bluuebunny/crossref_metadata_2025 huggingface dataset:
T‐Cell Chemiluminescence
Authors: BENICHOU G. , KANELLOPOULOS J. M. , MITENNE F , GALANAUD P. , LECA G.
Published: June 2006

The binding of mitogenic lectins phytohaemagglutinin (PHA), concanavalin A (Con A) and/or of monoclonal antibodies to different receptors such as antigen receptor complex or CD2 on human T cells generates increases in the concentrations of inositol triphosphate (IP3) and cytoplasmic free calcium. This T lymphocyte requires the delivery of two signals; the first can be provided by specific monoclonal antibodies or by mitogenic lectins, and the second by a phorbol ester, phorbol myristate acetate (PMA). In other cells such as macrophages, the rise of intracellular calcium via the generation of IP3 and stimulation of protein kinase C can activate the phospholipase A2, a calcium‐dependent enzyme. This enzyme initiates the release of reactive oxygen intermediates and metabolites of arachidonic acid. In order to know whether this other metabolic pathway can be generated in T cells, we tested the capacity of different T‐cell lines and clones to produce superoxide anion after stimulation by the above‐mentioned activating agents. In this paper, we demonstrate that treatment of the Jurkat human cell line with Con A, PHA, and PMA results in a significant release of reactive oxygen metabolites. Of the various T‐cell lines and clones tested, only Jurkat exhibited an oxidative burst. Moreover, none of the antibodies tested (anti‐CD3, anti‐CD2, and anti‐CD28) and known to activate T cells, and none of the immune complexes was able to mediate such an effect. The existence of an oxidative metabolism in at least one T‐cell line suggests that T‐cell activation may in some instances use another metabolic pathway.
Comparison between Thymus‐ and Spleen‐Derived B‐Cell Hybridomas
Authors: ZÖLLER M.
Published: June 2006

When fusing thymocytes and spleen cells (SC) of 7‐ and 28‐day‐old BALB/c mice with Sp2/0, comparable numbers of clones were obtained. Immunoglobulin secretion was observed in 53‐79% of splenic, but only 10–18% of thymic hybridomas. This was irrespective of tolerization through prenatal treatment with trinitrobenzenesulphonic acid (TNBS). Differences between control and tolerant mice were observed with respect to the frequency of anti‐trinitrophenol (TNP)‐producing hybridomas: in 7‐day‐old tolerant litters their frequency was increased in thymus and spleen as compared with controls, but it was decreased in 28‐day‐old tolerant mice. It is concluded that the majority of thymic B cells are in an activated, but non‐producing state and that the repertoire of thymic B cells is influenced by prenatal contact with nominal antigen.
Detection of Individual Interleukin 4‐ and Gamma Interferon‐Producing Murine Spleen Cells after Activation with T‐Cell Mitogens
Authors: SANDER B. , CARDELL S. , HEREMANS H. , ANDERSSON U. , MÖLLER G.
Published: June 2006

Murine spleen cells were activated with concanavalin A (Con A), pokeweed mitogen (PWM), or phorbol myristate acetate (PMA) and the calcium Ionophore A23187. Cells producing gamma interferon (IFN‐γ) or interleukin 4 (IL‐4) could be detected by lymphokine‐specific monoclonal antibodies and indirect immunofluorescence. The frequency and kinetics of the lymphokine‐producing cells were examined and were approximately the same after stimulation with Con A or PMA and A23187. Thirty hours after activation. 3–9% of the cells produced IFN‐γ. There were few IL‐4‐producing cells, and the maximal frequency was 1 out of 400 spleen cells 48 h after activation. When the cells were activated with PWM, the frequency of IFN‐γ‐producing cells was still high 72 h after culture. The majority of the IFN‐γ‐producing cells were CD8+ and expressed receptors for IL‐2.
Differential Binding of Natural Monoclonal Antibodies to the Surface of Fixed or Living Cells
Authors: ERMONVAL M. , ROSSI C. PEÑA , COUTINHO A.
Published: June 2006

A few hundred monoclonal antibodies derived from normal mice were tested for binding to cell surface antigens in one T‐cell hybridoma and one I‐Ek‐transfected fibroblast cell line. The assay, which is suitable for large screenings, used glutaraldehyde‐fixed cells followed by immunoenzymatic detection of immunoglobulin. Of the 331 antibodies tested, 75 showed significant binding, not only on these cells, but also on a macrophage, fibroblast, thymoma, and pre‐B cell line, and on normal syngeneic and allogeneic thymocytes. If the assay was modified so is to use live cells in a simplified ELISA on living cells, only 10 of 253 antibodies were found to be positive with the T‐cell hybridoma line and 7 with the transfected fibroblast cell line. In both sets of conditions, about 75% of the positive antibodies were found to be ‘multireactive’ after being tested on a panel of antigens. In contrast, conventional ‘immune antibodies’ to cell surface antigens could be tested by routine methods in either type of assay We conclude that, while glutaraldehyde fixation does not affect the reactivity of conventional antibodies, this technique is inappropriate for testing the binding of natural antibodies to cell surface antigens.
Antibodies to β2‐Microglobulin, the Light‐Chain Component of Class I Histocompatibility Molecules, Provide an Activation Signal to Human Lymphocytes
Authors: HASHIMOTO S. , McCOMBS C. C. , MICHALSKI J. P.
Published: June 2006

Antibodies to β2‐microglobulin (β2m), the light‐chain component of class I histocompatibility antigens, provide a strong co‐stimulatory signal to human lymphocytes in the presence of phorbol ester. This activation signal requires a high concentration it antibody, whereas the effect on responses to a mitogenic lectin is exclusively inhibitory over a broad dose range. A rabbit polyclonal and a mouse monoclonal antibody to β2m were similarly co‐stimulatory. Antibody to β2m was co‐stimulatory with phorbol ester, but not calcium ionophore, suggesting that class I antigens play a role in the initiation of the ‘first’ signal of a recently described two‐signal model of lymphocyte activation.
Complement Activation is Associated with the Presence of Specific Human Immunodeficiency Virus (HIV)‐Anti‐HIV Immune Complexes in Patients with Acquired Immunodeficiency Syndrome‐Related Complex or Lymphoadenopathy Syndrome
Authors: CARINI C. , PERRICONE R. , FRATAZZI C. , FONTANA L. , DE CAROLIS C. , D'AMELIO R. , SIRIANNI M. C. , AIUTI F.
Published: June 2006

