bluuebunny/crossref_metadata_2025 huggingface dataset:
Interleukin‐10 Response Abnormalities in Systemic Lupus Erythematosus
Authors: MONGAN A. E. , RAMDAHIN S. , WARRINGTON R. J.
Published: November 2003

It has been previously reported that the production of interleukin‐6 (IL‐6) is often enhanced in systemic lupus erythematosus (SLE). The authors examined the secretion of IL‐6, tumour necrosis factor‐α (TNF‐α), granulocyte–macrophage colony‐stimulating factor, IL‐1α and IL‐4 by B cells and monocytes from lupus patients and compared this to the production in normal controls and in rheumatoid arthritis patients. IL‐6 production was increased an average of 3.4‐fold compared to that in normal subjects and 8.4‐fold compared to rheumatoid arthritis patients. In SLE, a strongly positive correlation was found between the levels of IL‐6 and TNF‐α (R = 0.8987, P = 0.002). Since production of both IL‐6 and TNF‐α is regulated by IL‐10, the enhancement of the production of these cytokines could reflect a defect in either IL‐10 production or responsiveness. However, spontaneous production of IL‐10 was enhanced in cultures of B cells and monocytes from lupus patients, compared to normal controls, the levels being increased 3.1‐ to 6‐fold for monocytes and B cells, respectively. The finding of increased secretion of these cytokines implies an abnormality in IL‐10‐mediated suppression in SLE. To assess this possibility, the authors examined recombinant human IL‐10‐mediated suppression of IL‐6 production by monocytes and B cells from lupus patients, compared to normal controls, and found that whereas IL‐10 caused a concentration‐dependent suppression of IL‐6 production in normal B cells and monocytes, this suppression was deficient in B cells and monocytes from lupus patients. In SLE, it therefore appears that there may be an intrinsic defect in IL‐10‐induced suppression of cytokine synthesis. This could explain the increased levels of IL‐10 and IL‐6 found in this condition, and may also be responsible for the characteristic polyclonal B‐cell activation that is seen.
Interferon‐γ‐Induced MHC Class I Expression and Defects in Jak/Stat Signalling in Methylcholanthrene‐Induced Sarcomas
Authors: SVANE I. M. , ENGEL A.‐M. , NIELSEN M. , WERDELIN O.
Published: November 2003

Seventy‐eight uncloned tumour cell lines, each established from a primary sarcoma induced with methylcholanthrene in immunocompetent nu/+ BALB/c and C.B.‐17 mice or in immunodeficient nu/nu BALB/c and severe combined immunodeficient (SCID) mice, were examined for sensitivity to interferon‐γ (IFN‐γ) as measured by tumour cell augmentation of major histocompatibility complex (MHC) class I expression. The tumour cells were cultured with IFN‐γ and their expression of Kd, Dd and Ld was measured by fluorescence‐activated cell sorter analysis. All but three of the 78 tumour lines up‐regulated Kd, Dd and Ld to a variable degree in response to IFN‐γ, indicating that IFN‐γ resistance is not a common property of these sarcomas. The tumour cell lines varied greatly in their MHC class I expression before as well as after IFN‐γ stimulation. There was a tendency towards a higher MHC expression after IFN‐γ stimulation in tumour lines from immunocompetent mice compared to immunodeficient mice, but no common maximum MHC class I expression level was found for the 78 tumour cell lines. Three of the tumour lines, all from immunodeficient mice, completely failed to respond to IFN‐γ by up‐regulating MHC class I expression. The same three also displayed absence of IFN‐γ‐induced Stat1β tyrosine phosphorylation and low Stat1α tyrosine phosphorylation, indicating a defect in the signal transduction pathway affecting phosphorylation of Stat1. These findings strongly suggest a link between defects in Stat1 phosphorylation and the failure to up‐regulate MHC class I. In all tumour lines tested, the Stat1 Western blotting revealed a 78 kDa protein (p78) not previously described.
Complement C6 and C2 Biosynthesis in Syngeneic PVG/c− and PVG/c+ Rat Strains
Authors: TIMMERMAN J. J. , VAN DIXHOORN M. G. A. , SCHRAA E. O. , VAN GIJLSWIJK‐JANSSEN D. J. , MUIZERT Y. , VAN ES L. A. , DAHA M. R.
Published: November 2003

A PVG rat strain with total deficiency of C6 and partial deficiency of C2 (PVG/c−), and a syngeneic control strain (PVG/c+), were used to study the production of extrahepatically synthesized complement. Livers of complement deficient rats were transplanted in sufficient rats (Tx−L). The C6 and C2 levels in Tx−L rats declined within 2 days to 25% and 30%, respectively, and remained stable for more than 6 weeks. To investigate the contribution of C6 synthesis by the liver, C6 sufficient livers were grafted in deficient rats (Tx+l). After an initial increase, with maximum C6 levels of 119% at 10 days following transplantation, the C6 levels decreased gradually and C6 was no longer detectable 28 days after transplantation. This decline in C6 levels was dependent on antibody production against C6. No significant change in the C3, C4, factor H and factor B levels was observed. Expression of C6 mRNA in the grafted PVG/c+ sufficient liver was comparable to the expression of C6 mRNA in control PVG/c+ livers while C6 mRNA expression in the transplanted PVG/c− liver and the control PVG/c− liver was lower. In conclusion, it was demonstrated in vivo that not only C6 but also C2 is synthesized extrahepatically in PVG/c rats.
Interferon‐γ Production in Antigen Specific T Cell Response: Quantitation of Specific mRNA and Secreted Protein
Authors: HALMINEN M. , KLEMETTI P. , VAARALA O. , HURME M. , ILONEN J.
Published: November 2003

