bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Two Murine Monoclonal Antibodies Reactive with Human B Cells
Authors: SMELAND E. , FUNDERUD S. , RUUD E. , BLOMHOFF H. KIIL , GODAL T.
Published: June 2006

We describe two monoclonal antibodies, HH1 and HH2. Both reacted selectively with surface immunoglobulin (slg)‐positive human B cells. Both antibodies stained on average 7–8% of peripheral blood mono nuclear cells. They have not been found to react with cells or cell lines of other haematopoietic cell lineages, except that HH2 was positive on a small percentage of cells of the erythroid cell line K562. The molecular weight of the HH1 antigen was 95 kD, as established by Western blotting. Neither of these two antibodies reacted with Ig determinants, Fc receptors, complement receptors, or known class‐I or class‐II molecules. A combination of these antibodies was used in a direct panning technique for high‐yield enrichment of normal B lymphocytes from peripheral blood. The enriched B cells could be further purified by lysis of T cells (final yield, on average 72 ± 8% of initial B cells) or by a second panning (yield, 35 ± 11%). The purified B cells contained <1% contaminating T cells and <0.5% monocytes and were used in an assay for B‐cell‐stimulating factor which they showed a normal and very reproducible proliferative response.
Retinoids Activate Superoxide Production by Polymorphonuclear Leucocytes
Authors: HEMILÄ H. , WIKSTRÖM M.
Published: June 2006

Retinol and retinoic acid were effective activators of oxygen consumption by human polymorphonuclear leucocytes (PMN) in micromolar concentrations. In contrast, retinyl acetate was ineffective as an activator. Retinol caused activation only after a lag lime, the length of which depended on retinol concentration. Oxygen consumption was due to Superoxide production by PMN. Superoxide production was observed as Superoxide dismutase‐inhibitable cytochrome c reduction. Previously, retinoids have been reported lo inhibit PMN activation by phorhol myristate acetate, a tumour promoter. This retinoid‐induced inhibition of PMN activation has been suggested to be a mechanism by which retinoids may protect against carcinogenesis in animals. However, the retinoid concentra‐lions at which PMN inhibition was reported were much higher than those found to cause activation in this study. We found lhat retinoic acid slightly inhibited phorbol myristate acetate‐activated Superoxide production, but only at concentrations that caused activation. In contrast, activation by formyl‐Met‐Lcu‐Phe was effectively inhibited at a retinoic acid concentration that did not cause activation by itself.
Transformation of Amyloid Precursor SAA to Protein AA and Incorporation in Amyloid Fibrils in Vivo
Authors: HUSEBEKK A. , SKOGEN B. , HUSBY G. , MARHAUG G.
Published: June 2006

Experimental amyloidosis was induced in mice by in t raped toneal injections of endotoxin (lipopolysaccharidc (LPS)). In addition to LPS. a group of mice received high‐density lipoprotein (HDL)‐SAA complexes isolated from human acute‐phase serum, whereas a group of control mice received saline in addition to LPS. Isolated amyloid fibrils from the mice given HDL‐SAA contained human AA protein, as shown by immunodiffusion, immunoblot. and enzyme‐linked Immunosorbent assay techniques, in addition to mouse AA. In contrast, amyloid from the control mice contained exclusively AA of mouse origin. Thus, the experiments provided solid evidence that SAA is the precursor for amyloid fibril proiein AA.
Impaired Gamma Interferon Production by Cells from Patients with Lymphoproliferative Disorders of Mature T and NK Cells
Authors: PANDOLFI F. , CAPOBIANCHI M. , MATRICARDI P. , FACCHINI J. , BONOMO G. , DE ROSSI G. , SEMENZATO G. , FIORILLI M. , DIANZANI F. , AIUTI F.
Published: June 2006