The complement system was examined in a group of eight patients (six with lymphoadenopathy syndrome (LAS); two with acquired immunodeficiency syndrome (AIDS)‐related complex (ARC)), who were found to be human immunodeficiency virus (HIV)‐positive, for the presence of specific HIV‐anti‐HIV complexes, A significant impartment of the classical and/or alternative pathway was found associated with the presence of cleavage fragments of C3 and/or B and a significant reduction in the complement factors studied. Ultracentrifugation fractions of serum samples obtained from one of the patients were assessed for the detection of specific HIV‐anti‐HIV (GP41‐anti‐GP41) complexes and were incubated with normal human serum to determine their complement activation capacity. A clear complement activation was found with the fraction in which a clear peak of HIV‐anti‐HIV (GP41‐anti‐GP41) immune complexes was present. The results demonstrate that specific immune complexes and complement activation are sometimes concomitantly present in patients with AIDS‐related disease and that specific immune complexes may be one of the causal factors of the pathogenesis of complement activation in these patients. Possible consequences for the severe immune regulation with relevance to the dramatic failure in treating the virus effectively are discussed.
Recombinant Human Tumour Necrosis Factor β (Lymphotoxin) Lacks Chemotactic Activity for Human Peripheral Blood Neutrophils, Monocytes, and T Cells
Authors: MROWIETZ U. , TERNOWITZ T. , SCHRÖDER J.‐M. , CHRISTOPHERS E.
Published: June 2006

Human recombinant tumour necrosis factor β (rhuTNFβ)/lymphotoxin was tested for human neutrophil granulocyte (PMN), monocytes (MO), and T‐cell chemotactic activity by means of a modified Boyden chamber system. Over a wide range of concentrations (10‐7‐10‐14 M) rhuTNFβ showed no chemotactic activity for PMN, MO, or T cells. In contrast, strong chemotactic migration was elicited in PMN and MO with the tripeptide N‐formyl‐methionyl‐leucylphenylalanine (FMLP) and in T cells when complement split product C5a and leukotriene B4 (LTB4) were used as chemotaxins. The results of this study indicate that rhuTNFβ/lymphotoxin is not a chemotaxin for human PMN, MO, or T lymphocytes in vitro.
The IgG Subclass Pattern of Complement Activation Depends on Epitope Density and Antibody and Complement Concentration
Authors: GARRED P. , MICHAELSEN T. E. , AASE A.
Published: June 2006

Using a matched series of human‐mouse chimaeric IgG anti‐5‐iodo‐4‐hydroxy‐3‐nitrophenacetyl (anti‐NIP) antibodies and NIP‐bovine serum albumin (NIP‐BSA) we examined how different variables influence the activation pattern of complement. When BSA was used with different hapten densities and the input of NIP‐BSA was altered, we observed a change in the subclass reaction pattern. IgG3 fixed more C1q than IgG1 and IgG2 in all situations. IgG1 was slightly better than IgG3 and IgG2 at high antigen concentrations at activating C4 and C3 and inducing formation of the terminal complement complex (TCC) When the epitope density and/or the NIP‐BSA concentration was reduced, IgG3 became best, followed by IgG1 and IgG2. IgG1 now revealed a marked prozone. Furthermore, IgG4 was found to activate C3 and mediate TCC formation at high epitope and complement concentrations.
In Situ Study of Haemopoiesis in Human Fetal Liver
Authors: KAMPS W. A. , TIMENS W. , DE BOER G. J. , SPANJER H. H. , POPPEMA S.
Published: June 2006

The anatomy of haemopoietic cells in human fetal liver was examined using immunohistological techniques on frozen sections of 31 fetuses (10–28 weeks gestational age). The immunohistological findings were consistent with reported cell suspension data. With regard to the location of haemopoietic activity no particular relationship existed between the various haemopoietic cell lineages. A large number of proliferating cells was present; only a few of these were reactive with haemopoietic progenitor cell monoclonal antibodies (MoAb) CD34. A population of haemopoietic cells expressed CD43 antigen (MoAb MTI) alone or together with anti‐vimentin MoAb reactivity; this population needs further delineation. Erythropoiesis and myelopoiesis occurred in clusters around sinusoids and portal triad vessels respectively. Lack of MoAb reacting exclusively with early developmental stages of erythropoiesis and myelopoiesis precluded dissection of these lineages. Lymphopoiesis occurred in a loosely scattered pattern without any sign of focal development. Pre‐B and B‐cell numbers increased with gestational age. Cells expressing markers of more mature B cells (surface IgD, CD35, and CD21) were rare. Also, few cells reacted with mature T‐cell markers, but CD7+ cells were obviously present. This expression of CD7 on haemopoietic fetal liver cells suggests that T‐cell precursors develop in fetal liver as well as B cells.
T‐Cell Abnormalities in Antibody Deficiency Syndromes
Authors: RAZIUDDIN S. , ELAWAD M. E. , BENJAMIN B.
Published: June 2006

We studied two patients with hypogammaglobulinaemia, three with selective IgA deficiency, and four with selective extreme IgM deficiency for T‐cell abnormalities in the circulating blood. Most patients had altered CD4+ helper/inducer and CD8+ suppressor/cytotoxic T‐cell subsets, and an elevated percentage of HLA‐DR+ and interleukin 2 (IL‐2) receptor+ antigens on lymphocytes. One patient with the selective IgA deficiency had an absence of CD4+ T cells in blood. The lymphocytes of eight patients showed a diminished proliferative response and deficient IL‐2 production in response to stimulation with phytohaemagglutinin or concanavalin A. The three patients with selective IgM deficiency were found to have a defective T‐cell abnormality in IgM synthesis by B cells. It is interesting that CD8+ T cells of the two patients with IgM deficiency demonstrated suppressor cell function for IgM synthesis by the normal B and T cells.
Enhancement of Human Immunodeficiency Virus (HIV) Replication in Human Monocytes by Low Titres of Anti‐HIV Antibodies in Vitro
Authors: MATSUDA S. , GIDLUND M. , CHIODI F. , CAFARO A , NYGREN A , MOREIN B. , NILSSON K. , FENYÖ E.‐M. , WIGZELL H.
Published: June 2006

