bluuebunny/crossref_metadata_2025 huggingface dataset:
Human T lymphocyte primingin vitroby haptenated autologous dendritic cells
Authors: Rustemeyer T , De Ligter S , Von Blomberg B M E , Frosch P J , Scheper R J
Published: March 2003

Dendritic cells (DC), generated from adherent peripheral blood mononuclear cells (PBMC) by culturing with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4, were used to study in vitro sensitization of naive, hapten-specific T cells and to analyse cross-reactivities to related compounds. DC were hapten-derivatized with nickel sulphate (Ni) or 2-hydroxyethyl-methacrylate (HEMA), followed by tumour necrosis factor-alpha (TNF-α)-induced maturation, before autologous T cells and a cytokine cocktail of IL-1β, IL-2 and IL-7 were added. After T cell priming for 7 days, wells were split and challenged for another 7 days with Ni or HEMA, and potentially cross-reactive haptens. Hapten-specificity of in vitro priming was demonstrated by proliferative responses to the haptens used for priming but not to the unrelated haptens. Highest priming efficiencies were obtained when both IL-4 and IL-12 were added to the cytokine supplement. Marked interferon-gamma (IFN-γ) release (up to 4 ng/ml) was found when IL-12 was included in the cultures, whereas IL-5 release (up to 500 pg/ml) was observed after addition of IL-4 alone, or in combination with IL-12. Nickel-primed T cells showed frequent cross-reactivities with other metals closely positioned in the periodic table, i.e. palladium and copper, whereas HEMA-primed T cells showed distinct cross-reactivities with selected methacrylate congeners. Similar cross-reactivities are known to occur in allergic patients. Thus, in vitro T cell priming provides a promising tool for studying factors regulating cytokine synthesis, and cross-reactivity patterns of hapten-specific T cells.
Use of reconstituted influenza virus virosomes as an immunopotentiating delivery system for a peptide-based vaccine
Authors: Pöltl-Frank F , Zurbriggen R , Helg A , Stuart F , Robinson J , Glück R , Pluschke G
Published: March 2003

Immunopotentiating reconstituted influenza virosomes (IRIV) were used as a delivery system for the synthetic peptide-based malaria vaccine SPf66. The reduced SPf66 peptide molecules containing terminal cysteine residues were covalently attached to phosphatidylethanolamine with the heterobifunctional crosslinker γ-maleimidobutyric acid N-hydroxysuccinimide ester. The SPf66-phosphatidylethanolamine was incorporated into IRIV and BALB/c mice were immunized twice by intramuscular injection with peptide-loaded virosomes. Titres of elicited anti-SPf66 IgG were determined by ELISA. These titres were significantly higher and the required doses of antigen were lower, when mice had been preimmunized with a commercial whole virus influenza vaccine. After preimmunization with the influenza vaccine, SPf66-IRIV elicited far more consistently anti-SPf66 antibody responses than SPf(66)n adsorbed to alum. MoAb produced by four B cell hybridoma clones derived from a SPf66-IRIV-immunized mouse cross-reacted with Plasmodium falciparum blood stage parasites in immunofluorescence assays. All four MoAbs were specific for the merozoite surface protein-1 (MSP-1)-derived 83.1 portion of SPf66. Sequencing of their functionally rearranged κ light chain variable region genes demonstrated that the four hybridomas were generated from clonally related splenic B cells. Biomolecular interaction analyses (BIA) together with these sequencing data provided evidence for the selection of somatically mutated affinity-matured B cells upon repeated immunization with SPf66-IRIV. The results indicate that IRIV are a suitable delivery system for synthetic peptide vaccines and thus have a great potential for the design of molecularly defined combined vaccines targeted against multiple antigens and development stages of one parasite, as well as against multiple pathogens.
Natural killer (NK) T cells are significantly decreased in the peripheral blood of patients with rheumatoid arthritis (RA)
Authors: Yanagihara Y , Shiozawa K , Takai M , Kyogoku M , Shiozawa S
Published: March 2003

The number of NK T cells was measured in relation to the Th1/Th2 imbalance observed in RA. Peripheral blood samples of patients with RA (n = 60) and healthy controls (n = 36) were stained with anti-NK receptor 1A (anti-NKR-P1A), anti-CD56, and anti-CD3 MoAbs, and examined by three-colour flow cytometry. NK T (NKR-P1A+CD3+) cells in the peripheral blood were decreased in RA compared with the controls: 25 ± 20/μl versus 143 ± 53/μl (P < 0.0001). CD56+CD3+ cells were also decreased in RA: 60 ± 46/μl versus 116 ± 54/μl (P < 0.0001). The decrease was significant when adjusted to the number of total lymphocytes (P < 0.0001) or NK (CD56+CD3−) cells (P < 0.0001), and showed no correlation with age, sex, disease duration, disease activity, functional class, x-ray stage, drug treatment, joint score, grip strength, C-reactive protein, rheumatoid factor or erythrocyte sedimentation rate of the patients. The results show that the levels of NK T cells are depressed in the peripheral blood of patients with RA, suggesting that the measurement of NK T cells in peripheral blood may have clinical importance for a Th1-type autoimmune disease like RA.
A switch towards Th2 during serological rebound in children with congenital toxoplasmosis
Authors: Kahi S , Cozon G J N , Pinon J M , Greenland T , Wallon M , Al Kurdi M , Ferrandiz J , Peyron F
Published: March 2003

