bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiparametric Flow Cytometric Analysis of the Kinetics of Surface Molecule Expression after Polyclonal Activation of Human Peripheral Blood T Lymphocytes
Authors: BISELLI R. , MATRICARDI P. M. , AMELIO R. D. , FATTOROSSI A.
Published: June 2006

In this report we have analysed the kinetics of modulation of human peripheral blood T lymphocyte membrane molecules upon activation with optimal amounts of phytohaemagglutinin (PHA) and concanavalin A (ConA). The following activation‐related and differentiation/adhesion molecules were selectively and concomitantly investigated on CD4+ and CD8+ subsets by dual colour flow cytometry: CD69, CD25 and CD71; CD2, CD45RA and L‐selectin. Cultures were assayed after 24, 48. 72. 120 and 168 h of incubation with PHA and ConA. This approach allowed a comprehensive evaluation of membrane phenomena occurring during activation of normal resting human T lymphocytes. Data show that the kinetics of expression of these molecules follows a precise and consistent time‐course with no major differences between CD4 and CD8 subsets. CD69 expression peaked at 24 h. whereas CD25 and CD71 expression peaked al 48/72 h with some differences between PHA and ConA activation. L‐selectin expression started an evident decrease in step with culture time whose magnitude was dependent on the lectin used, being higher with PHA than with ConA. Conversely, the expression of CD45RA remained stable for 72 h and then briskly decreased with no major differences between PHA and ConA activation. CD2 molecules increased with time in number and density, although the percentage of positive cells remained essentially constant (>85%). After 48/72 h of stimulation about 10% of cells co‐expressed CD4 and CD8 molecules. To ascertain whether the phenomenon was restricted to cells in a particular activation state, the phenotype of cells in the diverse phases of the cell cycle was established. Results obtained show that only actively proliferating cells, that is cells in S and G2‐M phases, co‐expressed the two molecules, suggesting that such a phenomenon reflects a momentary dysregulation of the normal sequence of gene expression.

The present data are also discussed in the light of the dynamic role of T lymphocyte activation and adhesion molecules in regulating cell‐cell interactions, tissue localization and eventual immunological function.
Properties of IgA‐Binding Receptors on Murine T Cells: Relative Importance of FcαR, β‐Galactosyltransferase and Anti‐Secretory Component Reactive Proteins (ASCP)
Authors: AICHER W. K. , McGHEE M. L. , McGHEE J. R. , MOLDOVEANU Z. , KIDD V. J. , TOMANA M. , MESTECKY J. , ELDRIDGE J. H. , MEYER T. F. , KIYONO H.
Published: June 2006

Murine T cells and T‐cell lines express receptors for the Fc of IgA (FcαR); however, their molecular properties remain to be elucidated. In the present study, we examined three candidate molecules for IgA‐binding receptors including FcαR, β‐galactosyltransferase (β‐GT) and anti‐secretory component (SC) reactive proteins (ASCP) expressed on T cells which might participate in the binding of different molecular forms of IgA. T‐cell lines derived from CD4+ T cells of mouse Peyer's patches (PP) (designated PPT 4–6and PPT 4–16) and from cloned PP T helper (Th) cell lines (ThHA1#9and #10) bound both monomeric and dimeric IgA (mIgA and dIgA), while the fusion partners (BW 5147 and R 1.1) did not. In contrast, both FcαR+ and FcαR‐ cell lines bound to high molecular weight polymeric or aggregated IgA (pIgA). All cell lines reacted with a monoclonal anti‐β‐GT(MoAb) and β‐GT enzyme activity was associated with the cell lysates and membrane fractions of all cells tested. The anti‐β‐GT MoAb stained a 47‐kDa band on immunoblots which was identical to that seen with native enzyme. mRNA analysis with β‐GT cDNA showed that all cell lines constitutively produced enzyme‐specific mRNA. Both FcαR+ T cells and FcαR‐ control cell lines showed cell surface specific β‐GT activity. This is the first study which shows that mouse T cells produce β‐GT. However, FcαR and β‐GT appear to be separate receptors, because FcαR+ T cells bound mIgA and dIgA, and this treatment did not affect staining with biotinylated anti‐β‐GT MoAb. Further, preincubation of the FcαR+ cells with anti‐β‐GT MoAb did not block mIgA binding. However, the anti‐β‐GT MoAb partially blocked binding of pIgA to both FcαR+ and FcαR‐ T cells, suggesting that β‐GT may be a receptor for pIgA. Others have shown that T cells may bind IgA through a receptor serologically related to SC. We found that antibodies both to human SC and to rat SC specifically bound to both FcαR+ and FcαR‐ T cells. Further, a 72‐kDa band was detected when cell membrane fractions were analysed with these antisera (ASCP) by solid phase immunoisolation technique and immunoblot analysis. The ASCP is not an IgA‐binding receptor, since anti‐SC did not block either mIgA or pIgA binding. Further, the effects of proteolytic enzymes were different on these three IgA‐binding molecule candidates. FcαR and ASCP were shown to be sensitive to pronase proteolytic degradation, but were resistant to trypsin and trypsin/EDTA treatments. In contrast, β‐GT was sensitive to both pronase and trypsin treatments. We conclude that multiple IgA receptors are present on mouse T cells, and include those which bind to mIgA or dIgA (FcαR) as well as those which bind to pIgA (β‐GT). Further, ASCP is also present on mouse T‐cell lines, but its role in IgA binding to T cells remains to be further determined.
Use of the Vδ1 Variable Region in the Functional T‐Cell Receptor α Chain of a WT31+ Cytotoxic T Lymphocyte Clone which Specifically Recognizes HLA‐A2 Molecule
Authors: CASTELLI C. , MAZZOCCHI A. , SALVI S. , ANICHINI A. , SENSI M.
Published: June 2006