Interferon gamma (IFN‐γ) production as a measure of cellular sensitization was studied by detection of the cytokine in culture supernatant by enzyme immunoassay (EIA) and by measuring cellular mRNA using the reverse transcriptase polymerase chain reaction (RT‐PCR) method. These assays were compared to the standard lymphocyte proliferation assay as a marker of T cell responsiveness to foreign antigens. When blood donors seropositive for herpes simplex virus (HSV) were compared to seronegative donors, all measurements of cellular sensitization separated the groups without overlap. There were significant correlations between the IFN‐γ mRNA titre and the secreted IFN‐γ (r = 0.57, P = 0.03), and the proliferative response and the secreted IFN‐γ (r = 0.78, P = 0.001), as well as between the IFN‐γ mRNA titre and the proliferative response (r = 0.78, P < 0.001). When tetanus toxoid (TT) responses were studied in immunized subjects, a wide range of responsiveness could be seen and correlation between various measurements was poor. However, constant individual levels of the cytokine production were demonstrated. Six people who had received their last TT booster vaccination more than 5 years ago were revaccinated and repeatedly studied. An increase in the levels of produced IFN‐γ could be seen in all subjects and two who lacked a lymphocyte proliferation response developed it after revaccination.
Induction of HIV‐1 Specific Mucosal Immune Responses by DNA Vaccination
Authors: ASAKURA Y. , HINKULA J. , LEANDERSSON A.‐C. , FUKUSHIMA J. , OKUDA K. , WAHREN B.
Published: November 2003

DNA vaccination has been shown to induce immunity against several different pathogens including HIV‐1. The authors demonstrate here that administration of DNA vaccines via the intranasal route is sufficient to induce immune responses both at distal mucosal sites and systemically. Since transmission of HIV‐1 occurs largely across mucosal surfaces, the intranasal route provides a further means of application for DNA immunization.
Serum Amyloid P Component Binds to Influenza A Virus Haemagglutinin and Inhibits the Virus Infection In Vitro
Authors: ANDERSEN O. , VILSGAARD RAVN K. , JUUL SØRENSEN I. , JONSON G. , HOLM NIELSEN E. , SVEHAG S.‐E.
Published: November 2003

Serum amyloid P component (SAP) is a member of the phylogenetically conserved and structurally related group of proteins called pentraxins. SAP exhibits multispecific calcium‐dependent binding to oligosaccharides with terminal N‐acetyl‐galactosamine, mannose and glucuronic acid. The authors report that SAP can bind to influenza A virus and inhibit agglutination of erythrocytes mediated by the virus subtypes H1N1, H2N2 and H3N2. SAP also inhibits the production of haemagglutinin (HA) and the cytopathogenic effect of influenza A virus in MDCK cells. The binding of SAP to the virus requires physiological calcium concentrations and is blocked by specific SAP antibodies. Denaturated and renaturated SAP retained inhibition of HA. Electron microscopy shows Ca2+‐dependent binding of SAP to spikes on the viral envelope and immunoblotting indicates that SAP binds to a 50–55 kDa peptide corresponding to the mass of the HA1 peptide. Of several monosaccharides tested only D‐mannose interfered with SAP's inhibition of both HA and infectivity. The glycosaminoglycans heparan sulfate and heparin, which bind SAP, reduced SAPs binding to the virus. The results indicate that the inhibition by SAP is due to steric effects when SAP binds to terminal mannose on oligosaccharides localized close to the sialic acid‐binding site of the HA trimer.
Release of Cytokines and Soluble Cell Surface Molecules by PBMC after Activation with the Bispecific Antibody CD3 × CD19
Authors: KLEIN S. C. , BOER L. H. , DE WEGER R. A. , DE GAST G. C. , BAST E. J. E. G.
Published: November 2003

Bispecific antibodies (BsAb) consist of two different heavy and light chains and may bind to two different antigens present on different cell types. With their dual specificity BsAb may recognize effector cells (e.g. T cells) on one hand and tumour cells (e.g. malignant B cells) on the other hand. The authors analysed whether T cell activation and subsequent killing of malignant B cells mediated by the bispecific antibody CD3 × CD19 was reflected by the release of cytokines. In addition, the authors investigated whether the in vitro cytokine release was similar to that observed in vivo in the patients treated with BsAb. The in vitro release of cytokines into the supernatant of cell cultures of peripheral blood mononuclear cells (PBMC) and malignant B cells was measured after incubation with either the bispecific antibody CD3 × CD19 or the monospecific anti‐CD3 (aCD3) antibody in the presence or absence of interleukin (IL)‐2. Release of tumour necrosis factor‐α (TNF‐α), interferon‐γ (IFN‐γ), IL‐6, IL‐8, IL‐10, soluble (s) CD4, sCD8 and sCD25 by PBMC was equal under both conditions and could be used as an indicator for T cell activation. However, the cytokine pattern and level did not correlate with the cytotoxic capacity, which was 4 logs higher with BsAb + IL‐2 compared to aCD3 + IL‐2. The in vitro pattern of cytokine release was similar to that observed in vivo in the serum of patients treated with BsAb and IL‐2, indicating the possibility of predicting cytokine release in future patients with other therapeutic regimens.
Effect of Treatments with Cyclosporin A and Anti‐Interferon‐γ Antibodies on the Mechanisms of Immune Tolerance in Staphylococcal Enterotoxin B Primed Mice
Authors: KUSCHNAROFF L. M. , VALCKX D. , GOEBELS J. , RUTGEERTS O. , HEREMANS H. , FROYENT G. , WAER M.
Published: November 2003