Serological rebounds occur frequently in patients with congenital toxoplasmosis, but remain poorly understood. A link between Th1 and Th2 cytokines and the pathophysiology of infectious diseases has been reported. Production of interferon-gamma (IFN-γ) and IL-4 in supernatants of whole blood after in vitro specific Toxoplasma gondii stimulation and serum-specific IgE levels were studied in 31 congenitally infected children. IFN-γ was produced at higher levels by lymphocytes from children with stable congenital toxoplasmosis (n = 18) than from children showing serological rebound (n = 13) (P < 0.04). Conversely, supernatants from children with serological rebound showed higher levels of IL-4 than those from children with stable congenital toxoplasmosis (P < 0.03). The polarized Th2 response was confirmed by a greater (IL-4:IFN-γ) × 100 ratio (P < 0.0001) and production of T. gondii-specific IgE in six out of 13 children showing serological rebound. These results suggest a role of Th2 cytokines in destabilization of congenital toxoplasmosis and perhaps in local reactivation of the parasite.
Overlapping but distinct specificities of anti-liver-kidney microsome antibodies in autoimmune hepatitis type II and hepatitis C revealed by recombinant native CYP2D6 and novel peptide epitopes
Authors: Klein R , Zanger U M , Berg T , Hopf U , Berg P A
Published: March 2003

Anti-liver-kidney microsome antibodies (anti-LKM) occur in autoimmune hepatitis (AIH) type II and in a subset of patients with hepatitis C. Anti-LKM1 in AIH are directed against cytochrome P4502D6 (CYP2D6), but conflicting data exist concerning the specificity of anti-LKM in hepatitis C. The aim of this study was to evaluate binding specificities of anti-LKM antibodies in both diseases using novel test antigens as well as their inhibitory capacity on CYP2D6 enzyme activity. Sera from 22 patients with AIH type II and 17 patients with hepatitis C being anti-LKM-positive in the immunofluorescence test were investigated for binding to native recombinant CYP2D6 and liver microsomes by ELISA and immunoblotting, and to synthetic peptides covering the region 254–339 (254–273, 257–269, 270–294, 291–310, 307–324, 321–339, 373–389) as well as the novel peptide 196–218 by ELISA. Furthermore, all sera were tested for inhibition of CYP2D6-dependent bufuralol 1′-hydroxylase activity. Twenty of the 22 AIH type II sera (91%) and nine of the 17 hepatitis C sera (53%) were positive for CYP2D6 by ELISA and/or immunoblotting. The previously described major peptide epitope comprising CYP2D6 amino acids 257–269 was recognized by 16 of the 22 AIH sera but by only one hepatitis C serum. A further epitope, 196–218, could be defined for the first time as another immunodominant epitope for AIH because it was recognized by 15 of the 22 AIH (68%) but only three of the 17 hepatitis C sera (18%). With the exception of the peptide 254–273, the other peptides showed no significant reactivity. Analysing the inhibitory properties of anti-LKM antibodies it emerged that 95% of AIH sera and 88% of hepatitis C sera inhibited enzyme function. These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257–269 a further immunodominant epitope exists on CYP2D6 which is recognized by sera from patients with AIH II but hardly by sera from patients with hepatitis C.
Comparative analysis of epitope recognition of glutamic acid decarboxylase (GAD) by autoantibodies from different autoimmune disorders
Authors: Powers A C , Bavik K , Tremble J , Daw K , Scherbaum W A , Banga J P
Published: March 2003

Autoantibodies to GAD, an important marker of the autoimmune process in type I or insulin-dependent diabetes mellitus (IDDM), are also found in non-diabetic individuals with autoimmune polyendocrine syndrome type 1 (APS1), APS2, and stiff man syndrome (SMS). Most IDDM sera contain two distinct GAD antibody specificities, one of which targets an epitope region in the middle-third of GAD65 (IDDM-E1; amino acids 221–359) and one of which targets the carboxy-third of GAD65 (IDDM-E2; amino acids 453–569). Using 11 chimeric GAD65/GAD67 proteins to maintain conformation-dependent epitopes of GAD65, we compared the humoral repertoire of IgG antibodies from an individual with APS2-like disease (b35, b78, and b96) and MoAbs from an IDDM patient (MICA-2, MICA-3, and MICA-4). Neither the APS2 IgG antibodies nor the IDDM MoAbs bind the amino-terminal third of GAD65, but instead target the carboxy-terminal two-thirds of GAD65. Amino acids 270–359 (IDDM-E1) are targeted by one APS2 IgG antibody and MICA-4, while two other APS2 IgG antibodies, MICA-2 and MICA-3, target amino acids 443–585 (IDDM-E2). Using GAD65/67 chimera that span the IDDM-E2 region, we found that MICA-2 binds amino acids 514–528 of GAD65, but two APS2 IgG antibodies require this region and amino acids 529–570. In contrast, the binding of MICA-3 requires two discontinuous amino acid segments of GAD65 (452–513 and 528–569), but not amino acids 514–528. These results indicate that there are both similarities and differences in the humoral response to GAD65 in APS2 and IDDM.
Properdin deficiency in a large Swiss family: identification of a stop codon in the properdin gene, and association of meningococcal disease with lack of the IgG2 allotype marker G2m(n)
Authors: Späth P J , Sjöholm A G , Fredrikson G , Misiano G , Scherz R , Schaad U B , Uhring-Lambert B , Hauptmann G , Westberg J , Uhlén M , Wadelius C , Truedsson L
Published: March 2003

