Further, using an adenovirus infection system containing an HIV long-terminal repeat (LTR) reporter plasmid, we showed that M. tuberculosis and its PPD induced HIV LTR. Therefore, the effect of M. tuberculosis and its PPD on HIV replication in monocytes is primarily one of transcriptional activation.
Distribution and antigen specificity of anti-U1RNP antibodies in patients with systemic sclerosis
Authors: Ihn H , Yamane K , Yazawa N , Kubo M , Fujimoto M , Sato S , Kikuchi K , Tamaki K
Published: March 2003

Systemic sclerosis (SSc) is a generalized connective tissue disease which is characterized by the presence of several autoantibodies. To determine the prevalence and antigen specificity of anti-U1RNP antibodies (anti-U1RNP) in patients with SSc, serum samples from 223 patients with SSc, 117 patients with systemic lupus erythematosus (SLE), 18 patients with mixed connective tissue disease (MCTD) and 40 healthy control subjects were examined by indirect immunofluorescent analysis (IIF), double immunodiffusion, and immunoblotting using nuclear extract of HeLa cells. Eighteen of the 223 (8%) serum samples from patients with SSc were shown to be positive for anti-U1RNP. The frequency of anti-U1RNP positivity in limited cutaneous SSc (14%) was significantly higher than that in those with diffuse cutaneous SSc (3%). Anti-Sm antibodies were detected in patients with SLE positive for anti-U1RNP, but not in those with SSc positive for anti-U1RNP or those with MCTD. Immunoblotting demonstrated that anti-70-kD antibodies were detected more often in patients with SSc positive for anti-U1RNP and in those with MCTD than in those with SLE. Furthermore, anti-U1RNP was closely correlated with pulmonary fibrosis and joint involvement in patients with SSc. These results suggest that anti-70-kD antibodies are useful in the classification of patients with anti-U1RNP.
Chromatin clearance in C57Bl/10 mice: interaction with heparan sulphate proteoglycans and receptors on Kupffer cells
Authors: Du Clos T W , Volzer M A , Hahn F F , Xiao R , Mold C , Searles R P
Published: March 2003

Chromatin is an important autoantigen in the pathogenesis of systemic lupus erythematosus (SLE) as an immunogen and as a part of nephritogenic immune complexes. Earlier studies focused on clearance of DNA. However, DNA released into the circulation from dying cells is found associated with histones in nucleosomes. The liver is the major organ involved in clearance of chromatin from the circulation of mice. Heparan sulphate proteoglycans (HSPG) have been implicated in the clearance of various charged molecules. Receptor-mediated clearance of ssDNA by the liver has also been reported. Because chromatin contains positively charged histones in addition to DNA, we wished to determine if HSPG and/or DNA receptors are involved in chromatin clearance. The rate of clearance of H1-stripped chromatin from the bloodstream of C57Bl/10 mice was markedly decreased by prior treatment of mice with Heparinase I. Clearance was also inhibited by heparin, heparan sulphate, and DNA, but not by colominic acid. DNA was the most effective inhibitor of clearance and released chromatin from sites of clearance. Depletion of Kupffer cells and splenic macrophages using liposome-encapsulated Clodronate (dichloromethylene bisphosphonate) markedly inhibited chromatin clearance. These data suggest that chromatin clearance is mediated by charge interactions with cell surface HSPG and by DNA receptors. Clearance and degradation of chromatin require functional macrophages in the liver and spleen.
Relevance of FcγRIIIa-158V-F polymorphism to recurrence of adult periodontitis in Japanese patients
Authors: Sugita N , Yamamoto K , Kobayashi T , Van Der Pol W L , Horigome T , Yoshie H , Van De Winkel J G J , Hara K
Published: March 2003

The immunoglobulin receptor FcγRIIIa (CD16) is distributed on natural killer (NK) cells, macrophages, and γδ T cells, and is polymorphic. FcγRIIIa-158V has a higher affinity for both monomeric and immune complexed IgG1, IgG3, and IgG4 than IIIa-158F. We determined FcγRIIIa-158V/F genotypes of Japanese patients with adult periodontitis. A significant over-representation of FcγRIIIa-158F was found in patients with recurrence, compared with patients without recurrence, making FcγRIIIA a candidate gene for recurrence risk of adult periodontitis.
Quick recovery in the generation of self-reactive CD4low natural killer (NK) T cells by an alternative intrathymic pathway when restored from acute thymic atrophy
Authors: Maruyama S , Tsukahara A , Suzuki S , Tada T , Minagawa M , Watanabe H , Hatakeyama K , Abo T
Published: March 2003

