bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Transcripts of the T Cell Antigen Receptor β Chain Gene and Major Histocompatibility Complex Class II Genes in Antigen‐Presenting Cloned BK‐BI‐2.6.C6 Cells
Authors: RESKE‐KUNZ A. B. , RÜCK G. , STEINLEIN P. , RESKE K.
Published: June 2006

The cloned murine cell line BK‐B1‐2.6.C6 has previously been shown to exhibit T cell characteristics, to synthesize and express MHC class II molecules, and to present protein antigens to antigen‐dependent I cell clones. As a more definitive proof of the T‐cell nature of these cells, transcripts of the rearranged T cell antigen receptor (TcR) β gene were assessed by Northern bios analysis. BK‐BI‐2.6.C6 cells constitutively transcribe mRNA for the light chain of TcR and express the disulphide‐linked α,β TcR heterodimer at the cell surface. In addition mRNA For the polymorphic MHC class II subunits Aα and Aβ as well as for the invariant γ chain were detected. BK‐BI‐2.6.C6T cells effectively stimulated bovine insulin‐reactive T hybridoma cells to lymphokine production in the presence of this antigen. Since the antigen‐presenting and the responding T cell populations are maintained in culture in the absence of feeder cells, contamination by conventional accessory cells is excluded. These data unequivocally demonstrate that cloned murine Ia‐expressing T cells can act as antigen‐presenting accessory cells.
Certain Human Gpl20‐HIV Antibodies React with Anti‐CD4 Antibodies
Authors: LUNDIN K. , KARLSSON A. , NYGREN A. , LÖFSTRÖM A. , GIGLIOTTI D. , WIGZELL H.
Published: June 2006

HIV+ human sera contain antibodies against most HIV proteins, including the envelope glycoprotein Gpl20. Some of these antibodies may have an epitope that sterically resembles the CD4 region to which the Gp120 molecule binds. Amongst 58 HIV+ sera tested, we found three with the capacity to block the binding of anti‐CD4 monoclonal antibodies to CD4+ cells. The serum with the highest blocking capacity was selected for further analysis. The inhibitor was shown to be an antibody that binds to the Gp120 molecule as well us to the anti‐CD4 monoclonal T4.2. These CD4‐mimicking antibodies were shown not to interfere with CD4‐dependent reactions in vitro. Virus neutralizing experiments in vitro could not show any neutralizing effect with these antibodies alone. The HIV+ individual providing this antibody is still healthy, although HIV since 1983.
A New Prealbumin Variant in Familial Amyloid Cardiomyopathy of Danish Origin
Authors: NORDLIE M. , SLETTEN K. , HUSBY G. , RANLØV P. J.
Published: June 2006

A C‐terminal fragment of a prealbumin variant was isolated from amyloid material obtained from the myocardium of a patient (Han) with familial amyloid cardiomyopathy of Danish origin. The prealbumin variant fragment was shown to have a methionine for leucine substitution in position 111.
Role of the Endothelial Antigen Eag‐1 in the Rejection of Rat Kidney Allografts
Authors: BLANKERT J. J. , MUIZERT Y. , WEENING J. J. , VAN ES L. A. , PAUL L. C.
Published: June 2006

The immunogenicity of the minor histocompatibility antigen Eag‐1 of the rat kidney endothelium was studied in renal allografts mismatched for antigens of the major histocompatibility complex (MHC). The rejection rates of BN.1L (RT11, Eag‐1+), (BN.1L × MAXX)F1 (RT1Vn, Eag‐1+), and LEW (RT11, Eag‐1−) kidneys transplanted into unsensitized, bilaterally nephrectomized MAXX (RT1n, Eag‐1−) recipients were comparable, indicating that incompatibility for Eag‐1 has no effect on the survival of MHC‐incompatible kidney grafts. Transplantation of BN (RT1n, Eag‐1+) and WKY (RT1k, Eag‐1+) kidneys into unilaterally nephrectomized MAXX recipients led to a weak and inconsistent antibody response against Eag‐1, indicating that MHC incompatibility does not influence the formation of antibodies against Eag‐1.
Autoantibodies from Rheumatoid Arthritis Patients Recognize Antigens on the Synoviocyte Surface
Authors: PÉREZ‐MACEDA B. , BERNABEU C. , LÓPEZ‐BOTE J. P. , MARQUET A. , LARRAGA V.
Published: June 2006

We have found autoantibodies in the sera from rheumatoid arthritis (RA) patients which recognize two cell surface antigens of approximately 70 kDa and 28 kDa from synoviocyte extracts as detected by immunoprecipitation analysis. These polypeptides were immuno‐precipitated from extracts containing mainly macrophage‐like synoviocytes (type A) but not from extracts of homogeneous fibroblast‐like synoviocytes (type B). These autoantigens are not selectively expressed by RA synoviocytes, since both RA and non‐rheumatoid synovia were reactive for RA sera. From the panel of different RA sera tested, 64% immunoprecipitated the 70 kDa band, and 27% recognized the 28 kDa polypeptide. These differences in the specificity of the sera seemed to be related to the clinical state of the donor. The sera from patients suffering from other autoimmune diseases such as autoimmune thyroiditis and systemic lupus erythematosus (SLE) do not appear to be reactive for these specificities, but sera from patients with Sjögren's syndrome, psoriatic arthritis, and Crohn's disease showed a weak cross‐reactivity with the 70 kDa polypeptide. This autoreactivity against synovial cells in RA supports the idea that these cells participate in the initial immune response of the disease.
Characterization of a Monoclonal Antibody MoAb bH6 Reacting with a Neoepitope of Human C3 Expressed on C3b, iC3b, and C3c
Authors: GARRED P. , MOLLNES T. E. , LEA T. , FISCHER E.
Published: June 2006

