bluuebunny/crossref_metadata_2025 huggingface dataset:
Purified Human T Cells Stimulated with Cross‐Linked Anti‐CD3 Monoclonal Antibody OKT3: rIL‐1 is a Co‐Stimulatory Factor for CD4+ CD29+ CD45RA− T Cells
Authors: PANZER S. , GELLER R. L. , BACH F. H.
Published: June 2006

Accessory cells (AC) are believed to play two major roles in T‐cell activation: they cross‐link certain stimuli such as monoclonal antibodies, and they provide needed cytokines. To differentiate between these roles, we cross‐linked OKT3 on highly purified T‐cells by means of Fc‐specific goat anti‐mouse IgG‐coated polystyrene heads and studied T‐cell activation after exogenously added cytokines. Following addition of AC, rIL‐2. or rIL‐1. CD25 was up‐regulated, and the cells proliferated and became cytotoxic. Both CD4+ and CD8+ cells were activated in the presence of AC or rIL‐2. In contrast, only CD4+ CD29+ CD4SRA cells responded in the presence of rIL‐1. Anti‐IL‐2R p55 (anti‐TAC) monoclonal antibody inhibited the proliferative response supported by rIL‐2 or rIL‐1. To inhibit proliferation of cells stimulated in the presence of AC. anti‐TAC needed to be supplemented with anti‐IL‐6 antibodies, or to be added in a 10‐fold higher concentration. Cultures with AC produced larger amounts of IL‐2 than those supplemented with rIL‐1. Only AC‐containing cultures also produced detectable amounts of IL‐6. These findings combined with the observation that none of 2000 purified T cells counted in each of six independent experiments expressed MHC class II antigens strongly suggest that rIL‐I can activate T cells directly, rather than indirectly by potentiating the function of contaminating AC.
Direct Evidence for Partial Target Specificity in Lymphokine‐Activated Killer Thymocytes
Authors: LECLERCQ G. , DE SMEDT M. , PLUM J.
Published: June 2006

Thymocytes were removed from mice at different times before and after birth, and their phenotype and killing repertoire were analysed after stimulation with human recombinant interleukin 2 (IL‐2). Whereas three different tumour targets were killed by all lymphokine‐activated killer (LAK) populations tested. EL4 lymphoma cells were only killed by LAK cells derived from thymocytes after, but not before, birth. Cold‐target competition tests showed that LAK thymocytes recognized antigenic structures on EL4 cells that arc different from those on other tumour targets. Analysis of EL4 target killing after removal of different subsets from LAK cells revealed that the major part of this killing is exerted by CD8+ cells. Our findings are additional and more direct evidence for partial target specificity in LAK cells.
CD4+ T‐Cell Clones from Autoimmune Thyroid Tissue Cannot be Classified According to their Lymphokine Production
Authors: GRUBECK‐LOEBENSTEIN B. , TURNER M. , PIRICH K. , KASSAL H. , LONDEI M. , WALDHÄUSL W. , FELDMANN M.
Published: June 2006

In order to define whether CD4+ T cells from autoimmune and non‐autoimmune thyroid tissue could be classified according to their mediator production, lymphokine production was studied in 63 thyroid‐derived CD4+ T‐cell clones from four patients with Graves’disease, one with Hashimoto's thyroiditis, and one with non‐toxic goitre (9‐12 clones per patient). The production of interleukin 2 (IL‐2). gamma interferon (IFN‐γ), tumour necrosis factor alpha(TNF‐α). lymphotoxin(LT), interleukin 6 (IL‐6) and transforming growth Factor β (TGF‐β) was assessed at the mRNA level by slot‐blot analysis in unstimulated clones as well as after activation with monoclonal anti‐CD3 (OKT3) and IL‐2 No lymphokine production was found in unstimulated clones, whereas 56% of the clones produced all six lymphokines simultaneously after stimuilation. In the remaining 44% usually not more than one lymphokine was missing from the complete panel Lymphokine mRNA concentrations varied between different clones and different patients, but. in this small sample, not between the diseases from which the clones were originated. There‐was a significant correlation between IL‐6.LT, and IL‐2 mRNA levels and T‐cell helper function. which was estimated by the stimulation of thyroid microsomal autoantibody production using autologous peripheral B cells. TGF‐β(and IFN‐γ mRNA expression was unrelated to T‐cell help. The results demonstrate that intrathyroid T cells from autoimmune and non‐autoimmune thyroid disorders cannot be classified according to their lymphokine production, unlike some results with in vitro‐induced mouse T‐cell clones, where two populations. Th1 and Th2, have been described. SingleT cells are capable of producing a whole panel of lymphokines and thus are capable of triggering a multitude of different processes.
Interleukin 1 in the in Vitro Antigen‐Induced Antibody Response in the Human Adult and Newborn
Authors: MARWITZ P. A. , TENBERGEN‐MEEKES A. J. , HEIJNEN C. J. , RIJKERS G. T. , ZEGERS B. J. M.
Published: June 2006

Previous studies have shown that in vitro stimulation of human B lymphocytes with antigens such as ovalbumin (OA) induces the Formation of small antigen‐specific plaque‐forming cells (PFC) but precludes the activation of the B cells into full‐blown antibody‐secreting cells insufficient production of T cell‐derived growth and differentiation factors appears to be the basis of the phenomenon. Furthermore, cord blood B lymphocytes required 100 limes less OA to become activated in vitro into antigen‐specific PFC, and the distinct antigen‐handling capacities of neonatal monocytes are the basis of this result. We have studied the role of interleukin 1 (IL‐1) in the in vitro response of B lymphocytes from either cord blood or adult blood to OA. Addition of IL‐1 to the B‐cell cultures significantly increased the number of PFC. and about 50% of the plaques now appeared to be high‐rate IgM anti‐OA secreting PFC. The IL‐1 ‐mediated increase in the PFC response was shown to be based on potentiation of T‐helper cell activity. The differences between cord blood and adult blood mononuclear cells in the optimal OA concentration required for effective in vitro activation of B cells remained the same upon addition of II‐1 This result shows that the phenomenon is independent of IL‐1.
Experimental Studies of Immunologically Mediated Enteropathy
Authors: FELSTEIN M. V. , MOWAT A. MCI.
Published: June 2006

We have attempted to investigate the relative roles of specific cytotoxic T lymphocytes (CTL) and allospecific suppressor T cells (T5) in the systemic and intestinal manifestations of acute graft‐versus‐host reaction (GvHR) in mice.

