bluuebunny/crossref_metadata_2025 huggingface dataset:
Clonotypic Dominance and Variable Gene Elements of Pathogenic Anti‐DNA Autoantibodies from a Single Patient with Lupus
Authors: CHASTAGNER P. , DEMAISON C. , THÈZE J. , ZOUALI M.
Published: July 2006

This study explores the usage and diversity of the variable gene elements expressed by human lupus antibodies to DNA bearing the 0–81 idiotype, a marker of pathogenic anti‐DNA autoantibodies. Rather than studying DNA‐specific clonotypes from different patients, a panel of idiotype positive anti‐DNA autoantibody‐secreting clones from a single individual were analysed. By cloning and nucleotide‐sequeneing the heavy‐chain variable gene segments, evidence was found for dominance of clonotypic patterns. Also noted was a high rate of diversification among the variable (VH), diversity (Dh) and junctional (JH) gene segments utilized, with a pattern of mutations indicative of antigenic selection. These features suggest that the clones secreting the lupus pathogenic autoantibodies have been selected over multiple generations through an affinity‐maturation process that is reminiscent of antigen‐driven immune responses.
Population Dynamics of CD4+ T Cells Lacking Thy‐1 in Murine Retrovirus‐Induced Immunodeficiency Syndrome (MAIDS)
Authors: MOUTSCHEN M. P. , COLOMBI S. , DEPREZ M. , VAN WIJK F. , HOTERMANS C. , MARTIN M.‐T. , GREIMERS R. , BONIVER J.
Published: July 2006

Increased numbers of CD4+ Thy‐1 cells have been described in the spleen (SP) of mice with retrovirusinduced immunodeliciency (MAIDS). Since this phenotypic abnormality might have considerable functional importance, the expansion of the CD4+ Thy‐1 subset in MAIDS was characterized further. CD4+ Thy‐1− and Thy‐1+ T‐cell is from infected mice expressed similar densities of CD3 and TCR γ/β. In contrast, the Thy‐I− subset was uniformly CD44hi, even early in the disease when part of Thy‐I+ cells were still CD4410. The emergence of CD4+ Thy‐1−cells occurred first in SP and lymph nodes and was observed later in thymus. The important fraction ofCD4+ cells lacking Thy‐1 normally present in Peyer's patches was only weakly modified. Despite the major expansion of the CD4+ Thy‐1− phenotype. the proliferating fraction was not higher in this subset than in CD4+ Thy‐1+ cells from infeeted miee. Persistence after hydroxyurea administration was identical in both subsets, indicating similar mean cell lifespans. Taken together, these results show that the major expansion of CD4+ Thy‐I− T‐cells in MAIDS is not ascribable solely to increased proliferation within this subset. Phenotypic analysis suggests that CD4+ Thy‐I− cells result from the differentiation of Thy‐I+ cells induced by activation signals related to retroviral infection.
Role of Enhanced Cellular Adhesion in IL‐6‐Augmented Lymphokine‐Activated Killer‐Cell Function
Authors: IHO S. , SHAU H.
Published: July 2006

The authors demonstrated previously that a short‐term treatment with IL‐6 of lymphokine‐activated killer (LAK) cells produces an increase in cytotoxic activity of CD56+/CD3− effector cells generated from human PBL as well as from human thymocytes. In the study described here, the mechanisms by which IL‐6 enhances LAK cytotoxicity were examined. Like untreated LAK cells, IL‐6‐treated LAK cells require Ca++ to initiate cytolysis. However, IL‐6 treatment of LAK cells does not alter the rate of programming for lysis. Instead, IL‐6 increases target‐binding capacity of CD56+/CD3− LAK cells in association with the increased cytotoxicity. Similar to target‐binding of untreated LAK cells, the binding between IL‐6‐treated LAK cells and target cells is dependent on Mg++. Cellular adhesion molecules (CAM), CD1 la‐c, CD18. CD54. CD56, CD58 and CD2 (T11, epitope). are up‐regulated in LAK cells by culture with IL‐2. Among MoAbs to these CAMs. only Abs to CD11a/CD18 (LFA‐1) and CD54 (ICAM‐1) decrease both target‐binding and cytolysis by LAK cells. IL‐6 treatment changes neither the proportion nor the intensity of CAM positive cells. However, MoAbs to CD11a/CD18 and CD54 reduce both target‐conjugation and cytotoxicity of IL‐6‐enhanced LAK cells to the same level as control LAK cells treated with the MoAbs. IL‐6‐enhanced LAK functions (both target‐conjugation and target‐lysis) are not abrogated by MoAbs to other CAM which do not inhibit standard LAK functions. These results indicate that IL‐6 up‐regulates cellular events mediated by CD11a/CD18 and CD54 molecules which are involved in standard LAK functions. These events may result in activation of lytic efieclor cells, associated with an increase in target‐binding and an increase in cytotoxicity.
Enhanced ICAM‐1‐Dependent Adhesion of Myelomonocytic Cells Expressing Increased Levels of ß2‐Integrins and CD43
Authors: TIISALA S. , MAJURI M.‐L. , CARPÉN O. , RENKONEN R.
Published: July 2006

Interaction of ICAM‐1 and its ligands plays an important role in the leukocyte binding to endothelium. The best characterized ICAM‐ligands belong to the family of ß2‐integrins (CD11/CD18), but recently it has been suggested that CD43, a molecule with no structural resemblance to integrins binds ICAM‐1 also. On the leukocytes the main regulatory pathway for ICAM‐mediated binding is believed to be a short‐term regulation of the avidity of CD11/CD18. In this study the authors investigated whether a quantitative increase in the surface expression of ICAM‐ligands also can lead to enhanced binding to purified ICAM‐I. PM A‐treatment differentiates myelomonocytic cell lines into macrophages with a concomitant increase in the surface expression and mRNA‐levels of the ß2‐integrin α‐ and ß‐chains as well as that of CD43, another ICAM‐ligand. The binding of the PMA‐treated THP‐1 ceils to ICAM‐1 was increased simultaneously compared to non‐treated cells. The binding was blocked completely with antibodies to CD18 and ICAM‐I. It is concluded that in addition to the transient qualitative regulation, a long‐term quantitative regulation of ICAM‐1 ligands also plays a role in increasing the adhesiveness of myelomonocytic cells. This may be relevant in chronic inflammation episodes.
Expression of CZ‐1: a CD45RB Epitope on Progenitors of Natural Killer and Other Haematopoietic Cells
Authors: MOORE T. A. , VARGAS‐CORTES M. , WELSH R. M. , BENNETT M. , KUMAR V.
Published: July 2006