The authors were interested to investigate the effect of Cyclosporin A (CsA), known to block interleukin‐2 (IL‐2) production, or of anti‐interferon‐γ antibodies (anti‐IFN‐γ Abs) in a model of T cell tolerance induced by the injection of the superantigen Staphylococcal Enterotoxin B (SEB) in BALB/c mice. After SEB immunization, tolerance was mainly achieved through deletion and anergy of SEB‐reactive Vβ8+ T cells. Association of CsA treatment with SEB led to a greater decrease of the percentage of Vβ8+ CD4+ lymphocytes in the spleen and an abolition of clonal anergy. In contrast, treatment of SEB primed mice with anti‐IFN‐γ Abs resulted in an increased percentage of Vβ8+ CD4+ cells without affecting the induction of clonal anergy. The authors found that 1–2 h after SEB priming, splenic mRNA levels of IFN‐γ and IL‐4 were decreased by either CsA and anti‐IFN‐γ Abs, whereas FasL, Bcl‐2, p. 53, and c‐myc levels were not influenced by either treatment. However, SEB‐induced IL‐2 and IL‐10 mRNA expression was suppressed only by CsA, whereas tumour necrosis factor‐α (TNF‐α) was decreased only by anti‐IFN‐γ Abs. To investigate whether the effect of CsA on the tolerance mechanisms was related to suppression of IL‐2, CsA was administered together with recombinant IL‐2. Whereas anergy was not influenced, the decreased percentage of Vβ8+ CD4+ cells seen in CsA‐treated animals in the second week after SEB injection was partially corrected by the administration of IL‐2. Experiments involving bromodeoxiuridine incorporation revealed that the latter effect of IL‐2 was mainly due to a correction of the defective proliferation of Vβ8+ T cells after SEB injection in CsA‐treated mice. These results suggest that the effect of CsA and anti‐IFN‐γ Abs on tolerance mechanisms are in part explained by their action on cytokines.
Increased Mortality and Impaired Clonal Deletion After Staphylococcal Enterotoxin B Injection in Old Mice: Relation to Cytokines and Nitric Oxide Production
Authors: KUSCHNAROFF L. M. , GOEBELS J. , VALCKX D. , HEREMANS H. , MATTHYS P. , WAER M.
Published: November 2003

In the present study peripheral T cell tolerance and the occurrence of shock were evaluated in young and old mice after injection of Staphylococcal enterotoxin B (SEB). In young mice SEB immunization leads to tolerance based on deletion and anergy of SEB‐reactive Vβ8+ T cells. With aging, mice developed resistance to SEB‐induced deletion of Vβ8+ T cells as well as a high sensitivity to toxic shock. Compared to young mice, older mice injected with SEB showed increased serum levels of interferon‐γ (IFN‐γ), interleukin‐2 (IL‐2) and IL‐4. These results were confirmed by reverse transcription‐polymerase chain reaction (RT‐PCR), as splenic mRNA levels taken 2 h after SEB injection showed higher values of IL‐2, IL‐4, and IFN‐γ in old mice. In contrast, mRNA levels for FasL and tumour necrosis factor‐α (TNF‐α) were lower. No difference in IL‐10 mRNA was found. Compared to young mice, old mice showed a high, but statistically not significantly different (P = 0.20), production of nitric oxide (NO). Blocking of IFN‐γ with antibodies or reducing IFN‐γ by depletion of natural killer (NK) cells resulted, respectively, in a complete or partial protection against mortality in aged mice. Suppressing the NO production by the NO synthase inhibitor N‐nitro‐L‐arginine methylester (L‐NAME) increased the mortality in both young and old mice, and abrogated clonal deletion in the surviving young mice. In conclusion, in young mice NO production is a key factor in the protection against mortality and the development of clonal deletion after SEB injection. The higher mortality seen in older mice is mainly related to the elevated production of IFN‐γ and occurs despite a sufficient production of NO. The decreased clonal deletion of old mice may be related to their decreased expression of Fas ligand or TNF‐α after SEB injection.
Interferon‐γ Production by Human T Cells and Natural Killer Cells In Vitro in Response to Antigens from the Two Intracellular Pathogens Mycobacterium tuberculosis and Leishmania major
Authors: KEMP K. , HVIID L. , KHARAZMI A. , KEMP M.
Published: November 2003

Acquired resistance to both mycobacteria and Leishmania is primarily mediated by interferon‐γ (IFN‐γ), which triggers mechanisms leading to the death of the microorganism in macrophages. In this study, cell activation and IFN‐γ production was investigated in human peripheral blood mononuclear cells (PBMC) from individuals previously sensitized to tuberculin and without known exposure to Leishmania parasites. Immune staining for intracellular IFN‐γ and surface markers allowed flow cytometric identification of the cellular sources of IFN‐γ in cell cultures incubated with purified protein derivative of tuberculin (PPD) and Leishmania antigens. It was found that IFN‐γ was produced in response to both PPD and Leishmania stimulant by T cells in the cultures. Activation of IFN‐γ producing natural killer (NK) cells was demonstrated only in some cultures, and only with concomitant T cell activation.
Linomide Enhances Apoptosis in CD4+CD8+ Thymocytes
Authors: HARRING A. C. , XU Z. , ANDERSSON G. , HEDLUND G.
Published: November 2003