Activation products of the complement cascade contain neoepitopes that are not present in the individual native components. Monoclonal antibodies detecting neoepitopes have been used for direct quantification of activation at different steps in the cascade. These methods are suggested to be more sensitive and reliable than conventional complement activation tests, which are hampered by precipitation or fractionation procedures. The present study describes production screening and characterization of a monoclonal antibody (MoAb) bH6, MoAb bH6 exhibited a significantly higher binding capacity to ELISA plates coated with zymosan‐activated human serum than to plates coated with EDTA plasma. When fixed to the enzyme‐linked immunosorbent assay (ELISA) plates, MoAb bH6 retained material from zymosan‐activated serum that only reacted with anti‐C3 antibodies. Crossed immunoelectrophoresis performed on zymosan‐activated serum demonstrated that MoAb bH6 co‐precipitated with anti‐C3c antibodies. In experiments using highly purified cell‐bound fragments MoAb bH6 showed reactivity with C3b and iC3b, but not with C3d. MoAb bH6 reacted in ELISA with purified C3c, but not with C3dg, both as capture antibody and in tests with the fragments absorbed to the solid phase. Thus, MoAb bH6 is highly specific for a neoepitope of human C3 expressed on the cleavage fragments of C3b, iC3b, and C3c.
Limiting Dilution Analysis of the Response of Murine L3T4+ Spleen Cells to Alloantigen
Authors: REIMANN J. , BELLAN A.
Published: June 2006

Cell sorter‐purified small splenic L3T4− cells from B6 mice were clonally expanded under limiting dilution (LD) conditions by coculture for 4–6 days with irradiated allogeneic stimulator cells in culture medium supplemented with various growth factor preparations. Proliferating L3T4+ cell clones were detected by [3H]thymidine uptake; interleukin 2 (IL‐2) production of restimulated L3T4+ cell clones was measured in is sensitive colorimetric assay. IL‐3 (but not IL‐1 or IL‐4) supported clonal expansion in vitro of many L3T4+ spleen cells reactive to class II MHC alloantigen. The large majority of proliferating L3T4+ cell clones produced IL‐2. The data were consistent with the hypothesis that only a single titrated precursor cell was limiting in the system. In the response to class II (bm12) H‐2 alloantigen. 1 in 40–200 L3T4+ cells was induced to clonal growth; in the response to class I (bm1) H‐2 alloantigen, a tenfold lower frequency (1 in 600–800) of inducible L3T4+ B6 cells was measured. A fraction of the generated L3T4+ cell clones showed IL‐2‐independent growth: anti‐IL‐2 receptor monoclonal antibodies (MoAb) (7D4 and PC61.5) blocked the proliferation of about 80% of the IL‐2‐producing L3T4+ cell clones, while about 20% of these clones seemed resistant to inhibition of proliferation by these MoAb. We have thus defined an LD system with high cloning efficiency for L3T4+ cells that does not depend on exogenous IL‐2 supplements.
Differences between Primed Allogeneic T‐Cell Responses and the Primary Mixed Leucocyte Reaction
Authors: ØDUM N. , HOFMANN B. , MORLING N. , PLATZ P. , RYDER L. P. , TVEDE N. , GEISLER C. , SVEJGAARD A.
Published: June 2006

Recent investigations have demonstrated that the primary mixed lymphocyte reaction (MLR) is dependent on certain accessory molecules, e.g. CD4 and LFA‐1. We have compared the requirements of the primary MLR and the responses of alloreactive, primed lymphocytes (PL) by inhibition studies using monoclonal antibodies (MoAb) directed against (i) adhesion molecules belonging to the CD11 cluster of leucocyte antigens (CD11a, LFA‐1; CD11b, MAC1=CR3; and CD11c, p 150.95); (ii) various T cell‐related antigens(CD2, CD4, CD5 and CD8); and (iii) recombinant IL‐1β. The CD5‐, CD11a‐ and CD11c‐reactive MoAb significantly inhibited the primary MLR (inhibition = 25%, P0.01; 48%, P0.01, and 13%, P0.05, respectively) but these MoAb did not inhibit the primed lymphocyte reaction (PLR). The CD11b‐reactive MoAb had no significant influence on either of the responses. CD2‐ and CD4‐reactivc MoAb significantly inhibited both primary MLR (>80%, P0.01) and to a lesser extent the PLR (40–65%, P0.01). A MoAb reactive with IL‐1β inhibited the primary MLR (38%, P<0.01) and the purified protein derivative (PPD) induced lymphocyte transformation response (42%, P0.01) of peripheral blood mononuclear cells (PBMC), whereas primed allogeneic responses to PBMC and Epstein‐Barr virus (EBV) cell lines were unaffected by this MoAb. In addition, preliminary data indicated that PL seemed neither to bind exogenous IL‐1 (as opposed to CD4+ PBMC) nor to possess membrane‐bound IL‐1. The differences between ‘virgin’ and primed, allogeneic T‐cell responses indicate that profound changes in the functional capability of the responding T‐cell population take place during the bulk expansion. The results indicate that during repeated priming with alloantigen and bulk expansion, the proliferative response of T lymphocytes becomes independent of (i) the interaction with the CD11 adhesion molecule(s). (ii) the CD5 molecule, and (iii) the cytokine IL‐1β.
Repopulation Potential of Thymocytes Forming Rosettes with Phagocytic Cells of the Thymic Reticulum
Authors: EL ROUBY S. , EZINE S. , PAPIERNIK M.
Published: June 2006

Thymocytes binding in vitro to phagocytic cells of the thymic reticulum (P‐TR), termed ‘rosetting thymocytes’, were injected intravenously into irradiated congenic mice and their migration patterns were compared with those that do not bind to P‐TR, called ‘non‐rosetting thymocytes’, similarly transferred. Donor cells, C57BL/Ka Thy 1.2, were distinguished from recipient cells, C57BL/Ka Thy 1.1 by a direct immunofluorescence technique using an anti‐Thy 1.2 monoclonal antibody. The results demonstrate that the rosetting thymocytes have a greater capacity for homing back to the thymus and for populating the mesenteric lymph node and the spleen. Intrathymic transfer assay revealed that the donor‐derived cells detected in the peripheral organs were of thymic origin.
Positive Selection of Antigen‐Specific B Lymphocytes by Means of Immunomagnetic Particles
Authors: EGELAND T. , HOVDENES A. , LEA T.
Published: June 2006