The thymus comprises the mainstream of T cell differentiation which produces conventional T cells and an alternative pathway which produces primordial T cells with intermediate density of T cell receptor (TCR)–CD3 complex on the surface (i.e. intermediate TCR cells or TCRint cells). We induced acute thymic atrophy in mice by an administration of hydrocortisone (10 mg) or irradiation (6.5 Gy). It was demonstrated that CD3intCD4lowNK1.1+ T cells were immediately generated by an alternative intrathymic pathway without passing through the double-positive CD4+8+ stage, when restored from thymic atrophy (days 3–14). These CD3intCD4lowNK1.1+ T cells mediated self-reactivity and appeared even in the periphery. mRNA of an invariant chain of TCR Vα14Jα281 gene product was detected in these CD4low T cells, but not remaining CD4high T cells. The mainstream of T cell differentiation in the thymus was not restored up to day 14 and there was no leakage of self-reactive clones into the population generated through the mainstream. These results reveal that an alternative intrathymic pathway is associated with the generation of self-reactive T cells, in an early restoration phase after thymic atrophy.
Kinetics of serum soluble tumour necrosis factor receptor (TNF-R) type-I and type-II after a single interferon-alpha (IFN-α) injection in chronic hepatitis C
Authors: Fabris C , Del Forno E , Falleti E , Toniutto P , Pirisi M
Published: March 2003

Circulating soluble TNF receptors, which act as TNF inhibitors, increase following the administration of IFN-α. Whether this is due to a direct IFN action or to indirect mechanisms involving the release of other cytokines is unclear. The kinetics of serum IFN, TNF, IL-6, IL-10, soluble TNF receptor type-I (sTNF-RI) and sTNF-RII were evaluated by enzyme immunoassays in 11 patients with chronic hepatitis C, following the first dose of recombinant human IFN-α2b (3 MU given subcutaneously). sTNF-RI concentrations paralleled IFN concentrations, rising from a mean ± s.e.m. value of 3.5 ± 0.3 ng/ml at baseline to a peak value of 5.5 ± 0.5 ng/ml after 9 h, followed by a return to 4.1 ± 0.4 ng/ml after 24 h (P = 0.0001). sTNF-RII concentrations, which were 7.6 ± 0.5 ng/ml at baseline, fell initially to 6.9 ± 0.5 ng/ml, to reach a peak at 24 h of 9.0 ± 0.7 ng/ml (P < 0.0001). In contrast, the concentrations of TNF, IL-6 and IL-10 fluctuated with no significant changes at any time point. The area under the curve (AUC) of incremental IFN values had a strong positive correlation with the AUC of incremental sTNF-RI values (r = 0.75, P < 0.01). In patients with hepatitis C, IFN concentrations reached after a single dose of IFN were paralleled by correlationally increased concentrations of sTNF-RI, which are a much better marker of administered IFN than sTNF-RII, IL-6 or IL-10.
Galactosylation of serum IgG and autoantibodies in murine models of autoimmune haemolytic anaemia
Authors: Barker R N , Young R D , Leader K A , Elson C J
Published: March 2003

A number of systemic autoimmune diseases are associated with increased levels of the agalactosyl (G0) IgG isoforms that lack a terminal galactose from the CH2 domain oligosaccharide. The current aim was to determine whether the galactosylation of serum IgG is also reduced in a classic antibody-mediated, organ-specific autoimmune condition, and whether the pathogenic autoantibodies are preferentially G0. In two murine forms of autoimmune haemolytic anaemia (AIHA), sera and autoantibodies eluted from erythrocytes were obtained, and the levels of G0 measured using a lectin-binding assay. Serum IgG galactosylation was unaffected following the induction of AIHA in CBA/Igb mice by immunization with rat erythrocytes, but in all animals with the disease the IgG autoantibodies generated were more G0 than the sera. The anti-rat erythrocyte antibodies were similar to the autoantibodies in being preferentially G0, and when CBA/Igb mice were immunized with canine erythrocytes as a control foreign antigen, there was again a bias towards the production of G0 IgG antibodies. In NZB mice with chronic, spontaneous AIHA, the concentration and galactosylation of both serum IgG and autoantibodies were lower than in the induced model, and the ratio of G0 IgG in the serum and erythrocyte eluates varied markedly between different individuals. Our interpretation of these results is that changes in serum IgG or autoantibody galactosylation are not consistent in different models of AIHA, and that production of low galactosyl antibodies can be a feature of a normal immune response.
The modulation of B7.2 and B7.1 on B cells by immunosuppressive agents
Authors: Jirapongsananuruk O , Leung D Y M
Published: March 2003

Several recent studies demonstrate that B7.2, but not B7.1, play an important role in allergic inflammation and IgE production. Agents that down-regulate B7.2 may therefore be of benefit for the treatment of Th2-driven allergic diseases. Our current study was carried out to investigate the effect of immunosuppressive agents, cyclosporin A (CsA) and dexamethasone, on B7.2 and B7.1 expression on B cells stimulated with the superantigen, toxic shock syndrome toxin-1 (TSST-1). The analysis of B7.2 and B7.1 on the same cells by flow cytometry demonstrated that TSST-1 up-regulated B7.2+B7.1− but not B7.1+B7.2− on B cells in a dose-dependent fashion. CsA and dexamethasone significantly down-regulated B7.2+B7.1− but up-regulated B7.2−B7.1+ B cells in the presence or absence of TSST-1 (100 ng/ml). Interestingly, the combination of CsA and dexamethasone was much more potent in the inhibition of B7.2 expression than either of these agents alone. As CD40 is known to up-regulate B7.2 expression on B cells, the mechanism of B7.2 down-regulation by CsA and dexamethasone was further studied by investigating the effect of these agents on CD40 expression on B cells. TSST-1 significantly increased CD40 expression on B cells. However, the addition of CsA or dexamethasone significantly down-regulated CD40 expression. Anti-CD40 MoAb significantly reversed the effects of CsA or dexamethasone on B7.2 and B7.1 expression, suggesting that T cell engagement of CD40 plays a role in the mechanisms by which CsA and dexamethasone acts on B cells. These data demonstrate the modulatory effect of CsA and dexamethasone on B7.2 and B7.1 expression on B cells and the potential role of CD40 in mediating this effect.
HLA-DRB1 leprogenic motifs in Nigerian population groups
Authors: Uko G P , Lu L Y , Asuquo M A , Fici D , Mahan S , Awdeh Z , Udim E R , Ding W , Umana U , Adewole T , Fraser P A
Published: March 2003