Linomide, a quinoline‐3‐carboxamide, has a pleiotropic immune modulating capacity and inhibits development as well as progression of disease in animal models of autoimmunity. Linomide treatment of mice resulted in a dramatic, dose‐dependent decrease of the thymic cell number shortly after the start of administration. Flow cytometric analysis revealed that the major thymocyte subset, the early immature type CD4+CD8+ thymocytes, were reduced in number by 75%, mature CD4+CD8− or CD4−CD8+ thymocytes were less sensitive to treatment. The polyclonal T cell activator Con A (Concanavalin A) was used together with IL‐2 to evaluate the potential proliferative responsiveness of ex vivo thymocytes. Thymocytes from mice treated with Linomide exhibited a more vigorous proliferation than control cultures. An effect shown to not only be due to the enrichment of mature thymocytes in the cultures from Linomide treated animals, but also when purified, mature thymocytes (CD4+CD8− and CD4−CD8+) were cultured with Con A and IL‐2, these cells responded with a significantly enhanced proliferation. In vivo Linomide treatment did not result in increased plasma concentrations of corticosterone and treatment of adrenalectomized mice resulted in a reduction of thymocytes which was comparable to the effect in intact mice, indicating that glucocorticoids (GC) are not major mediators of Linomide‐induced thymocyte deletion. In addition to this, and supporting a glucocorticoid independent mode of action, Linomide treatment of thymocytes in vitro resulted in a significant increase in the number of apoptotic cells, specifically in the CD4+CD8+ subset, implicating apopotosis as one component in the course of thymocyte reduction. In addition to this, in vivo treatment with Linomide resulted in an identical pattern to that seen in vitro in that there was significantly increased apoptosis only in the CD4+CD8+. These data indicate that Linomide modifies thymocyte development using a glucocorticoid independent pathway and results in the increased apoptosis of the CD4+CD8+ subset.
Selective Cytotoxicity of Two Rodent T Cell Lymphomas to Rat Yolk Sac Tumours Involves a Retroviral Envelope Protein Expressed by the Lymphoma
Authors: LINDVALL M. , ERIKSSON H. , HEDLUND G. , SJÖGREN H. O.
Published: November 2003

A Gross virus induced rat T cell lymphoma G1‐Tc1 and a Moloney virus induced mouse T cell lymphoma YAC‐1 are shown to exert a strong cytotoxic activity against rat yolk sac tumours but not to various types of rat, mouse or human normal cells or tumour cell lines including carcinomas, sarcomas, lymphomas and gliomas. Both lymphomas are CD3+, CD4−, CD8− and T‐cell receptor (TCR)αβ+. The cytotoxicity was not MHC restricted or dependent on the density of MHC class I of the target cells, and the mouse lymphoma killed the rat yolk sac tumour target. The cytotoxic action was fast and up to 80% specific killing was observed in 4‐h 51Cr release assays. A rat B cell hybridoma was established from a Wistar/Furth (WF) rat immunized with the syngeneic lymphoma G1‐Tc1 producing an immunoglobulin (Ig)G2c monoclonal antibody (MoAb) 1F2. This binds to the lymphomas G1‐Tc1 and YAC‐1 and also to a murine non‐cytolytic Rauscher lymphoma RMA, but not to any other of several rat, mouse or human cell types tested. The 1F2 completely inhibited the killing of rat yolk sac tumours by the two cytolytic lymphomas, but did not interfere with the killing mediated by natural killer (NK) cells or cytolytic lymphokine‐activated killer (LAK) cells. Immunochemical analysis of solubilized cell membranes of the lymphoma G1‐Tc1 demonstrates that the 1F2 antibody recognizes an epitope on a retroviral gp 70 envelope protein. This indicates that a retroviral protein is involved in the lytic activity of the two lymphomas.
Down‐Regulatory Effect of Mycobacterium leprae Cell Wall Lipids on Phagocytosis, Oxidative Respiratory Burst and Tumour Cell Killing by Mouse Bone Marrow Derived Macrophages
Authors: MOURA A. C. N. , MODOLELL M. , MARIANO M.
Published: November 2003

The authors have previously demonstrated that lipids from Mycobacterium leprae cell walls inhibit macrophage functions and are endowed with anti‐inflammatory properties in vivo. To investigate these observations further, the authors describe here the influence of dead M. leprae or of the lipids extracted from the cell wall of the mycobacterium, enclosed in liposomes, on the phagocytic, oxidative respiratory burst and tumouricidal ability of bone marrow derived macrophages in vitro. Dead M. leprae or its cell wall lipids abrogated the oxidative respiratory burst and phagocytic ability of mouse bone marrow derived macrophages. A dose‐dependent inhibitory effect of the bacterial lipid extract on tumour cell killing by lipopolysaccharide (LPS)‐activated bone marrow derived macrophages was demonstrated. However, when delipidated M. leprae was added to cultures of bone marrow derived macrophages, immune phagocytosis and superoxide production was up‐regulated. Mycobacterium leprae or its lipids did not appear to be toxic to those cells assayed by the MTT (methyl thiazol tetrazolium) test. These data, added to our preceding observations, support the hypothesis that the down‐regulatory activity of M. leprae wall lipids on macrophage function might be one of the evasive mechanisms of the bacterium to enable it to perpetuate itself in the host tissues.
Nasal Lymphoid Tissue (NALT) as a Mucosal Immune Inductive Site
Authors: WU H.‐Y. , NGUYEN H. H. , RUSSELL M. W.
Published: November 2003

Intranasal (i.n.) immunization is a very effective route for inducing mucosal immunity, but the cellular mechanism responsible for regulating and disseminating these responses is not fully understood. The authors studied the role of nasal lymphoid tissue (NALT) as a mucosal inductive site by using highly purified NALT cells obtained by a new method of mechanical isolation. The NALT cells, like Peyer's patch (PP) cells, were smaller in size and less granular than lymphocytes from salivary glands (SG) and small intestinal lamina propria (LP). The NALT cells isolated from i.n. immunized mice contained antigen‐specific antibody‐secreting cells (ASC) predominantly of immunoglobulin (Ig)A isotype, similar to those also recovered from salivary glands in a time course study. However, the higher proportion of smaller sized spots formed by NALT cells in ELISPOT assays suggested that these cells were less differentiated precursors of those found in salivary glands. This was supported by the fact that after i.n. immunization, IgA ASC appeared in NALT, as well as in mucosal effector sites SG and LP, but none or very few in another mucosal inductive site, PP. In contrast, after intragastric (i.g.) immunization, IgA ASC were detected in PP, along with the SG and LP, but none or very few in NALT. Furthermore, after i.n. immunization, lymphocytes from NALT but not PP proliferated in response to the specific antigen in culture. These findings imply that NALT served as an inductive site for IgA antibody responses at mucosal effector sites.
T‐Cell Receptor BJ Gene Segment Expression in Human Umbilical Cord Blood CD4+ and CD8+ T‐Cell Subsets
Authors: JEDDI‐TEHRANI M. , HODARA V. , ESIN S. , TÖRÖK C. , WIGZELL H. , ANDERSSON R.
Published: November 2003