This paper presents a method for the isolation of highly enriched antigen‐specific B lymphocytes from peripheral blood mononuclear cells (PBMC) by means of an immunomagnetic procedure. The method is illustrated by the isolation of B cells positive for rheumatoid factors (RF) from patients with rheumatoid arthritis and healthy blood donors. After Epstein‐Barr virus transformation of isolated cells, more than 90% of the generated immunoglobulin‐secreting cells produced RF in several experiments. Compared to the low frequency of B cells positive for RF in PBMC, this represents a 103‐ to 104‐fold enrichment of antigen‐specific B cells.
On the Validity of Using Lipopolysaccharide‐Driven Limiting Dilution Systems for Clonable B‐Cells to Analyse Functional Antibody Repertoires
Authors: PORTNOÏ D. , LUNDKVIST I. , COUTINHO A.
Published: June 2006

Analyses of B‐cell repertoires by mitogen‐driven limiting dilution systems (LDA) followed by specific antibody detection on immobilized antigens (ELISA), while constituting the only method available to determine absolute frequencies of any given specificity, provide no indications as to the functional ability of clonal precursors scored as positive to actually respond to antigen in vivo. We have now addressed this question by quantitating dextran alpha 1→6‐specific clonal precursors among small, resting, and large activated B cells in the spleens of mice, before and after priming with optimal doses of antigen. The results demonstrate that virtually all B cells scored as antigen‐specific in LDA/ELISA systems do respond to antigen and undergo blast transformation after priming in vivo.
Comparative Analysis of Natural Antibody Specificities among Hybridomas Originating from Spleen and Peritoneal Cavity of Adult NZB and BALB/c Mice
Authors: KAUSHIK A. , LIM A. , PONCET P. , GE XI‐RUI , DIGHIERO G.
Published: June 2006

A preliminary experiment showed that the supernatants of in vitro cultured peritoneal cells (rich in Ly‐1 B cell subset shown to secrete most IgM autoantibodies against bromelain‐treated mouse red blood cells (BrMRBC) and DNA) from different mouse strains did not contain any significant antibody activity against DNA and cytoskeleton proteins, although the presence of anti‐BrMRBC antibodies was clearly evident. Therefore, we investigated comparative natural antibody (NAb) specificities against an antigen panel (DNA, cytoskeleton proteins, IgG. bovine serum albumin (BSA), BrMRBC, trinitrophenyl (TNP), and trimethylammonium (TMA) haptens) among Ig‐secreting hybridoma collections from the splenic (158) and peritoneal (230) immune compartments of autoimmune New Zealand black (NZB) and lipopolysaccharide (LPS)‐stimulated BALB/c mice. The data showed: (i) isotypic restriction (μ and γ3 only), predominance of TMA ion‐reactive (including BrMRBC) but negligible anti‐DNA‐reactive antibody specificities, and lack of simultaneous polyspecific widespread reactivity (i.e. at least four or more antigens) against DNA and cytoskeleton proteins in the peritoneal cavity; (ii) predominance of simultaneous widespread polyspecific reactivity against DNA and cytoskeleton proteins but negligible or no TMA hapten‐reactive antibody specificities in the spleen. These observations reflect certain differences in the B cell repertoire of peritoneal cavity (rich in Ly‐1 B cells) compared with spleen. The NAb against BrMRBC and those reactive with DNA and cytoskeleton proteins, which have been suggested to be secreted by the Ly‐1 B cell subset, are distinguishable on the basis of the presence of separate recurrent idiotypes and preferential localization of B lymphocytes directed against these autoantigens.
Histamine Inhibits Interleukin 1 Production by Lipopolysaccharide‐Stimulated Human Peripheral Blood Monocytes
Authors: DOHLSTEN M. , KALLAND T. , SJÖGREN H.‐O. , CARLSSON R.
Published: June 2006

Histamine inhibited the production of interleukin 1 (IL‐1) induced by lipopolysaccharide (LPS) in cultures of purified human peripheral blood monocytes. The effect of histamine on IL‐1 production was dose‐dependent and significant at histamine concentrations of 10−4‐10−5m. The histamine H2 receptor agonists dimaprit and 4‐methylhisiamine, hut not the H1 receptor agonists 2‐pyridylethylamine. aminoethylthiazole and 2‐methylhistamine, modulated the IL‐1 production in a similar manner to histamine. The inhibitory effects of histamine could be reversed by the H2 receptor antagonist cimetidine but not by the H1 receptor antagonist mepyramine. This indicates that the inhibitory effects of histamine on LPS‐induced IL‐1 production are mediated through H2 receptors on human peripheral blood monocytes.
Cellular Immune Responses in the Murine Lung to Local Immunization with Influenza A Virus Glycoproteins in Micelles and Immunostimulatory Complexes (Iscoms)
Authors: JONES P. D. , THAHLA R. , MOREIN B. , LOVGREN K. , ADA G. L.
Published: June 2006

Primary immunization with a single inoculum of either micelles or iscoms containing influenza A virus glycoproteins failed to induce either B or cytotoxic T (Tc) cell responses. In contrast, immunization with two inocula of iscoms, but not micelles, resulted in the appearance of influenza virus‐specific antibody‐secreting cells (ASC) but not Tc cells in the lung. There was a 10‐fold increase in Tc cell precursor frequency and an increase in ASC generated by secondary in vitro stimulation of lung cell cultures obtained from mice primed with iscoms but not micelles. In mice primed with infectious virus, secondary immunization with either micelles or iscoms increased the number of ASC in the lung and elicited virus‐specific Tc cell responses. In contrast homologous virus challenge failed to induce detectable secondary B or Tc cell responses.
Endotoxin‐Stimulated Human Monocyte Secretion of Interleukin 1, Tumour Necrosis Factor Alpha, and Prostaglandin E2 Shows Stable Interindividual Differences
Authors: MØLVIG J. , BAEK L. , CHRISTENSEN P. , MANOGUE K. R. , VLASSARA H. , PLATZ P. , NIELSEN L. S. , SVEJGAARD A. , NERUP J.
Published: June 2006