We report here the molecular characterization of the T‐cell receptor (TCR) expressed by a human HLA‐A2 specific cytotoxic T‐cell clone named CTL 49. Flow cytometry analysis with a panel of and‐TCR antibodies revealed an OKT3+, WT31+, A13+, BB3‐, TCRδri‐, δTCS1‐, TCRγ/δ1‐, OKT4‐, and OKT8+ phenotype, suggesting that, in CTL 49, the Vδ1 ‐encoded A13 epitope could be included in its α/β TCR. Northern blot analysis confirmed the presence of Cα, Cβ and Vδ1 specific transcripts while no hybridization signal was detected by a Cδ specific probe. Polymerase chain reaction (PCR) amplification of the first strand cDNA from CTL 49 with TCR‐specfic primers and sequence analysis revealed that Vδ1 region is productively rearranged Jα and to Cα regions. This α chain pairs with a β chain composed of Vβ13.2/Dβ/Jβ2.3/Cβ2 leading to the expression of a functional TCR complex. These results, in addition to providing further evidence for the sharing of Vδ1 by α/β and γ/δ TCR, indicate that an α/β T‐cell receptor which includes the Vδ variable region can be involved in alloreactive recognition.
Binding of a Bacterial Acylpoly(1,3)Galactoside to Human Blood Leucocytes
Authors: HMAMA Z. , KOUASSI E. , PANAYE G. , DELASSAN S. , NORMlER G. , BlNZ H. , REVILLARD J.‐P.
Published: June 2006

The binding of a 34‐kDa (mol. wt.) acylpoly(1,3)galactoside (APG) extracted from a membrane proteoglycan of Klebsiella pneumoinae to human blood leucocytes was investigated. APG is made of a long polyl (1,3)galactose chain, a core‐like region and a lipid moiety which comprises two glucosamine residues bound to a phosphate group and two βOH myristic acids, Fluoresceinated APG was shown to bind preferentially to monocytes and to a lesser extent to polymorphonuclear neutrophils, as determined by flow cytometry. Binding of fluoresceinated APG was inhibited by unlabelled APG; it was concentration dependent, but not saturable, with rapid kinetics. It occurred at +4°C but was markedly increased at 37°C. It involved trypsin‐sensitive molecules on the membrane of monocytes. Neither the parent proteoglycan nor lipopolysaccharide from K. pneumoniae or Salmonella minnesota competed for APG binding. A minor non‐specific binding to lymphocytes, occurring predominantly on B cells, was observed. Unlike that of lipopolysaccharide, the APG binding was not blocked by polymyxin B sulphate. Interaction between the galactose chain of APG and the galactose receptor does not account for the binding of APG to monocytes because the galactose receptor (Mac‐2) is expressed at high density on activated macrophages but not on monocytes. Despite its strong binding to human blood monocytes, APG displayed a much weaker activity than K. pneumoniae membrane proteoglycan with respect to induction of monocyte cytokine synthesis. When administered as a Technetium 99 conjugate, APG was shown to label inflammatory foci in experimental animals, and its property as a marker of macrophages is currently being evaluated in clinical trials.
Common Variable Immunodeficiency with Increased Surface igM‐Positive Double‐Bearing B Cells
Authors: MOTOYOSHI F. , MORI S. , KONDO N. , KANRKO H. , OZAWA T. , KUWABARA N. , KATO Y. , TAKEMURA M. , NOMA A. , ORII T.
Published: June 2006

We report a case of common variable immunodeficiency (CVI) that shows low levels of IgG and IgA, but a normal quantitative or qualitalive level of IgM. T‐cell functions were not disturbed. Increased numbers of surface IgM (sIgM) and sIgD, sIgM and sIgA, sIgM and sIgA double bearing B cells were observed as compared with a control. No IgG and IgA induction upon stimulation with Staphylococcus aureus Cowan I (SAC)and recombinant interleukin‐2(rIL‐2), or pokeweed mitogen (PWM) and rIL‐4 or rIL‐6 was observed, although there was proliferation. Although; μ mRNA was expressed as much as in a healthy control, transcription of γ mRNA and α mRNA was very low. Furthermore, no enhanced effects of γ mRNA and α mRNA were recognized upon stimulation with rIL‐4 and rIL‐6. These results suggest that the patient's B cells might be detective at the switching process from μ, μ and δ, μ and γ to γ or μ and α to α.
Inhibition of Interleukin‐1 (Alpha and Beta), Interleukin‐2 Secretion and Surface Expression of Interleukin‐2 Receptor (IL‐2R) by a Novel Cytokine Interleukin‐1 Receptor Antagonist (IL‐lra)
Authors: CONTI P. , PANARA M. R. , PORRINI A. M. , GAMBI D. , BARBACANE R. C. , REALE M. , BONGRAZIO M. , DEMPSEY R. A.
Published: June 2006

IL‐1 is a mediator of the acute inflammatory response and plays a key role in influencing growth and differentiation of immunocompetent lymphocytes. It can enhance transcription and secretion of the T‐cell growth factor interleukin‐2 (IL‐2) and can stimulate the expression of membrane receptors for IL‐2. However, the regulation and control of IL‐1 activities are poorly understood. Recently an IL‐1 inhibitor, interleukin‐1 receptor antagonist (IL‐1ra), has been described and cloned. This protein is a monokine originally found in the urine of febrile patients and in supernatants of human monocytes adhering to an IgG‐coated surface, with an approximate molecular weight of 17 kDa, which is similar to IL‐1β but having no IL‐1‐like activity and antagonizing IL‐1 by binding to its cell surface receptor.