Properdin deficiency was demonstrated in three generations of a large Swiss family. The concentration of circulating properdin in affected males was < 0.1 mg/l, indicating properdin deficiency type I. Two of the nine properdin-deficient males in the family had survived meningitis caused by Neisseria meningitidis serogroup B without sequel. Two point mutations were identified when the properdin gene in one of the properdin-deficient individuals was investigated by direct solid-phase sequencing of overlapping polymerase chain reaction (PCR) products. The critical mutation was found at base 2061 in exon 4, where the change of cytosine to thymine had generated the stop codon TGA. The other mutation was positioned at base 827 in intron 3. The stop codon in exon 4 was also demonstrated by standard dideoxy sequencing in three additional family members. The question was asked if genetic factors such as partial C4 deficiency and IgG allotypes could have influenced susceptibility to meningococcal disease in the family. No relationship was found between C4 phenotypes and infection. Interestingly, the two properdin-deficient males with meningitis differed from the other properdin-deficient persons in that they lacked the G2m(n) allotype, a marker known to be associated with poor antibody responses to T-independent antigens. This implies that the consequences of properdin deficiency might partly be determined by independent factors influencing the immune response.
Role of JAK2 signal transductional pathway in activation and survival of human peripheral eosinophils by interferon-gamma (IFN-γ)
Authors: Ochiai K , Tanabe E , Ishihara C , Kagami M , Sugiyama T , Sueishi M , Koya N , Tomioka H
Published: March 2003

The purpose of this study was to determine whether the JAK pathway is involved in eosinophil activation and survival through IFN-γ receptor signalling in human peripheral eosinophils. Eosinophils were purified from the blood of six atopic disease patients by anti-CD16 magnetic bead-negative selection. IFN-γ significantly up-regulated survival and CD69 expression in 24–48 h cultured eosinophils. Further, IFN-γ induced tyrosine phosphorylation of JAK2 in eosinophils, as indicated by Western blot analysis. Finally, the specific JAK2 inhibitor AG-490 inhibited the tyrosine phosphorylation of JAK2, IFN-γ-induced survival and CD69 expression in eosinophils. In conclusion, these results indicate that IFN-γ induces eosinophil survival and CD69 expression through the activation of JAK2 in peripheral eosinophils, suggesting that JAK2 may play a significant role in eosinophil regulation by IFN-γ–IFN-γR interaction.
Circulating antibodies against α-enolase in patients with primary membranous nephropathy (MN)
Authors: Wakui H , Imai H , Komatsuda A , Miura A B
Published: March 2003

MN is characterized by the glomerular deposition of IgG4 immune complexes. This suggests that nephritogenic immune responses in MN are of the Th2 T helper cell type; however, the pathogenesis of MN is still unknown. In this study we examined sera from patients with primary MN for antibodies to renal proteins. A 47-kD protein in both human and porcine renal extracts was found by immunoblotting to react specifically with serum IgG from some patients. This protein was purified from porcine kidney and identified as α-enolase on the basis of its partial amino acid sequences. Sera from 87 patients with primary MN, 24 patients with secondary MN (15 rheumatoid arthritis patients, nine systemic lupus erythematosus patients), and 16 healthy subjects were examined by ELISA using purified α-enolase. In 60 (69%) patients with primary MN and 14 (58%) patients with secondary MN, the measured optical density values, and hence serum anti-α-enolase antibody levels, were greater than the mean + 2 s.d. of healthy subjects. Immunoblot analysis showed that IgG1 or IgG3 was the predominant subclass (Th1 T helper cell type subclass) of antibodies against α-enolase in patients with primary and secondary MN. Since circulating antibodies against α-enolase have recently been reported in patients with various autoimmune disorders, our results suggest that a number of patients with presumed primary MN may also have abnormalities in Th1 T helper cell-mediated immune responses.
Adhesion molecules (E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1)) in sera from patients withStaphylococcus aureusbacteraemia with or without endocarditis
Authors: Söderquist B , Sundqvist K-G , Vikerfors T
Published: March 2003

The aim of this prospective study was to evaluate if patients with endocarditis display a more extensive endothelial activation than those with bacteraemia but without endocarditis. Sixty-five patients with blood culture-verified Staphylococcus aureus bacteraemia were included and serum samples collected on admission were analysed by enzyme immunoassays. Elevated serum concentrations of adhesion molecules were found in most of the patients with S. aureus bacteraemia. Patients with endocarditis (n = 15) showed significantly higher serum E-selectin (median 156 ng/ml) and VCAM-1 (median 1745 ng/ml) concentrations compared with those with S. aureus bacteraemia but without endocarditis (80 ng/ml and 1172 ng/ml, respectively; P = 0.01 and P = 0.003). No significant difference was found between the groups concerning ICAM-1 (median 451 ng/ml versus 522 ng/ml). In addition, serum tumour necrosis factor-alpha (TNF-α) concentrations were significantly correlated (P < 0.002) to serum levels of E-selectin, ICAM-1 and VCAM-1.
Serum thrombomodulin—a reliable marker of disease activity in systemic lupus erythematosus (SLE): advantage over established serological parameters to indicate disease activity
Authors: Boehme M W J , Raeth U , Galle P R , Stremmel W , Scherbaum W A
Published: March 2003