The secretions of interleukin 1 (IL‐1), tumour necrosis factor α (TNF), and prostaglandin E2 (PGE2) of low‐dose E. coli lipopolysaccharide (LPSJ‐stimulated human monocytes (Mø) were investigated in an endotoxin (ET)‐free milieu (<1.6 pg LPS/ml). Human Mø cultures from nine healthy men were stimulated with 0, 12.5–500, and 250,000 pg LPS/ml as measured by a very sensitive Limulus test. The IL‐1 activity was tested by the mouse costimulatory thymocyte (LAF) assay, which was thoroughly standardized and characterized (interassay variation 22–24%, intra‐assay variation 3–7%). Spontaneous Mø secretions of IL‐1, TNF, and PGE2 were negligible, but 12.5 pg LPS/ml significantly stimulated the secretions of these Mø products and the monokine responses to 500 and 250,000 pg LPS/ml were almost in the same range. It was demonstrated that the secretions of IL‐1‐TNF and TNF‐PGE2 were strongly correlated. Pronounced interindividual differences in LPS responsiveness were demonstrated, and two low‐responders, one of whom was HLA‐DR 1,2‐positive, were identified. Three first‐degree relatives of the DR1.2‐positive low‐responder had similar low responses. Furthermore. Mø cultures were prepared weekly for 4 weeks from four HLA‐DR different men and the only DR2.2 homozygous individual had low monokine responses. In conclusion, stable interindividual differences in in vitro monokine and PGE2 secretions of LPS‐stimulated Mø were demonstrated. It is suggested that HLA‐DR2‐positive individuals may be low responders.
Heterogeneous Responses of B‐Cell Tumours to Anti‐Ig and Anti‐Idiotypic Antibodies
Authors: ALLEBES W. A. , WETZELS R. H. W. , CAPEL P. J. A.
Published: June 2006

Anti‐Ig antibodies can have two opposing effects on B‐cell proliferation, resulting either in stimulation or inhibition. We have examined the proliferative response of 30 B‐cell tumours to anti‐Ig in the presence of absence of B‐cell growth factor. Three reaction patterns were observed. In 12 cases a dose‐dependent synergism between anti‐Ig and B‐cell growth factor was present in the induction of proliferation, in ten cases anti‐Ig did not induce any response, and in eight cases anti‐Ig suppressed the B‐cell growth factor (BCGF)‐induced proliferation. Similar responses to anti‐Ig were found in the absence of BCGF. When these B‐cell tumours were typed for expression of Ig isotypes, HLA class II antigens, several B‐cell markers, activation markers, complement receptors, Fc receptors, cell size, and cell cycle phase, no correlation could be found with the proliferate response of these tumour B cells to anti‐Ig. T cells or T‐cell factors were not involved, because T‐cell depletion did not change they tumour B‐cell proliferative response to incubation with anti‐Ig. The observed inhibition of proliferation did not correlate with the expression of Fc receptors, indicating the involvement of suppressor mechanisms other than the cross linking of Fc receptors with surface immunoglobulins. Tumour B cells, for which monoclonal anti‐idiotypic antibodies (MoAb anti‐id) were available, responded to MoAb anti‐id in the same way as they did to anti‐Ig. In view of the treatment of B‐cell malignancies with MoAb anti‐id, the question of whether these responses in vitro correlate with in vivo clinical outcome of anti‐id therapy is of interest. So far our data show that the proliferative response of B‐cell tumours to anti‐Ig or MoAb anti‐id is heterogeneous and cannot be linked to phenotype, is T cell‐independent, and is most likely an intrinsic property of the malignant cell.
Modulation of Major Histocompatibility Complex (MHC) Expression by Interferons and Microbial Agents
Authors: KELLER R. , JOLLER P. , KEIST R. , BINZ H. , VAN DER MEIDE P. H.
Published: June 2006

In a pure population of rat bone marrow‐derived mononuclear phagocytes (BMMø), the expression of major histocompatibility complex (MHC) molecules and ability to manifest tumoricidal activity were simultaneously studied. Resting BMMø, which express low levels of MHC class II molecules and do not manifest tumoricidal activity, become strongly MHC class II‐positive, and evolve tumoricidal activity within 24 h when incubated with macrophage‐activating lymphokines (MAF) or gamma interferon (IFN‐γ). In contrast, BMMø which were interacted for 24 h with heat‐killed microbial agents (Corynebacterium parvum, Listeria) evolve tumoricidal activity without parallel enhancement of MHC class II expression. IFN‐α,β neither induced tumoricidal activity nor enhanced MHC class II expression. Further experiments have shown that (a) the kinetics of MAF‐ and/or IFN‐γ‐induced amplification of MHC class II expression and of tumoricidal activity are different; (b) enhancement of MHC class II expression by rIFN‐γ is not invariably paralleled by induction of tumoricidal activity; and (c) inhibitors of macrophage tumoricidal activity differ in their ability to affect MHC class II expression. It is concluded from these findings that in a population of pure BMMø, i.e. in the complete absence of lymphocytes, the expression of MHC molecules and induction of tumoricidal activity are independently regulated phenomena; in particular, the enhanced expression of MHC class II molecules is not a prerequisite for induction and/or manifestation of tumoricidal activity by mononuclear phagocytes.
Human T Lymphocyte Differentiation Antigens as Target for Immunotoxins or Complement‐Mediated Cytotoxicity
Authors: PREIJERS F. W. M. B. , DE WITTE T. , RIJKE‐SCHILDER G. P. M. , TAX W. J. M. , WESSELS J. M. C. , HAANEN C. , CAPEL P. J. A.
Published: June 2006

Graft‐versus‐host disease (GVHD) after allogeneic hone marrow transplantation (BMT) is initiated by immunocompetent T fells present in the graft. Selective elimination of distinct T‐cell subsets or a sufficient, but not complete T‐cell depletion, might abolish severe GVHD without graft rejection and loss of the anti‐tumour potential. In this study we analysed the efficacy of different monoclonal antibodies (MoAb) WT32(CD3), OKT4(CD4), T101 (CDS), WT1 (CD7), and WT82 (CD8) with respect to their cytotoxicity to T cells cither as immunotoxin (IT) or in combination with complement. The cytotoxic potential was assessed by protein synthesis inhibition and clonogenic a minor effect on blood or bone marrow T cells, although they were highly inhibitory to T‐cell lines. However, in the presence of 20 mm ammonium chloride, IT directed against CD3, CDS, and CD7 were highly cytotoxic. IT directed against CD4 and CD8 were less effective, due to a low internalization. The complement‐mediated cytotoxicity was efficient for all antigens used.