These studies have examined some biological properties of hrIL‐1ra, such as its effects on the secretion of IL‐1α or IL‐1β and IL‐2, the surface expression of 1L‐2R and DNA synthesis by peripheral blood mononuclear cells (PBMC). PBMC from normal volunteers were separated and used at a concentration of 2.5 x 106 cells/ml. The cells were pretreated for 2h with hrIL‐1ra (0.025‐250 ng/ml), treated with LPS (10 ng/ml), and IL‐1α and IL‐1β secretion were determined by an ELISA method. In addition the influence of hrIL‐1ra (25 ng/ml) on IL‐2 generation was determined. In another set of experiments, flow cytometric analysis with an anti‐CD25 monoclonal antibody was determined on PHA‐stimulaled PBMC pretreated wilh hrIL‐1ra (2 h) and cultured for 48 h. The inhibition by hrIL‐1ra of IL‐2R expression was dose‐dependent and when hrIL‐1ra was used at 250 ng/ml the IL‐2R was completely abolished. Lymphocyte DNA synthesis calculated from the net uptake of [3H]‐thymidine (3H‐TdR) was also inhibited by hrIL‐1ra (0.025‐25 ng/ml). In this report we found that hrIL‐1ra inhibits, in a dose‐dependent manner, the secretion of IL‐1α, IL‐1β, IL‐2, the surface expression of IL‐2R and 3H‐TdR incorporation in PBMC in vitro. These data suggest a new biological activity of hrIL‐1ra and further extend the immunomodulatory potential and significance of this new cytokine. The action of IL‐1ra on modulating the synthesis of IL‐1 may be of paramount importance in the regulation of these effects.
Association of the Mycobacterial 30‐kDa Region Proteins with the Cutaneous Infiltrates of Leprosy Lesions
Authors: RAMBUKKANA A. , DAS P. K. , KRIEG S , FABER W. R.
Published: June 2006

The granulomatous skin lesions ol human leprosy are known to be due to the cutaneous immune reaction to various mycobacterial antigens. In the present study, by immunohistochemical analysis using a previously characterized monoclonal antibody (MoAb) 3A8 we have demonstrated a selective expression of the 3A8 epitope of mycobacterial 30‐kDa proteins, the major secreted proteins of mycobacteria, in various forms of leprosy lesions across the clinical spectrum. The localization of MoAb 3A8 staining is confined to the areas of cellular infiltrates of the lesions. In tuberculoid lesions the intense 3A8 staining was seen mostly in association with the membrane of the dermal cellular infiltrates whereas in highly bacilliferous lepromatous lesions the staining seems to be diffused with granular appearance but not in the form of bacteria. In patients with reversal reaction the staining was specifically extended to cells infiltrating the epidermis. MoAb 3A8 did not show any reactivity with inflammalory skin lesions of patients other than those with leprosy. Since the 3A8 epitope of 30‐kDa proteins has been shown to be present in all cellular compartments of the mycobacteria and in the actively secreted BCG 85 antigen complex. MoAb 3A8 reactive protein(s) in leprosy lesions may be derived either from degraded somatic mycobacterial products or from antigens actively secreted by live bacilli. The latter could be true in the cases of untreated lepromatous lesions with high bacterial load since live M. leprae has also been considered to secrete corresponding 30‐kDa proteins similar to other closely related mycobacteria. By double immunoenzyme staining we clearly demonstrate the expression of 3A8 epitope on CD68+ macrophagos in the granulomas of tuberculoid leprosy, whereas in highly bacilliferous lepromatous lesions most of the double staining was seen in a diffuse pattern within the interstitial space of the cellular infiltrate as well as in the cytoplasm of CD68+ macrophages. In lesions from reversal reaction the 3A8 epitope is more strongly expressed on CD1a+ dendritic Langerhans cells <LC) both in the epidermis and in the dermis as compared with other types of leprosy. This provides evidence for the involvement of LC in handling of mycobacterial antigenic epitopesin leprosy lesions. Further, immunoenzyme double staining revealed that the expression of this mycobacterial 3A8 epitope on antigen presenting cells such as CD68+ macrophages and CD1a+ LC is present in juxtaposition with CD3+ T cells including the αβ and γδ receptor‐bearing T cells in the granuloma. Our results suggest that 3A8 may be a potential T‐cell epitope that could be involved in the local tissue immune response of leprosy.
Immunoglobulin G, A, and M Light Chain Ratios in some Humoral Immunological Disorders
Authors: HARALDSSON Á. , JAMINON M. , BAKKEREN J.A.J.M. , STOELINGA G. B. A. , WEEMAES C. M. R.
Published: June 2006

The total kappa/lambda immunoglobulin light chain ratio and the kappa/lambda ratios within each of the serum immunoglobulin classes G. A. and M were measured in thirteen patients with humoral immunological disorders. Of those patients, eight had common variable immunodeficiency whereas live patients had other forms of humoral immunological deficiencies. Eleven patients had abnormal antibody response in vivo. All but three of the thirteen patients had clearly abnormal light chain ratios in one or more of the immunoglobulin classes.

We conclude that humoral immunological disorders, usually characterized by abnormal heavy chain production and a disturbed antibody response, may frequently have a concomitant abnormal synthesis of the light chains resulting in an abnormal kappa/lambda light chain ratio.
Reactivity and Self‐Association In Vivo of a Human Monoclonal IgG Rheumatoid Factor
Authors: OTTEN H. G. , DAHA M. R. , DE ROOY H. H. , BREEDVELD F. C.
Published: June 2006