CZ‐1 is a novel sialic acid‐dependent epitope of the murine CD45RB molecule which is expressed on cells that proliferate when cultured in IL‐2. Because IL‐2 appears to be Important in the differentiation of NK cells, the authors examined the expression of CZ‐1 on immature NK‐Iineage cells within the bone marrow. All mature NK1.1+ cells as well as their NK1. l− IL‐2 responsive precursors were CZ‐1+. Furthermore, IL‐2 unresponsive transplantable NK progenitor cells expressed CZ‐1 also. To examine expression of CZ‐1 on other immature lymphoid progenitor cells. CZ‐1+ and CZ‐1 marrow cells were tratisplanted Into lightly irradiated scid mice. Transfer of CZ‐1+ cells resulted iti rapid and sustained generation of thymocytes and splenic B cells, whereas CZ‐1− cells caused delayed repopulation. This suggested that the slowly repoptilating pluripotent stem cells lacked CZ‐1. Therefore, expression of CZ‐1 on Ly66 Lin− c‐kit+ cells, highly enriched for pluripotent stem cells, was examined. This population appeared lo be homogeneously CZ‐1dull. Thus, it appears that expression of CZ‐1 is developmentally regulated, with diflerentiation associated with increased expression. Since CZ‐1 is expressed on a protein tyrosine phosphatase, it is likely that this molecule regulates differentiation of NK and other lymphoid cells.
Cellular and Humoral Immune Responses of Cattle to Purified Mycobacterium bovis Antigens
Authors: FIFIS T. , CORNER L. A. , ROTHEL J. S. , WOOD P. R.
Published: July 2006

Cellular responses to several purified antigens oi Mycobacterium bovis were examined in experimentally infected cattle over a period of 36 months, using in vitro cellular proliferation and interferon‐γ assays. These antigens (12, 19, 22a, b. 24, 25.30, 32, 39.65 and 70 kDa) included the majority of M. /lom protein antigens described to date and are highly homologous to those purified from M. tuberculosis. Cellular responses vi'ere examined at 3‐month time intervals during the 36‐month course of infection. All purified antigens induced cellular immune responses in the infected animals. The onset and magnitude of response to individual antigens varied among the animals. At any specific time during the period of infection one or more antigens appeared to be immunodominant but the immunodominance profile changed as the infection progressed. Humoral immune responses were low or absent in the first half of the infection period, but increased substantially for some of the antigens during the second half. Variation was observed among the different animals as to which antigens they recognized.
All Forms of Human IgA Antibodies Bound to Antigen Interfere with Complement (C3) Fixation Induced by IgG or by Antigen Alone
Authors: NIKOLOVA E. B. , TOMANA M. , RUSSELL M. W.
Published: July 2006

Polyclonal human secretory IgAI and lgA2 antibodies to a bacterial protein antigen Streptococcus mutans Agl/II, and polyclonal human serum IgA1 and IgA2 antibodies to staphylococcal a‐toxin, were found to interfere with antigen‐mediated C3b fixation. In fluid phase, immune complexes of antigen and IgA failed to fix C3b, whereas antigen‐IgG complexes did fix C3b. Partial removal of glycan chains with Streptococcus mitis SK96 glycosidases diminished the capacity of IgA antibodies to interfere with antigen‐mediated C3b fixation by the alternative complement pathway. The authors conclude that native serum or secretory IgA antibodies suppress C3b fixation, and that the glycan chains play a significant role in maintaining this property.
Treatment of Rheumatoid Arthritis with a Chimeric CD4 Monoclonal Antibody (cM‐T412): Immunopharmacological Aspects and Mechanisms of Action
Authors: VAN DER LUBBE P. A. , REITER C. , MILTENBURG A. M. , KRÜGER K. , DE RUYTER A. N. , RIEBER E. P. , BIJL J. A. , RIETHMÜLLER G. , BREEDVELD F. C.
Published: July 2006

To investigate the mechanisms of action underlying the therapeutic effect of CD4 monoclonal antibody therapy in rheumatoid arthritis (RA), clinical responses were compared with several laboratory parameters. Twenty‐nine RA patients received either 10 mg, 50 mg or 100 mg of cM‐T412, a chimeric CD4 MoAb, for 7 days. The CD4 binding sites on circulating lymphocytes were saturated directly with cM‐T412 and serum levels of unbound cM‐T412 accumulated towards day 7 of treatment only in the patients treated with 50 and 100 mg. The treatment induced an instant and prolonged depression of the number of circulating CD4+ cells, similar for all dosages. Clinical improvement was observed predominantly in the patients treated with 50 or 100mgcM‐T412daily and did not correlate with changes in counts of circulating leucocyte subsets nor with changes in serum cytokine levels. An antiglobulin response against cM‐T412 developed in a majority of the patients. Side effects on the first day of treatment were correlated with an increase of serum IL‐6 levels. This study indicates that a favourable clinical effect of cM‐T412 administration was associated with the presence of unbound cM‐T412 in the circulation of RA patients. Therefore penetration of unbound cM‐T412 into the site of inflammation might determine the therapeutic effect in RA.
Intra‐Embryonic Haemopoietic Cells and Early MHC Expression
Authors: LAMPISUO M. , LASSILA O.
Published: July 2006