Treatment adult (C57Bl/10xDBA/2)F1 (BDF1) mice with the suppressor cell‐specific toxin 2'‐deoxyguanosine (dGuo) inhibited the weight loss and mortality which normally occur after induction of GvHR and C57BI donor cells. dGuo also delayed the development of a destructive enteropathy as typified by jejunal villus atrophy. Paradoxically, dGuo completely prevented villus atrophy during an acute GvHR in neonatal (CBA × BALB/c)F1 hosts, despite having only a slight ability to inhibit the systemic disease. In both models. dGuo had no effect on the generation of splenomegaly or anti‐host CTL. and dGuo‐treated mice with GvHR actually had increased proliferative alterations in the intestine, as assessed by crypt hyperplasia, In parallel. dGuo prevented the loss of NK cells which normally occurs in acute GvHR.

Thus dGuo inhibits many of the destructive features of systemic and intestinal GvHR without affecting the development of CTL. We conclude that a dGuo‐sensitive mechanism causes the transition from a proliferative to a destructive GvHR.
Expression of the Alpha‐Chain Gene in Heterogeneous IgA Immunodeficiency
Authors: KANEKO H. , KONDO N. , MOTOYOSHI F. , MORI S. , KOBAYASHI Y. , OZAWA T. , ORII T.
Published: June 2006

Five heterogeneous IgA‐immunodeficient patients were analysed for expression of the α‐chain gene. The number of surface IgA‐bearing B cells was low in four patients Southern blot analysis indicated no deletion of immunoglobulin structural genes coding for Cα or α switching‐region genes. The number of surface IgM and IgA double‐bearing B cells increased in some patients. Addition of recombinant tnterieukin 4 (rIL‐4). rIL.‐5. and rIL‐6 to the normal B cells enhanced IgA production. However. B cells of the patients showed no or one‐third lower IgA production in response to these lymphokines, even though there was proliferation ill 4, rIL ‐5, and rIL‐6 induced low or no expression of α mRNA of the patients B cells These results suggested that the patients lacked B cells able to produce transcripts for the IgA heavy chain, and that some patients’B cells might be defective at the switch‐recombination process from u to a or from μ to α or from μ and α to α.
Tγδ Cell Subsets in Cord and Adult Blood
Authors: SMITH M. D. , WORMAN C. , YÜKSEL F. , YÜKSEL B. , MORETTA L. , CICCONE E. , GROSSI C. E. , MACKENZIE L. , LYDYARD P. M.
Published: June 2006

A minor population of T cells expresses a heterodimeric antigen receptor composed of y and A chains (TcR‐1). In blood from adults, two subsets of Tγδ cells can be identified by the monoclonalantibodies (MoAb) BB3 and A13. Little is known about the distribution and markers of these subsets early in life. We have therefore examined both the frequencies of these cells in cord blood and their expression of the cytotoxicity‐associated marker serine esterase (SK). using immunocytochemical techniques.

Our data show lower percentages of TcR‐1+ cells in the blood of newborns compared with that in adults. However, the ratio of the Al3+/BB3 cells was significantly higher in cord than in adult blood. Whereas virtually all the adult TcR‐1+ cells in blood were SE‐positive. only a small proportion of the cord blood cells earned ibis enzymes. This was; restricted lo the BB3+ Tγδ ‐cell subset in the cord.

Our data suggest different characteristics of the TcR‐1+ cells in blood from newborns compared with adult blood, and study of the functions of the different subsets, e.g. cytotoxicity. will be important in understanding their particular role in immunity.
Enhancement of Complement Activation and Cytolysis of Human IgG3 by Deletion of Hinge Exons
Authors: MICHAELSEN T. E. , WESTBY A. AASE. C. , SANDLIE I.
Published: June 2006

The capacity to induce complement‐mediated cell lysis is greatly enhanced by truncating the hinge of IgG3 through exon deletions. This was shown by establishing five new cell lines which secreted chimeric IgG3 molecules with specificity for the hapten 4‐hydroxy‐3‐nitrophenacetyl (NP) and having 47,45,32,15, and 0 amino acid hinge regions (the wild‐type IgG3 has 62 amine acids in the hinge). Efficient complement activation and complement‐mediated cell lysis did not depend on a long total hinge or on a long ‘upper’ hinge (the stretch From the beginning of the hinge to the first inter‐heavy chain S‐S bond).On the contrary, the mutant having a 15 amino acid hinge element was up to 10 times more efficient in complement lysis than the wild type. Thus the complement activation potential appeared to be down‐regulated in the wild type. On the other hand, the mutant lacking the hinge altogether did not activate complement or induce complement‐mediated cytolysis. These findings have to be taken into account when antibodies are designed for human therapy.
Alteration of Membrane Oligosaccharides by Castanospermine, an Alpha Glucosidase Inhibitor, Enhances Immunoglobulin Production in Staphylococcus aureus Cowan I‐Stimulated Lymphocyte Culture
Authors: KARASUNO T. , KANAYAMA Y. , NISHIURA T. , NAKAO H. , KURATA Y. , YONEZAWA T. , TARUI S.
Published: June 2006