In order to study the pathogenic potential of IgG rheumatoid factor (IgG‐RF) we generated a human monoclonal IgG4‐RF‐producing cell line, OR‐1, by Epstein‐Barr virus transformation of B cells derived from a healthy donor. Characterization of OR‐1 RF specificity demonstrated that this RF binds only to IgG and not to dsDNA or seven different proteins tested. Although both OR‐1 RF and Clq bind to the Fc part of IgG, no influence could be observed of OR‐1 RF on the complement‐fixing potential of heat‐aggregated IgG, suggesting that OR‐1 RF does not interfere with Clq binding to IgG. This was confirmed by blocking studies which showed that binding of OR‐1 RF to IgG could be prevented by Staphylococcal protein A (SpA), but not by Clq. Comparison of OR‐1 RF with SpA regarding their ability to bind to IgG derived from different species and human IgG subclasses demonstrated that OR‐1 RF and SpA have an identical IgG specificity. The possibility that a structural homology exists between SpA and OR‐1 RF was ruled out, however, by using affinity‐purified chicken anti‐SpA antibodies, which were not able to bind to OR‐1 RF. The potential of self‐recognition of OR‐1 RF in vivo was examined by injecting OR1 cells in SCID mice. Two months after injection IgG‐RF was present in the circulation in monomeric, dimeric and polymeric forms whereas circulating IgG without RF activity, derived from an injected control cell line, was present in the monomeric form only. In vitro studies indicated that IgG‐RF is secreted in monomeric form and that polymerization is a concentration dependent phenomenon. The fact that IgG‐RF is able to form immune complexes in vivo indicates that IgG‐RF has a pathogenic potential by itself and therefore IgG‐RF may play a role in the pathogenesis of RA.
Cell‐Surface Regulation of the Human Alternative Pathway of Complement
Authors: EZZELL J. L. , PARKER C. J.
Published: June 2006

When incubated in normal human serum, rabbit erythrocytes are haemolysed as a result of activation of the alternative pathway of complement (APC), but sheep erythrocytes do not spontaneously activate the human APC under physiological conditions. The mechanism for this difference has been attributed to differences in the relative affinity of membrane‐bound C3b for its natural ligands, factor B and factor H, that favour the formation and stability of the APC C3 convertase on rabbit erythrocytes and inhibit convertase activity on sheep erythrocytes. Previous studies have also suggested that factor I inactivated C3b on sheep erythrocytes more effectively than on rabbit erythrocytes. Further, sheep erythrocytes have recently been shown to have a membrane protein that associates non‐covalently with cell‐bound C3b, but rabbit erythrocytes lack a predominant C3b binding protein. Together, these results suggested the possibility that sheep but not rabbit erythrocytes have a membrane constituent with factor I cofactor activity. To investigate this hypothesis, rabbit and sheep erythrocytes bearing radiolabelled C3b were treated either with factor I or with factor I and factor H, and conversion to iC3b was assessed by autoradiography. Factor I caused a concentration‐dependent conversion of C3b to iC3b on sheep erythrocytes; however, only trace amounts of C3b on rabbit erythrocytes were degraded even when high concentrations of factor 1 (83 μg/ml) were used. While C3b on rabbit erythrocytes was converted to iC3b by the combination of factor H and factor I, much less factor H was required for the same degree of conversion of C3b on sheep erythrocytes. Treatment of sheep erythrocytes with neuraminidase had no effect on either factor I‐dependent cofactor activity or the capacity of factor H to serve as a factor I cofactor. Sheep erythrocytes did not manifest decay accelerating activity, however, suggesting that the factor I cofactor constituent is a functional analogue of the human membrane cofactor protein.
Affinity Purification of Antigen‐Specific Serum Immunoglobulin from the European Eel (Anguilla anguilla)
Authors: BUCHMANN K. , ØSTERGAARD L. , GLAMANN J.
Published: June 2006

Immunization of specimens of the European eel with a hapten‐carrier conjugate resulted in a significant rise in anti‐hapten titres. Antigen‐specific immunoglobulin was purified on a matrix onto which the hapten‐carrier conjugate had been immobilized. Rabbit antisera raised against the product of the affinity purification recognized two molecular moieties. The first was eel immunoglobulin as inferred by the polypeptide composition. i.e. disulphide‐linked heavy and light chains of 72 kDa and 25 kDa respectively. The second was a 110‐kDa protein. A 800‐kDa and a 400‐kDa molecular form of eel immunoglobulin were disclosed by a combination of gel filtration and immunoelectrophoretic detection. The latter was the more abundant serum form. The 110‐kDa protein was found non‐covalently associated with the 400‐kDa immunoglobulin. Both molecular forms of immunoglobulin from immune sera exhibited antigenic specificity and reactivity.
Reactivity of γδ T Cells Induced by the Tumour Cell Line RPMI 8226: Functional Heterogeneity of Clonal Populations and Role of GroEL Heat Shock Proteins
Authors: SELIN L. K. , STEWART S. , SHEN C. , MAO H. Q. , WILKINS J. A.
Published: June 2006

The human tumour cell lines RPMI 8226 and Daudi are potent inducers of Vγ9‐expressing T cells. The inducing element of RPMI 8226 has not been defined but evidence suggests that a member of the GroEL heat shock protein (HSP) family (HSP 58) may have a role in the induction by Daudi cells. The present study examined the reactivity patterns of γδ T‐cell clones generated in response to RPMI 8226 and addressed the possible rule of MSP 58 in this process.

RPMI K226 induced a population of Vγ9 TCR+ cells which were heterogeneous in terms of their cell surface markers, patterns of proliferation and cytotoxic responses. All clones expressed CD3, CD2, CD18 and CD29). They demonstrated variability in expression of CD56, CD8 and HLA‐DR. RPMI 8226 stimulated proliferation in purified bulk γδ cultures and clones. Daudi was also capable of inducing these cells to proliferate while mycobacterial products were not effective. The clones demonstrated a limited non‐MHC‐restricted cytotoxicity pattern with some evidence of clonal heterogeneity. Although both Daudi and RPMI 8226 were sensitive to lysis by the clones, cold inhibition experiments indicated differential activity towards these targets.