The natural killer (NK) activity, as measured by cytotoxicity to K562, was hardly depressed by anti‐CD3, anti‐CD4, anti‐CD5, and anti‐CD8, but was eliminated by ami‐CD7. All procedures used had only a minimal effect on haematopoietic progenitors as measured by CFU‐GM and BFU‐E assays. We concluded that, although the T‐cell population can be eliminated with the combination of anti‐CD3, anti‐CD5, and anti‐CD7 antibodies plus complement, IT with 20 mm NH4CI appear to kill higher amounts of T cells‐ Selective elimination of CD4‐ and CD8‐positive cells is effectively obtained by MoAb with complement.
Abnormal Helper‐Inducer/Suppressor–Inducer T‐Cell Subset Distribution and T‐Cell Activation Status are Common to All Types of Chronic Synovitis
Authors: KINGSLEY G. , PITZALIS C. , KYRIAZIS N. , PANAYI G. S.
Published: June 2006

We have previously shown that rheumatoid synovial T cells are virtually all helper‐inducer (CD4+4B4+ UCHL1+) rather than suppressor‐inducer (CD4+ 2H4+) cells. CD8 cells were also largely 4B4+. In addition, the majority of T cells were HLA‐DR+. To investigate whether these findings were specific for rheumatoid disease, we studied the prevalence of these markers in a variety of chronic inflammatory arthropathies such as ankylosing spondylitis, Reiter's syndrome, and psoriatic arthritis. Again, almost 90% of the T cells were 4B4+UCHL1+ and only 11% were 2H4+; 50% expressed the HLA DR antigen. Thus this phenotype distribution represents a final common pathway of chronic synovitis and may help to explain the immunopathology of the lesion.
Immunogenic and Antigenic Epitopes of Immunoglobulins
Authors: MAGEED R. A. , CARSON D. A. , JEFFERIS R.
Published: June 2006

The expression of idiotypic and variable region‐associated isotypic determinants on a panel of human monoclonal rheumatoid factors (RF) was studied by means of murine hybridoma antibodies produced to two IgM‐RF paraproteins. Fourteen RF paraproteins from patients with cryoglobulinaemia and one (RF‐AN) from an Epstein‐Barr virus (EBV)‐established B‐cell line from a patient with rheumatoid arthritis (RA) were studied. Nine RF paraproteins expressed a VkIIIb light chain sub‐subgroup‐associated cross‐reactive idiotope and seven of these nine also expressed a heavy chain‐associated cross‐reactive idiotope. The reactivity of the monoclonal RF with human IgG subclass paraproteins revealed four patterns of molecular specificities: (1) RF reactive with an epitope common to all IgG subclasses; (2) RF reactive with an epitope expressed on IgG 1,2,4 and G3m(s,t) which has histidine al 435, but not G3m(b) or G3m(g) which have arginine at 435; (3) RF reactive with an epitope expressed on IgG 1,2, and 4, but not IgG3 irrespective of allotypic markers; (4) RF reactive with epitopes expressed on some, but not all paraproteins within the subclasses. Four of five RF paraproteins that expressed both the heavy and light chain‐associated idiotopes showed a similar pattern of reactivity with IgG subclass proteins.
Vaccinia‐Interleukin 2 Recombinant Virus or Exogenous Interleukin 2 Does Not Alter the Magnitude or Immune Response Gene Defects of the Cytotoxic T‐Cell Response to Vaccinia Virus in Vivo
Authors: MÜLLBACHER A. , RAMSHAW I. A. , COUPAR B. E. H.
Published: June 2006

We investigated the role of interleukin 2 (IL‐2), a T cell‐derived lymphokine, in the generation of in vivo cytotoxic T‐cell responses to vaccinia virus. We made use of a recombinant vaccinia virus encoding and expressing the murine IL‐2 gene and recombinant IL‐2 to test the role of IL‐2 in the expression of major histocompatibility complex (MHC) class I determined immune response (Ir) gene defects in the response to vaccinia virus. IL‐2 expressed either by the vaccinia virus vector or exogenous IL‐2 does not alter Ir gene defects nor does IL‐2 under such conditions elevate the cytotoxic T‐cell response in general.
Activity of Two Types of Fc Receptors, FcγRI and FcγRII, in Human Monocyte Cytotoxicity to Sensitized Erythrocytes
Authors: VAN DE WINKEL J. G. J. , BOONEN G. J. J. C. , JANSSEN P. L. W. , VLUG A. , HOGG N. , TAX W. J. M.
Published: June 2006

We investigated the cytotoxicity of human monocytes mediated by two types of receptors for the Fc portion of IgG, FcγRI and FcγRII. Erythrocytes sensitized with human IgG(EA‐human IgG1) were used to assay FcγRII function, and erythrocytes sensitized with mouse IgG1 (EA‐mouse IgG1) were used to assay FcγRII. Both types of FcγR were observed to mediate antibody‐dependent cell‐mediated cytotoxicity (ADCC), which was Further characterized by using different monoclonal anti‐FcγR antibodies (MoAb) and monomeric IgG. Lysis of EA‐human IgG was inhibited by both monomeric human IgG and mouse IgG2a in a dose‐dependent way, and also by anti‐FcγRI MoAb 10.1. Cytolysis of EA‐mouse IgGI was inhibited by monomeric mouse IgG1 and by two anti‐FcγRII MoAb, IV.3 and CIKM5. Antibodies of the mouse IgG2b isotype affected neither type of ADCC. The effectiveness of cytotoxicity mediated by either of the FcγR was studied by means of targets sensitized with a calibrated number of IgG molecules. At least 20 times more IgG molecules per target cell were necessary to obtain half‐maximal cytotoxicity mediated by FcγRII than for FcγRI‐mediated cytolysis. Furthermore, the previously described polymorphism of FcγRII was also reflected in FcγRII‐dependent cytotoxicity. These studies demonstrate that FcγRII can mediate ADCC, although a higher degree of target cell sensitization is required than for FcγRI‐mediated ADCC.
Immunohistological Analysis of Human Fetal Lymph Nodes
Authors: WESTERGA J. , TIMENS W.
Published: June 2006