Low concentrations of serum obtained from a patient with acquired immunodeficiency syndrome (AIDS) enhanced the replication of human immunodeficiency virus type 1 (HIV‐1) in a particular subclone of the CD4‐positive monocytoid cell line U937 clone 2. Cells of this subclone have a high expression of Fc receptors and a considerable degree of Fc‐mediated phagocytic activity. IgG purified from the serum was also able to enhance the replication. These results indicate that low concentrations of human anti‐HIV antibody may enhance HIV replication on human monocyte macrophages. Furthermore, two mouse IgG1 monoclonal antibodies against gp120, the envelope glycoprotein of HIV‐1, also induced enhancement at low concentrations. The binding of radiolabelled gp120 to the cells was increased at the same low concentrations. Antibodies against envelope glycoproteins may cause enhancement of HIV infection. Both normal and enhanced replication of HIV were completely inhibited by the masking of the binding site of CD4 molecules with F(ab')2 fragments of anti‐CD4 antibody. Moreover, CD4‐positive, FcγRI‐negative K562 cells and mouse macrophages failed to show any infection in the presence of antibody. These results suggest that CD4 molecules on the cell surface are necessary to cause enhancement of infection of HIV on monocyte macrophages.
Immunodeficiency after Allogeneic Bone Marrow Transplantation in Man
Authors: MØLLER J. , HOFMANN B. , LANGHOFF E. , JACOBSEN K. DAMGÅRD , ØDUM N. , DICKMEISS E. , RYDER L. P. , THASTRUP O. , SCHARFF O. , FODER B. , HARTVIG‐JENSEN T. , JACOBSEN N. , SVEJGAARD A.
Published: June 2006

This study was undertaken to clarify the mechanism behind the severely decreased lymphocyte proliferative response upon stimulation with mitogens and antigens seen after allogeneic bone marrow transplantation (BMT) in man. We investigated eight BMT patients and eight controls and found that the proliferative response of patient cells was reduced both when the cells were stimulated with phytohaemagglutinin (PHA) and when they were stimulated with a combination of phorbol myristate acetate (PMA), which is an activator of protein kinase C (PKC), and the calcium ionophore A23187, which irreversibly opens for calcium transport into the cell (median relative responses were 41 and.37%, respectively). However, the PHA‐induced increase in the concentration of intracellular tree calcium in post‐BMT cells was not significantly different from the values found in control cells and the expression of interleukin 2 (IL‐2) receptors (CD25) was only slightly decreased. However, the production of IL‐2 was severely decreased in patient cells after stimulation with A23187/PMA (median 3541 units), although it was higher than in PHA‐stimulated control cells (median 354 units). These results show that a direct activation of PKC by PMA combined with an increase in intracellular free calcium by A23187 cannot overcome the lymphocyte proliferation deficiency in cells from patients after allogeneic BMT. The data suggest that the defect is affecting the diacylglycerol pathway considerably more than the inositol triphosphate pathway.
Immune Response against P815X2 Mastocytoma Growing in Syngeneic DBA/2 Mice
Authors: LAATIKAINEN A.
Published: June 2006

Histamine was shown to suppress the in vitro generation of secondary syngeneic tumour‐specific Ly‐2+, L3T4− cytotoxic T cells from Ly‐2+, L3T4− precursor cells. The sensitivity of the spleen cells from P815X2 mastocytoma‐bearing DBA/2 mice to histamine‐induced suppression changed during tumour progression; by the time of cytotoxic peak reaction (between days 12 and 16 after P8I5X2 inoculation), the spleen cells were more resistant to histamine than the spleen cells obtained from mice a few days before or a few days after maximal cytotoxicity. Histamine had no effect on the effector function of in‐vitro‐generated cytotoxicity. The results suggest histamine‐induced modulation of cytotoxic T‐cell reactions in P815X2‐bearing mice.
Expression of Heterozygous lpr Gene in MRL Mice
Authors: CARLSTEN H. , TARKOWSKI A.
Published: June 2006

The presence of the homozygous lpr gene (lpr/lpr) in MRL mice has been regarded as mandatory for the development of the early onset of lupus disease, T‐cell dysfunctions, and polyclonal B‐cell activation. Congeneic MRL mice lacking the lpr gene (MRL +/+) display neither the lupus disease nor the immunological abnormalities within the first year of life. In this study we examined the cellular functions of MRL mice heterozygous at the lpr locus. The results indicate that MRL mice heterozygous at the lpr locus display intermediate delayed‐type hypersensitivity compared with homozygous lpr/lpr mice on the one hand and congeneic +/+ mice on the other. Furthermore, proliferative responses to concanavalin A, measured by uptake of [3H]thymidine, were significantly lower in MRL mice heterozygous at the lpr locus than in +/+ mice, but significantly higher than in homozygous MRL lpr/lpr mice. Polyclonal B‐cell activation, assessed by measurement of frequencies of IgG‐secreting spleen cells, a prominent feature in MRL lpr/lpr mice, was significantly lower in lpr/+ mice and totally absent in +/+ mice. Furthermore, spleen cells spontaneously secreting auto‐antibodies were found in large numbers in MRL lpr/lpr mice and in considerably lower but still significant numbers in heterozygous MRL+/lpr mice. In contrast, spleen cells from matched MRL +/+ mice did not display any spontaneous autoantibody production. Taken together, these data provide evidence for immunomodulatory properties of the heterozygous lpr gene.
Release of Interleukin 2 and Gamma Interferon by Peripheral Mononuclear Cells in Human Schistosoma mansoni Infection Normalizes after Chemotherapy
Authors: ZWINGENBERGER K. , IRSCHICK E. , VERGETTI J. G. SIQUEIRA , DACAL A. R. CORREIA , JANSSEN‐ROSSECK R. , BIENZLE U. , HUBER C. , FELDMEIER H.
Published: June 2006