Anti‐HSP 58 was inhibitory to γδ T‐cell induction by RPMI 8226, Daudi and mycobacterial products. However, the anti‐HSP 58 antibody appears to bind to the surface of at least six different tumour cell lines with no correlation to their ability to induce γδ cells and the anti‐HSP 58 inhibited non‐γδ responses.
Effect of rIFN‐γ on Antibody‐Mediated Cytotoxicity via Human Monocyte IgG Fc Receptor II (CD32)
Authors: VAN SCHIE R. C. A. A. , VERSTRATEN H. G. G. , TAX W. J. M. , VAN DEN BERKMORTEL F. W. P. J. , VAN DE WINKEL J. G. J. , DE MULDER P. H. M.
Published: June 2006

Human monocytes and macrophages express an isoform of IgG Fe receptor II (FcγRII), FcγRII. Two allotypic variants of this receptor could be distinguished with respect to their ability to bind murine (m)IgG1 complexes either strongly or weakly, defined as high‐responder (HR) and low‐responder (LR). respectively. We investigated the effect of recombinant (r)IFN‐γ on the ability of freshly isolated monocytes, and those cultured for 40 h and 9 days, to mediate antibody‐dependent cell‐mediated cytotoxicity (ADCC), Using human erythrocytes (E) sensitized with mlgGl as target cells, FcγRII was studied selectively. Cells which had been cultured for 40 h exhibit a significantly decreased FcγRII expression, and FcγRll‐mediated ADCC activity as compared with freshly isolated monocytes. Co‐culture with rlFN‐γ (40 h) reversed this decrease. Short‐term rlFN‐γ‐cultured cells, and fresh cells express similar numbers of FcγRII, and exhibit comparable FcγRII‐mediated ADCC activity. Phagocytic activity was not affected. Prolonged culture of monocytes for 9 days, co‐cultured with rlFN‐γ either from day 0 or from day 7, did not affect expression or functional activity of FcγRII. Furthermore, the effects were observed in both HR and LR individuals.

Our results show that rlFN‐γ has strong effects on FcγRII‐mediated responses specifically during the early stages of monocyte maturation, most likely by affecting receptor expression levels.
The T‐Cell Repertoire in Myasthenia Gravis Involves Multiple Cholinergic Receptor Epitopes
Authors: LINK H. , XU Z.‐Y. , MELMS A. , KALBACHER H. , SUN J.‐B. , WANG Z.‐Y. , FREDRIKSON S. , OLSSON T.
Published: June 2006

Antibodies against the α‐subunit of the acetylcholine receptor (AChR) are found in most patients with myaslhenia gravis and are considered to contribute to the receptor damage which leads to the characteristic signs and symptoms of the disease. This B‐cell response is T‐cell driven. Elevated T‐cell reactivities to AChR and its α‐subunit have been described in myasthenia gravis, and AChR α‐subunit peptide reactive T‐cell lines and clones preferentially recognizing certain defined sequence segments have been reported, thereby disclosing the possibility of specific immunotherapy. We have defined the T‐cell repertoire to AChR, its α‐subunit and the synthetic peptide sequences 1OO‐117,113‐130,143‐163,161‐179,207‐225,221‐240, and 235‐255 of the α‐subunit in an immunospot assay which is based on secretion of interferon‐gamma (IFN‐γ) by individual memory T cells upon stimulation with specific antigen in short‐term cultures. Most patients with myasthenia gravis displayed T‐cell reactivities to 1 to 6 different peptides. The mean numbers of T cells recognizing individual peptides varied in the myasthenia gravis patients between 1 per 77,000 and 1 per 167,000 peripheral blood mononuclear cells. None of the seven peptides evaluated could be identified as an immunodominant T‐cell epitope, and any of them was found to dominate in individual patients. The numbers of T cells reacting with AChR and recombinant human AChR α‐subunit were slightly higher (mean numbers 1 per 26,000 and 1 per 50,000 mononuclear cells, respectively). Such cells, as well as AChR α‐subunit peptide reactive T cells, were also found in patients with other neurological diseases and in healthy subjects, but at lower frequencies and numbers. In myasthenia gravis, the elevated numbers of memory T cells recognizing multiple AChR α‐subunit peptides may be crucial for the development of the disease, and the IFN‐γ released by such T cells might be important for its perpetuation.
Qualitative Shift of Lymphokine Production in Response to Stimulation, as a Consequence of Preactivation In Vivo or In Vitro
Authors: CARDELL S. , SANDER B. , MÖLLER G.
Published: June 2006

Lymphokine production, analysed at the single cell level, was compared in resting and primed T‐cell populations. Cells were preactivated in vitro by repeated mitogen stimulalions, or isolated as large, low density cells naturally activated in vivo, from normal spleens of unimmunized animals, A similar qualitative shift in the pattern of lymphokines synthesized after restimulation was found as a resull of in vivo and in vitro preactivation of cells. Repeated stimulations in vitro resulted in a qualitative shift in the lymphokines produced in response to activation, from a dominance of IL‐2 during the first and second culture, to a dominance of IL‐4 and IL‐5 in the later slimulations. In vivo activation lead to a similar separation of lymphokine production as primarily IL‐2 was made by small resting cells, while large cells preferentially produced IL‐4 and IL‐5. IFN‐γ was produced by both small and large cells. Preactivation in vitro lead to a more rapid appearance of lymphokines during restimulation. In contrast, the in vivo naturally aclivated cells responded with a slow onset of lymphokine production when stimulated in vitro.
Immunohistology of Joint Inflammation Induced in Rats by Cell Wall Fragments of Eubacterium aerofaciens
Authors: KOOL J. , GERRITS‐BOEYE M. Y. , SEVERIJNEN A.J. , HAZENBERG M.P.
Published: June 2006