A panel of monoclonal anybodies directed against various lymphoid and non‐lymphoid cell subsets was used to study the lymph nodes of human fetuses of 16–40 weeks. B cells were of intermediate size and were present at all ages in primitive follicles and in the outer cortex. The fetal B‐cell immunophenotype is indicative of an intermediate stage of development, just preceding the differentiation to mature B cell. Forty to sixty percent Leu1+ B cells were observed in the follicles until the end of the second trimester. At all stages, T cells showed an immunophenotype similar to type III thymocytes, different from adult peripheral T cells, with a marked predominance of CD4+ T cells. Leu7+ NK cells were generally absent. OKIa+ interdigitating reticulum cells were present in T‐cell areas. Some axillary lymph nodes showed strongly CD1+ dendritic cells, probably Langerhans'cells. Macrophages and granulocytes were present in varying numbers Altogether, our results indicate that fetal lymph nodes are quite well differentiated at an early fetal age, although T and H cells do not (yet) show adult immunophenotypes. The expression of the CD38 antigen may be a main marker related to the immaturity of fetal T and B cells.
Enhanced T‐Cell Activation Due to Combined Stimulation by Both Endothelial Cells and Monocytes
Authors: TEITEL J. M. , SHORE A. , McBARRON J. , SCHIAVONE A.
Published: June 2006

Mitogen‐induced interleukin 2 (IL‐2) secretion by T cells was greatly enhanced by the combined presence of endothelial cells (EC) and monocytes (AC). EC also altered the lime course of IL‐2 secretion by peripheral blood mononuclear cells (PBM) in response to mitogens. The response to EC did not require expression of HLA‐DR antigen and occurred equally well in response to autologous EC. At least one live accessory cell was required to induce T cells to secrete IL‐2. When added to T cells plus live AC, both fined EC and EC supernatant partially reproduced the enhancing effect of EC. Surface membrane IL‐1 was present on both live and fixed EC. However, active EC supernatant contained no detectable IL‐1 activity. Anti‐IL‐1 abolished the enhancement of T‐cell responses by fixed but not live EC.
Production of Human Antibodies to Bee Venom Phospholipase A2 in Vitro
Authors: HELD W. , STUCKI M. , HEUSSER C. , BLASER K.
Published: June 2006

Phospholipase A2 (PLA) is the major antigen of bee venom. Whereas individuals frequently stung by bees, such as bee keepers, show high levels of IgG4 anti‐PLA antibodies in serum, most patients sensitive to bee venom possess increased IgE anti‐PLA. We have established a culture system by which anti‐PLA antibodies can be induced in vitro. Peripheral blood mononuclear cells were stimulated in a first step with PLA and/or pokeweed mitogen (PWM). After 3 days of culture the cells were washed and further incubated with fresh medium. Anti‐PLA antibodies were estimated by an enzyme‐linked immunosorbent assay (ELISA)and anti‐PLA antibody secreting cells were counted by means of an ELISA plaque assay. Cells from bee keepers, but not those from normal donors, produced anti‐PLA IgG in vitro. The isotype pattern of anti‐PLA antibodies produced in vitro was identical to that found in serum of the respective donor. Anti‐PLA IgM antibody‐secreting cells developed at low frequencies in both bee keepers and normal donors whereas PLA‐specific IgE could not be detected. The formation of anti‐PLA IgG was suppressed by high amounts of antigen, while the IgM response was not affected. We conclude that PWM‐induced antibodies reflect the in vivo situation of the donors and that anti‐PLA IgG and IgM are regulated by different pathways and mechanisms.
Liver Sinusoidal Blood Containing Natural Killer‐Like Cells
Authors: LUKOMSKA B. , OLSZEWSKI W. L. , RYFFA T. , ZIOLKOWSKA A. , SADOWSKA D.
Published: June 2006

Rat liver sinusoidal washout cells were examined. These cells, which arc marginated in sinusoids, could he washed out by simple flushing of the vasculature with culture media without enzymes and under physiological portal pressure. They revealed, in comparison to peripheral blood mononuclear cells, which cytotoxic activity commonly attributed to the natural killer (SK) and natural cytotoxic (NC) cells, and were found to be anti‐asialo‐GM1‐negative. Liver sinusoidal Cytotoxic cell (LSCC) activity has been found to be associated with the large granular lymphocytes in low‐density cells in OX8‐positive as well as in OX8‐negative populations. The mononuclear cells washed out from the liver microvasculature could be stimulated with NK‐sensitive targets to release soluble factors which selectively lyse YAC‐I tumour cells and inhibit growth of normal haematopoietic granulocyte‐macrophage colony‐forming cells in vitro. The cytotoxic cell population in the liver turned out to be blood‐borne in origin and not resident Our findings suggest that liver sinusoidal cytotoxic cells represent an NK population with a predilection for marginating in the liver and may be important in eliminating tumour or virus infected cells passing through the liver from the circulation. The mechanism of their accumulation in liver sinusoids remains unclear.
Interferon β2/B‐Cell Stimulating Factor 2/Interleukin 6 Affects Glycosylation of Acute Phase Proteins in Human Hepatoma Cell Lines
Authors: MACKIEWICZ A. , KUSHNER I.
Published: June 2006