We investigated Interferon (IFN) production by peripheral blood mononuclear cells from four patients with chronic OKT4 T‐lymphocytic leukaemia and three patients with abnormal expansions of granular lymphocytes. No spontaneous production of IFN‐γ was found in supernatants of cultures from both patients and normal controls. However, whereas the enzyme galactose oxidase or staphylococcal enterotoxin B was able to induce IFN‐γ production by normal cells, no production could be obtained in the cells under study. The possibility that this lack of production might have been attributed to an excess of N‐acetylneuramic acid masking galactose residues or to a defect of monocyte accessory cells was ruled out either by pre‐treating the cells with neuraminidase or by adding normal adherent cells to the cultures, both of which resulted in a lack of production. On the contrary, the calcium ionophore A23187 (considered to act as a second specific step, following oxidation of galactose residues, toward genetic derepression of IFN‐γ) induced considerable IFN‐γ production in all the three tested patients. It can be concluded that, although in rare cases, as previously reported by other authors, cells from patients with T or NK lymphoproliferative disorders may spontaneously produce IFN‐γ, this is not a general mechanism that underlies the disease. In fact, in all our cases a defect of IFN‐γ production was found. This defect seems due to an alteration at the membrane level of the galactose‐containing glycoproteins and can be restored by induction with a calcium ionophore.
Localization and Turnover Rate of Rat Renal ‘Dendritic’ Cells
Authors: LESZCZYNSKI D. , RENKONEN R. , HAYRY P.
Published: June 2006

The turnover rate of rat renal dendritic cells was analysed by irradiation and bone marrow transplantation and by visualizing the dendritic cells in frozen sections of renal tissue via double indirect immunofluorescence and peroxidase assays. Interstitial dendritic cells disappear from rat renal tissue shortly after irradiation; after 7 days they can be seen again. However, since the renal proximal tubular cells also simultaneously lose and regain their class II contents, we assume that irradiation has resulted in the disappearance of the Ia antigen, not the dendritic cells proper. After allogeneic bone marrow transplantation, bone marrow‐derived dendritic cells appear in renal tissue between days 7 and 10, indicating a relatively fast turnover rate of these cells in vivo.
Induction by Monoclonal Anti‐Idiotypic Antibodies of an Anti‐Poly(Glu60 Ala30 Tyr10) (GAT) Immune Response in GAT‐Responder and GAT‐Nonresponder Mice
Authors: ROTH C. , SOMME G. , GOUGEON M.‐L. , THEZE J.
Published: June 2006

Two different monoclonal anti‐idiotypic (Id) antibodies, HP‐Id20 and HP‐Id22, recognizing two discrete idiotopes characteristic of the anti‐poly(Glu60 Ala30 Tyr10) (GAT) response were used to immunize BALB/c (GAT‐responder) and DBA/1 (GAT‐nonresponder) mice. The monoclonals were injected either copolymerized with keyhole limpet haemocyanin or polymerized with glutaraldehyde. The specific response was studied by two assays: (a) inhibition of binding of monoclonal anti‐GAT antibody G5Bb2–2 to HP‐Id20 and HP‐Id22 and (b) GAT binding assays. In BALB/c GAT‐responder mice, HP‐Id20 and HP‐Id22 immunization led to the preferential stimulation of immunoglobulin idiotypically related to anti‐GAT antibodies (Ab1′) and expressing anti‐GAT activity. The results obtained with BALB/c nu/nu mice indicated that this response is T‐cell‐dependent. By means of the same experimental protocol GAT‐nonresponder animals could be induced to produce anti‐GAT antibodies after HP‐Id immunization. This last result indicates that anti‐Id immunization can bypass Ir gene control and does not preferentially stimulate the induction of GAT‐specific T suppressor cells.
Langerhans Cells and Extra‐Epidermal Dendritic Cells
Authors: ROWDEN G. , BOUDREAU S. , HIGLEY H.
Published: June 2006

S‐100 protein was demonstrated in the cytoplasm of dendritic cells (DCs) in normal and pathologic lymphoid tissues and epidermis in man and several other species. The presence of S‐100) protein served to distinguish these cells from other mononuclear cells, most importantly from those of macrophage/histiocyte lineage. Fractionation procedures to isolate and enrich suspensions of DCs were coupled with immunocytochemical techniques to identify S‐100‐positive cells. Langerhans cells in the epidermis and in aural cholesteatomata and nodal, splenic, and thymic interdigitating cells were S‐100‐positive. Lymph node and splenic follicular dendritic cells (except in rats) were negative, indicating that this DC may be a separate cell type.
The Possibility of Distinguishing a Subset of Antigen‐Presenting Cells from Macrophages by Means of Anti S‐100 Protein Sera
Authors: DE PANFILIS G. , ROWDEN G.
Published: June 2006