After a single intraperitoneal injection of cell wall fragments of Eubacterium aerofaciens, a main resident from the human intestinal flora, an acute arthritis develops within 2 days which is followed by a chronic arthritis that lasts at least 90 days. In an earlier report the histological appearance of the joint inflammation during this period has been described. In this study we investigated in more detail the cell types that are involved in the developmet of arthritis by using cell‐type‐specific monoclonal antibodies in an immunohistoiogical assay. In the acute phase of arthritis, T‐helper cells appeared in the synovial tissue together with ED1‐positive (ED1+) and ED3‐positive(ED3+) macrophages. After a temporary decline at day 12 all macrophage subsets, as well as T‐helper cells, reappeared or increased again at day 33. Later, in the chronic phase (days 47‐90). an increased number of ED1 ‐positive (ED1+) cells in the synovial tissue and a decreased number of ED2‐positive (ED2+s) cells in the synovial lining was the most prominent finding when compared with control rats. These results indicate that, apart from T lymphocytes, macrophages also play an important role in the development and continuation of chronic arthritis in this model.
Lymphocyte Recirculation: the Need for Site‐Specific Receptors to Dictate T‐Lymphocyte Localization into Different Tissue Sites
Authors: Frogner Fredrik J. , O'Neill Helen C.
Published: June 2006

This paper addresses the need for receptors involved in recirculation of T lymphocytes both during development and during an immune response or inflammation. Some known receptors present on T lymphocytes which are important in maintaining normal T‐cell localization and function, i.e. the integrins, LECAMs, LPAM‐1 and H‐CAM (CD44) are considered in terms of the specificity which they confer on lymphocyte recirculation. A clear understanding of lymphocyte trafficking patterns and of the receptors involved may provide, for example, novel therapies for treatment of malignant cancer, alleviation of damage caused by lymphocytes during inflammatory responses, and targeting of cells to sites of infection.
Secretion of Macrophage Fusion Factor (MFF) by Schistosome Egg Granulomas Maintained In Vitro
Authors: RODRIGUEZ‐ACOSTA A. , GIRÓN M. E. , AGUILAR I.
Published: June 2006

The schistosome granuloma cultured in vitro under antigenic specific and unspecific stimulation releases macrophage fusion factor (MFF) into the medium, adjusting the production dynamics to the spontaneous modulation model already described. These findings demonstrate the feasibility of studying granulomatous response in mammalian schistosomiasis utilizing an in vitro model of lymphokine granuloma secretion.
Soluble Interleukin‐2 Receptor Levels and Immune Activation in Patients with Schistosomiasis and Carcinoma of the Urinary Bladder
Authors: RAZIUDDIN S. , SHETTY S. , IBRAHIM A.
Published: June 2006

Soluble interleukin‐2 receptor (sIL‐2R) level in serum is a marker of immune regulation and lymphocyte activation. Highly elevated levels of sIL‐2R in serum were observed in patients of schistosomiasis with carcinoma of the bladder (SCB) and carcinoma of the bladder without schistosomiasis (CB) compared with patients with carcinoma of the prostate with or without schistosomiasis and normal healthy controls. Patients with SCB, who had an elevated percentage of cells expressing CD38+ activation antigen and CD71+ transferrin receptors in circulation, also had elevated levels of sIL‐2R in serum. There were few interleukin‐2 receptor (CD25+) positive cells in circulation in some patients with SCB. Despite this, the sIL‐2R levels were extremely elevated. Our data suggest that in SCB, CD38+ and CD71+ cells may be the source of secretion of sIL‐2R in serum. This relationship was confirmed by phenotypic characterizations of mononuclear cells and sIL‐2R levels in individual patients. Measurements of sIL‐2R levels in serum may provide a sensitive method of immune activation in patients with SCB.
Real Time Analysis of Antibody‐Antigen Reaction Kinetics
Authors: MALMBORG A.‐C. , MICHAËLSSON A. , OHLIN M. , JANSSON B. , BORREBAECK C. A. K.
Published: June 2006

Surface plasmon resonance, i.e. detection of changes in refractive index on a surface, was used in a biosensor to evaluate the dissociation/association rate and affinity constants of human monoclonal IgG and IgM antibodies and Tab fragments. The results showed that an observed difference in affinity constants between intact and fragmented IgG anti‐tetanus antibody was related to approximately 10‐fold differences in dissociation rate constants, since the association rate constants were in the same range, i.e. 2–3×105 (m‐1s‐1). Affinity constants, as determined by conventional solid phase enzyme immunoassays, were substantially higher than the constants produced by the biosensor. Human monoclonal IgM anti‐Tnα antibodies showed, furthermore, one order of magnitude higher association rate constants, as compared with the IgG antibodies, but since the dissociation rate constants were more than ten times higher, the resulting affinity constants of the anti‐carbohydrate IgM antibodies were still somewhat lower than those of the IgG antibodies.
Complete Amino Acid Sequence of the Variable Regions of Two Highly Related Heavy and Light Chains of Human IgG (SFL) and IgM (RIV) Rheumatoid Factors
Authors: NEWKIRK M. M.
Published: June 2006

The complete amino acid structure of the variable regions of two monoclonal human rheumatoid factors (RF), antibodies that bind to the Fc portion of IgG, is presented. Although these RFs are of different isotypes, IgG (SFL) and IgM (RIV), they are highly related. They probably derive from the same KIII light chain variable region used, but the heavy chains are derived from genes of the VHIII family that are probably evolutionarily related. An analysis of the level of somatic mutation reveals that antigen selection was probably involved in the maturation of these clones. These antibodies, although highly related, are not merely IgM to IgG switch variants which occurred independently in different individuals. Little is currently known about the structure of IgG RFs and this study indicates that the level of somatic mutation of SFL is similar to other autoantibodies or antiviral antibodies of the IgG isotype.
Spontaneous IgM Autoantibody Production In Vitro by B Lymphocytes of Normal Human Neonates
Authors: BARBOUCHE R. , FORVEILLE M. , FISCHER A. , AVRAMEAS S. , DURANDY A.
Published: June 2006