In the avian embryo the haemopoietic stem cells originate from the intra‐embryonic area near dorsal aorta. The surface‐marker expression of haemopoietic stern cells and their potential to produce different haemopoietic cells are still largely unknown. The surface antigen expression and particularly the MHC antigen expression on intra‐embryonic haemopoietic cells was studied. Expression of B‐F antigens, homologous to mammalian MHC class‐I antigens, was found already on embryonic day (ED) 5. The first B‐L antigens, analogous to mammalian MHC class‐II antigens, were detected also from ED5 onwards. The appearance of surface antigens defined by MoAbs T10A6 and 3–298 during embryogenesis also was studied. The antigen defined with T10A6 was detected from ED4 onwards on endothelial cells but not on haemopoietic cells in the para‐aortic region. The first 3–298+ haemopoietic cells were found on ED6, whereas endothelial cells were negative. These findings imply that some surface markers are shared with haemopoietic and endothelial cells indicating either a common embryonic origin or the importance of these molecules in embryonic stem‐cell homing.
Protection from Experimental Autoimmune Thyroiditis in CBA Mice with the Novel Immunosuppressant Deoxyspergualin
Authors: NICOLETTI F. , DI MARCO R. , BARCELLINI W. , BORGHI M. O. , LUNETTA M. , MUGHINI L. , MERONI P. L.
Published: July 2006

The effects of the novel immunosuppressant Deoxyspergualin (DSP) on the development of experimental autoimmune thyroiditis (EAT) in CBA mice were studied. For EAT induction, the mice were immunized with 100 μg of porcine thyroglobulin (p Tg) emulsified in CFA on day 0 and in IFA, for boosting, on day 14. Twenty‐eight days after primary immunization, histological and serological signs of EAT occurred in control mice treated with PBS which showed marked lymphoid infiltration of the thyroid glands along with increased serum titres of anti‐pTg antibodies. Development of both these EAT features was significantly suppressed when the mice were treated with 2.5 mg/kg body weight DSP, given daily, five times a week, from day —2 to day + 28 after immunization. The effect appeared to be dose‐dependent and DSP was ineffective when given under the same experimental conditions at the dose of 0.5 mg/kg body weight. No DSP‐toxic effects could be observed during the experiment. These results provide further evidence for the powerful immunosuppressive properties of DSP and suggest that this drug may be used in the treatment of autoimmune thyroid diseases and other T‐cell mediated autoimmune disorders in humans.
Lipoxin A4 Induces Neutrophil‐Dependent Cytotoxicity for Human Endothelial Cells
Authors: BRATT J. , LERNER R. , RINGERTZ B. , PALMBLAD J.
Published: July 2006

The authors have assessed the capacity of neutrophil granulocytes (PMN) to kill cultured human umbilical–vein endothelial cells (HUVEC) in vitro (as release of 51Cr) in response to the recently described double dioxygenation product of arachidonic acid, lipoxin A4 (LXA4). LXA4 conferred a marked cytotoxicity, whereas formyl–methionyl–leucyl–phenylalanine (fMLP) was less potent. The LXA4 and fMLP effects were dose dependent, with a maximum at 100 nM (which caused 2.7–and 2.3–fold increases of 51 Cr release, respectively, relative to buffer–treated controls). The LXA4 and fMLP responses increased with the PMN concentration, depended on the fetal calf serum concentration, incubation temperature and duration and the presence of calcium and magnesium ions.
HIV‐1 Inhibits Leishmania‐lnduced Cell Proliferation but not Production of Interleukin‐6 and Tumour Necrosis Factor Alpha
Authors: WOLDAY D. , AKUFFO H. , BRITTON S. , HATHAWAY A. , SANDER B.
Published: July 2006

The immune response of normal human peripheral blood mononuclear cells (PBMC) after stimulation with human immunodeficiency virus‐1 (HIV‐1) antigens plus Letshmania donovani promastigotes in vitro was investigated. HIV‐I‐antigen stimulation of PBMC did not induce the intracellular accumulation of interleukin‐6 (IL‐6),. tumour necrosis factor‐alpha (TNF‐α), or Interferon‐gamma (IFN‐γ). However, cells stimulated with L. donovani antigens exhibited the production of IL‐6 and TNF‐α, but not IFN‐γ. Furthermore, co‐stimulation of PBMC with HIV‐1 antigen plus L. donovani resulted in the intracellular accumulation of IL‐6 and TNF‐α comparable to that of cells that were activated with L. donovani antigen alone. Heat‐inactivated HIV‐1 antigen did not appear to induce or suppress cytokine production by PBMC. However, the same HIV antigens did suppress L. donovani‐induced proliferation as well as PPD‐induced proliferation in a dose‐dependent fashion. Elevated levels of serum cytokines have been demonstrated in patients with HIV infection indicating their role in the pathogenesis of HIV‐associated immunosuppression. The results may partially support the idea that the abnormally increased cytokine levels in the sera of HIV‐infected subjects is due to the various opportunistic pathogens that these patients contract, rather than a response to HIV antigens. As cytokines have been shown to up‐regulatc HIV replication, the data suggest a role for opportunistic infections in cytokine‐induced transactivation of HIV‐1 and disease progression.
B‐ and T‐Lymphocyte Subset Numbers in the Migrating Lymphocyte Pool of the Rat: the Influence of Interferon‐γ on its Mobilization Monitored through Blood and Lymph
Authors: WESTERMANN J. , MATYAS J. , PERSIN S. , VAN DER MEIDE P. , HEERWAGEN C. , PABST R.
Published: July 2006

The subset composition of the migrating lymphocyte pool is largely unknown. In order to determine the number of B, T, CD8 +, CD4+ and CD4+‘naive’(CD45RC+) and ‘memory’ (CD45RC−) lymphocytes in this pool, the thoracic duct lymph of the rat was drained for 7 days. The effect of lymphocyte deplction on the number of blood lymphocytes was also monitored. In addition, the influence of continuously applied interferon‐γ (IFN‐α) on the mobilization of the migrating lymphocyte pool was investigated.

Within 1 week 2 × 109 thoracic duct lymphocytes (TDL) were collected, which represents about 50% of the total lymphocyte pool of an adult rat. Among the migrating lymphocytes an early and a late mobilized population could be differentiated. In the former the CD4+‘naive’ (CD45RC+) T lymphocytes constituted the largest population, whereas in the latter it was the B lymphocytes.