Castanospermine (CSP) inhibits α‐glucosidase. which is involved in the initial step of N‐linked oligosaccharide processing of secretory and membrane glycoproteins. In Staphylococcus aureus Cowan I (SAC)‐stimulated human lymphocyte culture, CSP at a dose of 20 μg/ml caused a twofold increase in immunoglobulin G (IgG) release after 7 days. An initial 48‐h exposure to CSP sufficed for this enhancing effect. Plaque‐forming cell assays on the seventh day disclosed that CSP caused an increase in the number of IgG‐, IgA‐ and IgM‐secreting cells. In cross‐culture experiments, only a mixture of B cells pretreated with CSP and untreated T cells showed an increase in IgG production. Tritiated thymidine incorporation studies revealed that CSP enhanced B‐cell responses to T cell‐derived soluble factor (TSF). When incubated with CSP for 18 h. B cells showed an increased surface binding on [3H] concanavalin A (Con A). These results indicate that the alteration in B‐cell membrane oligosaccharides enhances the response to TSF at in early stage of SAC culture, leading to an increase in Ig‐secreting cell number at later stages. The present study provides evidence that cell‐surface oligosaccharides of B cells play an important role in the responses of B cells to lymphokines.
The Occurrence and Sources of Natural Antibody in Human Bile and Serum Against the O Antigens of Two Escherichia coli Serotypes
Authors: HANSEN P. G. C. , JACKSON G. D. F.
Published: June 2006

Paired serum and bile samples from normal subjects as well as patients with biliary disease were tested for natural antibody to two individual Escherichia coli O antigens by ELISA. Serum antibody was most commonly of IgM and IgG class. Antibody was less frequently detected in bile and was more commonly IgM than IgA. with IgG activity detected infrequently. Little relation was apparent between antibody in paired samples: activity could be present in both serum and bile or in either fluid alone. Titres in paired samples also did not correspond when normalised with respect to the concentrations of relevant isotypes: bile was Frequently enriched for natural antibody as a proportion of total immunoglobulin compared with serum Secretory component‐bound antibody was detectable in some biles that contained IgA and/or IgM activity and in the serum of 33%. of subjects with biliary disorders but not in normal sera A series of paired samples taken from three individuals was also examined for antibody against each subject's own intestinal commensal E. coli. Serum IgM and IgG activity was present in all samples, but antibody in bile was less frequent and was of IgM or IgA class. These results suggest that natural antibody in human bile occurs independently of antibody in serum and that it is substantially derived from local sources.
Synthesis of C3, C5, C6, C7, C8, and C9 by Human Fibroblasts
Authors: GARRED P. , HETLAND G. , MOLLNES T. E. , STOERVOLD G.
Published: June 2006

We investigated the ability of human fibroblasts to produce the components of the final common pathway (C3‐C9) of complement in vitro by co‐culturing an alternative complement activator (agarose beads) with the cells. The test system involved incubation of beads with anti‐complement antibodies followed by radioactive‐labelled anti‐Ig detection antibodies. Subsequently, the beads were examined in a radioimmunoassay. Our results indicate that human fibroblasts produce C3, C5, C6, C7, C8, and C9. A neoepitope selectively expressed on activated C9 was detected, indicating assembly of the terminal complement complex and thus formation of a functional terminal complement pathway by the fibroblasts.
Fcγ Receptor Heterogeneity in the Human Placenta
Authors: KRISTOFFERSEN E. K. , ULVESTAD E. , VEDELER C. A. , MATRE R.
Published: June 2006

Fc receptors for IgG, FcRI (CD64), FcRII (OD32), and FcRIII (CD 16) in human placenta were studied by indirect immunohistochemistry using avidin biotin‐peroxidase complexes For the sunning of cryostat sections. The MoAb 32.2 against FcRI stained cells in the loose connective tissue of the placental villi. The MoAb IV3 (FcRII) and C1KM5 (FcRII) also stained stromal cells and in addition stained the endothelium of the placental villi. The MoAb anti‐Leu‐11b against FcRIII and BID6 against a 40‐kDa FcR from placenta stained both stromal cells and endothelium as well as the fetal trophoblasts lining the villi. The MoAb 3G8 (FcRIII) also stained trophoblasts and stromal cells but did not stain the endothelium

The heterogeneity of FcR expression on human placenta is established. The function of the different receptors is still unclear.
Thymic Epithelial Cells
Authors: CLAESSON M. H. , ROPKE C.
Published: June 2006

We show that thymic epithelial cells grown under serum‐free conditions in a chemically defined culture medium can act as veto cells in vitro. The veto activity of thymic epithelial cells results in inactivation of specific alloreactive cytotoxic T‐cell precursors at the clonal level. It is concluded that the epithelial stromal cells of the thymus, by acting as veto cells, may he responsible for the negative intrathymic selection of self‐reactive thymocytes leading to elimination of the vast majority of immature thymic lymphocytes.
Cells Involved in the Immune Response XXXVII. Antigen‐Specific Suppressor Cells, Capable of Secreting an Antigen‐Specific Suppressor Factor, Migrate from the Thymus to the Spleen Following Primary Immunization
Authors: RICHTER M. , TRUDEL I. , TALOR E.
Published: June 2006

The splenic mononuclear cells (MNC) of rabbits 7‐14 and 30‐48 days following primary intravenous immunization with sheep erythrocytes generated large numbers of antibody‐secreting or plaque‐forming cells (PFC) in secondary immune responses induced in vitro, whereas the splenic MNC obtained from rabbits 18‐30 days following primary intravenous immunization generated poor secondary immune responses (few PFC) in vitro. However, these latter splenic MNC depleted of T cells consistently generated many PFC in the secondary immune response in vitro. Furthermore, the splenic MNC of rabbits thymectomized prior to day 3 following primary intravenous immunization also generated good secondary immune responses in vitro, irrespective of the time of killing post‐immunization, whereas the splenic MNC of rabbits thymectomized after day 7 following primary immunization generated poor secondary immune responses in vitro. These results indicate that the depressed ability of the splenic MNC, obtained from rabbits killed between days 18 and 30 post‐primary immunization, to generate significant secondary immune responses in vitro is due to suppressor T cells. The suppressor cells are referred to as immune spleen suppressor cells or ISSC. It was demonstrated that the suppression by the ISSC is antigen‐specific and that the ISSC secrete an antigen‐specific suppressor factor referred to as immune spleen suppressor factor or ISSF. It is concluded that the ISSC are generated in the thymus within a few days following primary immunization, that they migrate to and infiltrate the spleen between days 3 and 7 following primary immunization, and that they suppress or down‐regulate further antibody synthesis via the secretion, locally of ISSF.
Inhibitory Effect of Mycoplasma‐Released Arginase
Authors: CLAESSON M. H. , TSCHERNING T. , NISSEN M. H. , LIND K.
Published: June 2006