To date no specific serological parameter is available to assess disease activity in SLE. Soluble serum thrombomodulin is a new marker of endothelial cell injury and vasculitis. The objective of this study was to compare in vivo soluble thrombomodulin as marker of disease activity in SLE with established and recent serological parameters. One hundred and twenty-four sera of 30 patients with proven SLE with different disease activities were tested for serum levels of thrombomodulin, intercellular adhesion molecule-1 (ICAM-1), E-selectin, vascular cell adhesion molecule-1 (VCAM-1), IL-2R, IL-6, IL-10, dsDNA by ELISA and dsDNA additionally by radioimmunoassay (RIA). C-reactive protein (CRP), complement component C3, IgG, creatinine, anti-nuclear antibodies (ANA) and intermediate filament antibodies were measured by standard laboratory tests. The clinical disease activity was evaluated by the Systemic Lupus Activity Measure (SLAM). Correlations of the different serological SLE disease activity parameters with the SLAM scores revealed the highest significance for serum thrombomodulin (correlation coefficient 0.82). This was further confirmed by the intra-individual analysis of follow-up sera. In addition, a moderate correlation could be found for IL-6, IL-10, ICAM-1, CRP and erythrocyte sedimentation rate (ESR). In summary, soluble thrombomodulin is the most important serological parameter of disease activity in SLE currently available, as shown by the in vivo studies. Soluble thrombomodulin might be a valuable serological parameter for therapeutical considerations.
Virulent or avirulent (dhfr-ts−)Leishmania majorelicit predominantly a type-1 cytokine response by human cellsin vitro
Authors: Brodskyn C , Beverley S M , Titus R G
Published: March 2003

In this study we have compared the immune response of normal human cells cultured in vitro to two virulent strains of Leishmania major (CC1 and LV39), and to an avirulent vaccine strain (dhfr-ts−) made by targeted deletion of the essential gene DHFR-TS. We utilized an in vitro system in which naive T cells from normal human donors were primed with autologous Leishmania-infected macrophages. All three parasites infected macrophages and transformed into amastigotes within the cells. However, whereas LV39 and CC1 replicated in macrophages, dhfr-ts− did not. When peripheral blood lymphocytes (PBL) were stimulated with autologous macrophages infected with any of the three parasites, the lymphocytes produced a type-1-biased cytokine response. Finally, addition of IL-12 during the first stimulation period increased the production of interferon-gamma but decreased IL-5 secretion. On the other hand, anti-IL-12 resulted in the opposite effect.
Effects of macrophage colony-stimulating factor (M-CSF) on anti-fungal activity of mononuclear phagocytes againstTrichosporon asahii
Authors: Sasaki E , Tashiro T , Kuroki M , Seki M , Miyazaki Y , Maesaki S , Tomono K , Kadota J-I , Kohno S
Published: March 2003

Trichosporon asahii is an emerging opportunistic pathogen in immunocompromised patients. Little is known about the mechanisms of host defence against T. asahii. We investigated the fungicidal activity of human peripheral blood monocytes and murine peritoneal macrophages against T. asahii isolates, and the effects of M-CSF on the anti-fungal activity of mononuclear phagocytes. We also established a neutropenic mouse model of disseminated trichosporonosis with T. asahii. M-CSF enhanced the phagocytic fungicidal activity of mononuclear cells, and infected mice treated with human M-CSF at 10 × 106 U/kg showed a significant improvement in survival rate, with fewer fungal colony counts in the lung compared with control mice. Mice treated with human M-CSF showed higher concentrations of tumour necrosis factor-alpha (TNF-α) in the lung and plasma compared with control mice. The survival rate was significantly reduced in mice treated with anti-mouse TNF-α. Our results showed that M-CSF enhanced the fungicidal activity of mononuclear phagocytes partly by production of TNF-α, and suggest that the administration of M-CSF to patients with disseminated trichosporonosis may be a useful adjunct to conventional anti-microbial therapy and prophylaxis.
Identification of distinct lymphocyte subsets responding to subcellular fractions ofMycobacterium bovisbacille Calmette–Guérin (BCG)
Authors: Batoni G , Esin S , Pardini M , Bottai D , Senesi S , Wigzell H , Campa M
Published: March 2003

In order to investigate the ability of Mycobacterium bovis BCG vaccination to induce immune responses toward different classes of mycobacterial antigens and the cell populations involved in such responses, proliferation of distinct human lymphocyte subsets from BCG-vaccinated donors in response to different subcellular fractions of BCG was analysed and compared with that of not sensitized subjects. Proliferation of different cell subsets was evaluated by flow cytometric determination of bromodeoxyuridine incorporated into DNA of dividing cells and simultaneous identification of cell surface markers. Although a certain degree of variability was observed among different donors, after 6 days of in vitro stimulation BCG-vaccinated subjects displayed, as a mean, a stronger blastogenic response to all the classes of antigens compared with non-sensitized ones. PPD, culture filtrates and membrane antigens induced a predominant proliferation of CD4+ T cells. In contrast, preparations enriched in cytosolic antigens elicited strong proliferation of γδ+ T cells which, as a mean, represented 55% of the proliferating cells. Although to a lesser extent, proliferation of γδ+ T cells was also elicited by preparations enriched in membrane and cell wall antigens. In response to the latter preparation proliferation of CD4+ T cells and CD16+/CD3− (natural killer (NK)) cells was observed, as well. In particular, cell wall antigens were found to induce significantly higher levels of proliferation of NK cells compared with all the other classes of antigens.
Immune response of tonsillar lymphocytes toHaemophilus parainfluenzaein patients with IgA nephropathy
Authors: Suzuki S , Fujieda S , Sunaga H , Sugimoto H , Yamamoto C , Kimura H , Abo T , Gejyo F
Published: March 2003

