bluuebunny/crossref_metadata_2025 huggingface dataset:
Binding Characteristics of Human Serum Amyloid P Component
Authors: SERBAN D. , RORDORF‐ADAM C.
Published: June 2006

Serum amyloid P comptinent (SAP), a normal human plasma glycoprotein. was found in a solid phase ELISA to have Ca2+‐dependent binding for keyhole limpet haemocyanin (KLH), pectic acid, trinitrophenylated (TNP) maeromolecules, and plastic surfaces. The binding U) TNPKLH was used to develop a sensitive ELISA. The binding of SAP to the ligands mentioned was inhibited by EDTA, KLH, pectic acid, TNP‐conjugated macromolecules (bovine serum albumin, polyacrylhydrazide), and p‐nitrophenylarsonic acid, Underivatized and DNP‐conjugated macromolecules did not inhibit the SAP binding; arsenilic acid, picric acid, and dinitrophenyl were weak inhibitors. SAP bound to TNP‐agarose was eluated by either EDTA or p‐nitrophenylarsonic acid. Thus, a unique region of SAP is responsible for the polyspecific binding. We suggest that the polyspecific binding of SAP takes place through a Ca2+ bridge: half of the metal coordination sphere is occupied by SAP. with the other half available to interact with metal ligand.
Inhibitory Effects of Anti‐HLA‐A, B, C Heavy Chain and Anti‐β2 Microglobulin Monoclonal Antibodies on Alloantigen and Microbial Antigen‐Induced Immune Responses in Vitro
Authors: SPAGNOLI G. C. , AUSIELLO C. M. , CASSONE A. , CASCIANI C. U. , BELLONE G. , MALAVASI F.
Published: June 2006

The role of HLA class I subunits in class Il‐restricted immune responses was investigated by means of a panel of monoclonal antibodies (MoAb) recognizing HLA‐A,B,C heavy chain and different β2 mitroglobulin (β2m) epitopes. MoAb against either class I subunit strongly inhibited mixed lymphocyte cultures, generation of cytotoxic T lymphocyte cultures, generation of cytotoxic T lymphoytes or natural killer‐like activity, and lymphoproliferation in response lo soluble or particulate microbial antigens derived from Candida alhicans. In general. anti‐β2m MoAb were more efficient inhibitors than anti‐HLA‐A, B, C heavy chain MoAb. The inhibitory effects were specific, in that the parental myeloma ascitic fluid or a low‐affinity MoAb against β2m, or MoAh directed against non‐HLA surface structures did not affect any of the immune responses studied. The MoAb‐induced inhibition could not be attributed to nonspecific toxic effects, since PHA‐induced blastogenesis and lL‐2‐dependent proliferation of mixed lymphocyte culture (MLC) blasts were not inhibited. Furthermore, exogenous IL‐2 did not reverse the block of MLC and microbial antigen‐induced proliferative responses by MoAb. Taken together, these data suggest an involvement ol both subunits of class I antigens in class II‐resiticted inmiune reponses.
Rat C3 Conversion by Rat Anti‐2,4, Dinitrophenyl (DNP) Hapten IgA Immune Precipitates
Authors: RITS M. , KINTS J. P. , BAZIN H. , VAERMAN J. P.
Published: June 2006

Moncmeric (m‐) and polymeric (p‐) anti‐DNP monoclonal (MC) rat IgA antibodies (Ab) were tested for precipitation with DNP‐bovine serum albumin (DNP‐BSA) and C3 conversion in rat serum, with rat MC anti‐DNP igG2b used as reference. At equivalence, p‐IgA rapidly precipitated DNP‐BSA, with little antigen (Ag) left in the supernatant. In contrast, m‐IgA at five‐fold higher concentration precipitated Ag very slowly, with <50% of Ag precipitated at equivalence. The Ag/Ab weight ratio at equivalence was 0.13 for both m‐ and p‐IgA, but the molar ratio was 0.3 for m‐IgA and close to 1.0 for p‐IgA, suggesting a higher avidity of p‐IgA. Rat C3 conversion by rat IgA immune precipitates (IP) was about 20% with m‐IgA and 40% with p‐IgA. EGTA did not significantly affect these figures. Therefore, rat MC IgA IP activated the rat alternative C pathway. Neither rat nor mouse IgA anti‐DNP IP activated C3 in normal human serum.
Characterization of Amyloid Proteins AA and SAA as Apolipoproteins of High Density Lipoprotein (HDL)
Authors: HUSEBEKK A. , SKOGEN B. , HUSBY G.
Published: June 2006

An AA‐like protein with a molecular weight of 8600 complexed to high‐density lipoprotein (HDL) was demonstrated in several acute‐phase sera with high levels of SAA. The protein ‘apo AA’(to distinguish it from tissue AA) was isolated by elution from sodium dodecyl sulphate (SDS)‐polyacrylamide gel, and showed antigenic identity with purified tissue protein AA in double immunodiffusion. Normal HDL was shown to bind purified tissue AA in vitro. When the in vitro‐associated HDL‐AA complexes were given intravenously to mice during induction of amyloidosis, human AA was incorporated in the amyloid fibrils. Both apo AI and apo AII were shown to displace SAA from acute phase HDL when added to HDL‐SAA complexes in vitro. This might be of importanee in amyloidogenesis, as the liver and the small intestine, which are the main sites for AI and AII synthesis, are also sites of early amyloid deposition.
Immunological Involvement in the Pathogenesis of Pristane‐Induced Arthritis
Authors: BEDWELL A. E. , ELSON C. J. , HINTON C. E.
Published: June 2006

Evidence is presented that the development of arthritis induced in mice by 2,6,10,14‐tetra‐methylpentadecane (pristane) involves the immune response. Mice irradiated (500 rad) before injection of pristane failed to develop arthritis. By contrast, irradiated mice given lymphoid cells from normal donors and challenged with pristane developed arthritis. Other experiments showed that lymphoid cells from irradiated mice given pristane suppressed the development of arthritis in recipients challenged with pristane. Finally, the incidence of arthritis was significantly higher in CBA/Igb mice given pristane than in the allotypic congenic strain CBA/H, suggesting that a gene linked to the heavy chain immunoglobulin locus controls the development of arthritis.
Suppression of Cytolytic T‐Lymphocyte Responses through Inactivation of Non‐T Accessory Cells
Authors: DEGIOVANNI G.
Published: June 2006