Continuous infusion of IFN‐γ did not affect the number of lymphocytes in the blood. In contrast, in the thoracic duct IFN‐γ reduced the appearance of all lymphocyte subsets. However, the pattern of reduction over time differed markedly depending on the population (early or late mobilized) and the phenotype (B‐ or T‐tymphocyte subsets.
Role of T Lymphocytes in Experimental Staphylococcus aureus Arthritis
Authors: ABDELNOUR A. , BREMELL T. , HOLMDAHL R. , TARKOWSKI A.
Published: July 2006

Using a recently developed murine model of haematogenously induced Staphylococcus aureus, the authors have characterized the phenotypes and functional properties of inflammatory cells present in the synovium of arthritic mice. The results show that large numbers of granulocytes and macrophages were observed in the inflamed synovia within 24 h of inoculation of S. aureus strain LS‐1. Many of the synovial macrophage‐like cells stained for cytoplasmic IL‐1α and TN F‐α. Subsequently (< 48 h later), a prominent infiltration of T lymphocytes, predominantly of CD4+ phenotype, was observed. Some of the T lymphocytes stained for IL‐2 receptor and intracytoplasmicinterferon‐γ (IFN‐γ). Surprisingly, in spite of the severe inflammatory process, very few cells expressed MHC class‐II molecules in the arthritic synovia. In addition, in vivo depletion of CD4 + T‐cells resulted in a considerably milder course of staphylococcal arthritis. The similarities in the phenotype expression of synovial cells and central role of T‐cells in S. aureus arthritis as well as in non‐infectious models of arthritis, indicate that the process governing joint destruction is likely to be the same, irrespective of the initial stimulus.
The Multifactorial and Multistage Character of Protective Immunity to Plasmodium falciparum, Naturally Acquired by an Indigenous Population in Burkina Faso
Authors: BOUDIN C. , SHEICK I. , CHUMPITAZI B. , PAZART L. , HOGH B. , PEYRON F. , DELORON P. , PICOT S. , AMBROISE‐THOMAS P.
Published: July 2006

In malaria‐endemic areas, protective immunity is acquired gradually. Some authors have proposed that different stages can be distinguished during development. To test this hypothesis, several in vitro assays of the host immune response to P. falciparum were performed in three groups of individuals: ‘unprotected’ children with clinical attacks, ‘semi‐immune’ children, without clinical attacks but with transient high parasitaemias during the transmission period, and ‘protected’ adults with low residual parasitaemias. By comparison of immune responses in these groups and multifactorial analyses, discriminant factors and potential protective mechanisms were identified. Anti‐RESA antibody levels were lower in ‘unprotected’ than in ‘semi‐immune’ children, while specific cellular responses, TNF levels and percentage of activated T lymphocytes were higher. Low humoral immunity and high cellular activation in children were followed by high humoral immunity and low cellular activation in adults. Therefore, protective immunity seems to pass through different stages and to result from the association of different immune mechanisms according to the level and duration of the individual experience of malaria.
Relevance of Antibody Valency in EGF Receptor Modulation
Authors: MORELLI D. , VILLA E. , TAGLIABUE E. , PERLETTI L. , VILLA M. L. , MENARD S. , BALSARI A. , LCOLNAGHI M.
Published: July 2006

Binding characteristics of a monovalenl bispecific monoclonal antibody (bsMoAb), which recognizes both epidermal growth factor receptor (EGF‐R) and drug doxorubicin (DXR) were compared with those of the parental bivalent MoAb directed against the EGF‐R binding site. Scatchard analysis indicated that both MoAbs bound to EGF‐R‐overexpressing A431 cells with the same affinity. In tracer amounts, both MoAbs also displayed the same capacity to be internalized after binding to the cell surface. However, when the MoAbs were used at saturating concentrations, down‐modulation of the receptor was greater with the bivalent MoAb. The bivalent MoAb also inhibited proliferation of A431 cells both in vitro and in vivo whereas the bsMoAb was inhibitory only in vivo. These data suggest that MoAb bivalency is required for EGF‐R down‐modulation and in vitro cell growth inhibition.
Significance of erb B‐2 Gene Product as a Target Molecule for Cancer Therapy
Authors: ISHIDA T. , TSUJISAKI M. , HANZAWA Y. , HIRAKAWA T. , HINODA Y. , IMAI K. , YACHI A.
Published: July 2006

The new monoclonal antibodies (MoAbs) E401, E811, E907 and E919 were prepared and characterized. These recognized an extracellular domain (amino acids No. 292–370) on the human c‐erbB‐2 gene product. Utilizing MoAb E811 and MoAb E919, a double determinant immunoassay (DDIA) was established to detect the soluble and the shed forms of the c‐erbB‐2 molecule. The levels of circulating erbB‐2 antigen in the sera of patients with benign diseases and healthy controls were very low. The incidence of positivity for shed c‐erbB‐2 antigen in gastric cancer, eolonic cancer, gall‐bladder caneer, pancreatic eancer and other cancers were 7.4%, 4.2%, 0%, 6.7% and 0%, respectively. Four of 54 patients with gastric carcinoma showed high levels of serum c‐erbB‐2 antigen. They belonged to clinical stage IV and their histological types were all well differentiated adenoeareinomas (two papillary and two tubular adenoeareinomas). Furthermore, the incidence of positive staining in gastric cancer was 34.6%; higher than that for shedding erbB‐2 antigen. Most of the cases v‐hich showed erbB‐2 expression on cells were well‐differentiated adenoeareinomas. Meanwhile, the distribution of erbB‐2 antigen was limited in normal tissues. The results suggest that the expression of erbB‐2 antigen is largely restricted to adenocarcinoma cells. It may not shed easily from these cells, and therefore It may be a very useful target molecule for passive immunotherapy.
3, 3′, 4, 4′‐Tetrachlorobiphenyl Inhibits Proliferation of Immature Thymocytes in Fetal Thymus Organ Culture
Authors: LAI Z‐W. , KREMER J. , GLEICHMANN E. , ESSER C.
Published: July 2006