The pathogenesis of IgA nephropathy (IgAN) is unclear. We have previously shown glomerular deposition of Haemophilus parainfluenzae (HPI) antigens and the presence of IgA antibody against HPI antigens in patients with IgAN. We examined the immune response to HPI antigens in tonsillar lymphocytes from patients with IgAN. Lymphocytes isolated from the palatine tonsils of 13 IgAN patients and 16 patients with chronic tonsillitis but without renal disease were used as controls. We examined lymphocyte proliferation and production of IgA antibody against HPI antigens by measuring thymidine uptake and IgA antibody in culture supernatants after lymphocyte incubation with HPI antigens. Patients with IgAN showed a significantly higher stimulation index to HPI antigens (thymidine incorporation in tonsillar lymphocytes with HPI/thymidine incorporation in unstimulated tonsillar lymphocytes) than controls (P < 0.002). Lymphocytes from patients with IgAN also showed a significantly higher level of IgA antibody and IgA1 antibody against HPI antigens in culture supernatants than lymphocytes from controls (P = 0.0002 and P = 0.004, respectively). Our results suggest that HPI antigens stimulate tonsillar T and B lymphocytes in patients with IgAN and that an immune response to HPI antigens may play a role in the pathogenesis of this disease in some cases.
Trypanosoma cruzi-induced immunosuppression: B cells undergo spontaneous apoptosis and lipopolysaccharide (LPS) arrests their proliferation during acute infection
Authors: Zuñiga E , Motran C , Montes C L , Diaz F L , Bocco J L , Gruppi A
Published: March 2003

Acute infection with Trypanosoma cruzi is characterized by multiple manifestations of immunosuppression of both cellular and humoral responses. B cells isolated at the acute stage of infection have shown marked impairment in their response to polyclonal activators in vitro. The present work aims at studying the B cell compartment in the context of acute T. cruzi infection to provide evidence for B cell activation, spontaneous apoptosis and arrest of the cell cycle upon mitogenic stimulation as a mechanism underlying B cell hyporesponse. We found that B cells from acutely infected mice, which fail to respond to the mitogen LPS, showed spontaneous proliferation and production of IgM, indicating a high level of B cell activation. Furthermore, these activated B cells also exhibited an increase in Fas expression and apoptosis in cultures without an exogenous stimulus. On the other hand, B cells from early acute and chronic infected mice did not present activation or apoptosis, and were able to respond properly to the mitogen. Upon in vitro stimulation with LPS, B cells from hyporesponder mice failed to progress through the cell cycle (G0/G1 arrest), nor did they increase the levels of apoptosis. These results indicate that B cell apoptosis and cell cycle arrest could be the mechanisms that control intense B cell expansion, but at the same time could be delaying the emergence of a specific immune response against the parasite.
Cultured human monocytes secrete fibronectin in response to activation by proinflammatory cytokines
Authors: Kitamura N , Nishinarita S , Takizawa T , Tomita Y , Horie T
Published: March 2003

We studied the effects of the cytokines IL-1α, IL-6, tumour necrosis factor-alpha (TNF-α), IL-4, IL-10, IL-13 and transforming growth factor-beta (TGF-β) on fibronectin (FN) production by cultured-human monocytes. IL-1α, IL-6 and TNF-α all increased FN production, an indicator of monocyte activation. These cytokines increased FN production in a dose-dependent fashion, with a 4-h treatment being sufficient to measure FN production by radioimmunoassay. Conversely, IL-4, IL-10 and IL-13 strongly inhibited cytokine-induced FN production, while TGF-β only partially inhibited FN production. The combination of suboptimal doses of cytokines (IL-1α+ IL-6, IL-1α+ TNF-α, IL-6 + TNF-α), which could not singly induce substantial amounts of FN, were able to induce FN production by cultured monocytes. Northern blot analysis with a cDNA specific for FN confirmed the expression of FN mRNA in cultured monocytes stimulated with a single cytokine or a combination of cytokines. Our data demonstrate that monocytes may not always require high concentrations of cytokines for activation in vitro, and that the synergistic or additive action of low levels of cytokines on monocyte activation may be sufficient to promote immune or inflammatory reactions. Our data also suggest that certain T cell cytokines may regulate monocyte activation.
Cross-reactivity of anti-galactocerebroside autoantibodies with aTrypanosoma bruceiproteolipidic epitope
Authors: Girard M , Bisser S , Buscher P , Bouteille B , Preud’Homme J-L , Jauberteau M-O
Published: March 2003

Pathogenic mechanisms of the demyelinating encephalopathy featuring the nervous phase of human African trypanosomiasis (HAT) are largely unknown. They might include autoimmune disorders. A variety of autoantibodies is detected during the disease and we have previously evidenced anti-galactocerebroside (GalC) antibodies in the serum and cerebrospinal fluid (CSF) from patients in the nervous stage (stage II) of HAT. We now show that anti-GalC antibodies recognize an antigen located on the parasite membrane and common to different strains of trypanosomes. By using affinity chromatography with a rabbit anti-GalC antiserum, a 52-kD proteolipid was isolated from the membrane of Trypanosoma brucei (T. b.) brucei AnTat 1.9, AnTat 1.1E, and T. b. rhodesiense Etat 1.2/R and Etat 1.2/S. Antibodies directed against this antigen were found in the CSF from patients with nervous stage HAT. These CSF also contained anti-GalC antibodies and adsorption with the proteolipid decreased anti-GalC reactivity. Immunization of mice with this antigen induced the production of antibodies which cross-reacted with GalC but no protection from experimental infection with T. b. brucei. These data support the hypothesis that anti-GalC antibodies detected in the CSF from HAT patients might be induced by molecular mimicry with a parasite antigen.
The antagonism of interferon-gamma (IFN-γ) by heparin: examination of the blockade of class II MHC antigen and heat shock protein-70 expression
Authors: Fritchley S J , Kirby J A , Ali S
Published: March 2003