Amino acid residues involved in the peptide binding groove of HLA-DRB1 alleles were examined in three Nigerian ethnic groups with leprosy (n = 287) and 170 controls to determine the role of DRB1 alleles in disease outcome with Mycobacterium leprae. Nine positively charged motifs and two others with neutral charge to the binding groove were detected. These motifs occurred more frequently in leprosy (leprogenic) than was expected by chance (P < 0.0001). In contrast, five motifs with net negative or ‘modified’ neutral charges to the pocket were negatively associated with leprosy. We conclude that clinical outcome of infection with M. leprae is largely determined by a shared epitope in DRB1 alleles marked by several motifs. These motifs occur in otherwise normal DRB1 alleles, characterized by net positive or neutral charges in the binding groove. We hypothesize that these polarities cause poor binding of DRB1 to M. leprae. On presentation, the signal via the T cell receptor results in muted cell-mediated immunity. The resulting response translates to various forms of leprosy depending on degree of charge consonance between M. leprae and host DRB1 allele. Other factors within or without the HLA complex, such as the T cell receptor repertoire, may also influence the resulting disease.
Effect of different sensitizing doses of antigen in a murine model of atopic asthma
Authors: Sakai K , Yokoyama A , Kohno N , Hiwada K
Published: March 2003

The dose of antigen is assumed to be one of the important factors in the polarized development of helper T cell subsets, i.e. Th1 or Th2 cells. We investigated the effect of the sensitizing antigen dose in a murine model of atopic asthma, which involved sensitization with ovalbumin (OVA) followed by repeated exposure to OVA aerosols. BALB/c mice were primed with varying doses of OVA (0, 10, 100 and 1000 μg) plus Al(OH)3 on days 0, 7 and 14, and were challenged with OVA aerosols (50 mg/ml for 20 min) on days 15–20. There were striking antigen dose-related differences in OVA-specific antibodies: high IgE and low IgG2a titres were found in mice sensitized at 10 μg, while low IgE and high IgG2a titres were seen at 1000 μg. The sensitizing dose was inversely correlated with the total cell count and the eosinophil count in bronchoalveolar lavage fluid (BALF), as well as with the extent of histological changes such as goblet cell hyperplasia of the bronchial epithelium and cellular infiltration into bronchovascular bundles. Antigen-induced bronchial hyper-responsiveness (BHR) to methacholine was observed with sensitization at 10 μg but not at 1000 μg. Splenic mononuclear cells (SMNC) obtained from mice sensitized at either dose showed proliferation in response to OVA. Production of IL-4 and IL-5 by OVA-stimulated SMNC was inversely correlated with the dose of sensitizing antigen. High-dose sensitization resulted in general suppression of cytokine production by SMNC, including interferon-gamma (IFN-γ). The BALF levels of IL-4 and IL-5 were increased by low-dose sensitization, whereas IFN-γ and IL-12 levels were increased by high-dose sensitization. These results suggest that the dose of sensitizing antigen defines the phenotypic changes in the present murine asthma model, presumably by influencing the pattern of cytokine production.
Impaired production of proinflammatory cytokines in response to lipopolysaccharide (LPS) stimulation in elderly humans
Authors: Bruunsgaard H , Pedersen A N , Schroll M , Skinhøj P , Pedersen B K
Published: March 2003

Ageing is associated with decreased resistance to bacterial infections and concomitant increased circulating levels of inflammatory cytokines. The purpose of the present study was to research age-related changes in levels of early mediators of the acute-phase response in whole blood supernatants following LPS stimulation, representing an ex vivo model of sepsis. Levels of tumour necrosis factor-alpha (TNF-α), IL-1β and IL-6 in whole blood supernatants were measured after in vitro LPS stimulation for 24 h in 168 elderly humans aged 81 years from the 1914 cohort in Glostrup, Denmark and in 91 young controls aged 19–31 years. Levels of TNF-α and IL-1β were significantly lower in elderly humans compared with young controls, whereas no difference was detected with regard to IL-6. Elderly humans with low body mass index had the lowest levels of IL-1β. Young women had lower levels of proinflammatory cytokines compared with young men, but this difference was blurred by ageing. No relation was found between circulating plasma levels of TNF-α and levels after in vitro LPS stimulation. In conclusion, decreased production of TNF-α and IL-1β after exposure to LPS may reflect impaired host defence against infections in the elderly and be of importance in elderly humans with underlying health disorders. However, the clinical relevance is questionable in healthy elderly people because decreased levels were found compared with young men but not compared with young women.
In vitroactivated CD4+ T cells from interferon-gamma (IFN-γ)-deficient mice induce intestinal inflammation in immunodeficient hosts
Authors: Bregenholt S , Brimnes J , Nissen M H , Claesson M H
Published: March 2003