The environmental pollutant 3, 3′, 4, 4′‐tetrachlorobiphenyl (TCB) leads to thymic atrophy and immuno‐suppression, the former possibly causing the latter. TCB binds lo the cytosolic aryl‐hydrocarbon receptor (AhR) and transforms it into a DNA‐binding state. The development of fetal thymocyles is severely affected by TCB and other AhR‐binding xenobiotics, leading to a skewed pattern of thymocyte maturation stages. Murine thymocyte proliferation after exposure to TCB was studied in fetal thymus organ culture (FTOC). C57BL/6 fetus thymic lobes from day 15 of gestation were explanted and grown for 2, 4, 6. and 8 days in organ culture in the presence or absence of 3.3 μM TCB. Subsets of thymocytes were defined by CD4 and CD8 surface markers, and their cell cycle was analysed by DNA staining with 7‐amino‐actinomycin D (7‐AAD). Exposure of fetal thymi in vitro to 3.3 μM TCB significantly reduced the total number of thymocytes. and fewer thymocytes were in S/G2M phase. The inhibition of cell proliferation induced by TCB treatment affected mainly the CD4− CD8− (double‐negative, DN) and CD4− CD8+ (single‐positive, SP) subsets, and these inhibition appeared mainly in more immature thymocytes, i. e. DNCD3− and CD8+CD3− subpopulations, whereas no effect of TCB on CD4+CD8+ (double‐positive, DP) cell proliferative activity was observed. Analysis of the relation of cell proliferation and development of subsets in differentiating fetal ihymocytes suggests that TCB enhanced thymocyte differentiation into mature CD8+ cells.
Phenotypic Characterization of the Human Mast‐Cell Line HMC‐1
Authors: NILSSON G. , BLOM T. , KUSCHE‐GULLBERG M. , KJELLEN L. , BUTTERFIELD J. H. , SUNDSTRÖM C. , NILSSON K. , HELLMAN L.
Published: July 2006

The cell line HMC‐1, derived from a patient with mast cell leukaemia, is the only established cell line exhibiting a phenotype similar to that of human mast cells. This paper reports on a detailed characterization of the expression of a panel of markers for various types of immature and mature haematopoietic cells in the HMC‐1. We also studied the potential of HMC‐1 to differentiate upon treatment with conditioned media from the human T‐cell line Mo, retinoic acid or DMSO.

HMC‐1 was found to express several mast cell‐related markers. A high expression of Kit, the receptor for stem‐cell factor, was detected. The majority of the cells were stained with a MoAb against the mast cell‐specific serine protease tryptase. Of particular interest was the finding that β‐tryptase mRNA, but not a‐tryptase mRNA, was expressed in HMC‐1. Using enzyme‐histochemistry we were able to show that the β‐tryptase was enzymatically active, indicating that tryptase can form active homotetramers. Both heparin and chondroitin sulfate were found to be present in approximately equal amounts. HMC‐1 lacked surface expression of the high‐affinity IgE receptor, which was confirmed by the absence of mRNA of the α‐ and β‐chains of the IgE‐receptor complex. However, a strong expression of the 7‐chain of the IgE‐receptor complex was detected. A positive staining of the monocyte/macrophage marker CD68 was obtained, as well as a strong hybridization signal for the eosinophilic/basophilic‐related differentiation marker the Charcot‐Leyden crystal. Treatment of HMC‐1 with conditioned media from the human T‐cell line Mo, retinoic acid or DMSO induced only moderate changes in the surface or intracellular expression of the studied markers. The agents tested neither induced any of the monocyte/ granulocyte markers examined, nor expression of the FceRIα‐chain.
Antisense Oligodeoxynucleotides for IL‐2, c‐myc and Transferrin Receptor Synchronize Mitogen‐Activated Lymphocytes in the G1 Phase
Authors: KATO J. , KOHGO Y. , KONDO H. , SASAKI K. , NIITSU Y.
Published: July 2006

In order to clarify the role and interrelationship of c‐myc, interleukin‐2 (IL‐2), and transferrin receptor (TfR) expressions on PHA‐stimulated lymphocyte prohferation, we examined the effects of antisense oligodeoxynucleotides directed against c‐myc, TfR, and IL‐2 mRNAs on DNA synthesis and cell‐cycle phase. Exposure of PHA‐stimulated lymphocytes to each antisense oligomer resulted in approximately 75 80% inhibition of DNA synthesis. TfR expression was not inhibited in PHA‐stimulated lymphocytes by c‐myc or IL‐2 antisense oligonucleotides, suggesting that the expression of c‐myc, TfR, and of IL‐2 is regulated by an independent mechanism. All three antisense oligonucleotides for c‐myc, TfR and IL‐2 synchronized mitogen‐activated lymphocytes to the G1 phase as assessed by morphologic blast formation and cell‐cycle phase analysis.
Peptide Specificity of Anti‐Myelin Basic Protein Antibodies in Patients with Acute Optic Neuritis and the HLA System
Authors: SELLEBJERG F. , FREDERIKSEN J. L. , OLSSON T. , LINK H. , MADSEN H. O. , RYDER L. P. , SVEJGAARD A.
Published: July 2006

Multiple sclerosis (MS) may be an autoimmune disease, partially caused by autoreactivity to myelin basic protein (MBP) and other central nervous system proteins. Acute optic neuritis (ON) is a frequent first symptom of MS. The role of the HLA system in anti‐MBP antibody production in ON was investigated employing a restriction fragment length polymorphism system for genomic HLA‐DQ and ‐DR typing and an immunospot assay for the detection of individual cells secreting antibodies to three different synthetic MBP peptides. Thirty‐two out of 40 patients (80%) with ON had cells in cerebrospinal fluid secreting anti‐MBP peptide antibodies while this occurred in 10/19 patients with other neurological diseases (53%; mainly in patients with inflammatory diseases in the central nervous system). This difference was statistically significant (P= 0.03). None of the three examined peptides were immunodominant in any patient group. It was found, however, that presence of HLA DR15, which is associated with MS, may be associated further with predominant production of antibodies to the MBP amino acids 63–88 in patients with ON (P= 0.002, corrected for multiple comparisons).
Individuals from Different Populations Identify Multiple and Diverse T‐Cell Determinants on Mycobacterial HSP70
Authors: ADAMS E. , BRITTON W. , MORGAN A. , SERGEANTSON S. , BASTEN A.
Published: July 2006