Human neonate B lymphocytes display unique phenotypic and functional characteristics: in addition to CD1c antigens, CD5+ and CD5‐ subsets both express activation markers such as CD23 and Bac‐1. They proliferate strongly in the presence of various lymphokines (rIL‐2, rIL‐4, low molecular weight BCGF), but differentiate poorly in the presence of the same lymphokines, pokeweed mitogen and Epstein Barr virus. It has also been reported that human neonate B lymphocytes produce polyreactive autoantibodies after in vitro activation by Staphylococcus aureus Cowan I and transformation by Epstein Barr virus. We now show that, in the absence of in vitro stimulation, human neonate B lymphocytes produce polyreactive antibodies of the IgM isotype against several autoantigens. The B lymphocytes involved expressed membrane IgD, IgM, CD23 and CD11b molecules; CD5 expression was variable. This phenotype was consistently found on a minority of B lymphocytes and is similar to that of polyreactive autoantibody‐producing B cells in mice. We also found that autoantibody production in vitro could occur in the absence of any T helper effect

The function of these autoantibodies is not clearly established, but their occurrence in a large proportion of human neonates strongly suggests that they play an important role in the development of the immune system.
Expression and Regulation of Adhesion Molecules ICAM‐1 (CD54) and LFA‐3 (CD58) in Human Intestinal Epithelial Cell Lines
Authors: KVALE D. , KRAJCI P. , BRANDTZAEG P.
Published: June 2006

T cells and other leucocytes regularly occur within and subjacent to the gut epithelium. Recent data suggest that intestinal epithelial cells may exert accessory immunological functions. Although interactions between leucocytes and accessory cells usually require expression of adhesion molecules, intestinal epithelium has generally been considered negative for intercellular adhesion molecule‐1 (ICAM‐1) by immunohistochemical techniques. We therefore studied the expression of ICAM‐1 and lymphocyte function‐associated antigen‐3 (LFA‐3) by two colonic epithelial cell lines and found that both adhesion molecules were constitutively present at low levels. ICAM‐1 protein expression could be enhanced within 4 h by cytokines, particularly alter co‐incubation with interferon‐γ(IFN) and tumour necrosis factor‐α(TNF), interleukin‐1β(IL‐1), or IL‐6. IFN also resulted in accumulation of ICAM‐1 mRNA. Conversely, the LFA‐3 expression was virtually unaffected by cytokine stimulation. These data imply that intestinal epithelial cells under certain conditions may bear adhesion molecules required for cooperation with juxtaposed leucocytes in situ, and that the expression of some of these molecules is modulated by cytokines from activated mucosal leucocytes.
Histamine Modulates the Interleukin‐6‐Regulated Acute Phase Protein Synthesis in Cultured Murine Hepatocytes
Authors: ROKITA H. , FALUS A. , BIRÓ J. , SMOLEN J. , KORDULA T. , STALINSKA K.
Published: June 2006

Murine hepatocytes cultured in the presence of human recombinant interleukin‐6 (IL‐6) show increased synthesis of fibrinogen and complement component C3 by the addition of histamine. No similar effect was achieved when murine hepatocytes were treated with histamine alone or with histamine and interleukin‐1 α together. Using histamine‐1 (H1) and H2 receptor antagonists a prevalence of histamine H1 receptor in the enhancement of IL‐6‐induced effect is suggested.
MHC Class II Beta‐Chain Expression in the Rainbow Trout
Authors: JUUL‐MADSEN H. R. , GLAMANN J. , MADSEN H. O. , SIMONSEN M.
Published: June 2006

A cDNA clone corresponding to the MHC class II β‐chain of the rainbow trout (Oncorhynchus mykiss) has been isolated and used in restriction fragment length polymorphism (RFLP) studies in a family of full siblings of rainbow trout. A very simple RFLP pattern was detected, suggesting segregation of a homozygote AA genotype and a heterozygote AB genotype. The MHC class II β‐chain of the rainbow trout seems to he transcribed in the same type of cells as class II genes of higher vertebrates even though the cDNA clone recognizes atypical messenger sizes of 2.2 kb and 3.6kb in the analysed family. Surprisingly the transcripts seem to be allele‐specific for the assigned genotypes.
Cells of Cerebrospinal Fluid of Multiple Sclerosis Patients Secrete Antibodies to Myelin Basic Protein In Vitro
Authors: CASH E. , WEERTH S. , VOLTZ R. , KORNHUBER M.
Published: June 2006

To characterize the role of B lymphocytes in the pathogenesis of Multiple Sclerosis (MS), we have isolated mononuclear cells from cerebrospinal fluid (CSF) and stimulated them with a polyclonal B‐cell mitogen (pokeweed mitogen). This study has been done with MS patients selected for the occurrence of an acute attack in the course of the disease and with patients hospitalized for other neurological diseases. Five of the 11 MS patients had B lymphocytes producing in vitro antibodies (Abs) directed against purified human myelin basic protein (hMBP), as revealed by Western blot analysis. None of the 20 patients with other neurological diseases showed such a reactivity. The produced Abs recognized only 1 or 2 hMBP peptides without dominance for a certain peptide. This result emphasizes the presence of B cells producing Abs against MBP in CSF of MS patients and shows the interest of studying mononuclear cells of CSF as a good marker of the pathogenesis
The Effect of Non‐Immune IgG on Antigen‐Antibody Complexation
Authors: ANDERSSON K. , HANSSON U.‐B. , ALKNER U.
Published: June 2006

Two preparations of human IgG, one acylated withβ‐propiolactone (acylated IgG) and one treated at pH 4 with (races of pepsin (pH 4‐IgG), were used to study the effect of non‐immune IgG on antigen antibody interactions in the antigen excess zone. Employing two immunological methods together with size‐exclusion chromatography, we found that the formation of human albumin‐rabbit anti‐human albumin complexes was inhibited in the presence of human IgG. In addition, IgG seemed to promote the aggregation of already formed complexes. Thus, non‐immune IgG may modulate immune complexation by direct molecular interactions. The effect was dependent on the size and composition of the immune complexes as well as on the conformation of the IgG molecules with respect to their shape, isotype, charge, and other surface properties. Some possible mechanisms for the reactions are discussed.
M. tuberculosis‐Complex Specific T‐Cell Stimulation and DTH Reactions Induced With a Peptide from the 38‐kDa Protein
Authors: VORDERMEIER H. M. , HARRIS D. P. , MEHROTRA P. K. , ROMAN E. , ELSAGHIER A. , MORENO C. , IVANYI J.
Published: June 2006