To investigate the role of IFN-γ in the immunopathogenesis of inflammatory bowel disease (IBD), severe combined immunodeficient (SCID) mice were transplanted with in vitro activated CD4+ T cells from either wild-type (WT) or IFN-γ-deficient (IFN-γKO) BALB/c mice. In vitro, the two types of T cells displayed comparable proliferation rates and production of tumour necrosis factor-alpha (TNF-α), IL-2, IL-4 and IL-10 after concanavalin A (Con A) stimulation. When transplanted into SCID mice, WT CD4+ blasts induced a lethal IBD, whereas IFN-γKO blasts induced a less severe intestinal inflammation with moderate weight loss. Intracellular cytokine staining of lamina propria lymphocytes (LPL) revealed comparable fractions of CD4+ T cells positive for TNF-α, IL-2 and IL-10 in the two groups of transplanted SCID mice, whereas a two-to-three-fold increase in the fraction of IL-4-positive cells was found in IFN-γKO-transplanted SCID mice. Flow cytometric analyses showed strong up-regulation of MHC class II expression of colonic epithelial cells of WT-CD4+ T cell-transplanted compared with IFN-γKO-transplanted SCID mice. A significantly higher fraction of CD4+ LPL were found to enter the cell cycle, i.e. to incorporate bromo-dexoy-uridine, and to undergo apoptosis in vivo in WT-transplanted compared with IFN-γKO-transplanted SCID mice. These data point towards an important role for IFN-γ in the development of IBD in SCID mice. The inflammation might be initiated and subsequently enhanced by the ability of IFN-γ to induce denovo MHC class II expression in the colonic epithelium, a change which could lead to increased antigen processing and production of local proinflammatory cytokines, CD4+ T cell turnover and thereby to exaggeration of disease.
Serum levels of soluble Fas ligand in patients with silicosis
Authors: Otsuki T , Isozaki Y , Kita S , Ueki H , Kusaka M , Kishimoto T , Ueki A
Published: March 2003

Certain patients with silicosis have been reported to exhibit immunological abnormalities such as the appearance of antinuclear antibodies and the occurrence of autoimmune diseases. Fas ligand (FasL) is a type II membrane protein which induces apoptosis by binding to its membrane receptor, Fas. FasL is converted to a soluble form by a metalloproteinase-like enzyme. We have already found serum soluble Fas (sFas) levels in silicosis patients as well as in patients with systemic lupus erythematosus (SLE) to be significantly higher than those in healthy volunteers. To examine further the role of the Fas/FasL system in silica-induced immunological abnormalities, we investigated serum soluble FasL (sFasL) levels in silicosis patients with no clinical symptoms of autoimmune diseases, using ELISA for sFasL. Although the serum sFasL levels in patients with SLE were significantly higher than those in healthy volunteers and showed a slight positive correlation with serum sFas levels, those in silicosis patients exhibited no significant difference from those in healthy volunteers, and there was no correlation with serum sFas levels. However, sFasL levels were elevated in silicosis patients with slight dyspnoea or normal PCO2 among various clinical parameters of silicosis. It may be speculated that the immunological disturbances presented by the abnormalities of apoptosis-related molecules in silicosis patients do not occur with a similar degree of respiratory involvement. Further studies are required to clarify which kinds of factors are involved in silicosis patients who exhibit immunological abnormalities.
Endogenous glucocorticoids modulate experimental anti-glomerular basement membrane glomerulonephritis
Authors: Leech M , Huang X R , Morand E F , Holdsworth S R
Published: March 2003

The influence of endogenous glucocorticoids (GC) on glomerular injury was studied in a rat model of heterologous anti-glomerular basement membrane (GBM) glomerulonephritis (GN). Sprague-Dawley rats underwent adrenalectomy (ADX) or sham-operation 3 days prior to i.v. administration of both nephritogenic (100 μg/g) and subnephritogenic (50 μg/g) doses of sheep anti-rat GBM globulin. Administration of a subnephritogenic dose of anti-GBM globulin resulted in GN in adrenalectomized animals only. Similarly, ADX performed prior to administration of anti-GBM in the nephritogenic dose range resulted in exacerbation of GN compared with sham-operated animals (24 h protein excretion: 190.8 ± 32.8 versus 42.5 ± 2.6 mg/24 h; P < 0.005). In ADX animals receiving subnephritogenic doses of anti-GBM injury was manifested by abnormal proteinuria (62.7 ± 5.8 mg/24 h), accumulation of neutrophils which peaked at 6 h (7.2 ± 1.37 neutrophils per glomerular cross-section (neut/gcs)) and macrophage accumulation in glomeruli at 24 h (6.8 ± 1.2 macrophages/gcs). Sham-adrenalectomized animals given the same dose of anti-GBM globulin developed minimal or no glomerular injury: urinary protein excretion (8.7 ± 1.5 mg/24 h, P < 0.001); neutrophils (0.2 ± 0.04 neutrophils/gcs, P < 0.001); macrophages (1.2 ± 0.5 macrophages/gcs, P < 0.001). The increased cellular recruitment to glomeruli in adrenalectomized animals was associated with glomerular endothelial P-selectin expression. P-selectin expression was not detected in sham-operated rats after anti-GBM injection. Complement deposition in glomeruli was minimal in both groups. Physiologic GC replacement of ADX rats receiving subnephritogenic-dose anti-GBM reversed the observed susceptibility to GN development, with urinary protein excretion (7.8 ± 1.12, P < 0.005) and no detectable P-selectin expression or leucocyte accumulation in glomeruli. These results suggest that endogenous GC modulate heterologous anti-GBM nephritis in rats and that this may be attributable, in part, to regulation of P-selectin expression.
Mouse strain and conditioning regimen determine survival and function of human leucocytes in immunodeficient mice
Authors: Tournoy K G , Depraetere S , Pauwels R A , Leroux-Roels G G
Published: March 2003