Interleukin 2(IL‐2) and gamma interferon (IFN‐γ) were determined in supernatantsof mitogen and antigen‐driven cell cultures from patients with hepatosplenic or intestinal schistosomiasis. Skin reactivity was tested using a panel of eight recall antigens. Results were compared with those of uninfected local controls. In both schistosomiasis groups, IL‐2 activity was reduced before treatment. In less than one third of the patients, schistosomal antigens elicited detectable IL‐2 activity. IFN‐γ production was reduced more severely in hapatosplenic cases, in particular after stimulation by anti‐CD3 monoclonal antibodies. After anti‐schistosomal therapy with praziquantel, mitogen‐induced IL‐2 and IFN‐γ activities became normal within 3 months in intestinal schistosomiasis, and within 6 months in the hepatosplenic patient group. Results of in vivo delayed‐type hypersensitivity tests paralleled those of in vitro lymphokine production. In conclusion, evidence is presented for severe, antigen‐unspecific suppression of lymphokine production and skin reactivity against recall antigens. Anti‐parasitic chemotherapy is shown to reverse the impairment of cell‐mediated immune responses at the cytokine level.
Forced Contact between Antigen‐Presenting Cells and T Cells: Consequences for T‐Cell Activation
Authors: HÖIDÉN I. , CLINCHY B. , MÖLLER G.
Published: June 2006

It is still not known how T cells ire activated, which T‐cell surface structures transmit activation signals, and if antigen‐presenting cells possess activation structures for T cells. We have studied whether the T‐cell receptor (TcR) must be engaged for T‐cell activation to occur. By using membrane‐incorporated monoclonal antibodies, we artificially forced T‐cell to bind to antigen‐presenting cells in a mixed lymphocyte reaction system and thereby bypassed the need for TcR engagement and also made it possible for any surface molecule on antigen‐presenting cells to deliver a stimulatory signal to the T cells. Theoretically, T cells would become polyclonally activated by this procedure. However, we found that they did not, even though they were intimately bound to the antigen‐presenting cell, thus demonstrating that the TcR must participate in antigen/MHC binding in order for the T cells in become activated. This study does not exclude the possibility that antigen‐presenting cells possess structures that can activate T cells.
Anti‐Idiotypic B‐Cell Lines from a Patient with Monoclonal Gammopathy of Undetermined Significance
Authors: ANDERSSON M. , HOLM G. , LEFVERT A. K. , MELLSTEDT H.
Published: June 2006

The B‐cell repertoire in a patient with benign monoclonal gammopathy of unknown significance was studied using Epstein–Barr virus transformation of peripheral lymphocytes. The presence of anti‐idiotypic B cells producing monoclonal antibodies that reacted with idiotypic determinants on the monoclonal immunoglobulin was verified. The two monoclonal anti‐idiotypic antibodies studied were of the IgM‐κ type. Such anti‐idiotypic antibodies may be part of an idiotypic network regulation of the monoclonal B‐cell population.
Preferential Expression of VH5 and VH6 Immunoglobulin Genes in Early Human B‐Cell Ontogeny
Authors: CUISINIER A.‐M. , GUIGOU V. , BOUBLI L. , FOUGEREAU M. , TONNELLE C.
Published: June 2006

Analysis of Ig transcripts by dot blot hybridization revealed that VH5 and VH6 RNA first occurred during the 7th week of gestation in human fetal liver. At the same time, a Cλ or Cλ‐like chain was also expressed, in the absence of detectable K chains. In adult B cells, VH3 appears to be the dominant family expressed. Because VH5 and VH6 were located as the most proximal V genes to the JH cluster, the orderly expression of human VH genes seems to resemble the situation reported for the mouse.
Gamma‐Interferon‐Mediated Down‐Regulation of Electrolyte Secretion by Intestinal Epithelial Cells: A Local Immune Mechanism?
Authors: HOLMGREN J. , FRYKLUND J. , LARSSON H.
Published: June 2006

Active chloride (Cl−) secretion by intestinal crypt enterocytes is the central pathophysiological disturbance in most cases of acute diarrhoea. We examined monolayers of the human intestinal cell line T84 mounted in Ussing chambers to see whether the T‐cell lymphokine gamma interferon (IFN‐γ) might affect the Cl− secretory properties of these cells, which morphologically and functionally resemble native crypt enterocytes. Pretreatment of T84 cell layers with IFN‐γ for 24 h (but not for 3 h) markedly decreased the Cl− secretory response to vaso‐active intestinal polypeptide (VIP) and to cholera toxin and carbachol without appreciably affecting the overall morphology, electrical resistance, or cyclic AMP response of the T84 cell monolayer. The IFN‐γ treatment, however, did induce subtle changes in the T84 cell membrane protein composition which might have affected ion channels regulating Cl− secretion. Our results may indicate a possible novel ‘cell‐mediated’ immune mechanism through which activated gut T cells could modulate the extent of intestinal electrolyte and fluid secretion in, for example, enteric infections.
Blocking of Mycobacterium leprae Adherence to Dissociated Schwann Cells by Anti‐Mycobacterial Antibodies
Authors: CHOUDHURY A. , MISTRY N. F. , ANTIA N. H.
Published: June 2006

The association of Mycobacterium leprae with Schwann cells may represent an early crucial step in M. leprae pathogenesis. Using a dissociated Schwann‐cell system and anti‐mycobacterial monoclonal and polyclonal antibodies directed against surface and cytoplasmic components, we investigated the nature of M. leprae epitopes that mediate cytadhesion. Antibodies to polysaccharide and lipid components of M. leprae cell wall inhibited cytadhesion, whereas those directed against both surface and cytoplasmic protein epitopes did not show any such effect. No synergistic or antagonistic activity in inhibiting cytadhesion was observed when antibodies were used in combination. Thus, the association of M. leprae with Schwann cells may be mediated collectively by more than one of its lipid/polysaccharide epitopes. Also, a role for humoral immunity in intervention in the initial steps of M. leprae pathogenesis needs to be considered.
Synoviocytes Type A Bind Exogenous Antigens Recognized by Antibodies Present in Rheumatoid Arthritis
Authors: BELLON T. , PÉREZ‐MACEDA B. , MARQUET A. , LOPEZ‐BOTE J. P. , LARRAGA V. , LANGA C , DE BLAS E. , BERNABEU C.
Published: June 2006