An immunodominant T‐cell‐stimulatory epitope located near the carboxy terminus of the 38‐kDa antigen from M. tuberculosis (38.G, residues 350–369) was found to be M. tuberculosis‐complex specific. This was demonstrated by the presence of proliferative and delayed type hypersensitivity (DTH) responses in mice immunized with Mycobacterium tuberculosis and Mycobacterium bovis BCG, whereas mice immunized with M. avium or other non‐tuberculous species of mycobacteria showed no such responses. Peptide 38.G stimulated the proliferation of peripheral blood lymphocytes from healthy purified protein derivative (PPD)‐positive individuals but not from PPD‐negative individuals. It also elicited DTH responses in M. tuberculosis sensitized mice and in PPD‐positive healthy human volunteers. Peptide 38.G could therefore prove to be an important component in any new molecularly defined reagent used in the immunodiagnosis of tuberculous infection.
Immunoglobulin Levels during Follow‐up of Children with Selective IgA Deficiency
Authors: DE LAAT P. C. J. , WEEMAES C. M. R. , BAKKEREN J. A. J. M.
Published: June 2006

Longitudinal serum immunoglobulin levels were studied in 36 children with selective IgA deficiency during a median follow‐up period of 5 years. Twenty‐five children were ‘sporadic’ cases, and 11 were ‘familial’. Serum and saliva IgA levels in 23 children remained below 2 mg/1. Eight children with IgA levels above 2 mg/1 showed considerable intra‐individual variance in serum IgA, but remained IgA deficient. Five children at various ages developed IgA levels above 50 mg/1 with detectable secretory IgA in saliva. In most of the children IgG subclass levels were found to be rather high, including at younger ages. There were no obvious differences between ‘sporadic’ and ‘familial’ cases except an association between IgD deficiency and serum IgA levels below 2 mg/1, and between serum levels of IgD above 1 1IU/ml and of IgA above 2 mg/1, which was found to be significant in the ‘sporadic’ group but not in the ‘familial’ group.
TNFa‐Induced Expression of Endothelial Adhesion Molecules, ICAM‐1 and VCAM‐1, is Linked to Protein Kinase C Activation
Authors: MATTILA P. , MAJURI M.‐L. , MATTILA P. S. , RENKONEN R.
Published: June 2006

The role of protein kinase C (PKC) in TNFα‐induced activation of endothelial adhesion molecules ICAM‐1 and VCAM‐1 was analysed. Phorbol myristate acetate, which is known to activate PKC, was able lo mimic TNFα‐induced up‐regulation of ICAM‐1 and partly also VCAM‐1 expression. Similarly a PKC inhibitor, H7, but not another kinase inhibitor. HA1004, inhibited TNFα‐induced enhancement of ICAM‐1 expression at both the mRNA and the protein level. Moreover we were able to measure a transient PKC activation peak at 16 min after TNFα induction in endothelial cells analysed by phorbol‐dibutyrate binding. These results indicate that the TNFα‐induced effect on the regulation of endothelial adhesion molecule expression is at least partly mediated by PKC activation.
Non‐MHC‐Restricted T‐Cell Interaction with B Cells: Role of the T‐Cell Receptor
Authors: BECKER J. C. , DUMMER R. , VON WUSSOW P. , BURG G , SCHMIDT R. E.
Published: June 2006

Non‐specific antibody production usually accompanies the T‐cell‐regulated B‐cell response. In this papaer the Machanisms involved in non‐MHC‐restricted T‐cell interaction were studied. As previously shown for NK cells, activated B cells induce IFN‐α and TNFα production in non MHC‐restricted cytotoxic T lymphocytes (NrCTL). Using an in vitro model system, we demonstrate that direct cell cell interactions are required to induce these cytokines in NrCTL. Receptor ligand systems involed are leucocyte function antigen‐1/intercellular adhesion molecule‐1 (LFA‐1/ICAM‐1)(CDlla, CD18/CDM).Tn/LFA‐3(CD2, CD58), andtheclonoty‐pic T‐cell receptor (TCR) strueture NKTa of JT9/JTI0 with ils no!i‐MHC‐related target antigen TNKtar(4F2), Cytokine produclion can be induced by activating motiockmahmtibodics against CD2R, Antibodies againsi the elonotypic TCR (NKTa) or CD3 had no cylokine‐iiiduciiig effect on NrCTL cullured alone, but were able to retrieve the effect of blocking the target antigen on co‐cuhured B eells. We eould lurther demonstrate that the inhibition of the TCR/targel antigen interaction eould be overcome by elose cell cell contae! culture conditions. From these findings il i s concluded that the role of the TCR in non‐MHC‐reslricted cell cell interaction is to facilitate LFA‐l. lCAM‐1‐mediated elfectorlarget adhesion in a specific way rather than lo mediate direct activating signals upon lymphokine produclion or cytoxicity.
The Interactions of γδ T Cells with Extracellular Matrix: Receptor Expression and Utilization Patterns
Authors: WILKINS J. , SELIN L. , STEWART S. , SIVANANTHAN K. , STUPACK D.
Published: June 2006

Purified populations and clones of human γδ T cells were examined for their ability to interact with extracellular matrix (ECM) components. The stimulation of these cells with phorbol ester induced cellular adhesion for ECM, The adhesion structures for fibronectin and collagen were shown to be members of the CD29 integrin family. The expression patterns of β1, β2 and β3, integrin‐s by these cells were examined. The receptor expression and utilization patterns suggest that αβ, γδ T cells and B cells have similar repertoires of adhesion structure.