The innate immune system of severe combined immunodeficient (SCID) mice represents an important barrier to the successful engraftment of human cells. Different genetic and pharmacological strategies improve the graft survival. Non-obese diabetic (NOD)-SCID mice are better hosts for reconstitution with human peripheral blood leucocytes (Hu-PBL) because of their reduced natural killer cell and macrophage activity next to defective T and B cell functions. We investigated effects of TM-β1, a rat monoclonal antibody recognizing the mouse IL-2 receptor β-chain, on Hu-PBL survival and function in NOD-SCID and SCID mice. Relative to untreated littermates, TM-β1 improved Hu-PBL survival in SCID and NOD-SCID mice. Moreover, TM-β1-pretreated NOD-SCID mice displayed significantly better Hu-PBL survival and tissue distribution than TM-β1-pretreated SCID mice. Irradiation of NOD-SCID mice further enhanced the effects of TM-β1. However, these animals died within 3 weeks post-grafting due to graft-versus-host disease. Secondary immune responses were evaluated with Hu-PBL from a donor immune to hepatitis B surface antigen (HBsAg). In TM-β1-pretreated NOD-SCID mice, human HBsAg-specific memory B cells produced high titres of anti-HBsAg immunoglobulin irrespective of the administration of a secondary antigen booster dose. This contrasts with secondary immune responses in TM-β1-pretreated SCID mice where high titred antigen-specific immunoglobulins were produced when the appropriate antigen booster was given. In conclusion, reducing the function of the innate immune system in immunodeficient mice improves survival of the human graft and can result in an activation of the memory B cells without the need for recall antigen exposure.
Bacille Calmette–Guérin (BCG)-associated inflammation and fibrosis: modulation by recombinant BCG expressing interferon-gamma (IFN-γ)
Authors: Wangoo A , Brown I N , Marshall B G , Cook H T , Young D B , Shaw R J
Published: March 2003

Immunization with existing BCG vaccines has failed to confer consistent protection against tuberculosis. One of the ways to improve the efficacy of BCG is by enhancing its ability to induce a type-1 T cell response. However, this approach carries the risk that enhanced immunoreactivity may exacerbate tissue pathology associated with vaccination. The aim of the present study was to determine whether use of a recombinant BCG expressing IFN-γ (BCG-IFN) would result in an alteration in the pattern of inflammation and local tissue fibrosis. A murine intravenous BCG infection model was used in which there was a time- and dose-dependent increase in the weight and number of granulomas in the liver. Infection was associated with increased inflammatory activity in the liver, as shown by the increase in expression of inducible nitric oxide synthase (iNOS) assessed by immunochemistry and by measurement of specific mRNA, and in fibrosis measured by hydroxyproline content of the liver and percentage of granuloma cells staining positively for type 1 procollagen. Infection with BCG-IFN resulted in a reduction in organ weight and bacterial load on day 21 compared with infection with control BCG transformed with vector alone (BCG-plasmid). By day 21, there was also a reduction in iNOS mRNA and iNOS+ cells in granulomas in mice infected with BCG-IFN compared with infection with BCG-plasmid, and a similar reduction in both total number of granulomas and liver hydroxyproline content. These results demonstrate that the granulomas in the areas of mycobacterial infection are active sites of both inflammation and fibrosis, and that the local expression of IFN-γ by the recombinant BCG results in more efficient bacterial clearance which is accompanied by a reduction in tissue pathology.
Variations in cytokine mRNA expression during normal human pregnancy
Authors: Kruse N , Greif M , Moriabadi N F , Marx L , Toyka K V , Rieckmann P
Published: March 2003