Undefined monocyte‐derived cytokines have previously been shown to affect glycan processing in glycoproteins secreted by human hepatoma cell lines. Hep 3B cells, when incubated with the cylokine interferon β2/B‐cell stimulating factor 2 interleukin 6, secreted forms of α1‐protease inhibitor, ceruloplasmin, and α‐fetoprotein with increased reactivity with concanavalin A (Con A) while incubation of Hep G2 cells with this cytokine led to secretion of forms of these proteins with decreased reactivity with Con A, reflecting changes in their oligosaccharide chains. The difference in response of these two transformed cell lines to this cytokine undoubtedly reflects differences in their intracellular glycan processing mechanisms. Changes in glycosylation patterns were dissociated from changes in rate of synthesis: this cytokine caused increased synthesis of α1 protease inhibitor and ceruloplasmin, and decreased synthesis of α‐fetoprotein in both cell lines.
Heterogeneity of Degradation of B‐Cell Endocytosed Monoclonal Antibodies Reacting with Different sIgM Epitopes
Authors: RUUD E. , MICHAELSEN T. , KINDBERG G. M. , BERG T. , FUNDERUD S. , GODAL T.
Published: June 2006

The degradation of a panel of monoclonal antibodies (MoAb) bound to surface IgM (sIgM) was studied in three human Burkitt's lymphoma cell lines. The panel included MoAb that recognize several distinct epitopes associated with the F(cμ)5 domain, the cμ2 domain, and δ or λ light chains. The amount of degraded MoAb and the rate of their degradation varied considerably between the various antibodies. Properties of MoAb such as avidity or ability to cross‐link sIgM did not significantly influence their degradation. The most consistent correlation between rate of degradation and MoAb used was the location of the epitope recognized by the individual MoAb. Thus, 7 out of 8 anti‐light chain MoAb were degraded at a higher rate than 5 out of 5 anti‐F(cμ)5 MoAb. One anti‐cμ2 MoAb was degraded at a rate similar to the majority of anti‐light chain MoAb. The intracellular transport of an anti‐δ light chain MoAb and an anti‐F(cμ)5 MoAb was studied in detail by subcellular fractionation in sucrose gradients. We found that the anti‐δ light chain MoAb was transported more rapidly to lysosomes than the anti‐F(cμ)5 MoAb, showing that they were sorted differently intracellularly.
Molecular Characteristics of IgA in Infant Saliva
Authors: CRIPPS A. W. , GLEESON M. , CLANCY R. L.
Published: June 2006

Saliva was collected from 57 infants aged ft weeks to 2.5 years and the molecular form of IgA was studied by centrifugation on sucrose density gradients. Two distinct populations were identified. Seventy‐two per cent of the children had secretory IgA in their salivary secretions, while 28% had a molecular form corresponding to monomeric IgA. No samples with concurrent monomeric and secretory forms were detected. Monomeric IgA was not detected in any infant over 12 months of age. Secretory component was detected in all samples but was not associated with monomeric IgA. Forty‐seven per cent of the samples contained IgA fragments of approximately 40,600 molecular weight. The presence of fragments dominated in the group of children with monomeric IgA. The presence of monomeric IgA in infant saliva did not result from degradation due to storage or proteolysis. The study demonstrated an apparent maturation sequence in the molecular form of IgA present in the salivary secretions of infants.
Enhancement of Human B‐Cell Proliferation by a Monoclonal Antibody to CD43
Authors: WIKÉN M. , BJÖRCK P. , AXELSSON B. , PERLMANN P.
Published: June 2006

Monoclonal antibodies (MoAb) to human leucocyte sialoglycoprotein, CD43, have been shown to deliver mitogenic signals to human T cells or to enhance T‐cell proliferation induced by concanavalin A, anti‐CD3 antibodies or phorbol ester. In this paper, we studied the effects of anti‐CD43 MoAb B1B6 on the activation of human B cells Anti‐CD43 MoAb B1B6 was not mitogenic by itself for human B cells. However, when added together with TPA, both resting and in vivo activated tonsillar B cells, containing 5–10% and about 35% CD43+ respectively, responded with three‐ to fivefold higher proliferation compared to that obtained with TPA alone. A peak in the proliferative response was reached on day 3. Optimal proliferation was obtained when the antibody was present from the start of culturing. Addition of MoAb B1B6 together with a calcium ionophore, ionomycin, did not induce B‐cell proliferation. Neither did mAb B1B6 sustain the growth of B cells that were already in the cell cycle, i.e. precultured with phorbol ester (PDB) and ionomycin for 3 days. The results are similar to those obtained with antibodies to CD22 and CD23 and show that early progression signals are delivered to resting B cells through CD43 in the presence of primary activators of protein kinase C.
Immunosuppression by a Novel Analgesic‐Opioid Agonist
Authors: HADJIPETROU‐KOUROUNAKIS L. , KARAGOUNIS E. , REKKA E. , KOUROUNAKIS P.
Published: June 2006

The effect of a new, centrally acting analgesic, 2‐n‐pentyloxy‐2‐phenyl‐4‐methyl‐morpholine (PM) on the humoral antibody isotype responses, mitogenic responses, and interleukin production and assay was studied. Treatment with this opioid agonist exerted a suppressive effect on the antibody responses to TD [sheep red blood cells (SRBC), fluoresceinated human gamma globulin (HGG‐HTC)] and TI [fluoresceinated dextran (DEX‐FITC), lipopolysac‐charide (LPS)] antigens in mice. The suppression was found to be dose‐ and time‐dependent for all antigens tested, suggesting that PM affected both T and B cells. PM impaired lymphocyte functions, as the in vitro T and B mitogen reactions were inhibited in a dose‐ and time‐dependent manner in mice and rats PM, even at the highest concentration used, could not completely inhibit the production of interleukin I (IL‐1)‐like activity, but it caused complete inhibition, in a dose‐dependent manner, of the production of IL‐2‐like activity. In addition, PM inhibited the assays of both IL‐1 and IL‐2. Naloxone counteracted all immunosuppressive effects of PM in vivo and in vitro. From this it was concluded that PM operates on the immune system directly, via opioid receptor mechanisms. Our data suggest that immunosuppression by PM, an opioid agonist, may be exerted by an inhibition of interleukin action on lymphocytes, and they confirm the important role of opiate receptors in lymphocyte function.
The Modulatory Effect of Lipoproteins on the Release of Interleukin 1 by Human Peritoneal Macrophages Stimulated with β‐1,3‐d‐Polyglucose Derivatives
Authors: RASMUSSEN L.‐T. , SELJELID R.
Published: June 2006