IFN-γ is a pleiotropic cytokine that is primarily involved in the regulation of immune cell activation and the development of tissue inflammation. It is capable of activating a range of non-immune cells, including those of the vascular endothelium. These cells respond by increasing the expression of intracellular and cell-surface molecules such as class II MHC antigens and adhesion molecules that, together, increase the tendency for interaction with immune cells. It is known that IFN-γ can bind cell surface and extracellular heparan sulphate. Furthermore, soluble heparin can inhibit the function of this cytokine, presumably by competitive displacement from the cell surface, resulting in the failure of normal receptor signal transduction. In this study it is shown that heparin can prevent normal induction of the class II transactivator and heat shock cognate protein-70 in an IFN-γ-treated endothelial cell line. Both of these molecules are dependent on the activation of intracytoplasmic STAT-1, which is the most receptor proximal component of their respective induction pathways. This provides further evidence for the blockade by heparin of ligand activation of the specific IFN-γ receptor.
Selective expansion of T cells in gingival lesions of patients with chronic inflammatory periodontal disease
Authors: Yamazaki K , Nakajima T , Ohsawa Y , Tabeta K , Yoshie H , Sakurai K , Seymour G J
Published: March 2003

Chronic inflammatory periodontal diseases are characterized by a cellular infiltrate and are similar in many respects to other chronic inflammatory diseases. While periodontopathic bacteria have been recognized as the principal causative agent and the immune response to these bacteria is thought to be responsible for the tissue destruction, the full aetiological spectrum is still incompletely understood. In addition to many cell types such as polymorphonuclear leucocytes and macrophages, T cells have been implicated in pathogenesis and are considered to have regulatory roles in progression of the disease. Based on our recent studies demonstrating biased expression of several Vβ families in periodontitis tissues, the aim of this study was to characterize further the T cells relevant to the disease process by reverse transcription-polymerase chain reaction-single-strand conformation polymorphism (RT-PCR-SSCP) and subsequent nucleotide sequence analysis of complementarity-determining region 3 (CDR3) of the TCR β-chain. In spite of the likely involvement of numerous bacteria, the present study has clearly shown the oligoclonality of infiltrating T cells in periodontitis lesions in contrast to low clonality of peripheral blood T cells as evidenced by the appearance of distinct bands in gingival tissue samples and smear pattern of peripheral blood on SSCP gels. These were confirmed by the DNA sequencing of the CDR3 of Vβ16 of selected samples. The analysis of deduced amino acid sequences demonstrated amino acid motifs in the CDR3 region of the periodontitis lesion-derived sequences from each patient. The results indicate that gingival tissue-infiltrating T cells recognizing a limited number of antigens or epitopes are involved in the disease process.
An autoantibody targeting glycated IgG is associated with elevated serum immune complexes in rheumatoid arthritis (RA)
Authors: Tai A W-H , Newkirk M M
Published: March 2003

Advanced glycation end-products (AGE) play a role in diabetes complications and in RA. An autoantibody to IgG-AGE has been shown to correlate with RA disease activity. Thus we sought to analyse serum immune complexes (IC) and AGE-modified proteins in Caucasians and North American Indians to see if the presence of anti-IgG-AGE influenced their composition. Polyethylene glycol precipitation of IC from the serum of anti-IgG-AGE-positive or -negative RA patients, and healthy and diabetic controls were examined. Concentrations of circulating IC were highest in anti-IgG-AGE+ RA patients, followed by anti-IgG-AGE− RA patients, which were greater than healthy controls. IC amounts in the Ojibwe were consistently higher than in Caucasians. Affinity purification of AGE-modified proteins from IC and immunoblotting with antibodies against Ig γ and μ heavy chains, κ and λ light chains, and AGE Nε(carboxymethyl)lysine and imidazolone yielded similar results: anti-AGE+ RA patients had elevated levels relative to those without the autoantibody. Levels in both RA groups were higher than in controls. Glycated albumin amounts followed a similar distribution, but were not influenced by the presence of anti-AGE antibodies. A heavily glycated κ-chain was present primarily in IC from anti-IgG-AGE+ patients. These studies indicate that anti-AGE antibodies have a direct impact on the accumulation of IgG-AGE but not glycated albumin, and may block the normal clearance of IgG-AGE through AGE receptors.
The role of Fcγreceptor polymorphisms and C3 in the immune defence againstNeisseria meningitidisin complement-deficient individuals
Authors: Fijen C A P , Bredius R G M , Kuijper E J , Out T A , De Haas M , De Wit A P M , Daha M R , Van De Winkel J G J
Published: March 2003