Non‐fermenting mycoplasma species deplete culture media for arginine through arginase activity linked to their arginine deiminase pathway, resulting in proliferation arrest and cell death in mycoplasma‐contaminated cell cultures. The presence of only 2‐3 Mycoplasma (M.) arginini‐contaminated T cells in a one‐way allogeneic mixed‐lymphocyte culture (MLC) significantly inhibits development of cytotoxic T‐cell activity. Likewise, strong degrees of inhibition are observed after addition of nanogram doses of M. arginini extracts (MAE) to MLC or cell proliferation cultures. M. arginini‐induced cell inhibition can be reversed by addition of excess arginine to the culture medium. Antisera raised against non‐fermenting, but not against fermenting, mycoplasma species block the inhibitory effect of MAE. SDS‐PAGE separation of MAE disclosed a broad band at 60 kDa which contained arginase activity when assayed in MLC and cell proliferation culture. SDS PAGE followed by western blotting and reaction with antisera raised against non‐fermenting mycoplasma species demonstrated a band at 43 kDa common for these micro‐organisms.
The Response of Human B Cells to Interleukin 4 is Determined by their Stage of Activation and Differentiation
Authors: MAHER D W. , PIKE BEVERLEY L. , BOYD A. W.
Published: June 2006

The effect of purified‐ recombinant human interleukin 4 (IL‐4) on proliferation and IgM secretion of normal and malignant human B cells was studied. IL‐4 was found to co‐stimulate the proliferation of splenic B cells in the presence of anti‐Ig coupled to polyacrylamide beads (anti‐Ig beads) for a period of 4 days In contrast. IL‐4 had little co‐stimulatory effect on the proliferative response of splenic B cells to the more potent mitogen Staphylococcus aureus Cowan strain I (SAC) Moreover, IL‐4 inhibited interleukin: 2(IL‐2) induced proliferation of cells co‐stimulated with SAC Mitogen‐induced pre‐activation of B cells in the presence of IL‐4 resulted in a reduction in subsequent IL‐2‐induced IgM secretion without significantly affecting proliferation Human B‐cell tumours were also cultured over a 2‐3 day period in the presence of anti‐Ig beads plus IL‐2. or IL‐4orboth IL‐2 and IL‐4. IL‐4 inhibited IL‐2‐induced proliferation in all cases of B‐cell chronic lymphocytic leukaemia (B‐CLL)and the majority of cases of low‐grade lymphoma (LGL)and hairy cell leukaemia (HCL). These findings suggest that IL‐4 has stimulatory actions on resting B cells, most evident in the presence of submaximal co‐mitogenic signals, and inhibitory actions on actuated B cells, especially antagonism of the effects of IL‐2.
Effects of Isoprinosine Treatment of HIV‐Positive Patients on Blood Mononuclear Cell Subsets, NK‐ and T‐Cell Function, Tumour Necrosis Factor, and Interleukins 1, 2, and 6
Authors: PEDERSEN B. K. , TVEDE N. , DIAMANT M. , GERSTOFT J. , HANSEN M. BAGGE , HAAHR P. M. , HØRDING M. , KAPPEL M. , KLOKKER M. , SØEBERG B. , SKINHØJ P.
Published: June 2006

The immunomodulatory drug isoprinosine has been found to delay the occurrence of opportunistic infections in HIV‐infected individuals. To elucidate the mechanism of action, eight HIV‐positive, healthy patients were treated with isoprinosine, 3 g/day for 28 days; six patients received no treatment but were examined in parallel, and two patients were withdrawn. All patients had blood collected just before the start as well as on days 14 and 28 of isoprinosine treatment.

Isoprinosine significantly enhanced the lymphoproliferative response after stimulation with phytohaemagglutinin (PHA) and purified derivative of tuberculin (PPD), while isoprinosine had no effect on the following immune parameters: the expression of surface markers on blood mononuclear cells including CD2, CD3, CD4, CD8, CD14, CD19, CD20, CD25, leu‐8, and HLA‐DR. Furthermore isoprinosine did not influence the ability of interleukin 2 (IL‐2) to stimulate the proliferation of lymphocytes or the natural killer (NK) cell activity either unstimulated or stimulated in vitro with alpha interferon (IFN‐α), IL‐2. or indomethacin. Neither did isoprinosine affect the in vitro production of (IL‐1) α or β, IL‐2, IL‐6. or tumour necrosis factor (TNF).
Tγδ Cells in Juvenile Rheumatoid Arthritis and Rheumatoid Arthritis
Authors: KJELDSEN‐KRAGH J. , QUAYLE A. , KALVENES C. , FØRRE Ø , SØRSKAAR D. , VINJE O. , THOEN J. , NATVIG J. B.
Published: June 2006