Epidemiological data provide evidence that disease activity of T cell-mediated, organ-specific autoimmune diseases is reduced during pregnancy. Although there are several experimental animal studies on the effect of pregnancy on the immune system, the situation in humans is less clear. We therefore performed a prospective analysis of cytokine mRNA expression in whole blood by a new on-line reverse transcriptase-polymerase chain reaction technique and of serum hormone levels during pregnancy in healthy women. The control group included age-matched non-pregnant healthy women. Quantitativecytokine mRNA expression revealed significantly reduced IL-18, interferon-gamma (IFN-γ), and IL-2 mRNA levels in the first and second trimester in pregnancy compared with non-pregnant women. No difference between groups was detected for tumour necrosis factor-alpha (TNF-α) mRNA. IL-4 and IL-10 mRNA were detected at low levels in only 20% of pregnant women and were reduced to a statistically significant extent in the second and third trimester compared with the control group. Changes in IL-18 mRNA expression correlated inversely with serum values for human choriogonadotropin (HCG) and IL-10 serum levels correlated with increases in serum 17β-oestradiol levels. These data indicate immunomodulatory effects of pregnancy at the cytokine level which may be related to the variations in the clinical course of organ-specific, T cell-mediated autoimmune diseases during pregnancy.
Over-expression of the decoy receptor 3 (DcR3) gene in peripheral blood mononuclear cells (PBMC) derived from silicosis patients
Authors: Otsuki T , Tomokuni A , Sakaguchi H , Aikoh T , Matsuki T , Isozaki Y , Hyodoh F , Ueki H , Kusaka M , Kita S , Ueki A
Published: March 2003

Dysregulation of apoptosis, particularly in the Fas/Fas ligand (FasL) pathway, is considered to be involved in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). Recently, a soluble decoy receptor, termed decoy receptor 3 (DcR3), that binds FasL and inhibits FasL-induced apoptosis, has been identified. Silicosis is clinically characterized not only by respiratory disorders but by immunological abnormalities. We have found that serum soluble Fas (sFas) levels are elevated in silicosis patients and that sFas message is dominantly expressed in PBMC derived from these patients. This study examined DcR3 gene expression in PBMC derived from patients with silicosis, SLE, or progressive systemic sclerosis (PSS), and compared it with that in healthy volunteers (HV). The relative expression level of the DcR3 gene was examined in PBMC derived from 37 patients with silicosis without clinical symptoms of autoimmune disease, nine patients with SLE, 12 patients with PSS, and 28 HV using the semiquantitative multiplex-reverse transcriptase-polymerase chain reaction (MP-RT-PCR). The correlation between the relative expression level of the DcR3 gene and multiple clinical parameters for respiratory disorders and immunological abnormalities in individuals with silicosis was analysed. The DcR3 gene was significantly over-expressed in cases of silicosis or SLE when compared with HV. In addition, the DcR3 relative expression level was positively correlated with the serum sFas level in silicosis patients. It is unclear, however, whether over-expression of the DcR3 gene in silicosis is caused by chronic silica exposure, merely accompanies the alteration in Fas-related molecules, or precedes the clinical onset of autoimmune abnormalities. It will be necessary to study these patients further, establish an in vitro model of human T cells exposed recurrently to silica compounds, and resolve whether the increase in DcR3 mRNA expression is a cause or consequence of disease.
Interferons and interferon (IFN)-inducible protein 10 during highly active anti-retroviral therapy (HAART)—possible immunosuppressive role of IFN-α in HIV infection
Authors: Stylianou E , Aukrust P , Bendtzen K , Müller F , Frøland S S
Published: March 2003

Interferons play an important, but incompletely understood role in HIV-related disease. We investigated the effect of HAART on plasma levels of IFN-α, IFN-γ, neopterin and interferon-inducible protein 10 (IP-10) in 41 HIV-infected patients during 78 weeks of therapy. At baseline HIV-infected patients had raised levels of both IP-10 and IFN-α compared with healthy controls (n = 19), with particularly high levels in advanced disease. HAART induced a marked decrease in levels of both IFN-α, neopterin and IP-10, though not to normal concentrations. In contrast, IFN-γ levels were low throughout the study, and not different from controls. While neopterin and IP-10 remained significantly decreased compared with baseline levels throughout the study, IFN-α levels returned to baseline at the end of the study. Persistently high IP-10 and IFN-α levels were associated with immunological treatment failure and even high baseline levels of IFN-α appeared to predict immunological relapse. Furthermore, we found a markedly suppressive effect of exogenously added IFN-α on phytohaemagglutinin-stimulated lymphocyte proliferation in both patients and controls, and this suppressive effect seemed not to involve enhanced lymphocyte apoptosis. Our findings suggest a pathogenic role of IFN-α in HIV infection, which may be a potential target for immunomodulating therapy in combination with HAART.
CD4−CD8− T cells bearing invariant Vα24JαQ TCRα-chain are decreased in patients with atopic diseases
Authors: Oishi Y , Sakamoto A , Kurasawa K , Nakajima H , Nakao A , Nakagawa N , Tanabe E , Saito Y , Iwamoto I
Published: March 2003