Macrophages may be distinguished from interdigitating cells and from Langerhans cells in paraffin sections, the latter cells being positive when an antiserum against brain S‐100 protein is used. This antiserum was utilized to conduct a retrospective analysis of 10 cases of lichen planus, including both early and late lesions. In addition, staining of macrophages was carried out by means of anti‐lysozyme. anti‐alpha‐1‐antitrypsin and anti‐alpha‐1‐antichymotrypsin. The anti‐S‐100 protein staining by immunoperoxidase methods showed large numbers of positive cells. Few macrophages were noted in the early lesions, but the ratios were reversed in the older lesions, in which macrophages predominated over dermal S‐100‐positive cells. Both Langerhans cells‐interdigitating cells and macrophages could play important roles in various cutaneous disorders. The involvement of Langerhans cells‐interdigitating cells or. on the other hand, of macrophages could distinguish among different pathological processes. Even in different evolutionary stages of the same lesion, as lichen planus, a different Langerhans cells‐interdigitating cells/macrophages ratio could be important in explaining the pathogenetic development of the disease.
Selective Inhibition of IgE versus β2‐Microglobulin in Human U‐266 Myeloma Cell Line Treated with T‐Cell‐Derived Factors
Authors: ROSSI P. , GALLI E. , GIDLUND M. , SALAHUDDIN Z. , LAAN K. , WIGZELL H.
Published: June 2006

Concanavalin‐A‐activated T cells and their crude supernatant were assayed for suppressivc activity un an IgE‐producing U‐266 cell line. Delectable and comparable degrees of suppression were obtained with the co‐culture and the supernatant protocols. Separation of the effector population into T4+ and TS+ subsets showed the most effective cells in the T8+ fraction. Control experiments demonstrated that the IgE down‐regulation was selective, since parallel measurement of β2‐microglobulin synthesis showed no effect of T cells or T‐cell‐derived supernatants. In addition, several human T‐cell lymphoma‐leukaemia virus I‐transformed T‐cell lines were explored for their capacity to produce factor(s) able to suppress IgE synthesis in the U‐266 cell line, and four out of 25 cell lines could be shown to do this in a constitutive manner. Kinetic studies suggested that the inhibition occurred at a transcriptional level, The results indicate that the T‐cell‐mycloma system is an interesting model to define belter the regulation of IgE in the human.
Passage of Undegraded Dietary Antigen into the Blood of Healthy Adults
Authors: HUSBY S. , JENSENIUS J. C. , SVEHAG S.‐E.
Published: June 2006

The absorption into the blood of ovalbumin (OA) and beta‐lactoglobulin (BLG) was investigated in eight healthy adults. Enzyme immunoassays showed up to 10.5 ng OA/ml serum in seven out of eight individuals 2‐3 h after a test meal, whereas no BLG was demonstrated. The apparent size distribution of the absorbed OA was investigated by high‐pressure liquid gel permeation chromatography fractionalion, followed by enzyme‐linked immunosorbemt assay, which in the fractionated sera showed OA in all eight individuals. OA was found at the elution volume of intact OA and, in addition, was present in high molecular weight fractions, as part of the immune complexes. The serum concentrations of OA could not be clearly correlated to levels of serum and secretory anti‐OA antibodies. No significant alterations of the levels of circulating immune complexes could be demonstrated by two antigen‐nonspecific assays. The presented data indicate that, for certain dietary proteins, low‐grade absorption of apparently undegraded protein into the blood occurs regularly in healthy adults.
The Genetic Background Modulates the Effect of the Beige Gene on Susceptibility to Cytomegalovirus Infection in Mice
Authors: SHELLAM G. R. , FLEXMAN J. P. , FARRELL H. E. , PAPADIMITRIOU J. M.
Published: June 2006