By employing RT‐PCR‐based technology, followed by Southern‐blot analysis, patterns of relative TCR BJ gene segment usage in human CD4+ and CD8+ umbilical cord blood T cells (UCT) from ten children were determined in relation to seven recombined TCR BV gene (sub) families (BV 3, 5S1, 6S1‐3, 8, 9, 12 and 18). Normal frequency of usage of individual BJ members was observed to be extremely nonrandom. BJ usage in association with each BV was ranked and mean ranking values were calculated for individual BJs. Moreover, BJ family usage and family ranges as well as individual BJ over‐representations were determined. In all these aspects of BJ exon expression, CD4+ and CD8+ UCT displayed similar distribution patterns. Comparisons of BJ usage in UCT subpopulations and in the adult peripheral blood lymphocyte (PBL) counterparts were performed and many similarities were observed. However, discrepancies in two parameters were recorded; contrary to observations in PBL, individual BJ over‐representations were virtually absent in UCT, and significantly less wide BJ family ranges were demonstrated in CD8+ UCT relative to CD8+ PBL T cells. These differences support the notion that UCT are in a less dynamic state than are PBL T cells. Hence, despite the fact that PBL T cells are subjected to continuous antigenic challenge, the striking resemblance of PBL and UCT with regard to the overall individual relative usage, ranking, mean ranking and family utilisation of BJ gene segments, irrespective of the choice of recombined BV exons, may suggest a relatively nondiscriminatory role for the BJ gene product in antigen recognition as compared to those encoded by the BV, (N) and BD gene segments.
Immunization with Alum–Collagen II Complex Suppresses the Development of Collagen‐Induced Arthritis in Rats by Deviating the Immune Response
Authors: MATTSSON L. , LORENTZEN J. C. , SVELANDER L. , BUCHT A. , NYMAN U. , KLARESKOG L. , LARSSON P.
Published: November 2003

Collagen‐induced arthritis (CIA) is an experimental rat model sharing a number of features with human rheumatoid arthritis (RA). The model is associated with a proinflammatory (TH1) type of immune response and treatments with cytokines associated with TH2 immune responses are beneficial. Since agents with TH1‐inducing properties, such as Freund's incomplete adjuvant (FIA), are necessary for disease induction, it is of interest to investigate whether an adjuvant with TH2‐inducing properties affects CIA in a different way than does FIA. The authors studied arthritis development in DA rats after immunization with the TH2 stimulatory adjuvant alum adsorbed to rat collagen type II (CII) or collagen II fragments. Such treatments suppressed disease development both prophylactically and therapeutically. This beneficial effect of alum–CII immunization was associated with an increase in the IgG1 anti‐CII antibody response as compared to untreated rats or rats pretreated with alum alone. Treatment with alum without the addition of collagen did not have any clinical effect. In addition, alum–CII treated rats had a significantly higher expression of IL‐4 mRNA than untreated rats in the lymph nodes, 7 days after CIA induction. The authors suggest that alum–CII induces a TH2 immune response against rat CII which counteracts the development of CIA.
Activated Human γδ T Lymphocytes Express Functional Lactoferrin Receptors
Authors: MINCHEVA‐NILSSON L. , HAMMARSTRÖM S. , Hammarström M.‐L.
Published: November 2003

Lactoferrin (Lf), an iron‐binding protein in milk, mucosal secretions and neutrophil granules has bactericidal properties and is a source of iron for breast‐fed infants. In this paper the authors show that most in vivo activated lymphocytes, i.e. freshly isolated lymphocytes from first trimester human decidua, and most in vitro activated human blood lymphocytes, express lactoferrin receptors (Lf‐R), while unstimulated blood lymphocytes do not. All major lymphocyte subsets, i.e. αβ T cells, γδ T cells, CD8+ T cells, CD4+ T cells, B cells and NK cells, express Lf‐R after activation. The proportion of Lf‐R expressing activated γδ T cells is significantly larger than that of activated αβ T cells. Lf‐R and transferrin receptors (Tr‐R/CD71) show the same kinetics of appearance on activated blood lymphocytes and are, to a large extent, expressed on the same cells. However, 35% of decidual lymphocytes and 15% of activated blood lymphocytes express Lf‐R only. Addition of Lf to cultures containing an optimal concentration of Tr augments the proliferative response to polyclonal T cell activators and alloantigens, suggesting that presently used standard culture conditions for in vitro activation are suboptimal in particular for γδ T cells. Lf‐R on decidual lymphocytes contain bound Lf, which probably is produced locally. The results suggest that Lf is a growth‐supporting factor, especially important in local immune responses in the mucosa.
Proliferative Effect of Dextran Sulfate Sodium (DSS)‐Pulsed Macrophages on T Cells from Mice with DSS‐Induced Colitis and Inhibition of Effect by IgG
Authors: SHINTANI N. , NAKAJIMA T. , SUGIURA M. , MURAKAMI K. , NAKAMURA N. , KAGITANI Y. , MAYUMI T.
Published: November 2003