The presence of antibodies in rheumatoid arthritis (RA) patients to antigens on the synoviocyte surface has recently been reported (Scand. J. Immunol. 27, 295, 1988). Here we have further characterized these antigens and found that they are exogenous proteins acquired from the bovine serum used in the culture medium. By immunoprecipitation and ELISA studies, we have identified bovine albumin and transferrin as the antigens recognized by the RA anybodies. These specificities were found not only in the sera but also in the synovial fluid from RA patients. A comparative study with a large panel or RA sera did not show a correlation in the antibody specificities for bovine albumin, bovine transferrin, or the 65‐kDa heat shock protein from Mycobacterium bovis. Similar experiments using rabbit and monkey sera as well as human synovial fluid and serum as a source of antigen did not reveal any reactivity with a highly positive RA serum. By sequence alignment, a high degree of homology between residues 142–156 from bovine albumin and residues 65 78 from human pro‐collagen α1 (I) was found. The capacity of the synoviocytes to bind exogenous antigens and the presence of antibodies to bovine proteins, normally present in the diet, suggest a role for these type A synoviocytes as well as a possible involvement of food antigens in the pathogenesis of RA.
T‐Cell Response to Phorbol Ester PMA and Calcium Ionophore A23187 in Down's Syndrome
Authors: BERTOTTO A. , CRUPI S. , ARCANGELI C. , GERLI R. , SCALISE F. , FABIETTI G. , AGEA E. , VACCARO R.
Published: June 2006

The proliferative response of purified T cells to anti‐CD2 monoclonal anybodies (TII2plus TII3) was found to be markedly reduced in 12 subjects with Down's syndrome (DS). The addition of phorbol ester PMA, which activates Ca2+/phospholipid‐dependent enzyme protein kinase C, or calcium ionophore A23187, which increases intracytosolic free Ca2+ concentration, enhanced, but did not normalize, the defective anti‐CD2‐mediated T‐cell mitogenesis. In contrast, the proliferation of resting lymphocytes from trisomic patients was comparable to that of the control cells when PMA and A23187 were used as co‐blastogenic reagents. Because PMA and A23187 together bypass the early activation pathways and promote T‐cell growth through the direct induction of membrane interleukin 2 (IL‐2) receptor expression and IL‐2 synthesis and secretion, it could reasonably be hypothesized that the faulty DS T‐cell activation induced by antigen or mitogen is due to a deranged transmembrane signal transduction, rather than a defect in the later intracellular events.
Massive Vascular AA‐Amyloidosis: A Histologically and Biochemically Distinctive Subtype of Reactive Systemic Amyloidosis
Authors: WESTERMARK G. T. , SLETTEN K. , WESTERMARK P.
Published: June 2006

Amyloid protein AA consists of several subspecies which mainly arise through proteolytic cleavage at various sites of the precursor, serum protein AA. The most common protein AA subspecies (the protein AA prototype) contains 76 ammo‐acid residues. In previous studies we have shown that distinctive patterns of amyloid infiltration occur in AA‐amyloidosis. The amyloid in different patterns of infiltration seems to consist of distinctive protein AA subspecies. In the present study we have analysed protein AA in three patients with a form of AA‐amyloidosis with heavy vascular infiltration and show that the amyloid fibrils contain two groups of protein AA subspecies. One quantitatively predominating, group contains large subspecies of up to 94 amino‐acid residues and a second group of protein AA‐molecules contains around 50 ammo‐acid residues. The AA molecules lack the N‐terminal arginine residue. It is concluded that AA‐amyloidosis with massive vascular infiltration is a distinctive subform with typical clinical and histological appearance and with fibrils containing characteristic protein AA subspecies.
Cytotoxic T Lymphocytes are the Prime Mediators of Suppression of the Mixed Lymphocyte Reaction by Alloactivated Cells
Authors: VANDEKERCKHOVE B. A. E. , JONG E. TIMMERMANS‐DE , DATEMA G. , CLAAS F. H. J.
Published: June 2006

An alloactivated secondary mixed lymphocyte reaction (MLR) culture (SMC), which was suppressive in the MLR with autologous responder cells, was studied in more detail. In particular, we investigated whether the suppressive activity of this SMC was mediated by cytotoxic T cells or whether bona fide suppressor cells were involved. The SMC suppressed an MLR when the stimulator cells shared Bw57, Bw60, or Dw 19 with the original stimulator. Separation of the SMC into CD4+ and CD8+ fractions demonstrated that the CD8+ fraction contained suppressive and cytotoxic activity against Bw57 or Bw60 antigens, while the CD4+ fraction contained both activities against the Dw19 specificity. The CD8+ fraction was also suppressive in the reverse MLR, while the CD4+ fraction was not. Limiting dilution analysis demonstrated that all CD8+ ‐suppressive cultures were also cytotoxic, whereas in the CD4+ fraction both cytotoxic and non‐cytotoxic suppressor cultures were found.
Intraepithelial T Cells of the TcRγ/δ+CD8− and Vδ1/Jδ1+ Phenotypes are Increased in Coeliac Disease
Authors: HALSTENSEN T. S. , SCOTT H. , BRANDTZAEG P.
Published: June 2006