Homozygous beige (bg/bg) mice were more susceptible to the development of fatal disease induced by murine cytomegalovirus (MCMV) than their bg/+ littermates. However, the increase in susceptibility depended on the genetic background of the strain carrying the bg gene. C57BL/6, SB/Le, DBA/2, and CBA bg/bg mice showed, respectively, 2.5‐, 3.2‐, 9.5‐, and 18.6‐fold increases in susceptibility compared with the corresponding bg/+ animals. Beige mice showed higher liver titres of MCMV than bg/+ by the 2nd or 3rd day after infection, and tissue damage was also greater. Splenic NK cells were not detected in uninfected bg/bg mice, and after virus inoculation the increment in cytotoxicity was greater in bg/+ than in bg/bg mice. However, cytotoxicity towards WEH1‐164 cells was not impaired in bg/bg mice and was not augmented by MCMV. Interferon titres were also not impaired by the beige mutation. Of the strains examined, CBA had the highest endogenous levels of NK cells and were most genetically resistant to MCMV. Thus, our observation that the beige gene had the greatest effect on susceptibilty in this strain suggests that NK cells are important mediators of genetically determined resistance to MCMV.
Quantification of the Terminal Complement Complex in Human Plasma by an Enzyme‐Linked Immunosorbent Assay Based on Monoclonal Antibodies against a Neoantigen of the Complex
Authors: MOLLNES T. E. , LEA T. , FRØLAND S. S. , HARBOE M.
Published: June 2006

The fluid‐phase terminal complement complex (TCC), consisting of the components C5b, C6, C7, C8, C9, and the S‐protein, has recently been detected in normal human plasma by using antibodies against native terminal complement components. Increased amounts of TCC were then found in several patients with in vivo activation of complement. We now describe a sensitive, specific, and reliable enzyme‐linked immunosorbent assay for quantification of the TCC, based on monoclonal antibodies against a neoantigen of the complex. The results indicate that the TCC is present in normal human plasma and in increased amounts in patients with complement activation in vivo, thus confirming previously obtained results. The assay is easy to perform and can be used for examination of large numbers of plasma samples.
Transformation of Trypomastigote Forms of Trypanosoma cruzi into Activators of Alternative Complement Pathway by Immune IgG Fragments
Authors: KIPNIS T. L. , KRETTLI A. U. , DA SILVA W. DIAS
Published: June 2006

In this report we examined the capacity of immune IgG fragments to prepare trypomastigote bloodstream forms (TBF) of Trypanosoma cruzi for lysis. F(ab′)2, fragments were capable of presensitizingTBF For complement (C) lysis, thus excluding the participation of Fc domains in the C activation process. An intact hinge region of the IgG molecule was not involved either, since the corresponding Fab' were almost as active as the original molecules in preparing TBF for lysis. Fab also retained such activity even after further reduction and alkylation. These findings indicate that neither the portions of heavy chains that make up the hinge region nor the intrachain disulphide bonds are involved in the process. The IgG fragments promoted lysis through the activation of the alternative C pathway (ACP). These results suggest that the immune IgG transforms TBF into ACP activators by blocking the capacity of some parasite cell surface components that are known inhibitors of C activation.
Class II Transplantation Antigens in the Late Human Skin Tuberculin Reaction
Authors: SCHEYNIUS A. , TJERNLUND U.
Published: June 2006