The authors have previously reported that homologous immunoglobulin (Ig)G reduces the occurrence of dextran sulfate sodium (DSS)‐induced colitis, mainly by suppressing recruitment of immunocompetent cells into colitis lesions. However, the mechanisms of cell recruitment and of its suppression by IgG remain unclear. In addressing these questions, this study focused on the activation of T cells in the presence of macrophages. The authors found that [3H]‐thymidine uptake of T cells from DSS‐induced colitis mice, but not from normal mice, was significantly enhanced when cultured with DSS‐pulsed macrophages. From the profile of cytokine production, it was suggested that T helper 1 (Th1)‐type cells become predominant during stimulation. Addition of homologous IgG significantly suppressed T cell proliferation in a dose‐dependent manner, while no suppressive effect was observed with heterologous IgG. Mouse IgG F(ab′)2, but not Fc, fragments partially mimicked the suppressive effect of whole IgG. These findings provide evidence that Th1‐type cells may play an important role in the development of DSS‐induced colitis and that homologous IgG exerts its protective action at least in part through the F(ab′)2 portion.
Difference in Binding of Killed and Live Streptococcus pneumoniae Serotypes by C‐Reactive Protein
Authors: DE BEAUFORT A. J. , LANGERMANS J. A. M. , MATZE‐VAN DER LANS A. M. , HIEMSTRA P. S. , VOSSEN J. M. , VAN FURTH R.
Published: November 2003

The binding and opsonic properties of C‐reactive protein (CRP) for various species of bacteria were investigated. CRP bound more avidly to killed than to live Streptococcus pneumoniae, the binding varying among various serotypes; CRP hardly bound to a number of other bacterial species studied. CRP enhanced complement‐dependent phagocytosis of live S. pneumoniae by granulocytes but did not enhance the phagocytosis of live Staphylococcus aureus or group B streptococci. We suppose that CRP may serve as an opsonin for killed bacteria and bacterial debris but is probably not an important opsonin for live bacteria other than S. pneumoniae.
Some Thoughts on the Response to Antigens that are Effector T‐Helper Independent (‘Thymus Independence’)
Authors: Cohn M.
Published: November 2003

The Self–Non‐Self discrimination is germline‐selected for defence mechanisms (‘innate immune systems’) whereas it is somatically learned for immune systems (‘adaptive immune systems’). It is proposed that immune systems evolved from defence mechanisms by adding large recognitive repertoires that, by aggregating with antigens, were able to trigger the already existent effector functions of defence mechanisms. Thus today there are two pathways to triggering each class of effector function (macrophage opsonization, complement lysis or natural killer/‐natural cytotoxic cell activity). The antigen–antibody complex and the T‐cell antigen–receptor interaction trigger the immune pathway; the receptors of the defence mechanism trigger the ‘alternate’ or ‘innate’ pathway. The evolutionary selection pressure on defence mechanisms was to increase the size of the recognitive repertoire, which in turn, necessitated the emergence of a somatically learned Self–Non‐Self discrimination. By contrast with defence mechanisms that are triggered effector T‐helper (eTh) independently by polymers (Signal[3]), immune systems can be activated by monomers, a pathway that requires associative recognition of monomer and the reading of two Signals, Signal[1] resulting from the binding of an epitope to the antigen–receptor complex, Signal[2] delivered by an eTh cell. The evolving immune system hijacked part of this eTh‐independent pathway (Signal[3]) into which Signal([1] + [2]) merged. A model of these relationships is proposed.
Involvement of ICE (Caspase) Family in γ‐Radiation‐Induced Apoptosis of Normal B Lymphocytes
Authors: HALLAN E. , BLOMHOFF H. K. , SMELAND E. B. , Lømo J.
Published: November 2003

Normal lymphocytes are highly sensitive to the damaging effects of ionizing radiation, and undergo cell death by apoptosis. We have investigated the possible involvement of the Interleukin‐1β‐converting enzyme (ICE) (Caspase) protease family, which appears to play an important role as intracellular mediator of apoptosis. Resting B lymphocytes isolated from human peripheral blood were irradiated (6 Gy) and cultured for 24 h, resulting in 25 ± 5.1% apoptotic cells, as measured by the TUNEL assay (mean ± SD, n = 6). Addition of the ICE family inhibitor Z‐VAD.fmk (50 μM) completely inhibited apoptosis (2.0 ± 1.5% at 24 h). By using fluorogenic substrates containing the peptide recognition sequences DEVD and YVAD, the type of ICE family protease involved was examined more closely. A marked transient increase in DEVD‐, and absent YVAD‐cleavage activity indicated the involvement of a CPP32‐like protease, not an ICE‐like protease. Western blot analysis demonstrated that untreated B lymphocytes expressed the proform of the ICE family members CPP32 and ICH1L, but no detectable ICE. The induction of cell death by radiation was accompanied by the activation of CPP32 as shown by the cleavage of the proform to the active subunit p17, and the cleavage of poly(ADP‐ribose) polymerase (PARP), one of the known substrates of CPP32. In contrast, no activation of ICH1L could be detected. These results indicate the involvement of CPP32 and possibly other CPP32‐like proteases in radiation‐induced apoptosis of resting B lymphocytes.
Progression of Articular Destruction and the Production of Tumour Necrosis Factor‐α in Antigen‐Induced Arthritis in Rabbits
Authors: Idogawa H. , IMAMURA A. , ONDA M. , UMEMURA T. , OHASHI M.
Published: November 2003

We examined the progression of articular destruction and the production of tumour necrosis factor‐α (TNF‐α) in antigen‐induced arthritis (AIA) in rabbits, i.e. flare‐ups of inflammation induced by repeated intra‐articular injections (single, twice and three times) of antigen. A marked progression of articular destruction and an infiltration of inflammatory cells in the synovium were observed with the increase in the number of antigen injections. An immunohistochemical analysis of the synovial lesions following three injections of antigen revealed that the lymphoid follicles consisted mainly of CD4+ T cells and IgG/IgM+ B cells. There were marked infiltrations of IgG+ plasma cells around the lymphoid follicles. In contrast, the production of TNF‐α in the synovial fluid and the erythrocyte sedimentation rate (ESR), which is a marker of systemic inflammatory activity in rheumatoid arthritis, peaked at 6 h and 24 h, respectively, following the last injection of antigen. These values were also greater following the repeated injections of antigen compared with the single injection. The TNF‐α was produced markedly in the joints at the onset of the flare‐ups of arthritis following the repeated injections of antigen, and the elevation of the ESR and an acceleration of the inflammatory response in the synovium were observed with a concomitant progression of severe articular destruction, suggesting that the marked production of TNF‐α at the time of flare‐ups may be involved in the exacerbation of AIA in rabbits.
Enrichment and Characterization of Dendritic Cells from Rat Renal Mesangium
Authors: GIESELER R. , HOFFMANN P. R. , KUHN R. , FAYYAZI A. , STOJANOVIC T. , SCHLEMMINGER R. , PETERS J. H.
Published: November 2003