Using the anti‐TcRγ/δ‐1 monoclonal antibody and flow cytometry, we examined the number of Tγδ cells in paired samples of peripheral blood and synovial fluid or tissue from 24 children with juvenile rheumatoid arthritis (JRA). five adult patients with JRA, and 14 patients with rheumatoid arthritis (RA). No significant difference was found in the synovial compartment Tγδ values compared with the blood in JRA, adult JRA, or RA patients. Nor was any significant difference found in the peripheral blood or synovial compartment Tγδ values in any of the three patient groups compared with the peripheral blood of normal controls. However, seven of the children with JRA had very high Tγδ values in the synovial compartment while none of the normal children had high Tγδ values in the blood (P= 0.02. Fisher's exact test). This may indicate a possible separate JRA patient group with high Tγδ levels in the synovial compartment. In six JRA patients further analysed for Tγδ subpopulations, a significant predominance of Vδ1 + cells was found in the synovial compartment compared with the corresponding peripheral blood samples (P<0 05. Wilcoxon's signed test) and with peripheral blood of child controls (P<0 05, Mann Whitney U test). In these six patients, the Tγδ ‐cell expression of the very early activation antigen CD69 were significantly higher (P<0 05. Wilcoxon's signed test) in the synovial compartment compared with the peripheral blood. Synovial Tγδ cells expressing HLA‐DR and interleukin 2 receptors could also be detected, in contrast to the peripheral blood in which no Tγδ cells expressing these antigens could be found. These data suggest that the synovial Tγδ cells had been activated in vivo.
Phagocyte Function in Familial Hypercholesterolaemia: Peripheral Blood Monocytes Exposed to Lipopolysaccharide Show Increased Tumour Necrosis Factor Production
Authors: LEIRISALO‐REPO M. , JÄÄTTELÄ M. , GYLLING H , MIETTINEN T. A. , REPO H.
Published: June 2006

We studied functions of polymorphonuclear leucocytes (PMN) and monocytes from peripheral blood of subjects with familial hypercholesterolaemia (FH). FH monocytes exposed to Escherichia coli lipopolysaccharide (LPS) in 10% human AB serum generated tumour necrosis factor (TNF) significantly more than did control monocytes. After lowering of serum low‐density lipoprotein (LDL) levels by drug treatment. FH monocytes exposed to LPS in the absence of exogenous lipoproteins generated significantly more TNF than did control monocytes. These findings suggest that increased TNF production is not affected by hypolipidaemic treatment and may not derive from differences between uptake of exogenous LDL by FH monocytes and control cells. Chemotaxis, chemokinesis, and random migration of both FH PMN and FH monocytes were normal, as determined by agarose assay and membrane filter assay. FH PMN showed increased luminol‐enhanced chemiluminescence in response to 2.5 × 10 ‐6 M, but not to 2.5X 10‐6 M, N‐formyl‐methionyl‐leucyl‐phenylalanine, and not to serum‐treated zymosan or to phorbol myristate acetate. Luminol‐ and lucigenin‐enhanced chemiluminescence responses of FH monocytes were normal. In summary, the major aberration found in the present study was that FH monocytes stimulated with LPS show enhanced production of TNF. The possibility that exaggerated TNF production contributes to an early development of atherosclerotic lesions in FH subjects warrants further studies.
Distribution and Characterization of Autoantibodies to Interleukin 1α in Normal Human Sera
Authors: SVENSON M. , HANSEN M. BAGGE , BENDTZEN K.
Published: June 2006

Antibodies against IL‐1α were detected in sera of apparently healthy individuals. The immunoglobulins belonged to the IgG and class, particularly IgG1. IgG2. and IgG4. [125I]rIL‐1α bound to Tab fragments of IgG. and IgG immune complexes of molecular weights from 160 to 700 kDa were formed in the sera by [125I]rIL‐1α. The occurrence of detectable anti‐IL‐1α IgG in sera of 32 male and 32 female donors was 25 and 22% respectively. As judged by Scatchard analysis of the binding data, the capacity and avidity of binding were greaser in the male than in the female sera (mean capacity to bind [l25I]rIL‐1α 10 [0.7 ‐27] versus 3.3 [0.5‐7.3] ng/ml; and mean Kd:5.5 [5‐7] versus 11 [4 16] PM). The antibodies did not cross‐bind human recombinant IL‐1β, IL‐2, 1L‐6. or tumour necrosis factor alpha (TNF‐α). It is concluded that native IL‐1α seems lo trigger production of specific, high‐avidity IgG antibodies in a relatively large number of normal individuals. These autoantibodies may regulate immunoinflammatory processes involving IL‐1α.
The Effect of HLA and Insulin‐Dependent Diabetes Mellitus on the Secretion Levels of Tumour Necrosis Factors Alpha and Beta and Gamma Interferon
Authors: SACHS J. A. , WHICHELOW C. E. , HITMAN G. A. , NIVEN M. , THODE H. , MEAGER A.
Published: June 2006

Tumour necrosis factors alpha and beta (TNF‐α and TNF‐β) and gamma interferon (IFN‐γ) were measured by ELISA in the supernatants of phytohaemagglutinin (PHA)‐activated peripheral blood mononuclear cells (PBMNC) from 98 individuals (60 controls and 38 patients with insulin‐dependent diabetes mellitus [IDDM]. The PBMNC were incubated with varying concentrations of PHA (0,1,5, and 10 μg/ml) for 72 h. In our population study we observed a correlation between the levels of secretion of TNF‐α and IFN‐γ but not TNF‐β. The complete data set was analysed by non‐parametric tests, and no associations with HLA phenotypes existed. Reduced levels of TNF‐β, but not TNF‐α or IFN‐γ, secretion were found in IDDM patients stimulated with 1 and 5 μg/ml of PHA (P ‐0.001 and 0.02 respectively). None of the lymphokine secretion levels at any PHA concentration correlated with particular HLA phenotypes.