The suppressive properties of nonspecific cytotoxic T lymphocyte (CTL) populations, derived from murine fetal calf serum (FCS)‐precultured cells expanded in interleukin 2 (operationally defined as FCS‐CM‐expanded cells), were investigated on CTL responses generated by syngeneic alloreactive lymphoid cells. Our results suggest that the addition of FCS‐CM‐expanded cell populations can inhibit the CTL response by elimination of the bone marrow‐derived macrophage (BM Mø) population used as non‐T accessory cells. Indeed, in the culture conditions used, removal of IL‐2 by the FCS‐CM‐expanded cells as well as a direct inactivating effect on the CTL precursors (CTL‐P) could be excluded as a reason for inhibition. On the other hand, we were able to show that the BM Mø population was very sensitive to the cytolytic activity exhibited by the inhibiting cells in a 3 h 51Cr‐release assay and that the suppressor effect observed could be partially circumvented by a second addition of BM Mø on the second day after the initiation of the culture.
Idiotypic Multireactivity of ‘Natural’ Antibodies
Authors: ARAUJO P. M. F. , HOLMBERG D. , MARTINEZ‐A C. , COUTINHO A.
Published: June 2006

One hundred and twenty IgM‐secreting hybridomas derived from unmanipulated 6‐day‐old BALB/c mice were screened for reactivity with the prototype idiotypic and anti‐idiotypic monoclonal antibodies, defining three well established systems, namely TEPC 15:10/13–15, J558:CD3.2, and MOPC 460:F6(51). Up to 25% of all IgM antibodies reacted with at least one of the six specific ligands, half of the latter being ‘monospecific’, the others reacting with two or more aniibodies. A detailed analysis of the four most multi‐reactive clones showed individually specific patterns of reactivity and revealed reactions of the same IgM molecule in idiotypic systems previously studied independently. Furthermore, when tested for functional interactions with syngeneic helper T cells expressing MOPC 460‐like clonotypes, one of these antibodies was found to inhibit effector helper activity. The results show the existence of ‘natural antibodies’ with idiotypic reactivities related to recurrent clonotypes in the strain. They may be either ‘specific’ or ‘mullireactive’, and might connect idiotypes on T and B cells and on antigenic systems so far studied independently.
A B Cell Growth Factor‐Dependent Cell Line Derived from a Human Lymphocytic Nodular Lymphoma
Authors: GENOT E. , KOLB J.‐P. B.
Published: June 2006

A B cell line derived from a human nodular lymphocytic lymphoma (Brill‐Symmers) was shown to be dependent on the presence of a low molecular weight B cell growth factor (BCGF) for its growth in vitro. The caryotype was normal and no contamination with Epstein‐Barr virus (EBV) could be detected. These cells did not respond to recombinant gamma interferon or to recombinant human interleukin 2 (IL‐2), although they displayed a weak density of IL‐2 receptor sites. They were both responsive to and dependent on BCGF for their multiplication in vitro. Furthermore, the putative receptor for this growth factor (CD23) was detected on these cells and the BCGF‐dependent proliferation could be blocked by a monoclonal anti‐CD23 antibody. A tumour‐derived cell line like this provides an interesting model for studying the mechanisms regulating B cell growth and the early events leading to the process of B cell immortalization.
The Amino Acid Sequence of an Amyloid Fibril Protein AA Isolated from the Horse
Authors: SLETTEN K. , HUSEBEKK A. , HUSBY G.
Published: June 2006

The amino acid sequence of the amyloid fibril protein AA from horse was established from charaeterization of cyanogen bromide fragments, tryptic peptides, and a peptide derived from a digest with Staphylococcus aureus V8 proteinase. The protein was found to consist of 80 amino acid residues. Sequence homologies with protein AA from other species were very striking, and revealed an insertion of two amino acid residues between positions 72 and 73. In position 44, two amino acid residues were found which provide further evidence for a polymorphism in the amyloid fibril protein AA.
Induction of Responsiveness to Interleukin 2 in Mouse Lymphocytes by Synergistic Action of Ionophore A 23187 and Diacylglycerol
Authors: STOECK M. , WARNCKE U. , BRENNECKE M. , RESCH K.
Published: June 2006

We investigated whether the protein kinase C‐binding agents 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA) and l‐oleoyl‐2‐acetyl‐rac‐glycerol (OAG) induced reactivity to interleukin 2 (IL‐2) in mouse lymphocytes. 10‐8m TPA was a strong inducer of reactivity to IL‐2 measured by [3H]thymidine incorporation. In contrast OAG alone (6‐25μg/ml) did not induce a significant IL‐2 mediated proliferative response. Cells stimulated with the ionophore A 23187+OAG neither proliferated nor produced IL‐2. In contrast, cells stimulated with A 23187+OAG+IL‐2 showed a significant proliferative response, indicating the expression of functional high affinity IL‐2 receptors. The expression of reactivity to IL‐2 induced by A 23187+OAG was inhibited by 0.04 mm Mn2+; in contrast the TPA‐mediated induction of IL‐2 responsiveness was not affected by Mn2+. The data suggest differences in the mechanism of induction of IL‐2 responsiveness by the two protein kinase C‐binding agents, TPA and OAG.
Catalase and Lipopolysaccharide Enhance Proliferation in the Rat Mixed Lymphocyte Reaction
Authors: LINDÉN O. , DOHLSTEN M. , BOKETOFT Å. , HEDLUND G. , SJÖGREN H.‐O.
Published: June 2006