Expression of the γ/δ T‐Cell receptor (TcR) for antigen on CD3+ intraepithelial lymphocytes (IEL) was studied in situ by two‐colour immunofluorescence on jejunal tissue secretions from 24 patients with coeliac disease and 17 controls. The proportion of intraepithelial TcRγ/δ+ cells was significantly increased (P<0.002) in untreated (median 20%, range 11–53%) as well in treated (gluten‐free diet) coeliac disease (median 23%, range 16–55%) compared with controls (median 2%, range 0–39%). Although TcRγ/β+ IEL dominated both in controls and coeliac disease. T cells expressing the TcRα/δ were preferentially located within the epithelium rather than in the lamina propria. Paired staining for TcRγ/δ and CD8 revealed that most (∼90%) intraepithelial TcRγ/δ+ lymphocytes in coeliac disease were CD8−. A remarkably large fraction (median 67%, range 58–94%) of intraepithelial TcRγ/δ+ cells expressed the Vδ1/Jδ1‐encoded epitope revealed by monoclonal antibody δTCS1. Our results suggested that increase of the intraepithelial TcRγ/δ+ CD8− subset of T cells is particularly related to coeliac disease.
Lymphocyte Binding to and Penetration through Vascular Endothelium is Stimulated by Platelet‐Activating Factor
Authors: RENKONEN R. , MATTILA P. , TURUNEN J.‐P. , HÄYRY P.
Published: June 2006

Lymphocytes have an important role in acute inflammatory reactions such as acute allograft rejection. Recirculating lymphocytes attach to vascular endothelium and penetrate through it into tissue parenchyma. Many recent studies have shown that different protein mediators, like gamma interferon, interleukin 1 and tumour necrosis factor enhance lymphocyte binding to and penetration through the endothelium, i.e. lymphocyte homing. We investigated the effect of platelet‐activating factor (PAF) in lymphocyte binding and penetration in vitro. Treatment of rat heart microvascular endothelial monolayers with PAF (10−6‐10−10M) increased the lymphocyte binding up to 1,6‐fold. The effect is dose‐ and time‐dependent. The PAF effect was reversible upon removal of the agonist: 60 min after removal of PAF no increase in the lymphocyte binding was detected. Pretreatment of endothelial cells, lymphocytes, or both of these cell types led to an increase in lymphocyte binding to endothelial monolayers. The effect of PAF in lymphocyte penetration through endothelium was investigated by using endothelial cell monolayers cultured on top of millipore filters. An optimal PAF dose (10−8 M) for 10 min increased the number of lymphocytes penetrating through the endothelial cell monolayer into the filter by a factor of 3. These results suggest that PAF has no important role in lymphocyte homing, since it can activate the endothelial cells, the lymphocytes, or both cell types.
Evidence that Tumour Necrosis Induced by Aminated β1‐3D Polyglucose is Mediated by a Concerted Action of Local and Systemic Cytokines
Authors: SELJELID R. , FIGENSCHAU Y. , BØGWALD J. , RASMUSSEN L. T. , AUSTGULEN R
Published: June 2006

Aminated β1‐3D polyglucose (AG) causes regression of Meth A sarcoma in syngeneic mice when injected systemically on day 7 after tumour inoculation. AG does not concentrate in the tumour, but distributes throughout the body. AG treatment cases release of large amounts of interleukin 1 (IL‐1) both in vivo and in macrophage cultures in vitro AG is a weak stimulus for tumour necrosis factor (TNF) release both in vitro and in vivo. However, tumour tissue and sera from untreated mice on days 3 and 7 after inoculation contain significant amounts of TNF, whereas tumour tissue and sera on day 14 contain insignificant amounts of TNF. This correlates exactly with the sensitivity to AG treatment IL‐1, and TNF when injected locally cause reduction in tumour blood circulation and also shrinkage of the tumour. All these facts taken together indicate that the tumour circulatory failure and necrosis induced by AG are mediated by local TNF—unrelated to the treatment—potentiated by systemic cytokines triggered by the AG.
Stimulation of Human B Lymphocyte Differentiation by the Neuropeptides Substance P and Neurokinin A
Authors: LAURENZI M. A. , PERSSON M. A. A. , DALSGAARD C.‐J. , RINGDÉN O.
Published: June 2006

Substance P (SP) at a concentration of 10−7m significantly increased the number of IgG‐producing cells induced by the polyclonal activator Staphylococcus aureus protein A (SpA) in 11 out of 22 cultures of enriched human blood B lymphocytes, in nine cultures SP did not significantly affect the SpA response and in three cultures IgG secretion was decreased in the presence of SP. Stimulation by SP was observed in cultures at days 6 and/or 8. In 3 out of 4 cell cultures depleted of monocytes SP did not affect the cell response to SpA stimulation. SP antagonists inhibited the enhancing effect of SP on B‐cell antibody secretion induced by SpA. SP alone did not stimulate B lymphocytes. Neurokinin A (NKA) had similar effects as SP and enhanced the IgG secretion induced by SpA in 5 out of 9 experiments, in two experiments was inactive, and in one decreased the IgG secretion. The effect of SP and NKA on B lymphocytes suggests that the neuropeptides interact with the regulation of the immune response.
The Anti‐Leu4 (CD3) Monoclonal Antibody Reacts with Proximal Tubular Cells of the Human Kidney
Authors: KARLSSON‐PARRA A. , DIMÉNY E. , JUHLIN C. , FELLSTRÖM B. , KLARESKOG L.
Published: June 2006

A recent observation that certain kidney tubular cells, especially those in the normal kidney, were positively stained with the anti‐Leu4 monoclonal antibody (MoAb) led us to investigate systematically the reactivity of three different anti‐CD3 MoAb with a panel of normal human kidneys. Using immunohistochemical and immunofluorescence staining techniques, the anti‐Leu4 MoAb was found to react with proximal tubular cells in all eight examined kidneys, while no tubular‐cells reactivity was observed with the OKT3 or DAKO‐T3 MoAb. In each kidney, however, all three antibodies reacted with a similar number of occasionally encountered T cells. The G11 MoAb, which has been reported to react with a calcium receptor‐associated molecule, and the anti‐Leu4 MoAb showed almost identical patterns of tubular‐cell reactivity. The observed co‐distribution of Leu4‐expressing structures with a putative Ca2+ sensor in the kidney and the fact that binding of anti‐Leu4 to T cells induces C2+‐mediated signal transduction, warrant further studies on a potential role of Leu4‐expressing structures in Ca2+ regulation of proximal tubular cells.
Oestrogen‐Mediated Suppression of Collagen‐Induced Arthritis in Rats
Authors: LARSSON P. , GOLDSCHMIDT T. J. , KLARESKOG L. , HOLMDAHL R.
Published: June 2006