Atopic disorders are caused by disregulated activation of T helper 2 (Th2) cells that produce IL-4 and IL-5. Because the presence of IL-4 potently augments the differentiation of naive T cells into Th2 cells, it is important to seek the cell population which provides IL-4 for naive T cells. Recently, a unique subpopulation of T cells, natural killer (NK) T cells, has been shown to produce a large amount of IL-4 upon activation, suggesting their regulatory role in initiation of Th2 cell differentiation. To determine whether NK T cells play a regulatory role in human Th2 cell-mediated atopic diseases, we analysed the frequency of invariant Vα24JαQ CD4−CD8− double-negative (DN) T cells, human NK T cells, in patients with atopic asthma and atopic dermatitis. We also studied cytokine production from Vα24+ Vβ11+ DN T cells, which comprise most of Vα24JαQ DN T cells. We found that the invariant Vα24JαQ DN T cells were greatly diminished in patients with asthma and atopic dermatitis. On the other hand, there was no significant difference in Vα24+ CD4+ T cells possessing invariant Vα24JαQ TCR between healthy subjects and atopic patients. We also found that Vα24+ Vβ11+ DN T cells from healthy subjects predominantly produced interferon-gamma (IFN-γ) but not IL-4 upon activation. These results suggest that NK T cells may not be essential for human atopic disease and that the disappearance of NK T cells, most of which produce IFN-γ, may be involved in the pathogenesis of atopic diseases.
Vaccination of BALB/c mice withLeishmania majoramastigote-specific cysteine proteinase
Authors: Rafati S , Baba A Abraham , Bakhshayesh M , Vafa M
Published: March 2003

Cellular immune mechanisms resulting in interferon-gamma (IFN-γ) production are essential for protection against cutaneous leishmaniasis. Antigens of the intracellular amastigote form of the parasite, found in mammalian hosts, are likely to be good candidates for the induction of T cell response and protection from development of leishmaniasis. We purified a stage-specific antigen from amastigote soluble antigen (A-SLA) of Leishmania major by immunoaffinity chromatography. The purified protein was characterized as a cysteine proteinase with enzymatic activity which is inhibited by E-64, and it was named the amastigote cysteine proteinase (ACP). BALB/c mice were immunized by two intraperitoneal injections, at a month interval, of 5 μg of ACP or A-SLA in Freund’s complete adjuvant (FCA). Animals were challenged 4 weeks later with 106L. major promastigotes and examined 4 months after the last injection. The immunized animals developed significantly smaller or no lesions compared with controls. Spleen cells from immunized mice showed a significant proliferative response and produced a high level of IFN-γ in response to ACP, suggesting the induction of Th1 cells after immunization. These results make 24-kD ACP a possible component for an eventual cocktail vaccine against L. major infection.
Down-regulation of the T cell receptor CD3ζchain in rheumatoid arthritis (RA) and its influence on T cell responsiveness
Authors: Berg L , Rönnelid J , Klareskog L , Bucht A
Published: March 2003

T cells implicated in chronic inflammatory diseases such as RA respond weakly when stimulated in vitro with mitogen or antigen. The mechanism behind this hyporesponsiveness is unclear, but a depressed expression of the T cell receptor (TCR)-associated CD3ζ chain has been suggested. In the present work we describe a low expression of CD3ζ in synovial fluid (SF) T cells from RA patients compared with peripheral blood (PB) T cells, but no difference in CD3ζ expression between RA and healthy control PB T cells. In vitro studies demonstrated that granulocytes but not SF macrophages are able to down-regulate the expression of CD3ζ. Through stimulation with anti-CD3 antibodies we demonstrated that the TCR-dependent proliferative response was decreased in SF T cells compared with PB T cells. Stimulation with phorbol ester and ionomycin also resulted in a low proliferative response of SF T cells, indicating that both signal transduction through the TCR (stimulation with anti-CD3) and events further downstream in the signalling pathways (stimulation with phorbol ester and ionomycin) are affected. A similar depression of T cell activity was observed when induction of IL-2 and IL-4 was measured. However, SF T cells were not defective in the induction of interferon-gamma (IFN-γ) when stimulated with phorbol myristate acetate (PMA)/ionomycin, in contrast to the diminished IFN-γ response observed after stimulation with anti-CD3. This indicates that the hyporesponsiveness of SF T cells can not be generalized to all T cell functions. The differential response to external stimuli is likely to be of importance for the capacity of SF T cells to influence inflammatory reactions.
Hydroxyurea inhibits the transactivation of the HIV-long-terminal repeat (LTR) promoter
Authors: Calzado M A , Macho A , Lucena C , Muñoz E
Published: March 2003

HIV-1 gene expression is regulated by the promoter/enhancer located within the U3 region of the proviral 5′ LTR that contains multiple potential cis-acting regulatory sites. Here we describe that the inhibitor of the cellular ribonucleoside reductase, hydroxyurea (HU), inhibited phorbol myristate acetate- or tumour necrosis factor-alpha-induced HIV-1-LTR transactivation in both lymphoid and non-lymphoid cells in a dose-dependent manner within the first 6 h of treatment, with a 50% inhibitory concentration of 0·5 mm. This inhibition was found to be specific for the HIV-1-LTR since transactivation of either an AP-1-dependent promoter or the CD69 gene promoter was not affected by the presence of HU. Moreover, gel-shift assays in 5.1 cells showed that HU prevented the binding of the NF-κB to the κB sites located in the HIV-1-LTR region, but it did not affect the binding of both the AP-1 and the Sp-1 transcription factors. By Western blots and cell cycle analyses we detected that HU induced a rapid dephosphorylation of the pRB, the product of the retinoblastoma tumour suppressor gene, and the cell cycle arrest was evident after 24 h of treatment. Thus, HU inhibits HIV-1 promoter activity by a novel pathway that implies an inhibition of the NF-κB binding to the LTR promoter. The present study suggests that HU may be useful as a potential therapeutic approach for inhibition of HIV-1 replication through different pathways.
Increased production of matrix metalloproteinase-3 and tissue inhibitor of metalloproteinase-1 by inflamed mucosa in inflammatory bowel disease
Authors: Louis E , Ribbens C , Godon A , Franchimont D , De Groote D , Hardy N , Boniver J , Belaiche J , Malaise M
Published: March 2003