Proliferation of rat spleen cells in a mixed lymphocyte culture was amplified fivefold or more in the presence of 2000 units of catalase/ml. as measured by [3H|thymidinc incorporation. A similar effect was observed with 1 μg of lipopolysaceharide(LPS)/ml. Addititin of polymyxin B abrogated the promotional effect of LPS. but not that of catalase. These results indicate that the hydrogen peroxide generated by some cells in the rat spleen cell mixed lymphocyte culture suppresses the proliferative response. The demonstration that removal of plastic adherent cells (reducing the percentage of monocytes/miicrophages by 75‐80%) also results in a 5‐ to 10‐fold increase in a subsequent MLR, indicates that some of the adherent cells may be the producers of hydrogen peroxide, which at higher concentrations suppresses the T‐cell proliferation. The enhanced proliferntion was not mainly due to increased interleukin 2 (IL‐2) production, since the IL‐2 concentrations of catalase and LPS‐containing cultures were lower than those of control cultures.
Three Kinds of Tumour‐Unique Surface Molecules on a Human T‐Cell Chronic Lymphocytic Leukaemia (T‐CLL) Detected by Monoclonal Antibodies
Authors: JANSON C. H. , TEHRANI M. JEDDI , MELLSTEDT H. , WIGZELL H.
Published: June 2006

Mouse monoclonai antibodies recognizing cell surface molecules on tumour cells from a patient with a T‐cetl chronic lymphatic lcukacmia (T‐CLL) have been produced. Three different types of idiotype‐like cell Surface structures were identified. One molecule had a relative molecular weight (Mr) of 90,000 under non‐reduced conditions and of 42,000 upon reduction, which corresponds well to the T‐cell receptor for antigen (Tt). The two other molecules, which also behaved like unique tumour markers, have not previously been described, to our knowledge. One molecule wasa monomer with an Mr, of 74,000–80,000 when non‐reduced and 80,000 upon reduction. The other idiotypic molecule was a dimer with a non‐reduced Mr of 74,000–80,000, and 38,000 after reduction.
Transduction of Mitogenic Signals in T Lymphocytes
Authors: MUSTELIN T. , PÖSÖ H. , STÅHLS A. , ELORANTA T. , ANDERSSON LEIF C.
Published: June 2006

Treatment of human T lymphocytes with mitogenic ligands, such as concanavalin A (Con A), induces a rapid activation of the enzyme ornithine decarboxylase (ODC). This activation occurs within minutes and is completely inhibited when the cells are treated with 1 mMLi* (in an inostiol‐free medium) prior to stimulation with Con A. In the presence of 1 mM myo‐inositol Li+ has no effect on the Con A‐induced activation of ODC. To elucidate why intositol is needed for the mitogen‐induced activation of ODC in T lymphocytes, we tested the ability of different inositol metabolites to reverse the inhibitory effect of Li+. Here we report that inositol phospholipids, in addition to inositol, reverse the Li+‐induced inhibition of ODC activation, while all other inositol derivatives tested were ineffective, This indicates that Li− does not block the activation of ODC by inhibiting the generation of inositol phosphates, but rather by a mechanism which is circumvented if inositol phospholipids are added. The molecular mechanisms involved in the rapid activation of ODC by mitogens in human T lymphocytes apparently require inositol phospholipids. but are not directly mediated by inasitol‐l,4.5‐trisphosphate (IP3) alone, diacylglycerol alone, or other inositol phosphates.
Separate but Complementary Roles for the Two Forms of Interleukin 1 in the Growth of Transformed Human B Lymphoblasts
Authors: GALLAGHER G. , TAYLOR N. , WILLDRIDGE J.
Published: June 2006

Epstein‐Barr virus (EBV)‐transformed human B cells were seeded at densities below their capacity for autostimulalory growth and the effects of interleukin I‐alpha (IL‐1‐α). interleukin 1‐beta (lL‐l‐β) and B‐cell growth factor (BCGF) were studied. When added separately. IL‐l‐α was able to support the growth of EBV‐transformed B cells, as was BCGF. In contrast, IL‐1‐β was unable to support the growth of these cells but was able to synergize with IL‐1‐α to promote cell growth. Further, the actions of BCGF and IL‐1‐α were seen to be synergistic. while those of BCGF and IL‐I‐β were not. The secretion of immunogiobulin was not affected by these reagents. These findings suggest separate, but complementary roles for the two forms of human IL‐1 in B‐cell growth.
Demonstration in Human Plasma of a Lectin Activity Analogous to that of Bovine Conglutinin
Authors: BAATRUP G. , THIEL S. , ISAGER H. , SVEHAG S‐E. , JENSENIUS J. C.
Published: June 2006

Evidence of the existence in human plasma of an activity analogous to that of bovine conglutinin is presented. The human plasma component was characterized antigenically and functionally. Human plasma was shown to agglutinate complement‐coated erythrocytes in the presence of Ca2+, and this conglutination was inhibited by EDTA. The molecule also binds to complement‐reacted solid phase IgG and to zymosan in the presence of Ca2+. The binding to complement is not inhibited by N‐acetyl‐D‐mannosamine, but is inhibited by N‐acetyl‐D‐glucosamine, as previously shown for bovine conglutinin. Antibodies raised against bovine conglutinin cross‐react with the human protein. The plasma concentration of the conglutinin‐like protein showed a high inter‐individual variation between apparently healthy donors. Unlike bovine conglutinin, the human conglutinin activity could not be demonstrated in serum but only in plasma. The activity was more stable in plasma containing metal‐ion chelators like EDTA and citrate than in heparin or hirudin plasma.
Expression of Restricted Immunoglobulin Isotypes in Plasmacellular Hyperplasia after Allogeneic Bone Marrow Transplantation
Authors: SCHUURMAN H. ‐J. , HENDRIKS R. W. , VERDONCK L. F. , VAN BAARLEN J. , DE GAST G. C. , SCHUURMAN R. K. B.
Published: June 2006

Plasmacellular hyperplasia in lymphoid tissue was found in 4 out of 9 patients 1‐6 months after allogeneic bone marrow transplantation as treatment for leukaemia. In the plasma cell populations. 13‐85% expressed a single immunoglobulin light and heavy chain isotype (monotypic Ig expression). DNA analysis, using a DNA probe specific for heavy chain JH gene segments and for light chains, did not reveal the presence of clonally restricted B lymphocytes. The patients' sera lacked homogeneous immunoglobulins. We conclude that plasmacellular hyperplasia found after allogeneic bone marrow transplantation represents a polyclonal B‐cell expansion‐with a restriction in Ig isotype.
Functional Characterization of Human B Cells Carrying the Lymphocyte Large Sialoglycoprotein gpl50
Authors: WIKÉN M. , ROBERTSSON E.‐S. , AXELSSON B. , PERLMANN P.
Published: June 2006