Administration or oestrogen to castrated female rats has previously been shown to exert a suppressive effect both on the development of collagen‐induced arthritis (CIA) and on the delayed‐type hypersensitivity (DTH) reaction to collagen II (CII). The present study is concerned with the mechanisms responsible for this suppression, particularly as to the role of the thymus and the CD8+ T lymphocytes; both the thymic epithelial cells and the CD8+ T cells have earlier been implicated as responsible for oestrogen‐mediated immunomodulation on the basis of their expression of oestrogen receptors. Adult thymectomy alone did not affect either the incidence or severity of arthritis. Furthermore, adult thymectomy did not change the observed suppressive effects of oestrogen treatment on arthritis development or auto‐anti‐CII T‐cell immunity. Elimination of CD8+ T cells was subsequently achieved in groups of thymectomized rats by utilizing the fact that efficient depletion of CD8+ T cells occurs after in vivo treatment with OX8 monoclonal antibodies; depletion of peripheral CD8+ T cells failed to influence the suppressive effect of oestrogen on CIA and on the in vitro proliferate response of lymph‐node cells to‐CII. Depletion of CD8+ T cells did, however, in itself reduce the incidence of CIA in non‐oestrogen‐treated and thymectomized rats. We conclude that oestrogen may exert its suppressive effect on development of CIA and on T‐cell responsiveness via mechanisms independent of both the thymus and the CD8+ T‐cell subpopulation, but that CD8+ T cells are nevertheless involved in the regulation and/or effectuation of the immune reactions responsible for development of collagen arthritis in rats.
The Antibody Repertoire of Early Human B Cells I. High Frequency of Autoreactivity and Polyreactivity
Authors: LYDYARD P. M. , QUARTEY‐PAPAFIO R. , BRÖKER B. , MACKENZIE L. , JOUQUAN J. , BLASCHEK M. A. , STEELE J. , PETROU M. , COLLINS P. , ISENBERG D. , YOUINOU P. Y.
Published: June 2006

antibodies from theresulting lines and clones were examined for their binding to a variety of auto‐antigens and micro‐organisms by ELISA and fluorescence assays. Auto‐antigens tested included Fc of IgG, ssDNA and dsDNA, cardiolipin, histones 1‐4, collagens type I and II. thyroglobulin, cytoskeletal components, and a tissue section screen. Of 71 cell lines tested, all but 19 showed some autoreactivity. All 32 fetal liver lines reacted to some seif‐antigens. In cord blood clones, 16 out of 26 bound to auto‐antigens. Many of the clones reacted with more than one auto‐antigen and were ‘polyrcactive’. Some of the cord blood clones bound to extracts of micro‐organisms, showing specificity for both endogenous and exogenous antigens. The high frequency of CD5+ B cells in the cord blood (> 50%) and fetal liver (> 70%) argues for many of these clones being derived from this subset. Therefore, our data support the concept that many ‘early’ B cells produce polyreactive IgM which can bind to a variety of different auto‐antigens and microorganisms. These IgM antibodies are similar to those described by others as ‘natural antibodies’.
The Importance of the Pathogenic 16/6 Idiotype in the Induction of SLE in Naive Mice
Authors: BLANK M. , KRUP M. , MENDLOVIC S. , FRICKE H. , MOZES E. , TALAL N. , COATES A. R. M. , SHOENFELD Y.
Published: June 2006

We have previously demonstrated the pathogenicity of the common anti‐DNA idiotype designated 16/6 Id. Immunization of naive mice with the 16/6 Id induced SLE‐like disease characterized by serological (e.g. anti‐dsDNA and anti‐Sm auto‐antibodies), clinical (increased ESR, leucopenia and proteinuria), and pathological (16/6 Id deposition in kidneys) parameters. To elucidate further the role of the 16/6 Id in SLE induction the following studies were carried out: BALB/c mice were immunized with SA‐1, a human anti‐DNA monoclonal antibody carrying the 16/6 Id; TB‐68, a mouse monoclonal anti‐tuberculosis (TB) glycolipid, which binds dsDNA and carries the 16/6 Id; TB‐72, a mouse monoclonal anti‐TB glycolipid that binds DNA and does not harbour the 16/6 Id; and 4B4, a human anti‐Sm antibody that carries the 16/6 Id. SLE was induced in BALB/c mice only when immunized with SA‐l, TB‐68, and 4B4, namely antibodies with diverse binding capacities albeit having the 16/6 Id. Our studies further support previous evidence on the pathogenic role attributed to the 16/6 Id in SLE, and suggest that SLE is most probably an idiotype‐induced disease.
Role of CD8+ T Cells in Mercury‐Induced Autoimmunity or Immunosuppression in the Rat
Authors: PELLETIER L. , ROSSERT J. , PASQUIER R. , VIAL M. C. , DRUET P.
Published: June 2006

In Brown‐Norway (BN) rats mercuric chloride induces an autoimmune disease characterized by an increase in serum IgE concentration, and by the production of anti‐glomerular basement membrane antibodies responsible for a glomerulonephritis with a heavy proteinuria. (i) This disease results from a B‐cell polyclonal activation probably due to frequent anti‐class II T cells. (ii) The self limitation observed in this model is associated with both a decrease in the frequency of anti‐class II T cells and the emergence of CD8+ T cells able to suppress these autoreactive T cells. (iii) In Lewis (LEW) rats which do not develop autoimmunity, HgC12 provokes the appearance of non‐antigen‐specific CD8+ T cells responsible for a depression of T‐cell functions. The aim of this work was to test the effect of treatment with an anti‐CD8 monoclonal antibody (MoAb) in both BN and LEW rates, Anti‐CD8 MoAb‐treated rats were effectively depleted in CD8+ T cells. However, neither the induction nor regulation phases of mercury‐induced autoimmunity were modified in BN rats. Mercury‐induced immunosuppression in LEW rats was abrogated; however, depletion in CD8+ T cells did not allow the disease to occur in that strain. Finally, CD8 depletion induced in normal BN rats rats the appearance of rare anti‐class II T cells showing that these cells are normally present in that strain but negatively controlled by suppressor T cells.
Both Dendritic Cells and Monocytes Induce Autologous and Allogeneic T Cells Receptive to Interleukin 2
Authors: VAKKILA J. , HURME M.
Published: June 2006