Analysis of the natural log‐transformed data indicated that only for the TNF‐β levels (at 5 μg/ml PHA) could subjects be divided into high and low secretors, which also did not correlate with a particular HLA‐B or ‐DR antigen.
Different Activation States of Human Lymphocytes after Antibody‐Mediated Stimulation via CD3 and the α/β T‐Cell Receptor
Authors: SCHLITT H. J. , SCHWINZER R , WONIGFIT K.
Published: June 2006

BMA031 is an IgG2b antibody directed towards the human α/β T‐cell receptor that is able to induce proliferation of peripheral blood mononuclear cells independent of antibody cross‐linking. The proliferative response to BMA031 during the first 1 days of culture is usually of similar magnitude lo that induced by the IgG2a CD3 antibody OKT3 but decreases quickly afterwards. Stimulation by BMA031 induces no measureable IL‐2 release, very low expression of the IL‐2 receptor, and does not trigger cytotoxic effector function. However, cross‐linking of the antibody or addition of IL‐2 leads So enhanced and prolonged proliferation, strong IL‐2 receptor expression, and cytotoxic activity, features that are usually found after Stimulation by the IgG2a CD3 antibody OKT3 in soluble form. The stimulatory effect of BMA031 cannot be diminished by IL‐2 receptor blocking, whereas stimulation by OKT3 is strongly reduced Moreover, proliferation induced by BMA031 has lower sensitivity to inhibition by ciclosporin than OKT3. From these results two major conclusions can be drawn: (I) an IL‐2‐independent way of activation may be important for the short‐term proliferation of the T cells stimulated by BMA031 and (2) after stimulation by BMA031. cells reach a state of activation that is different from that induced by OK.T3. These differences arc most likely related to the different specificities of the antibodies, α/β TcR versus CD3, suggesting that different activation signals are triggered via CD3 and via the α/β TcR.
SHORT PAPER
Authors: OHKUBO T. , TSUDA M. , TAMURA M. , YAMAMURA M.
Published: June 2006

A method of separating neutrophils from the peripheral blood of rats with 95% purity is described. To determine the role of antigenic stimulation in neutrophil function, neutrophils front germ‐free (GF) rats were compared with those of conventional (CV) rats. Neutrophil counts were lower in GF rats but the total number of monocytic cells was the same.

To measure phagocytic killing, superoxide anion production was determined and found to be lower in GF neutrophils (2.1 ± 0.5 nmol/min. 106 cells) than in CV neutrophils (9.5 ± 2.9 nmol/min/106 cells). Myeloperoxidase activity was found to be twofold higher in GF neutrophils. When a recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) was intravenously injected, superoxide production did not change in either GF or CV neutrophils, but the myeloperoxidase activity of neutrophils in both types of rats decreased. rhG‐CSF increased the number of neutrophils in both GF (10‐fold) and CV rats (three‐ to fourfold).
Transmembrane Signalling via HLA‐DR Molecules on T Cells from a Sezary T‐Cell Leukaemia Line
Authors: GEISLER C. , KUHLMANN J. , MØLLER T. , PLESNER T. , RUBIN B.
Published: June 2006

The human Sezary T‐cell leukaemia line. HUT.78, represents a population of activated T cells, i.e. they are HLA‐DR+ and IL‐2R+. We have analysed the capacity of HUT.78cells (1) to stimulate HLA‐DR‐specific T‐cell lines or clones and (2) to be induced to synthesize IL‐2 by anti‐HLA‐DR monoclonal antibodies. The results of our experiments show that HLA‐DR molecules on HUT.78 cells can stimulate at least one HLA‐DR‐specific T‐cell clone and can act as transmembrane signal transmitters.
Strong Donor Mononuclear Cell Reactivity for Herpes Simplex Virus (HSV) Antigen in HSV Immune Donors Combined with Recipient Seropositivity for HSV is Associated with Acute Graft‐versus‐Host Disease
Authors: BOSTRÖM L. , RINGDÉN O. , FORSGREN M.
Published: June 2006

Prior to bone marrow transplantation (BMT) titres of IgG antibodies for cytomegalovirus (CMV), herpes simplex virus (HSV) and varicella zoster virus (VZV) were analysed in 51 donors and recipients of allogeneic bone marrow. Donor mononuclear cells from peripheral blood and bone marrow cells were stimulated with antigen prepared from CMV, HSV and VZV. High IgG titres for HSV in the recipient were associated with grade II–III acute graft‐versus‐host disease (GVHD) (P= 0.05). Furthermore, the combination of positive IgG titre for HSV antibodies in the recipient, and strong donor blood mononuclear cell reactivity to HSV antigen in HSV immune donors, significantly increased the incidence of grade II–III acute GVHD (P= 0.04). The data suggest that HSV immune donor mononuclear cells may initiate a GVH reaction.
Deposition of IgA is Associated with Macrophage Influx in the Kidney of Rats
Authors: STAD R. K. , BOGERS W. M. J. M. , MUIZERT Y. , ES L. A.VAN , DAHA M. R.
Published: June 2006

In the present study we treated rats with N‐nitrosodimethylamine (DMN) or D‐galactosamine (GALN) to achieve increased circulating IgA levels in rats. GALN‐treated rats showed a six‐fold increase in scrum IgA levels after the first intraperitoneal (i.p.) injection, whereas a 10‐fold increase after I second i.p. injection of GALN was seen. DMN‐treated rats showed a three‐fold increase in serum IgA levels. No differences were observed in IgG and IgM levels between treated and non‐treated rats. Sequential renal biopsies analysed by immunofluorescence exhibited mesangial deposits of IgA with different intensities of C3 deposition. Rats treated with GALN showed more IgA deposition in the kidney than DMN‐treated rats. The IgA deposition together with C3 was more prominent in rats treated with GALN than in rats treated with DMN. The deposition ofC3 together with IgA was associated with an influx of monocytes as detected by ED‐I, an antibody directed against a rat monocyte marker. These studies provide evidence that an increase in serum IgA levels is associated with deposition of IgA in the kidney and that IgA has an inflammatory potential.
Fibril Amyloid Enhancing Factor (FAEF)‐Accelerated Amyloidosis in the Hamster is Not Dependent on Serine Esterase Activity and Mononuclear Phagocytosis
Authors: NIEWOLD TH. A. , GRUYS E. , KISILEVSKY R. , SHIRAHAMA† T. S.
Published: June 2006