Inflammatory bowel diseases (IBD) are characterized by a sustained inflammatory cascade that gives rise to the release of mediators capable of degrading and modifying bowel wall structure. Our aims were (i) to measure the production of matrix metalloproteinase-3 (MMP-3), and its tissue inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), by inflamed and uninflamed colonic mucosa in IBD, and (ii) to correlate their production with that of proinflammatory cytokines and the anti-inflammatory cytokine, IL-10. Thirty-eight patients with IBD, including 25 with Crohn’s disease and 13 with ulcerative colitis, were included. Ten controls were also studied. Biopsies were taken from inflamed and uninflamed regions and inflammation was graded both macroscopically and histologically. Organ cultures were performed for 18 h. Tumour necrosis factor-alpha (TNF-α), IL-6, IL-1β, IL-10, MMP-3 and TIMP-1 concentrations were measured using specific immunoassays. The production of both MMP-3 and the TIMP-1 were either undetectable or below the sensitivity of our immunoassay in the vast majority of uninflamed samples either from controls or from those with Crohn’s disease or ulcerative colitis. In inflamed mucosa, the production of these mediators increased significantly both in Crohn’s disease (P < 0·01 and 0·001, respectively) and ulcerative colitis (P < 0·001 and 0·001, respectively). Mediator production in both cases was significantly correlated with the production of proinflammatory cytokines and IL-10, as well as with the degree of macroscopic and microscopic inflammation. Inflamed mucosa of both Crohn’s disease and ulcerative colitis show increased production of both MMP-3 and its tissue inhibitor, which correlates very well with production of IL-1β, IL-6, TNF-α and IL-10.
Prevaccination with SRL172 (heat-killedMycobacterium vaccae) inhibits experimental periodontal disease in Wistar rats
Authors: Breivik T , Rook G A W
Published: March 2003

Periodontal disease is a bacterial dental plaque-induced destructive inflammatory condition of the tooth-supporting tissues, which is thought to be mediated by T lymphocytes secreting T helper 2 (Th2) cytokines, resulting in recruitment of high numbers of antibody-producing B lymphocytes/plasma cells as well as polymorphonuclear leucocytes (PMN) secreting tissue-destructive components, such at matrix metalloproteinases and reactive oxygen metabolites into the gingival connective tissues. One treatment strategy may be to down-regulate the Th2 response to those dental plaque microorganisms which induce the destructive inflammatory response. In this study we have examined the effects of a potent down-regulator of Th2 responses on ligature-induced periodontal disease in an experimental rat model. A single s.c. injection into Wistar rats of 0·1 or 1 mg of SRL172, a preparation of heat-killed Mycobacterium vaccae (NCTC 11659), 13 days before application of the ligature, significantly reduced the subsequent destruction of the tooth-supporting tissues, as measured by loss of periodontal attachment fibres (P < 0·001) and bone (P < 0·002). This protective effect occurred not only on the experimental (ligatured) side but also on the control unligatured side. SRL172 has undergone extensive toxicological studies and safety assessments in humans, and it is suggested that it may provide a safe and novel therapeutic approach to periodontal disease.
Follow up of patients with chronic granulomatous disease diagnosed since 1990
Authors: Cale C M , Jones A M , Goldblatt D
Published: March 2003

Outcomes for children with chronic granulomatous disease (CGD) have historically been poor, but significant improvements have occurred with the use of effective antibacterial prophylaxis. The present study aimed to document the clinical course of a cohort of children diagnosed with CGD since 1990 in a single centre. Twenty-one patients were identified, with a median age at last assessment of 4 years and 5 months. A third of these children were diagnosed in infancy because of a positive family history. Of the remaining, there was a median delay between the onset of symptoms and diagnosis of 13 months. No invasive or fungal infections were documented after diagnosis, nor were there any deaths in this cohort. A variety of non-infectious complications were noted, which responded well to steroids. As a group, these children were thriving and weight and height distributions fell within the population norm. All patients were receiving antibacterial prophylaxis, 90% with co-trimoxazole, and all but one patient were receiving a prophylactic anti-fungal agent (itraconazole). Both drugs were well tolerated. In conclusion, this cohort of patients, diagnosed in the last decade, tolerated antibacterial and anti-fungal prophylaxis well and on this regimen have a significantly decreased incidence of infection when compared with historical cohorts. Careful follow up of patients who have had aggressive antibacterial and anti-fungal prophylaxis should continue. The data reported on this cohort of patients should inform the debate about the use of more aggressive treatments, such as bone marrow transplantation, in this disease.