Activation of resting T cells to proliferate is usually accompanied by their expression of interleukin 2 receptors (IL‐2R) and secretion of (IL‐2). We studied the mechanisms by which human blood‐derived dendritic cells (DC) and monocytes induce IL‐2R and stimulate IL‐2 secretion in autologous and allogeneic mixed luecocyte reaction (auto‐ and allow‐MLR, respectively). We found that only DC were fully effective as stimulator cells in MLR. DC stimulated both autologous and allogeneic T cells to express high‐affinity IL‐2R, secrete IL‐2, and vigorously proliferate in MLR. The stimulatory properties of monocytes were more complicated: although they stimulated the proliferation in allogeneic MLR, the proliferation rates, duration, and amount of IL‐2 secretion were different than in DC‐induced MLR. Autologous T cells did not proliferate in response to monocytes, but were induced to express the low‐affinity IL‐2R. If the cultures were supplemented with exogenous recombinant IL‐2, the proliferative responses to DC and monocytes in auto‐ and allo MLR were of the same magnitude, indicating that the responsiveness to IL‐2 was stimulated by both the stimulator cells. The stimulator cell number was important, since large numbers of monocytes, but not of DC, were suppressive to the proliferative responses. Thus, we concluded that the higher capacity of DC, as compared to monocytes, to stimulate T‐cell proliferation is based primarily on the more efficient stimulation of IL‐2 secretion.
Interleukin 5 Regulation of Peritoneal B‐Cell Proliferation and Antibody Secretion
Authors: WETZEL G. D.
Published: June 2006

The influence of recombinant interleukin 5 (rIL‐5) on murine peritoneal B‐cell proliferation and antibody secretion was examined. Larger, Low buoyant density peritoneal B cells proliferated better with rIL‐5 than the smaller resting B cells. This was also true for splenic B cells; however, comparison of the respective populations showed the large peritoneal B‐cell responses to be cells proliferated in response to rIL‐5 when lipopolysaccharide (LPS) was present. No detectable difference in the fraction of proliferating splenic B cells was seen in the presence of rIL‐5. These results are consistent with expression of IL‐5 receptors on about 70% of low‐density peritoneal B cells as determined by fluorescent staining with anti‐II‐5 receptor monoclonal antibody (MoAb). IL‐5 also enhanced spontaneous and mitogen‐driven IgM secretion by both peritoneal and splenic B lymphocytes; the increases exhibited by peritoneal B cells, however, were at least twice those exhibited by splenic B cells. Spontaneous and mitogen‐driven secretion of auto‐antibodies to bromelain‐treated mouse erythrocytes (BrMRBC) by peritoneal B cells were also increased by this interleukin. Furthermore, rIL‐5 enhanced peritoneal B‐cell plaque‐forming cell (PFC) responses to TNP‐LPS but not to TNP‐Ficoll. Both an anti‐IL‐5R MoAb and an anti‐IL‐5 MoAb blocked the rIL‐5‐induced enhancement of proliferation and auto‐antibody PFC responses. Hence, IL‐5 appears to be important for the regulation of proliferation and antibody secretion by many murine peritoneal B cells.
Evidence that Protein Kinase C Activation is Essential for Killing by IL‐2‐Activated Lymphocytes
Authors: KVANTA A. , NORDSTEDT C. , FREDHOLM B. , GULLBERG M. , JONDAL M.
Published: June 2006

Previous pharmacological evidence has suggested that activation of protein kinase C (PKC) is necessary for T and natural killer (NK) killing of different target cells. In the present study we find, using interleukin 2 (IL‐2)‐actuvated ktnogicttes (LAK cells), that phosphorylation of a well‐characterized 80‐kDa PKC substrate increases during conjugation to target cells. Furthermore, down‐regulation of PKC by pretreatement with the active phorbol esters PDB (24 h) ir PMA (2 h), but not with the inactive phorbolester PDD, simultaneoulsy inhibits inhibits killing by LAK cells, H‐7, an inhibitor of PKC, also inhibited LAK‐cell killing without affecting the target‐effector cell conjugate formation. We also demonstrate that pretreatment of target cells with phorbol ester (PMA) decreases killing, suggesting that PKC activation in the target cell population may also influence killing although the effect amy vary depending on the particular target cell used. We conclude that PKC activation is essential for triggering of lysis in LAK cells.
Dominant T‐Cell Receptor β‐Chain Gene Rearrangements Indicate Clonal Expansion in the Rheumatoid Joint
Authors: MILTENBURG A. M. M. , VAN LAAR J. M. , DAHA M. R. , DE VRIES R. R. P. , VAN DEN ELSEN P. J. , BREEDVELD F. C.
Published: June 2006

Miltenburg, A.M.M., van Laar, J.M., Daha, M.R., de Vries, R.R.P., van den Elsen, P.J. & Breedveld, F.C. Dominant T‐Cell Receptor β‐Chain Gene Rearrangements Indicate Clonal Expansion in the Rheumatoid Joint. Scand. J. Immunol. 31, 121‐125, 1990

T‐cell receptor (TcR) β and δ gene rearrangements were studied in anti‐CD3 expanded T‐cell populations cultured from the synovial membrane (SM) (n=5) or synovial fluid (SF) (n=2) of rheumatoid arthritis (RA) patients. Dominant TcR β‐chain gene rearrangements to Cβ1 were demonstrated in all the patients tested and 1‐3 expanded clones per patient were found. Clonal rearrangements to Cβ2 were detected in one SM sample (two clones) and one SF sample (one clone). The TcR δ gene was deleted in all the samples tested. We conclude that clonal dominance may be present, either using the Cβ1 or Cβ2 gene segment.