The 70 kDa heat‐shock protein (HSP) of Mycobacterium leprae stimulates both cellular and antibody responses in leprosy patients and subclinically infected individuals despite partial homology with host HSP70. Furthermore, mycobacterial HSP70 can act as a carrier protein in unprimed mice, suggesting the presence of widely shared T‐cell determinants on this protein. In order to elucidate the frequency and genetic restriction of these T‐cell epitopes, we have undertaken a systematic analysis of the proliferative responses to 20mer peptides encompassing the whole protein in different populations. Caucasian BCG vaccinees who responded to recombinant M. leprae HSP70 identilied multiple scattered T‐cell determinants, four of which were recognized by 60% of subjects in association with a variety of HLA‐DR haplotypes. When a group of Nepali leprosy and tuberculosis patients were tested, significant differences in the pattern of peptide recognition were observed. The dominant peptides recognized by Caucasian subjects were infrequently reactive and other peptides were stimulatory, again in association with a variety of HLA‐DR phenotypes. The C‐terminal 70 residues of the M. leprae HSP70 are specific to M. leprae and sera from lepromatous leprosy patients bind to this region. However, few T‐cell determinants were identified in these residues, indicating that this region is unhelpful as a diagnostic tool for detecting M. leprae‐specific T‐cell responses. When compared with the equivalent regions of the human HSP70, the commonly recognized peptides showed significant differences in amino‐acid sequence. When taken in conjunction with the failure of human HSP70 to stimulate M. leprae HSP70‐reactive T‐cell clones (E. Adams et al., unpublished observations), this finding indicates that the human T‐cell response to this protein is largely directed at mycobacterial‐specific determinants. The presence of multiple T‐cell epilopes on M. leprae HSP70 with varied patterns of HLA‐DR association suggests that the whole protein is required for stimulating effective T‐cell responses in genetically diverse populations.
Interleukin‐1 Augments the Diminished Interleukin‐2 mRNA Expression and Proliferative Response of Neonatal T Lymphocytes to Anti‐CD2 Antibodies
Authors: HASSAN J. , REEN D. J.
Published: July 2006

Expression of IL‐2 mRNA by unstimulated and stimulated purified T cells and mononuclear cells from adult and cord blood was investigated in an attempt to better understand the underlying defective neonatal host immune defense system. Using RNA dot‐blot analysis, IL‐2 mRNA expression in anti CD2‐stimulaled neonatal T cells revealed significantly reduced levels when compared to adult T cells (P<0.01). Purified neonatal T cells also showed a significantly reduced proliferative response to antiCD2 antibodies (P<0.01). Addition of IL‐1ß enhanced the hyporesponsiveness of neonatal T cells at both the level of proliferation and IL‐2 mRNA expression. Unseparated mononuclear cells from adult and cord blood revealed similar IL‐2 mRNA levels and proliferation when activated by anti‐CD2 stimulation. The reduced IL‐2 mRNA expression observed in neonatal T cells may explain, in part, the difference in host defense between the newborn and adult during states of increased demand such as infection.
Mycobacteria Precipitate Autoimmune Rheumatic Disease in NOD Mice Via an Adjuvant‐Like Activity
Authors: BAXTER A. G. , HEALEY D. , COOKE A.
Published: July 2006

NOD mice spontaneously develop organ‐specific autoimmunity and are widely used as a model for diabetes. NOD mice also exhibit some features of non‐organ specific autoimmune rheumatic disease such as thymocytotoxic and anti‐nuclear autoantibodies and they develop haemolytic anaemia in senescence. A single dose of 2.6x107 heat‐killed Bacillus Calmette‐Guerin (BCG) i. v. in 8‐week‐old NOD mice prevented diabetes but precipitated a syndrome similar to systemic lupus erythematosus (SLE), in which treated mice rapidly developed haemolytic anaemia, high litre anti‐DNA and anti‐Sm antinuclear autoantibodies, perivascular lymphocytic infiltration in the kidneys and glomerular immune complex deposition. Here, we examined the mechanism of action by which BCG precipitated rheumatic autoimmune disease in NOD mice. Two weeks after injection, reticuloendothetial cell function was dramatically increased in BCG‐treated NOD mice. By 4 weeks, treated mice had a three‐ to four‐fold increase in Mac‐1+ and class‐II+, B220‐negative splenocytes and in vitro antigen‐presentation capacity was enhanced two‐ to four‐fold. In vivo responses to SRBC confirmed enhancement of DTH 4 weeks after BCG injection, consistent with an adjuvant‐like activity.
Binding of Ras Oncogene Peptides to Purified HLA‐DQ(αl*0102, ß1*0602) and ‐DR(α, ß1*0101) Molecules
Authors: JOHANSEN B. H. , GEDDE‐DAHL T. , SOLLID L. M. , VARTDAL F. , THORSBY E. , GAUDERNACK G.
Published: July 2006

Mutated oncogene peptides may be presented to T cells by HLA molecules. To be able to design the optimal peptides for stimulation of T cells in individuals with different HLA molecules, it is important to analyse the binding characteristics of oncogene peptides to HLA. HLA‐DQ6 (DQ(α1*0102, ß1*0602)) and HLA‐DRI (DR(α, ßl*0101)) molecules were purified from lysates of homozygous EBV‐transformed cell lines. Purified HLA molecules were then tested for their ability to bind synthetic peptides in gel filtration assays. A p21 ras oncogene peptide (previously found to stimulate DQ6‐restricted T‐cell clones) and an influenza matrix peptide were labelled with 125I and served as indicator peptides for binding to DQ6 and DR1 respectively. Binding of homologous truncated and mutated p21 ras peptides and unrelated peptides was then evaluated by their capacity to inhibit binding of the indicator peptides. p21 ras‐derived peptides were found to bind to both DQ6 and DR1 molecules indicating the existence of a promiscuous binding motif in these peptides. The binding affinities seemed to vary between the different peptides, but the amino acid substitutions resulting from natural mutations were not critical for binding. Notably, the results obtained for DQ6 in the biochemical peptide binding assay correlated well with results obtained in a functional assay using T‐cell clones as probes.
Mycobacterial Heat‐Shock Protein 65 Induces Proinflammatory Cytokines but does not Activate Human Mononuclear Phagocytes
Authors: PEETERMANS W. E. , RAATS C. J. I. , LANGERMANS J. A. M. , VAN FURTH R.
Published: July 2006