Human B cell‐enriched populations were prepared from buffy coats of healthy donors. By means of affinity chromatography, the B cells were separated into two fractions, one enriched in and the other depleted of cells expressing gpl50, the large sialoglycoprotein of lymphocytes. In the presence of autologous T cells, monocytes and pokeweed mitogen B cell populations enriched for gpl50+ cells gave rise to significantty more plasma cells (clg+ cells) and secreted significantly more IgG than gpl50‐depleted populations. In contrast, more or an equal amount of IgM was secreted in cultures containing gpl50‐depleted cells. The differences between the fractions could not be ascribed to uneven distribution of T3+ cells, OKM1+ cells or B1+ (CD20) cells. However, the gpl50‐enriched population contained significantly more B2+ (CD21) cells than the gpl50‐depleted population. These results suggest that the gpl50+ B cells differ from gpl50‐B cells, not only in their responsiveness to T cell differentiation signals but also in their commitment to Ig heavy chain isotype secretion.
Copper(II)(3,5‐Diisopropylsalicylate)2 Accelerates Recovery of B and T Cell Reactivity Following Irradiation
Authors: SODERBERG L. S. F. , BARNETT J. B. , BAKER M. L. , SALARI H. , SORENSON R. J.
Published: June 2006

Copper(II)(3,5‐diisopropylsalicylate)2 (Cu‐DIPS), administered subcutaneously to mice at 80 mg/kg body weight, bad marked radioprotective activity. Given 3 h before exposure to 8.0 Gy (800 rad) irradiation. Cu‐DIPS increased the 42‐day survival from 40% to 86%. Seven days after exposure to 8.0 Gy, there were severe reductions in spleen weight (73%) and cellularity (98%) in both Cu‐DIPS‐and vehicle‐treated mice. Viable spleen cells collected 7 days after irradiation were totally unresponsive to mitogenic or antigenic stimulation regardless of Cu‐DIPS or vehicle treatment, suggesting that Cu‐DlPS did not prevent radiation‐induced damage to mature lymphocytes. At 14 days, when Cu‐DIPS‐treated mice started to show improved survival over vehicle‐treated mice, spleen weights and cellularity were 2.5‐ and 3.5‐fold higher, respectively, in Cu‐DIPS‐treated mice. Treatment with Cu‐DIPS not only enhanced splenic repopulation. but also accelerated the reappearance of both B and T cell reactivities. Spleen cell responsiveness to the B cell mitogen, lipopolysaccharide (LPS), and the T cell mttogen, concanavalin A (Con A), regenerated significantly faster in Cu‐DIPS‐treated mice. Cu‐DIPS also significantly accelerated the regeneration of T‐dependent antibody induction. Based on these assays of immunocompetence, Cu‐DIPS‐treated mice had, on average, a seven‐fold greater capacity to respond to immune stimulation than vehicle‐treated mice 24 days after irradiation.
In Situ Characterization of the Cutaneous Immune Response in Ethiopian Cutaneous Leishmaniasis
Authors: NILSEN R. , MSHANA R. N.
Published: June 2006

Cryoslat sections from 10 patients with localized cutaneous leishmaniasis (LCL) and eight patients wiih diffuse cutaneous leishmaniasis (DCL) from Ethiopia were studied wtih immuno‐fluorescence methods for the phenotypic characterization of cells in the lesions. Higher numbers of Leuu 2+ and Leu 3+ cells (P<0.005) were found in LCL than in DCL, while the Leu 3a+b/Leu 2a ratios were the the same. No differences were found in the numbers of transferrin receptor. HLA‐DR, and HLA‐DQ expressing cells in the granulomas. Significantly (P<0.0001) lower numbers of IL‐2 receptors expressing (Tac+) cells were found in DCL than LCL lesions, suggesting interference in the activation of the T cells, IL‐2‐containing cells were absent in DCL and were found in LCL lesions. Epidermal keratinocytes above the LCL but not the DCL lesions expressed HLA‐DR (but not HLA‐DQ) antigen, suggesting a lower γ‐interferon production in the DCL granulomas. The number of Lancerhans' cells (Leu 6+) was higher in the epidermis of DCL (P<0.005) than in LCL, while a lower number of Leu 6+ cells were seen in the dermal lesions (P<0.001). These observations could account for some of the mechanisms responsible for the disturbed immunostimulation and immunoregulation obsereved in the lesions of DCL.
Characteristics of Human Rheumatoid Synovial and Normal Blood Dendritic Cells
Authors: WAALEN K. , FØRRE Ø. , PAHLE J. , NATVIG J. B. , BURMESTER G. R.
Published: June 2006

Dendritic cells (DC) were isolated from synovial tissue and synovial fluids of patients with rheumatoid arthritis and from peripheral blood of healthy donors. The cells were analysed for various surface antigens in indirect immunofluorescence by means of monoclonal antibodies. Surface antigen expression and accessory activity of the DC during short‐term cultures were also investigated. Both the rheumatoid synovial and the normal blood DC were strongly positive for panleucocyte antigen and class II major histocompatibiligy complex (MHC) antigens (HLS‐DP, HLA‐DQ, and HLA‐DR). The DC suspensions (Purity ∼80‐85%) showed very low percentages of cells staining for various other cell membrane markers, including B cell, T cell, natural killer (NK) cell, and various monocyte/macrophage markers as well as markers specific for dendritic reticulum cells and Reed Sternberg cells. Moreover, neither rheumatoid nor normal DC reacted with the RFD1 monoclonal antibody, which is specific for interdigitating cells of human thymus. In contrast to Langerhans' cells, the DC lacked the thymocyte (T6) marker. The various DC expressed neither complement receptors (CR1, CR3), transferrin receptors, nor Fc receptors. They also lacked enzyme markers like peroxidase and nonspecific esterase. The DC formed clusters with autologous T cells. Cluster formation was readily inhibited by anti‐HLA‐DR and anti‐CD2 (T11) monoclonal antibodies. After 3 to 5 days in culture the DC still expressed class II MHC antigens and were potent stimulators in allogeneic mixed lymphocyte reactions (MLR). Only a small number of cells in the DC suspensions from synovial tissue expressed fibroblast antigens before and after culture.
Macrophages in T and B Cell Compartments and Other Tissue Macrophages Recognized by Monoclonal Antibody MOMA‐2
Authors: KRAAL G. , REP M. , JANSE M.
Published: June 2006