Individuals with either a late (C5–9) complement component deficiency (LCCD) or properdin deficiency are at increased risk to develop meningococcal disease, often due to serogroups W135 and Y. Anti-meningococcal defence in both LCCD persons and properdin-deficient individuals without bactericidal antibodies depends mainly on phagocytosis. Three types of opsonin receptors are involved in phagocytosis by polymorphonuclear cells (PMN). These represent the polymorphic FcγRIIa (CD32) and FcγRIIIb (CD16b) receptors, and the C3 receptor CR3 (CD11b/CD18). When the distribution of FcγRIIa and FcγRIIIb allotypes was assessed in 15 LCCD and in 15 properdin-deficient patients with/without previous meningococcal disease, we found the combination of FcγRIIa-R/R131 with FcγRIIIb-NA2/NA2 allotypes to be associated with previous meningococcal disease (odds ratio 13·9, Fisher’s test P = 0·036). No such relation was observed in the properdin-deficient patients. The importance of FcγRIIa allotypes was also demonstrated using in vitro phagocytosis assays. PMN from FcγRIIa-R/R131 homozygous donors internalized IgG2 opsonized meningococci W135 significantly (P < 0·05) less than PMN from FcγRIIa-H/H131 donors. When properdin-deficient serum was tested, it was observed that reconstitution with properdin resulted in enhanced PMN phagocytosis of the W135 meningococci (P = 0·001). This enhanced phagocytosis was parallelled by an increase in C3 deposition onto the opsonized meningococci W135 (r = 0·6568, P = 0·01). We conclude that the occurrence of meningococcal disease in LCCD patients is associated with certain FcγR allotypes. Properdin-deficient individuals are susceptible to meningococcal disease because of an insufficient C3 deposition on the surface of meningococci, resulting in insufficient phagocytosis.
Differential regulation of nitric oxide synthase isoforms in experimental acute Chagasic cardiomyopathy
Authors: Chandrasekar B , Melby P C , Troyer D A , Freeman G L
Published: March 2003

We have previously demonstrated induction and high level expression of IL-1β, IL-6 and tumour necrosis factor-alpha in the myocardium during the acute stage of experimental Trypanosoma cruzi infection (Chagas' disease). The myocardial depressive effects of these cytokines are mediated in part by the induction of nitric oxide synthase (NOS), production of nitric oxide (NO) and formation of peroxynitrite. In this study we investigated the expression, activity and localization of NOS isoforms, and the levels of NO, malondialdehyde (a measure of oxidative stress), and peroxynitrite in rats at 1·5, 5, 10 and 15 days after infection with T. cruzi trypomastigotes. The myocardial inflammatory infiltrate and number of amastigote nests increased over the course of infection. A significant increase in tissue nitrate + nitrite levels, NOS2 mRNA, and NOS2 enzyme activity was observed at all time points in the infected compared with uninfected animals. The enzyme activity of constitutive NOS, tissue malondialdehyde levels, and NOS3 mRNA levels was only transiently increased after infection. The protein levels of the NOS isoforms paralleled their mRNA expression. While no positive nitrotyrosine immunoreactivity was detected in control myocardium, its levels increased in infected animals over time. Thus, by 1·5 days post-infection, when no parasite or immune cell infiltration could be detected, the myocardium expressed high levels of NOS and NO metabolites. Nevertheless, the early production of NO in the myocardium was not sufficient to clear the parasites.
A novel point mutation in CD18 causing the expression of dysfunctional CD11/CD18 leucocyte integrins in a patient with leucocyte adhesion deficiency (LAD)
Authors: Mathew E C , Shaw J M , Bonilla F A , Law S K A , Wright D A
Published: March 2003

Leucocyte adhesion deficiency type 1 (LAD-1) is characterized by the incapacity of leucocytes to carry out their adhesion functions via their CD11/CD18 antigens, which are also referred to as the leucocyte integrins. The patients generally suffer from poor wound healing and recurrent bacterial and fungal infections. In severe cases, the infections are often systemic and life-threatening. A LAD patient (AW) of moderate phenotype has been identified but, unlike most other cases, the level of CD11/CD18 antigens on her leucocytes are uncharacteristically high for a LAD patient. Molecular analysis revealed that she is a compound heterozygote for CD18 mutations. She has inherited a D231H mutation from her father and a G284S mutation from her mother. By transfection studies, it was established that the G284S mutation does not support CD11/CD18 antigen expression on the cell surface. In contrast, the D231H mutation does not affect CD18 forming integrin heterodimers with the CD11 antigens on the cell surface. However, the expressed integrins with the D231H mutation are not adhesive to ligands.
Soluble CD30 is more relevant to disease activity of atopic dermatitis than soluble CD26
Authors: Katoh N , Hirano S , Suehiro M , Ikenaga K , Yamashita T , Sugawara N , Yasuno H
Published: March 2003

It is suggested that CD30 and CD26 are surface molecules expressed on activated Th2 and Th1 cells, respectively. We examined plasma levels of soluble CD26 (sCD26) and sCD30 in patients with atopic dermatitis (AD) when their eruptions were aggravated and in non-atopic healthy controls, and then analysed the possible correlation between these values and the levels of several clinical markers. The plasma levels of both sCD30 and sCD26 were significantly higher in AD patients than in controls, both in exacerbation status and after conventional treatment. Multiple regression analyses showed that plasma sCD30 was a much better predictor of the levels of serum IgE, serum LDH and plasma sCD25, and the area and the score of AD eruption than sCD26, although elevated levels of both sCD30 and sCD26 are associated with these clinical predictors of AD. Importantly, sCD30 plasma levels decreased significantly in AD patients after conventional treatment, while no significant transition was noted in the concentration of sCD26. Moreover, a significant reduction of sCD30 levels was observed in the group of patients whose eruption score was reduced > 50%, whereas it was not in those < 50%. These findings provide evidence that the successful treatment of AD is associated with down-activation of Th2.
Role of caspases in dexamethasone-induced apoptosis and activation of c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase in human eosinophils
Authors: Zhang J P , Wong C K , Lam C W K
Published: March 2003