Dendritic cells (DC) initiate primary immune reactions and are distributed throughout most tissues. The most potent DC population of the kidney has long been suggested to reside within the glomerular mesangium. Using LEW.1A rats, we enriched and characterized such low‐density cells. Mesangial DC generally exhibited round to oval cell bodies and cytoplasmic veils. Phenotypically, these cells were 100% OX‐6++, 45% OX‐42++, 35% ED1low, 10% OX‐62low, and negative for ED2 and α‐naphtylbutyrate esterase. Introducing a new monoclonal antibody, R3, which stains a subset of splenic DC, we showed strong antigen expression on 60% of mesangial DC. Correlating cell populations were detected immunohistochemically. Functionally, mesangial DC potently stimulated allogeneic mixed leucocyte reactions, but did not phagocytose opsonized Escherichia coli. In addition to their striking phenotypic similarity with autologous splenic DC, mesangial DC exhibited 88% of the allostimulatory activity of splenic DC. Calculation indicated approximately two mesangial DC per glomerulum. We suggest that these cells comprise different maturation‐dependent subsets. The OX‐62 integrin especially appears to be expressed only on mature mesangial DC, which may correlate to lymphoid veiled cells or interdigitating DC. An employment of mesangial DC in experimental models of acute allograft rejection or glomerulonephritis is discussed.
Analysis of the MHC Class I Antigen Presentation Machinery in Human Embryonal Carcinomas: Evidence for Deficiencies in TAP, LMP and MHC Class I Expression and their Upregulation by IFN‐γ
Authors: SELIGER B. , DUNN T. , SCHWENZER A. , CASPER J. , HUBER C. , SCHMOLL H. J.
Published: November 2003

The expression of the major histocompatibility complex (MHC) class I antigens is suppressed in early post‐implantation embryonic cells as well as in embryonal carcinoma (EC) cells, but could be upregulated by treatment with interferon (IFN)‐γ or retinoic acid. In a number of human and murine tumours, defects in the expression of the different components of the MHC class I antigen processing machinery, such as the proteasomal subunits LMP‐2 and LMP‐7 and the peptide transporters TAP‐1 and TAP‐2, account for impaired MHC class I surface expression. Here, we analysed the constitutive and IFN‐γ regulated mRNA and protein expression of the LMP, TAP and MHC class I molecules in the human EC line 577LM. In comparison to lymphoblastoid control cells, poor constitutive mRNA and protein expression of LMP‐7, TAP‐1, HLA class I, and β2‐microglobulin, but not of TAP‐2 and LMP‐2, was detected in 577LM cells. The lack of MHC class I surface expression on 577LM cells could not be enhanced either by culturing cells at low temperature or by their incubation with exogenous MHC class I specific binding peptides: thus, the defective MHC class I surface expression was not only caused by impaired generation and processing of antigenic peptides. IFN‐γ treatment of 577LM resulted in a significant increase of MHC class I surface expression which was preceded by an upregulation of TAP, LMP and MHC class I transcripts as well as of TAP‐1 and TAP‐2, but not of LMP‐2 and LMP‐7, protein expression. These data suggest that human EC cell lines show a stable expression of a MHC class I low/deficient phenotype. The deficiencies associated with this phenotype involve different levels of the MHC class I restricted antigen presentation machinery and could be modified by treatment with IFN‐γ.
Immunological Induction of Flavour Aversion in Mice. II. Passive/Adoptive Transfer and Pharmacological Inhibition
Authors: CARA D. C. , CONDE A. A. , VAZ N. M.
Published: November 2003

Mice immunized with ovalbumin develop a strong aversion to ingesting sweetened egg white dilutions or ovalbumin solutions. In immunized animals, gavage or voluntary ingestion of ovalbumin triggers an increase of vascular permeability in the intestine; pretreatment with a mixture of histamine and serotonin antagonists blocked this reaction, but not the aversion; dexamethasone inhibited both the aversion and the increase in permeability. The aversion was transferred to normal recipient mice with high‐titre anti‐Ova sera obtained with complete Freund’s adjuvant, but not with lower‐titre serum pools of mice immunized with the help of Al(OH)3 adjuvant. However, the aversion was also (adoptively) transferred with whole spleen cells from immune donors. This later condition is inefficient to transfer the formation of high titres of specific antibodies.
Characterization of the 5′ Flanking Region of the Human Complement Factor H Gene
Authors: WILLIAMS S. A. , VIK D. P.
Published: November 2003

The promoter region of the human factor H gene was cloned and a 3 kb Eco RI fragment was sequenced. Primer extension and S1 nuclease analysis were used to determine the transcription start site, which was found to be 10–11 nucleotides upstream of the published cDNA sequence. No canonical TATA or CCAAT boxes were found in conjunction with this site. The sequence from the human H promoter region was compared to that from the mouse gene. There was a region of 800 bp that was 62.5% identical between the two sequences. The sequences of the two promoter regions were compared to a database of transcription factor binding sites. Five elements were identified that matched the consensus sequence 100% and were identical in the two promoter sequences. Promoter assays using the luciferase reporter gene demonstrated that this region contained a functional transcription start site and putative enhancer elements. U118‐MG astroglioma cells and Hep3b hepatoma cells were incubated with various cytokines to measure effects on their factor H mRNA levels. Interferon‐γ (IFN‐γ), but not interleukin‐1 (IL‐1), tumour necrosis factor α (TNF‐α) or IL‐6, was able to increase the level of H mRNA in both cell lines.
Inhibition of Neutrophil Apoptosis by Antioxidants in Culture Medium
Authors: OISHI K. , MACHIDA K.
Published: November 2003