A new monoclonal antibody, MOMA‐2, is described, which recognizes monocytes and macrophages in the mouse. The antibody reacts with the majority of mononuclear phagocytes in various tissues as determined by immunohistochemistry. It differs from other macrophage markers that have been described by the strong reaction with macrophages in the lymphoid organs such as the tingible body macrophages and macrophages in T cell‐dependent areas. The antibody recognizes predominantly a cytoplasmic component, although a membrane component can also be demonstrated. Isolated Langerhans' cells, interdigitating cells and dendritic cells, members of the mononuclear phagocyte system that are involved in antigen presenting, stain weakly with the antibody. Because of the intense staining the antibody is very useful for defining tissue macrophages by immunohistochemistry.
Characterization of Two Fc Receptors for Mouse Immunoglobulins on Human Monocytes and Cell Lines
Authors: VAN DE WINKEL J. G. J. , TAX W. J. M. , VAN BRUGGEN M. C. J. , VAN ROOZENDAAL C. E. P. , WILLEMS H. W. , VLUG A. , CAPEL P. J. A. , KOENE R. A. P.
Published: June 2006

We have previously reported a polymorphism in the mitogenic effect of murine (m) IgG1 anti‐CD3 monoclonal antibodies. This polymorphism was genetically determined and could be attributed to polymorphism of the Fc receptor (FcR) for mIgG1 present on human monocytes. We have now extended these studies by quantitating FcR expression on monocytes and cell lines by a recently developed EA rosette assay, using the erythrocyte‐associated pseudoperoxidase activity. The data show that the polymorphism of the monocyte FcR for mIgG1 is based on a quantitative rather than an absolute difference. Furthermore, this FcR is specific for mIgG1 and does not bind mIgG2a or mIgG2b nor, surprisingly, human IgG. The expression of this FcR on cell lines correlates with their accessory function in IgG1 anti‐CD3‐induced T cell proliferation. mIgG2a can inhibit the rosetting of monocytes with erythrocytes sensitized with human IgG. The FcR detected by this rosette technique can interact with all four human IgG subclasses but not with mIgG1 or mIgG2b. The expression of this type of FcR on human cell lines correlates well with their ability to support mIgG2a anti‐CD3‐induced mitogenesis. These direct measurements of FcR expression support the concept that human monocytes have two independent FcR with affinity for mouse IgG: one receptor specigic for mIgG2a (which also binds human IgG), and a second specific for mIgG1.
In Vivo Activated Lymphoid Cells (IVALC) Affect the Cloning Efficiency of Human T Lymphocytes Reactive to a Soluble Antigen, Purified Protein Derivative
Authors: SIA D. Y. , CHOU J. L.
Published: June 2006

Peripheral blood mononuclear cells (PBMC) of normal individuals were found to contain a proportion (4–9%) of in vivo activated lymphoid cells (IVALC), These IVALC were characterized by their expression of interleukin 2 (IL‐2) receptors, and by the abilily to proliferate in the presence of exogenous IL‐2. There was a good correlation between the proportion of IVALC in different cell populations and the level of cell proliferation to IL‐2. It was found that IVALC isolated from autologous PBMC of Bacillus Calmette‐Guerin (BCG)‐immunized individuals contained no significant proportion of purified protein derivative (PPD)‐reactive lymphocytes. The addition of IVALC markedly enhanced proliferative responses of the autologous T4+T8−IL‐2 receptor‐negative cell cultures to antigen stimulation. An increased proportion of activated (IL‐2 receptor‐positive) lymphocytes was generated in PBMC as compared to autologous T4+T8−IL‐2 receptor negative cell cultures after stimulation with PPD. Limiting dilution analysis showed that IL‐2 responsive IVALC through expansion markedly affected the cloning efficiency of antigen‐proliferating T cells of autologous PPD‐stimulated PBMC cultures. Only 1 out of every 11–25 blast cells generated in the PBMC cultures could establish itself as a growing colony based on determinations in six BCG‐positive individuals. By using a T4+T8− population depleted of IVALC to generate PPD‐reactive lymphocytes, a three to four‐fold increase in the cloning efficiency of antigen‐specific cells was obtained.
An in Vivo Functional Immune System Lacking Polyclonal T‐Cell Surface Expression of the CD3/Ti(WT31) Complex
Authors: REGUEIRO J. R. , LOPEZ‐BOTET M. , DE LANDAZURI M. O. , ALCAMI J. , CORELL A. , MARTIN‐VILLA J. M. , VICARIO J. L. , ARNAIZ‐VILLENA A.
Published: June 2006