Eosinophils are the principal effector cells for the pathogenesis of allergic inflammation. Glucocorticoids such as dexamethasone have long been used therapeutically for eosinophilia in allergic inflammation by inducing eosinophil apoptosis, but little is known about the intracellular mechanisms mediating dexamethasone-induced apoptosis. In the present study, we investigated the effect of dexamethasone on three mitogen-activated protein kinases (MAPK) involved in the intracellular signalling pathway: c-Jun NH2-terminal kinase (JNK), p38 MAPK and extracellular signal-regulated kinase (ERK). We found that dexamethasone could activate JNK and p38 MAPK in a time-dependent manner but not ERK. Further, SB 203580, a specific p38 MAPK inhibitor, was additive with dexamethasone in inducing eosinophil apoptosis, while JNK1/2 antisense phosphorothioate oligodeoxynucleotides did not show any significant effect. These suggest that dexamethasone-induced JNK1/2 and p38 MAPK activation are not crucial to the induction of apoptosis. Pretreatment of eosinophils with benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD.FMK), a broad-spectrum caspase inhibitor, could inhibit dexamethasone-induced apoptosis in eosinophils dose-dependently. Moreover, Z-VAD.FMK partially inhibited dexamethasone-activated JNK and p38 MAPK activities. However, dexamethasone treatment did not activate specific caspase-3, -8 activity in eosinophils compared with spontaneous apoptosis. We therefore conclude that dexamethasone-induced apoptosis and activation of JNK and p38 MAPK activity in eosinophils are regulated by caspases but not through the common apoptosis-related caspase-3, -8 as in other cell types. Elucidation of the important role of caspases in eosinophil apoptosis may facilitate the development of more specific and effective treatment for allergic inflammation.
Thep53status in juvenile chronic arthritis and rheumatoid arthritis
Authors: Taubert H , Thamm B , Meye A , Bartel F , Rost A-K , Heidenreich D , John V , Brandt J , Bache M , Würl P , Schmidt H , Riemann D
Published: March 2003

The aim of this study was to investigate the p53 status in two autoimmune diseases; juvenile chronic arthritis (JCA) and rheumatoid arthritis (RA). In a PCR-sequencing analysis of exons 4–9 of the p53 gene, no mutation was identified, except for the case of an RA synovectomy sample with two mutations of intron 7. p53 gene polymorphisms for codons 36, 47, and 213 were not detected. Codon 72 polymorphism showed an indication of an increased occurrence of the Pro/Pro allelotype in JCA. Expression of P53 protein was comparable for JCA and RA synovectomy samples. For all RA samples P53 protein was detectable, whereas one sample of a JCA patient failed to express P53 protein.
Effects of peroxisome proliferators on the thymus and spleen of mice
Authors: Yang Q , Xie Y , Depierre J W
Published: March 2003

The effects of peroxisome proliferators on the immune system of male C57Bl/6 mice have been investigated. Significant atrophy of the thymus and spleen was observed in animals treated with potent peroxisome proliferators (e.g. perfluorooctanoic acid (PFOA), di(2-ethylhexyl)phthalate (DEHP), Wy-14 643 and nafenopin), whereas the effects of a moderate peroxisome proliferator (i.e. acetylsalicylic acid (ASA)) were relatively weak. The time course of thymic and splenic atrophy caused by PFOA was found to resemble the time course of the increase in liver weight and of peroxisome proliferation. Analysis of the numbers and phenotypes of thymocytes and splenocytes from PFOA-treated mice revealed the following: (i) the numbers of thymocytes and splenocytes were decreased > 90% and about 50%, respectively, by PFOA treatment; (ii) although all populations of thymocytes were decreased, the immature CD4+CD8+ population was decreased most dramatically; (iii) the numbers of both T and B cells in the spleen were decreased by PFOA treatment. Analysis of the cell cycle of thymocytes indicated that the thymic atrophy caused by PFOA in mice results, at least in part, from inhibition of thymocyte proliferation. Interestingly, in vitro exposure to PFOA for up to 24 h did not produce analogous effects in either thymocytes or splenocytes. Thus, the thymic and splenic atrophy caused by PFOA appears to involve an indirect pathway.
Characterization of the T cell recognition of hepatitis B surface antigen (HBsAg) by good and poor responders to hepatitis B vaccines
Authors: Desombere I , Gijbels Y , Verwulgen A , Leroux-Roels G
Published: March 2003

To study the regulation of the human cellular immune response to HBsAg we produced a series of HBsAg-specific T cell lines from good and poor responders to the hepatitis B vaccine. All T cell lines expressed CD4 on their membrane and could therefore be considered of the helper/inducer phenotype. The different HBsAg-specific T cell lines were restricted by HLA-DRB5*0101, DRB1*1201, -DRB1*0701, -DRB1*0301, -DPB1*0201, -DPB1*0402, and -DPB1*0901. In good responders to the hepatitis B vaccine different HLA molecules could act as restricting element. In poor responders the diversity of HLA class II restriction determinants was more limited. This leads us to conclude that the immune response to HBsAg is multispecific and polyclonal in good responders and paucispecific and oligoclonal in poor responders to the hepatitis B vaccine. By using a panel of synthetic peptides representing selected sequences of the HBsAg, the fine specificities of each of these T cell lines could be determined. Strikingly, the majority of the identified T cell epitopes was located in and around the first hydrophobic transmembranous region of the HBsAg. This was observed in T cell lines from good and poor vaccine responders, without distinction. The remarkable T cell immunogenicity of this region may reside in its richness in binding motifs for a variety of HLA class II determinants.