Human peritoneal macrophages were stimulated in vitro with β‐1,3‐d‐polyglucose‐derivatized microbeads (GDM) or soluble animated 0–1,3‐D‐polyglucOK (AG) in combination with lipoproteins. The release of interleukin 1 (IL‐1) was analysed in cell supernatants in a thymocyte proliferation assay. We report that the release of IL‐1 is markedly enhanced in macrophages stimulated with polyglucose in either form in combination with native low‐density lipoprotein (LDL) or acetyl LDL at a concentration of 100 μg/ml. By increasing the amount of lipoproteins up id 10‐fold, the IL‐1 release decreased sharply. There was only a slight increase in activity when high‐density lipoprotein (HDL) or very low‐density lipoprotein (VLDL) were added. Other stimulatory agents, such as gamma interferon (IFN‐γ) and lipopolysaccharide (LPS) showed about half the activity of polyglucose. There was no significant difference between native LDL and acetyl LDL in potentiating effect. Our observations also suggest that the potentiating effect of LDL or acetyl LDL is not dependent on binding to their specific receptors. These findings provide a connection between macrophages, lipoproteins, and cytokines with regard to their role in the inflammatory response.
Inheritance of a Large Deletion within the Human Immunoglobulin Heavy Chain Constant Region Gene Complex and Immunological Implications
Authors: HENDRIKS R. W. , VAN TOL M. J. D. , DE LANGE G. G. , SCHUURMAN R. K. B.
Published: June 2006

A deletion of the immunoglobulin heavy chain (IgH) pseudo‐γ, γ‐2, γ‐4, ɛ, and α‐2 constant region gene segments was found to segregate unchanged in three generations of a family. The IgG1 locus on the IgH allele carrying the deletion was expressed to the same extent as its normal counterpart. One individual who was heterozygous for the deletion had an IgG2 deficiency, whereas the four other heterozygous individuals had serum levels of IgG2 and IgG4 within the normal ranges. IgA2 levels were low or below the normal range in all heterozygous individuals. The data indicate that the expression of some Ig isotypes can be decreased by hemizygous deletions, possibly due to a lower probability for switching.
A Prospective Study of Immunoglobulin Changes in Relation to Human Immunodeficiency Virus Infection in a Cohort of Homosexual Men
Authors: BRATT G. , WALDENLIND L. , VON KROGH G. , KARLSSON A. , MOBERG L. , BIBERFELD G. , SANDSTRÖM E.
Published: June 2006

Changes in IgG levels and patterns in association with human immunodeficiency virus, (HIV) infection were characterized in a prospective investigation by studying serum electrophoresis and antibodies to HIV at least once a year in 144 homo/bisexual (HS) men during a 4‐year period. Initially, 25 men (17.4%) were HIV‐positive, and this increased to 44 at the end of the study period. HIV‐negative men had IgG levels of 11.2 ± 2.2 g/l. In the 19 HIV seroconverters the mean IgG level rose with time according to the equation IgG = 0.054×+ 12.56 (x= months after the last HIV‐negative test). Oligoclonal IgG bands were found in three of the 19 seroconverters (16%) prior to conversion and in 2/16 (13%), 5/13 (38%), 7/11 (64%), and 3/8 (38%) 1,2, 3, and 4 years after conversion, respectively. Of the 25 initially HIV‐positive men, five have developed acquired immunodeficiency syndrome (AIDS) during the 4.5 year follow‐up. At the first investigation these five men had higher mean IgG levels (16.0 ± 2.7 g/l) than the 20 men who have remained healthy (14.6 ± 2.8 g/l), and all live had oligoclonal bands as compared to 9/20 of those who did not develop AIDS. Oligoclonal IgG bands reflect the IgG increase and seem to indciate long‐standing HIV infection and a poor prognosis.
Engraftment of T‐Depleted Major Histocompatibility Complex‐Mismatched Bone Marrow in T‐Deficient versus Natural Killer‐Deficient Recipients
Authors: SCHOFER O. , BUETTNER H. J. , KRAEMER M. , ZEPP F. , MANNHARDT W.
Published: June 2006

When bone marrow transplantation recipients undergo standard pre‐transplant immunosuppressive therapy, engraftment failures are significantly more frequent with the use of T‐depleted allogeneic donor bone marrow cells than with T cell‐containing allogeneic donor bone marrow cells. The relative importance of T versus natural killer (NK) cells in the rejection process of T‐depleted donor bone marrow cells remains debatable. Here, NK‐ and T‐deficient mouse mutants were transplanted across the same major histocompatibility complex (MHC) differences with homozygous or heterozygous T‐depleted bone marrow cells. Results show that under the experimental conditions described, residual host NK cells are almost exclusively responsible for the increased rejection rate.
Effects of Purified Protein Derivative (PPD)‐Activated Syngeneic Epidermal Cells on a PPD‐Specific Rat T‐Helper Cell Line
Authors: SCHEYNIUS A. , LARSSON P. , SKOGLUND C. , HOLMDAHL R. , KLARESKOG L.
Published: June 2006

An important question in local immune regulation in the skin is how keratinocytes at inflammatory sites can modify a local T‐cell response to antigens introduced via the skin. In the present study we investigated the effects of rat epidermal cells obtained from the site of a tuberculin reaction, on the proliferate response of a syngeneic purified protein derivative (PPD)‐specific CD4+ T‐cell line. Epidermal cell suspensions from the tuberculin‐reactive can contained 23–37% cells expressing class II transplantation antigens as judged by immunocytochemistry compared with 2–3% in normal epidermis. When comparing the capacity of these two different epidermal cell populations to induce a PPD‐specific T‐cell response in vitro, it was found that the PPD‐reactive epidermal cells induced a lower T‐cell response than did normal epidermal cells. This discrepancy cannot be explained by an infiltration of inflammatory cells into the epidermis of tuberculin‐reactive ears. Our data indicate that epidermal cells modified during a delayed‐type hypersensitivity reaction in vivo may suppress an antigen‐specific T‐cell proliferation.