A polyclonal T‐cell receptor complex (TCR) expression defect (as detected with monoclonal antibody WT31) has been found in two children belonging to an otherwise healthy Spanish family. One of the sibs (V, who had been vaccinated with attenuated poliomyelitis virus) showed clinical signs of immunodeficiency with an autoimmune syndrome, but the other (older) sib (D, vaccinated with attenuated rubella, measles, mumps, and poliomyelitis viruses) has been symptomless throughout life. In contrast to both sibs' normal expression of other peripheral leucocyte markers, as measured by flow cytometry (including CDl, CD2, CD4, CD8, and CD16), only about 6% of CD2+ polyclonal T cells expressed surface antigen‐specific T‐cell receptor (Ti/WT31), and only about 23% weakly expressed surface CD3 determinants. On the remaining CD2+ T cells in each sib the expression of Ti and CD3 was undetectable; the defect in CD3 expression is very likely secondary to the defect in Ti expression. Natural killer (NK) activity was not increased in any of the sibs, ruling out a high content of NK cells among their CD2+ lymphocytes. Functional data indicate that CD3‐mediated T‐cell activation with anti‐CD3 monoclonals and Ti‐mediated responses to allogeneic and tetanus toxoid antigens were severely depressed, whereas activation via CD2 was normal in the T lymphocytes of both sibs. Genes encoding for Ti alpha, beta, and gamma chains did not show major alterations by southern blot analysis, and polyclonal beta chain genes rearrangements were detected in both children's T‐cell blasts. Family clustering suggests a genetic pathogenesis, but linkage to HLA or other blood group markers has not been found. Sib V had a concomitant autoimmune disease and died after a severe autoimmune haemolytic anaemia, indicating a relationship between the TCR and generation of autoimmune clones. However, the resistance of both individuals to infection and to vaccination with attenuated viruses, and the fact that sib D has been symptomless to date questions the relative importance of the TCR in the immune response against infection, and suggests that alternative T‐cell activation pathways and non‐specific defence mechanisms (external surfaces–bound and/or cellular) may suffice under certain circumstances.
Persistence and Selectivity of the Immune Phagocytosis Inhibition by Major Histocompatibility Complex Antibodies
Authors: NEPPERT J.
Published: June 2006

Major histocompatibility complex (MHC) antibodies induce immune phagocytosis inhibition (IPI) which lasts for at least 7 days. IPI‐inducing antibodies do not inhibit the phagocytosis medialed by ihe beta‐glucan receptor. This corresponds well to recent findings (hat these antibodies do not interfere with the phagocytosis of deactivated saccharomyces. mediated by the mannose‐fueose receptor, or polyaerylic aeid particles, also mediated by non‐Fc receptors. Substances that interact with certain MHC antigens or with Fc receptors, certain toxins that inhibit surface molecule mobility, and ciclosporin do noi cause IPI and do nol suppress the induction of IPI by MHC antibodies. These substances are: opioid peptides, insulin, penicillin G, immune complexes, aggregated IgG, Fc fragments, ciclosporin. botulinum C2 toxin, sodium azide. Some lectins and EDTA are inhibitory in a non‐selective fashion, since the Fc receptor independent phagocytosis is also abrogated.
Semi‐Purification of an Immunosuppressor Substance Secreted by Streptococcus mutans that Plays a Role in the Protection of the Bacteria in the Host
Authors: SANTARÉM M. M. G. , PORTO M. T. , FHRREIRA P. , SOARHS R. , ARALA‐CHAVES M. P.
Published: June 2006

Crude extracellular products of Streptococcus mutans (CEP‐Sm) suppress the proliferative response to phytohaemagglutinin of human peripheral blood mononuclear cells and the primary immune response of C57BL/6 mice to sheep erythrocytes. This immunosuppressive effect favours the survival of the microorganism, and the bacteria lose the ability to secrete immunosuppressor substance if previously subcultured several times. Cells incubated with CEP‐Sm and subsequently washed recover the ability to proliferate. Traces of CEP‐Sm or too short a time of contact between CEP‐Sm and the target immune system induced higher proliferative ratios or higher in vivo immune responses than controls, respectively. The proliferative values of cultures supplemented with CEP‐Sm were parallel to the control values up to a certain time, after which they dropped abruptly. This drop is followed by a prolileration, and the higher the amount of CEP‐Sm added to the cultures, the shorter the time until the proliferation. CEP‐Sm was fractionated by means of ion exchange chromatography followed by double preparative isoelectrofocusing, ending in a subfraction of isoelectric point between 3.9 and 4.2, containing a heat‐unstable material stainable by Coomassie blue bui unstainable by periodic acid Schiff or methylene blue, and having a maximum optical density of 280 nm.
Identification of a Human C5 β‐Chain Epitope Exposed in the Native Complement Component but Concealed in the SC5b‐9 Complex
Authors: MOLLNES T. E. , KLOS A. , TSCHOPP J.
Published: June 2006

Monoclonal antibodies obtained after immunization of mice with human C5 were screened for activity against native C5 and SC5b‐9. Clone 568 reacted with the C5 β‐chain in western blotting and with purified native C5 in double antibody enzyme immunoassays. The reactivity of done 568 against serum decreased markedly when serum was activated with zymosan. The residual activity was found to be against free C5, whereas the antibody did not read at all wish the SC5b‐9 complex. Thus, the antibody 568 reacts with an activation‐dependent C5 epitope, which is concealed when C5 is incorporated into the terminal complement complex
Changes in Idiotypic Predominance in the Anti‐Arsonate Response by Priming with Anti‐Idiotypic Antibodies
Authors: GAYA A. , ALSINET E. , FREIXAS M. , VIVES J.
Published: June 2006

The predominant selection of CRI‐A‐bearing antibodies during the anti‐arsonate (ARS) response of A/J mice has been used as a model to analyse the mechanism involved in the process of clonal selection and establishment of predominance. In order to assess the importance of the affinity and adaptability of CRI‐A clones in this process, we tested the capability of a minor recurrent idiotype (id‐1A3), present in a CRI‐Aanti‐ARS monoclonal antibody (65–1 A3), to develop a normal anti‐ARS response. Our results show that the id‐1 A3 predominance, established by anti‐id‐1A3 administration was stable during the primary and secondary anti‐ARS response and that this predominance occurred concomitantly with tow levels of CRI‐A. Thus, a change in the idiotype predominance was achieved. In spite of the high levels of id‐1A3, the anti‐ARS antibody concentration, the affinity values, and the kinetics of the Immune response were similar to those of the control group. All these results show that CRI‐A clones arc not essential in the normal development of the anti‐ARS antibody response of A/J mice, and suggest that factors other than affinity could be involved in the stablishment of the CRI‐A predominance.
Primary Biliary Cirrhosis: Indication for a Single Mitochondrial Antigenic Epitope Detected by Patient Autoantibodies and a Novel Monoclonal Antibody
Authors: MENDEL‐HARTVIG I. , BJORKLAND A. , NELSON B. D. , NORBERG R. , YTTERSTROM U. , TÖTTERMAN T. H.
Published: June 2006