Neutrophil apoptosis is an important mechanism that has implications for understanding the life span and toxic potentials of neutrophils at inflamed sights. In this study the authors examined the possibility that reactive oxygen species (ROS) released by neutrophils can regulate neutrophil survival. Cu,Zn‐superoxide dismutase (Cu,Zn‐SOD), Mn‐SOD, and catalase in culture media were significantly effective in delaying the spontaneous apoptosis, suggesting that ROS play an important role in the resolution of inflammation by inducing neutrophil apoptosis. In this experiment, boiled Cu,Zn‐SOD had no effect on inhibiting the apoptosis, but boiled Mn‐SOD from Bacillus stearothermophilus was more effective in inhibiting the apoptosis than untreated Mn‐SOD at the same dose. However, the boiled Mn‐SOD showed only 80% of O‐2 inhibitable activity compared with the untreated Mn‐SOD. This effect may be attributed to the partial liberation of manganese because MnCl2 inhibited the apoptosis effectively. Furthermore, Cu,Zn‐SOD was effective in delaying apoptosis only when added to the culture within the first 3 h of incubation, suggesting that the isolation of neutrophils from peripheral blood enhances apoptosis of neutrophils.
Lymphokine‐Activated Cytotoxicity in Peripheral Blood Mononuclear Cells of Severely Immunocompromised HIV‐Infected Patients
Authors: FORTHAL D. N. , LANDUCCI G. , ROBINSON JR W. E.
Published: November 2003

The authors determined the natural killer (NK) and lymphokine‐activated killer (LAK) activities of peripheral blood mononuclear cells (PBMCs) from a severely immunocompromised (CD4 cell counts <100/mm3) group of AIDS patients, using K562 and U937 target cells. An increase in cytotoxicity was observed in the PBMCs of all 17 patients following a 48 h incubation with the combination of 400 U/ml of recombinant gamma interferon plus 20 U/ml of natural interleukin‐2. Although NK and LAK activities were significantly higher in healthy controls than in patients, patients' LAK activity was higher than the NK activity of controls. The authors also demonstrated that the use of medium containing fetal bovine serum, when compared with medium containing autologous serum, increases NK activity without affecting LAK activity. Lymphokine augmentation of cytotoxicity is achievable in severely immunocompromised AIDS patients and might be of benefit in delaying opportunistic infections and malignancies.
HIV Antigens and T‐Cell Receptor Variable Beta Chain Families
Authors: JASON J. , INGE K. L. , ORLOFF S. L.
Published: November 2003

The authors investigated whether the human immunodeficiency virus (HIV) has restrictive effects on the variable region of the β chain (Vβ) of the T‐cell antigen receptor (TCR), by in vitro cultivation of non‐HIV‐infected peripheral blood lymphocytes with one of six HIV antigens or heat‐inactivated whole virus (HIV‐HI). Resting and blastic CD4+ and CD8+ cells were assessed with 3‐colour cytofluorometry and monoclonal antibodies to various Vβ families/subfamilies. The Vβ families affected include Vβ's 13.1/.3, 8, and 21 with gp120; Vβ21 with gp160 and RT; Vβ8 with p25; Vβ's 8 and 21 with Rev; and Vβ's 3 and 21 with HIV‐2 Vpx. Vβ family‐specific effects with HIV‐HI did not differ significantly from those found with IL‐2 stimulation. Findings differed between CD4+ and CD8+ cells. For CD4+ lymphocytes, significant Vβ‐specific decreases were found, not the expansions found with superantigens or mitogens. CD8+ lymphocytes showed slight but significant expansions. The effects on Vβ's 8, 13, and 21 are consistent with previous studies of HIV‐infected persons. However, it is difficult to accept that antigens encoded by different HIV genetic regions cause proportionate diminutions of similar Vβ families. The authors suggest that these effects may be secondary to changes in cytokine profiles rather than direct interactions with TCR Vβ's.
The Susceptibility to Cytotoxic T Lymphocyte Mediated Lysis of Chemically Induced Sarcomas from Immunodeficient and Normal Mice
Authors: SVANE I. M. , ENGEL A.‐M. , THOMSEN A. R. , WERDELIN O.
Published: November 2003

A panel of sarcomas induced with 3‐methylcholanthrene in normal and immunodeficient mice was studied for their capacity to present antigen by the endogenous, MHC class I restricted pathway. Lymphocytic choriomeningitis virus was used to infect cultured tumour cells, and the infected cells were tested for susceptibility to cytolysis by virus specific cytotoxic T cells. Tumour cells originating from tumours induced in immunocompetent C.B.‐17 mice presented virus antigen more efficiently than tumour cells from immunodeficient SCID mice. No significant difference in virus antigen presentation was found between tumours from nude and nu/+ BALB/c mice. The sensitivity of target cells from the individual tumours to cytotoxic T lymphocyte (CTL) mediated lysis correlated negatively with their sensitivity to natural killer (NK) cell mediated lysis. There was a positive correlation between the sensitivity to CTL mediated lysis and surface expression of the MHC class I molecule Ld of the tumour cells. Tumour cells incapable of in vitro presentation of viral antigen to specific cytotoxic T cells originated from tumours known from previous experiments to be readily accepted after transplantation to immunocompetent, histocompatible recipients.