The 65 kDa heat‐shock protein (Hsp65), a well‐conserved and immunodominant antigen which elicits a cellular and humoral immune response, may play a role in host defence against invading microorganisms and autoimmune disorders. The aim of the present study was to assess the effects of Hsp65 on the functional activities of human mononuclear phagocytes in the absence of lymphocytes. Incubation with Hsp65 resulted in an enhanced release of TNF‐γ and IL‐1γ by human monocytes and monocytederived macrophages (MDM). The amount of cytokines released by these cells in response to Hsp65 was similar to that released in response to IFN‐γ together with LPS. Incubation with ovalbumin did not stimulate the release of these cytokines. In vitro stimulation of monocytes with Hsp65 enhanced the membrane expression of complement receptor III but did not influence either the expression of Fc‐receptor I and HLA class‐II antigens or the release of reactive oxygen intermediates. Therefore, Hsp65 stimulated monocytes cannot be considered to be activated according to classical criteria. The release of the proinflammatory cytokines TNF‐γ and IL‐1γ by human mononuclear phagocytes in response to Hsp65 indicates that this protein can contribute to both host defence and tissue damage in inflammatory lesions characterized by an abundant expression of Hsp65.
In Vivo Study of mIgM and mIgD Cross‐Linking on Murine B Cells
Authors: DENIS O. , MACEDO‐SOARES F. , LATINNE D. , NISOL F. , BAZIN H.
Published: July 2006

In this study, we have analysed in mice the effects on the immune response of in vivo treatment with different rat monoclonal antibodies (MoAb) against IgM and IgD. Although the effects of IgD cross‐linking have been studied already, no attempt has been made to characterize the effects of in vivo IgM crosslinking, probably because of the higher IgM serum levels compared to IgD.

We have used a panel of nine monoclonal rat anti‐mouse IgM and three anti‐IgD antibodies and we have characterized their isotypes, avidities, immunoglobulin (Ig) cross‐linking and internalization abilities. Our results show that injection of mice with some rat MoAb against IgM led to an important decrease of IgM serum level and internalization of membrane IgM (mIgM) on almost all B cells. Similarly, treatment with a high‐avidity anti‐IgD antibody induced disappearance of mIgD on B cells. Treatment with rat MoAb against IgM or IgD led to a synthesis of specific antibodies and there was a direct relationship between the Ig internalization abilities of rat MoAb and the induction of specific antibody production. Finally, treatment with a high‐avidity rat MoAb against IgD induced a polyclonal IgE and IgGl secretion. The significance of these results on mIg receptor functions is discussed.
CD26 Surface Antigen Expression on Peripheral Blood T Lymphocytes from Children with Down's Syndrome (Trisomy 21)
Authors: BERTOTTO A. , GERLI R. , SPINOZZI F. , MUSCAT C. , FABIETTI G. M. , CRUPI S. , CASTELLUCCI G. , De BENEDICTIS F. M. , De GIORGI G. , BRITTA R. , VAGLIASINDI C. , FORENZA N. , VACCARO R.
Published: July 2006

A phenotypical analysis carried out by two‐colour flow cytometry showed that the proportion of circulating CD4+T lymphocytes co‐expressing the membrane‐associated ectoenzyme dipeptidyl peptidase IV (CD26 antigen), a functional collagen receptor involved in T‐cell triggering through its interaction with the CD45 protein tyrosine phosphatase, was significantly lower in 28 children with non‐translocated trisomy 21 (Down's syndrome) (DS) than that calculated in the bloodstream of 27 age‐ and sex‐matched healthy controls. Agonist anti‐CD26 monoclonal antibodies (MoAbs), such as anti‐lF7, not only modulate the surface expression of this molecule, but also enhance the proliferative activity of normal human T cells via the CD3‐ and CD2‐mediated activation pathways. T‐lymphocyte proliferation induced by antigen or polyclonal T‐cell activators, including anti‐CD3 or ‐CD2 MoAbs, is severely impaired in DS. Although the physiological ligand of CD26 surface structure is unknown, the fact that CD4+T lymphocytes found in the blood of trisomic subjects are mostly CD26−(anti‐lF7−) suggests that their faulty mitogenic response may be due to phenotypical and, perhaps, strictly correlated functional abnormalities.
Inhibition of Spontaneous and Mitogen‐Induced Lymphocyte Proliferation by Murine Bone Marrow‐Derived Macrophages: Role of Prostaglandins, Nitric Oxides and Cell‐to‐Cell Contact
Authors: ZWADLO‐KLARWASSER G. , PLATEN S. , SCHMUTZLER W.
Published: July 2006

Spontaneous and mitogen‐stimulatcd proliferation of spleen lymphocytes was inhibited by coculturing the cells with murine bone marrow derived macrophages (BM‐Mφ). The inhibitory effect was found to be dependent on the maturation stage of BM‐Mφ reflected by the appearance of the phenotype BM 8 and on the number of BM‐Mφ added to the lymphocytes. The spontaneous proliferation was only inhibited by the addition of high numbers of BM‐Mφ of late maturation stage. The lipopolysaccharide (Lps) induced response was strongly suppressed by increasing proportions of BM‐Mφ of either cultivation stage. The suppressive effect on the concanavalin A (Con A)‐induced proliferative activity increased with the maturation of the macrophages. Inhibition of prostanoid release with indomethacin had no effect. Blocking of nitric oxide synthesis partially reversed the inhibitory effect of macrophages mainly on the Con‐A response. Addition of culture supernatant of BM‐Mφ to the lymphocytes did not mimic the effect of the macrophages themselves. BM‐Mφ only slightly inhibited the proliferation when 1ymphocyte‐BM‐Mφ cell‐to‐cell contact was prevented. These results show that BM‐Mφ differently influence the spontaneous and mitogen‐induced lymphoproliferation and that the inhibitory effect of BM‐Mφ on the lymphocyte proliferation is only partially mediated by secretory products of macrophages but apparently requires cell‐to‐cell contact between both cell types.
Anti‐CD45 Augments Response of a Th2 Clone to TCR Cross‐Linking
Authors: WOLFF H. , JR C. JANEWAY
Published: July 2006

The CD45 molecule is a transmembrane tyrosine phosphatase that may be associated with the T‐cell receptor (TCR). This has led to the suggestion that CD45 may be important for the regulation of signal transduction in T cells. This idea is supported by the finding that antibodies against CD45 are comitogenic in proliferation assays.