A monoclonal antibody specific for the major primary biliary cirrhosis (PBC)‐associated mitochondrial antigen (subunit I of NADH‐ubiquinone reductase) was produced and used to study the binding sites recognized by anti‐mitochondrial autoantibodies (AMA) in PBC sera. Immunization of mice with purified beef heart mitochondrial inner membranes resulted in one monoclonal antibody which reacted with mitochondrial proteins. This antibody (PBC‐MoAb), which was of the IgG2b subclass with kappa light chains, exhibited a pattern of immunofluorescence reactivity with rat kidney, human thyroid, and cultured human epithelial cells (Hep‐2) similar to that obtained with sera from PBC patients. Similar binding patterns between PBC‐MoAb and AMA were also found in western blot analysis using mitochondria as antigen. Both types of antibodies revealed a major antigen of 75 kDa, a minor antigen of 60 kDa, and a third antigen (70 kDa), which was detected only in samples that had not been boiled prior to electrophoresis. Furthermore, optimal binding of the PBC‐MoAb and AMA to the 75 and 70 kDa antigens required reduction of the antigen with mercaptoethanol prior to electrophoresis. Competition ELISA experiments were conducted to compare the epitopes recognized by PBC‐MoAb and AMA. Of 28 PBC sera tested, 27 inhibited the binding of PBC‐MoAb to mitochondrial inner membranes by almost 100% and one serum inhibited binding by 50%, indicating that most PBC sera contain autoantibodies reactive with the same or a closely related antibody binding site as the PBC‐MoAb. PBC‐MoAb inhibited AMA binding to the inner membrane by more than 80% in 10 sera, 60–80% in 11 sera, and 40–59% in seven sera, with an average inhibition of 71%. Our observations strongly indicate that anti‐mitochondrial autoantibody binding sites are restricted to a highly immunogenic epitope on the major PBC‐specific antigen (NADH‐ubiquinone reductase subunit I), and that the anti‐mitochondrial monoclonal antibody obtained has a specificity identical with the human PBC‐specific M2 type anti‐mitochondrial autoantibody.
Induction of Interleukin‐2 Production in CD4+ and CD8+ T‐Cell Subsets after Activation via CD3 and CD2
Authors: HALVORSEN R. , LEIVESTAD T. , GAUDERNACK G. , THORSBY E.
Published: June 2006

The activation signals necessary for interleukin‐2 (IL‐2) receptor induction, IL‐2 production, and DNA synthesis in resting T cells were investigated. IL‐2 receptors were induced after activation via CD2 or CD3 alone, while IL‐2 production in both CD4+ and CD8+ T cells required activation via both CD3 and CD2. The sequence of activation signals via CD3 and CD2 was shown to be important since DNA synthesis was induced when the primary activation signal was delivered via CD3, and the CD2 signal within 8h. In contrast, no DNA synthesis was demonstrated when the primary activation signal was delivered via CD2 and the CD3 signal later. Ciclosporin A (CyA) inhibited T‐cell DNA synthesis after activation via CD2 and CD3. The inhibition seemed to be due to the prevention of IL‐2 synthesis.
Characterization of Human CD4+ T‐Cell Clones that Secrete Helper Factor(s) for B‐Cell Proliferation and Maturation
Authors: BERZINS T. , VARGAS‐CORTES M. , AXELSSON B. , HAMMARSTRÖM M.‐L. , HAMMARSTRÖM S. , PERLMANN P.
Published: June 2006

Human peripheral blood lymphocytes (PBL) were activated with K46M, a mitogenic monoclonal antibody against La‐reactive T lymphocyte surface structures. The cultures were expanded in the presence of interleukin 2 (IL‐2). After 1 month of culture, the activated T cells were cloned by limiting dilution at 0.5 cells/well. Five clones with the CD3+CD4+ phenotype and one clone with the CD3+CD8+ phenotype wore obtained The CD3+CD8+ clone (K99) displayed a strong major histocompatibility complexe (MHC)‐unrestricted cytolytic activity against MOLT‐4 and a weaker reactivity against the bladder tumour cell lines T24 and RT4. The natural killer (NK)‐susceptible K562 cells were not lysed. Two of the CD3+CD4+ clones (K91 and K914) showed a helper activity in pokeweed mitogen (PWM)‐induced IgG production by B cells. These cells differed in the expression of CD45R and CDw29 antigens, as defined by the monoclonal antibodies 2H4 or D10D11 and 4B4. When stimulated with PWM for 48 or 72 h, clone K91 and an additional CD4‐positive clone (K913) secreted a factor into the supernatants which helped B ceils to produce IgG. The K913 supernatant also induced some IgM production. The supernatant obtained after similar simulation of K914 cells was inactive. None of these supernatants induced B cells to proliferate when tested together with phorbol myristate acetate (PMA). However, when K91 and K914 cells were activated with phytohaemagglutinin (PHA) for 48 or 72 h, the supernatant from K91 was strongly helpful in B‐cell proliferation, whereas the supernatant from K914 cultures was only moderately active In conclusion, we have established human T helper clones that release different factors supporting either B‐cell proliferation or maturation when stimulated with PWM or PHA.
Immunological Mapping of the Human Leucocyte Adhesion Glycoprotein gp90 (CD 18) by Monoclonal Antibodies
Authors: NORTAMO P. , PATARROYO M. , KANTOR C. , SUOPANKI J. , GAHMBERG C. G.
Published: June 2006