Cells of the mononuclear phagocytic system (MPS) were described as playing a decisive role in amyloidogenesis. A relationship between the amyloid enhancing factor (AEF) and MPS cells was suggested and recently AEF activity was attributed to a serine esterase (SE) of leucocytic origin. In the present study, no correlation was found between the SE content and AEF activity in either peritoneal cell lysates or AEF preparations of different origin. Furthermore, pretreatment of fibril AEF (FAEF) with the SE inhibitor phenylmethylsulphonyl fluoride (PMSF) did not affect its activity in the hamster. Blockade of the MPS by dextran sulphate did not inhibit deposition of amyloid after intravenous injection of FAEF but amyloid deposition was inhibited when FAEF was administered intraperitoneally. These results suggest that MPS cells could be involved in transport of AEF, but that phagocytic activity of MPS cells is not essential in AA‐amyloid fibrillogenesis. It is concluded that these results are not consistent with the previously suggested nature of the AEF or with the proposed central role of the MPS in amyloidogenesis.
Antibodies to Viral and Mammalian Native DNA in Response to BK Virus Inoculation and Subsequent Immunization with Calf Thymus DNA
Authors: FREDRIKSEN K. , BRANNSETHER B. , TRAAVIK T. , REKVIG O. P.
Published: June 2006

Recent studies have demonstrated that anti‐DNA antibodies share important genetical features with antibodies to exogenous antigens, suggesting that anti‐DNA antibody responses may be (auto‐) antigen driven. We have earlier defined three out of five rabbits as anti‐dsDNA antibody responders based on reactivity with calf thymus (CT) dsDNA after inoculation with the human dsDNA virus BK. In the present study we demonstrate that all five animals that received BK virus inoculations produced antibodies to BK virus dsDNA. These antibodies did not cross‐react with CT dsDNA, as shown by inhibition experiments. The anti‐BK dsDNA antibodies persisted over time, in contrast to the anti‐CT dsDNA antibodies that decreased shortly after a peak following the first boost of BK virus. While the anti‐CT dsDNA antibodies decreased, the anti‐BK dsDNA antibodies remained elevated, thus supporting the results of the inhibition experiments which showed that two independent antibody populations are produced after BK virus inoculations. In the three animals producing anti‐mammalian dsDNA antibodies, antibodies recognizing CT dsDNA reappeared after intravenous administration of a complex of CT dsDN A and methylated bovine serum albumin (MBSA) without adjuvant. The latter anti‐CT dsDNA antibodies did not cross‐react with BK dsDNA. In contrast to earlier studies we conclude that mammalian dsDNA may be immunogenic, and that discrete molecular differences in DNA antigens from different sources may induce anti‐dsDNA antibodies specific for dsDNA molecules of different origin.
Cyclic Adenosine Monophosphate Decreases the Secretion, but not the Cell‐Associated Levels, of Interleukin‐1β in Lipopolysaccharide‐Activated Human Monocytes
Authors: VIHERLUOTO J. , PALKAMA T. , SILVENNOINEN O. , HURME M.
Published: June 2006

Interleukin‐1β (IL‐1β) is a cytokine produced mainly by activated monocytes though the mechanism by which it is released is still unknown. Elevation of intracellular cyclic adenosine monophosphate (cAMP) is considered an important down‐regulative signal in the production of IL‐1β in lipopolysaccharide (LPS)‐induced monocytes. In this study we show that in LPS‐activated human monocytes, elevated cAMP concentrations (induced by either prostaglandin E2, forskolin or dibutyrylcyclic AMP) affected specifically secretion of IL‐1β; the amount of secreted IL‐β was clearly reduced whereas the cell‐associated level remained unchanged. TNF‐α, a normal secretory protein, was used as a control. Cyclic AMP also inhibited TNF production by monocytes, but the decrease was of the same magnitude in the extracellular and intracellular compartments. Thus, the down‐regulative effect of cAMP on the production of these monokines is clearly different.
Anti‐Granulocyte Antibodies (C‐ANCA, P‐ANCA, GS‐ANA) Studied by Confocal Scanning Laser Fluorescence Microscopy, ELISA, and Chemiluminescence Techniques
Authors: SKOGH T. , DAHLGREN C. , HOLMGREN K. , PEEN E. , STENDAHL O.
Published: June 2006

Fifty‐nine patient sera with antibodies against human polymorphonuclear neutrophil granulocyte(PMN)antigens, as determined primarily by indirect immunofluorescence microscopy (UF) screening, were further analysed by enzyme‐linked Immunosorbent assays (ELISA). The antibodies were primarily characterized by their immunomorphological staining patterns on ethanol‐fixed PMN as judged by conventional IIF microscopy, i.e. anti‐neutrophil cytoplasmic antibodies (ANCA) giving a pancytoplasmic granular staining pattern (C‐ANCA) or a diffuse perinuclear cytoplasmic pattern (P‐ANCA), or granulocyte‐specific anti‐nuclear antibodies (GS‐ANA) producing a homogeneous or peripheral nuclear staining pattern. The three distinct patterns were confirmed by confocal scanning laser IIF microscopy.

As antigen substrates in the ELISA tests we used an extract from azurophil PMN granules, myeloperoxidase (MPO), and lactoferrin. As expected, most (but not all) of the C‐ANCA positive sera turned out positive in the α‐ELISA assay. Both P‐ANCA and GS‐ANA positive sera had high frequencies of antibodies against MPO. Occasional P‐ANCA positive sera contained anti‐lactoferrin antibodies. Although P‐ANCA and GS‐ANA in general probably represent the same type of auto‐antibodies, we regard it appropriate to make a distinction between the two patterns, until the existence of‘true’granulocyte‐specific ANAs has been ruled out.