In the present work, we have examined the comitogenicity of CD45 antibodies by studying the effect of CD45, CD45RA, and CD45RB monoclonal antibodies (MoAbs) on proliferation of D10 cells induced with T‐cell receptor (TCR) MoAbs. In addition interactions with some other proliferation inducing agents namely CD3 antibodies, lectins, and IL‐2, are examined here. We have found that in general the CD45 MoAbs would significantly enhance proliferation induced by a wide spectrum of TCR MoAbs and other proliferation inducing agents, with some minor quantitative differences. The CD45 and CD45RB MoAbs were equally potent in their comitogenic activity while the CD45RA antibody was somewhat less potent. The comitogenic effect was maximal when CD45 antibodies were added simultaneously with the TCR MoAb, but significant comitogenicity could be detected when CD45 MoAbs were added up to 24 h after the initiation of the culture indicating that the CD45 antibodies also affect other processes than the initial signal transduction cascade.
The Cross‐Reactive Idiotopes Recognized by the Monoclonal Antibodies 9G4 and LCI are Located in Framework Region 1 of Two Non‐Overlapping Subsets of Human VH4 Family Encoded Antibodies
Authors: POTTER K. N. , LI Y. C. , CAPRA J. D.
Published: July 2006

The monoclonal anti‐idiotopic antibodies LCI and 9G4 bind two non‐overlapping sets of VH4 encoded antibodies. 9G4 exclusively binds VH4–21 encoded antibodies, while LCI binds antibodies derived from VH4 family gene segments V71‐2, V71‐4, VH4‐18, VH72‐I and V2‐1. The VH4–21 gene segment is utilized by most cold agglutinin (CA) antibodies with I/i specificity, while antibodies encoded by other VH4 gene segments are associated not with CA disease, but primarily with rheumatoid‐factor (RF) activity.

We previously determined that the idiotope to which 9G4 binds in VH4‐21‐derived antibodies is located in framework region l (FR1). In the present study, by using mutational analysis involving individual framework‐ and complementarity‐determining region exchanges between VH4‐2I‐ and V71‐2‐encoded antibodies, we have found that the idiotope to which LCI binds in V71‐2‐derived antibodies also maps to FR1. The LC1 idiotope is heavy (H)‐chain associated, but requires pairing with a light (L) chain for LCI binding. Recombinant antibodies composed of a variety of kappa (k) and lambda L chains paired with either a V71‐2 or VH4–21 chain were produced in the baculovirus expression system. LCI bound all of the k‐containing antibodies but did not bind the V71‐2‐encoded H chain alone nor to the two A‐containing antibodies. This experiment demonstrates that not all light chains exert equivalent influence on the conformation of the H‐chain idiotope. These results indicate that the FR1 of VH4‐encoded antibodies is immunogenic and suggest a physiological role of FR l during an immune response.
IFN‐γ Inhibits Internalization of Soluble Aminated β‐1, 3‐D‐Glucan by Macrophages and Thereby Down‐Regulates the Glucan Induced Release of TNF‐α: and IL‐1β
Authors: KONOPSKI Z. , SELJELID R , ESKELAND T.
Published: July 2006

We have previously shown that soluble aminated β‐1, 3‐D‐glucan (AG) and glucan‐derivatized micro‐beads (GDM) bind to the specific β‐glucan receptor on mouse peritoneal macrophages. Phagocytosis of GDM by macrophages is mediated through the β‐glucan receptor. IFN‐γ which increases macrophage phagocytic capacity, also increased the phagocytosis of GDM. In the present study we show that IFN‐γ inhibits Internalization of AG in macrophages in a dose‐ and time‐dependent manner. The inhibitory effect of IFN‐γ was neutralized by treatment of the macrophages with cycloheximide. These results were confirmed by confocal laser scanning microscopy which showed that IFN‐7 treated cells incorporated less fluorescein‐labelled AG than did untreated cells. IFN‐γ did not change the macrophage‐binding capacity for AG showing that the inhibitory effect of IFN‐γ is not caused by decreased number of β‐glucan receptors on the cells. The stimulatory effect of AG on IL‐β and TNF‐α release from macrophages was reduced by pretreatment of the cells with IFN‐γ.

We conclude that the uptake of AG and GDM in macrophages, both mediated through the β‐glucan receptor, are differently regulated by IFN‐γ. The reduced internalization of AG after IFN‐γ treatment of macrophages, is probably responsible for the down‐regulation of IL‐1 and TNF‐α secretion.
Immunoregulatory Effects of Cytokines on Natural Killer Cells
Authors: NAUME B. , ESPEVIK T.
Published: July 2006

Natural killer (NK) cells are able to kill tumour cells or virus‐infected cells spontaneously and independent of classical MHC‐restriction. The activities of these cells can be regulated by different cytokines. Interleukin‐2 has been shown to be a potent stimulatory factor for NK cells, inducing proliferation, cytokine production and increased cytotoxic activity. During recent years, the influence of various cytokines on NK cells have been studied, like interferons, IL‐1, IL‐6, IL‐4 and TGF‐β. Recently, new cytokines like IL‐7 and IL‐12 have been shown to possess direct and potent stimulatory effects on NK cells. Furthermore, endogenous production of TNF seems to play an important role in mediating effects induced by several stimulatory cytokines. Here, an overview of the different regulatory effects of these cytokines on NK cells are presented.