The leucocyte surface glycoproteins CD11a (gp160, LFA‐1 antigen, TA‐1 antigen), CD11b (gp155, Mac‐1 antigen, Mo‐1 antigen), CD11c (gp 130, Leu‐M5 antigen), and CD18 (gp90) constitute three heterodimers with different α chain and a common β chain Monoclonal antibodies to CD11a, b, or c block adhesion of certain types of leucocytes only, while several antibodies to CD 18 inhibit adhesion in all of them. The functionally important site or sites on CD 18 are not known. We have now isolated the CD11a,b,c‐CD18 leucocyte antigen complex in large amounts from human leucocytes, and produced several new monoclonal antibodies reacting with CD18. One of these antibodies, like those described earlier, inhibits leucocyte adhesion, whereas the others do not. By means of competition experiments, at least four epitope regions were found. These antibodies should be valuable in elucidating the regions essential in CD18‐mediated leucocyte functions.
Most B Cells in Acute Trypanosoma cruzi Infection Lack Parasite Specificity
Authors: MINOPRIO P. , BURLEN O. , PEREIRA P. , GUILBERT B. , ANDRADE L. , HONTEBEYRIE‐JOSKOWICZ M. , COUTINHO A.
Published: June 2006

The specificity of B lymphocytes activated in the acute phase of murine Trypanosoma cruzi infection was analysed in a panel of immunoglobulin‐secreting hybridomas derived by fusion of lymph node cells 7 days after intraperitoneal parasite inoculation. The immunoglobulin isotype distribution of the hybrids reflected the total plaque‐forming cell (PFC) response in the animal at this point, with a predominance of IgG2a, IgM, and IgG2b. Screening of the hybridoma antibodies on parasite antigens by three independent methods (western blot, ELISA, and immunofluorescence) revealed only one (out of a total of 51) that bound a parasite molecule with an apparent molecular mass of 180 kDa. In contrast, antibodies of both IgM and IgG classes were found to react with a panel of autologous antigens. These results establish that most B cells activated by T. cruzi infection are not specific for parasite antigens and therefore indicate the relevance of analysing the totality of host responses to infection.
Suppression of in Vitro Production of Anti‐U1‐Ribonucleoprotein Antibody by Monoclonal Anti‐Idiotypic Antibody to Anti‐U1‐Ribonucleoprotein Antibody
Authors: KOIDE J. , TAKEUCHI T. , HOSONO O. , TAKANO M. , ABE T.
Published: June 2006

We produced monoclonal anti‐idiotypic antibody against immunoaffinity purified anti‐U1‐ribonucleoprotein (RNP) antibody from a patient (K.T.), by the cell fusion procedure. The specificity of monoclonal anti‐idiotypic antibody (IgG1, x) was determined by inhibition studies. With the monoclonal anti‐idiotypic antibody, cross‐reactive idiotypes on anti‐U1‐RNP antibodies from unrelated patients with anti‐U1‐RNP antibody was detected in 57% of the samples. The anti‐idiotypic antibody specifically suppressed the in vitro production of anti‐U1‐RNP antibody by lymphocytes from the patient K T., and unrelated patients with a cross‐reactive idiotype, in whom idiotype‐reactive T cells were demonstrated. The results indicate that anti‐idiotypic antibody may modulate the regulation of in vitro anti‐U1‐RNP antibody production.
Antigen‐Specific Modulation of Graft‐versus‐Host Reactions by Two Distinct Placental Factors
Authors: BOBÉ P. , KANELLOPOULOS‐LANGEVIN C. , BLEUX C. , KINSKY R.
Published: June 2006

We have previously shown that two distinct mouse placental fractions (PF) are potent immunomodulators in vivo. A 40 kDa PF induces a marked decrease of plaque forming cell (PFC) responses, while a 60 kDa PF increase them. Both effects are specific for the priming antigen. In the present study, these two PF are assayed on a cell‐mediated response to allogeneic cells, i.e. in a local graft‐versus‐host reaction (LGVHR). Mice were primed with allogeneic cells in the presence of various amounts of the 40 kDa or 60 kDa PF, or liver extract (LE) as control. Six days later, their spleen cells were injected into the footpads of F1 recipients Precise dose‐response curves were established and the kinetics of the GVH response were carefully followed. Parallel with the modulation of PFC responses, the 40 kDa PF caused a potent inhibition of the LGVHR, while the 60 kDa PF greatly enhanced it. Both effect were specific for the alloantigens injected with the PF. Furthermore, we showed that these modulations were observed whatever the intensity of the GVH reaction, which varied according to the number of primed spleen cells transferred. This report also demonstrates that these PF Can be greatly enriched by passage over affinity columns made of insolubilized lectins. The 40 kDa PF is retained on and can be eluted from columns of insolubilized concanavalin A (Con A) or wheat germ agglutinin (WGA), which indicates that it is a glycoprotein. Conversely the 60 kDa PF does not bind to any of the above lectins and is probably not a glycoprotein. This biochemical purification step is also a good procedure for obtaining an even cleaner separation of the two fractions from each other. Thus, this paper demonstrates that both PF have important regulatory properties on specific cellular immune responses.
Kupffer Cells May Autoregulate Interleukin 1 Production by Producing Interleukin 1 Inhibitor and Prostaglandin E2
Authors: SHIRAHAMA M. , ISHIBASHI H. , TSUCHIYA Y. , KUROKAWA S. , HAYASHIDA K. , OKUMURA Y. , NIHO Y.
Published: June 2006

Rat Kupffer cells stimulated with bacterial lipopolysaccharide (LPS) produced high levels of interleukin 1 (IL‐1), as determined by thymocyte proliferation assay. Indomethacin revealed a dose‐dependent augmentation in IL‐l production, in parallel with a dose‐dependent reduction in prostaglandin E2 production by Kupffer cells. The addition of exogenous prostaglandin E2, dibutyryl cAMP, or isoproterenol led to a dose‐dependent suppression of IL‐I production. The supernatant from UPS‐stimulated Kupffer cells also contained factors that Inhibited IL‐1‐induced thymocyte proliferation. Upon gel filtration, two inhibitory peaks, at apparent MW of 27,000 and 6000, were obtained. The latter but not the former fraction also affected Interleukin 2 (IL‐2)‐induced thymocyte proliferation. Increasing amounts of IL‐1 overcame the inhibitory activity derived from the 27,000 MW fraction. These results suggest to us that prostaglandin E2 and IL‐1 inhibitor released by Kupffer cells may be involved in negative self‐control in regulating IL‐1 production and its action.