All sera were analysed for their ability to activate PMN in vitro as judged by the generation of a chemiluminescence(CL) response. Sera containing C‐ANCA, as well as sera containing P‐ANCA or GS‐ANA, showed high frequencies of positive CL tests using‘resting’isolated PMN. The reactions were diminished, but not always abolished, by heat‐treatment of the sera.
Protein Kinase C Regulates MHC‐Class II Expression on Endothelial Cells
Authors: MATTILA P. , RENKONEN R.
Published: June 2006

Cultured endothelial ceils (EC) were negative for class II antigen in native suite, whereas 49% of the endothelial cells began to express this antigen after 24 h of interferon‐gamma (IFN‐γ) stimulation. IFN‐γ induced relatively slowly the elevation of class II antigen on endothelial cells, since it took more than 10 h before the first signs of mRNA signal of class II were detected. Class II antigen instead began to appear during 16‐20 h after the initiation of IFN‐γ treatment. Committed step analysis revealed that IFN‐γ could not be washed away at any time point without affecting the number of class II positive cells after a 24‐h incubation period. Protein kinase C (PKC) activator phorbol‐12‐myristate‐13‐acctate (PMA) could partially mimic IFN‐γ effect in inducing class II expression on endothelial cells. PMA together with another PKC activator arachidonic acid (AA) induced class II expression on endothelial cells as welt as IFN‐γ. The crucial role of activation of PKC in the IFN‐γ induced class II expression can also be demonstrated by using PKC inhibitors in combination with IFN‐γ. PKC inhibitor H7 was able to decrease almost totally IFN‐γ induced class II induction both on the mRNA as well as on the protein level. PKC activation has often been linked to its translocation from the cytosolic compartment to the inner surface of the plasma membrane. IFN‐γ induced a transient 2.4‐fold increase in the membrane‐associated PKC in endothelial cells within 10 min after the initiation of the stimulus. Taken together these data show that IFN‐γ requires a long time before class II mRNA or protein are expressed in endothelial ceils. PKC activation is crucial for this class II induction. The regulation of class II expression occurs at transcriptional level and requires de novo protein synthesis as shown by cycloheximide inhibition.
Abnormal T‐Cell Expansion and V‐Gene Usage in Myasthenia Gravis Patients
Authors: GRUNEWALD J. , ÅHLBERG R. , LEFVERT A.‐K. , DERSIMONIAN H. , WIGZELL H. , JANSON C. H.
Published: June 2006

To determine the extent of V‐gene heterogeneity of blood T lymphocytes in patients suffering from Myasthenia Gravis (MG), we used eight recently available monoclonal antibodies (MoAb), directed against different Vα and Vβ gene products of the variable part of the T‐cell receptor (TCR), covering approximately 25% of the α/β T cells in normal peripheral blood (PBL) of healthy individuals. Using a two‐colour immunofluorescence method, we could calculate the expression of α/β V segments within the two major T‐cell subsets, CD4‐/CD8+ and CD4+/CD8‐ lymphocytes. Twenty‐seven per cent (4/15) of the MG patients had T cells showing signs of abnormal expansion. Furthermore, among these expanded T cells, a restricted Vβ12 gene expansion could be seen, in three out of four patients. No correlation between TCR V‐gene usage and HLA haplotypes (HLA‐A, ‐B, ‐DR and ‐DQ) could be seen. Our data suggest that the majority of MG patients have abnormally expanded T‐cell clones. The relevance of these findings is discussed.
In Situ Hybridization of Interferon‐Gamma Producing Peripheral Blood Mononuclear Cells
Authors: RUTENFRANZ I. , KRUSE A. , KIRCHNER H.
Published: June 2006

Individual interferon‐gamma (IFN‐gamma) producing cells in activated human peripheral blood mononuclear cells (PBMC) were characterized by in situ hybridization using [35S]‐labelled antisense RNA probes. The proportion of positive cells expressing IFN‐gamma mRNA varied according to the substances used for stimulation. IFN‐gamma mRNA expressed a relatively low percentage of 1 8% PBMC after a single stimulus with mitogens or OKT‐3 antibody and 20‐30% of the cells were identified to synthesize IFN‐gamma mRNA after stimulation with PHA + P‐MA+OKT‐3 antibody. The expression of IFN‐gamma mRNA and production of the lymphokine was dependent on accessory cells. If accessory ceils were replaced by recombinant interleukin‐1 (IL‐l) plus interleukin‐6 (IL‐6). then T‐cell proliferation to phytohaemagglutinin (PHA) could be partially restored and measurable amounts of IFN‐gamma were detected. The addition of interIeukin‐2 (IL‐2) or phorbol‐12‐myrislate‐13‐acetate to T cells stimulated with PHA. IL‐1 and IL‐6 did not restore the production of IFN‐gamma to an extent comparable to that produced by T cells stimulated in the presence of accessory cells. In further studies, depletion of T‐cell subsets showed that CD3+, CD4+, CD8+, CD29+ and CD45RA+ cells were involved in IFN‐gamma production after mitogenic stimulation. In conclusion, our data demonstrate that IFN‐gamma production is dependent on signals from accessory cells and IFN‐gamma is synthesized by only a small proportion of T cells, that did not belong to a unique population, characterized by conventional cellular surface antigens.
Reduced CD4 and CD8 Expression in Human Thymuses Treated with Soluble CD4
Authors: ZEPP F. , EHLERT K. , OTHMER M.
Published: June 2006

Recent data suggest that accessory molecules like CD4 and CD8 act as co‐receptors in intrathymic T‐cell development. Soluble CD4 (sCD4) molecules offer a novel experimental approach to investigate the relevance of CD4 interaction with its putative intrathymic receptor for T‐cell maturation. We attempted to inhibit binding of surface CD4 on thymocytes to its intrathymic receptor competitively by introduction of human sCD4 into human thymus tissue cultures. Our results demonstrate that sCD4, while not affecting peripheral T‐cell responses as shown in control experiments, significantly affects intrathymic development of T lymphocytes. Immature CD4CD8 double positive(DP) thymocytes responded with reduced expression of both CD4 and CD8 molecules. This phenomenon could be followed up to the stage of single positive (SP) thymocytes: density of CD4 molecules on CD4 SP thymocytes and, even more interestingly, CD8 expression on CDS SP cells, were reduced, indicating that the effect observed in immature DP thymocytes persists during their further development. Beyond that, analysis of T‐cell receptor (TCR) expression in the low density CD4CD8 DP population revealed a slight decrease of αβ‐TCR surface expression, suggesting a possible role ofCD4 engagement in the generation of TCR in man. Since sCD4 is considered a therapeutical agent in HIV infections, these findings are not only of basic but also of clinical interest.