The presence of class II transplantation antigens on keratinocytes and the phenotypes of the inflammatory cells in the late human skin tuberculin reaction were analysed with immunohistochemical double staining techniques in frozen sections of skin biopsies taken 10‐45 days after intradermal purified protein derivative (PPD) injection. Dermal cell infiltrates decreased with time but were found throughout the observation period. Most of the cells in the perivascular infiltrates expressed HLA‐DR antigens. Some of these cells are probably ‘activated’ macrophages, since they expressed OKM1 and OKT9 antigens in consecutive sections. Another less frequent cell population which reacted with RFD1 antibodies are presumably interdigitating cells. About half the perivascular cells were anti‐Leu 3a‐positive (T ‘helper/inducer’ phenotype). HLA‐DR but not HLA‐DO antigens were detected on keratinocytes. This acquired expression of HLA‐DR antigens on the epithelial cells disappeared between 17 and 30 days. If HLA‐DR‐expressing keratinocytes have immunoregulatory functions these might be different from those of other HLA‐DR‐expressing cell types that also express HLA‐DO molecules.
The Immunodeficiency of Bone Marrow‐Transplanted Patients
Authors: ØDUM N. , HOFMANN B. , PLATZ P. , RYDER L. P. , LANGHOFF E. , JAKOBSEN B. K. , SVEJGAARD A. , JACOBSEN N.
Published: June 2006

Lymphocytes from patients after bone marrow transplantation (BMT) are in most cases predominantly of the Leu‐2+ (cytotoxic/suppressor) phenotypes and are almost unresponsive to mitogens. In contrast, normal Leu‐3+‐depleted, Leu‐2+‐enriched lymphocyte suspensions retain approximately 50% of the mitogenic response compared with that of unseparated cells. To investigate whether this discrepancy was due to active suppression, we selected nine BMT patients from whom sufficient numbers of cells were available and whose lymphocyte phenotypes were predominantly Leu‐2+ after BMT. These post‐BMT lymphocytes were tested for functional suppressor activities against donor and recipient pre‐BMT lymphocytes in the lymphocyte transformation test. None of these post‐BMT cells suppressed the response of donor or pre‐BMT cells to phytohaemagglutinin A or concanavalin A. In contrast, the response of donor cells in mixed lymphocyte cultures to HLA‐DR‐different third‐party cells was suppressed by highly X‐irradiated post‐BMT cells by approximately 40%. Addition of T‐cell growth factor (=interleukin 2 (IL‐2)) or X‐irradiated donor cells to post‐BMT lymphocytes partially restored the mitogenic respose. These findings indicate that the early post‐BMT cells lack production of IL‐2 but are capable of responding to IL‐2 and that the almost extinct mitogen response of these cells is due to immaturity rather than active suppression. The suppression of the allogeneic but not the mitogenic response might be explained by differences in the modes of activation; for example, the allogeneic response must involve the T‐cell receptor, while the mitogenic response may not.
Tissue Distribution of T‐Lymphocytes and Ia‐Expressing Cells in Rat Kidney Grafts
Authors: CLAESSON K. , FORSUM U. , KLARESKOG L. , ANDRÉEN T. , LARSSON E. , FRÖDIN L. , TUFVESON G.
Published: June 2006

In a rat kidney transplantation model, DA kidneys were transplanted into Lewis rats. Syngeneic Lewis transplantations were studied as controls. Histologic evaluation was made, and immunohistochemical staining with a single‐staining peroxidase–antiperoxidase technique on frozen sections was performed after 2, 4, 6, and 8 days. Antibodies for Ia antigen (Ox 6), ‘suppressor/cytotoxic’ cells (Ox 8), pan‐T cells (W 3/13), and ‘helper/inducer’ cells (W 3/25) were used. Allogeneic grafts were almost completely rejected in 8 days. Syngeneic grafts also showed lymphocyte infiltrates, somewhat later than allogeneic ones, but were not rejected. In these infiltrates W 3/25‐positive cells dominated, being even more numerous than W 3/13‐positive cells. Relatively fewer Ox 8‐positive cells were seen in the infiltrates of syngeneic than in allogeneic transplants. Infiltrates occurred later in the renal medulla than in the cortex. Perivascular infiltrates with cells of all investigated phenotypes were seen earlier in allogeneic grafts than in syngeneic ones. All tubular cells within one renal tubule appeared either Ox 6‐positive or ‐negative. With time, all tubules in the allogeneic transplants became Ox 6‐positive. Some increase of Ox 6‐positive tubules was also seen in syngeneic transplants.
Human Cytotoxic T Lymphocytes
Authors: KABELITZ D. , HERZOG W.‐R. , ZANKER B. , WAGNER H.
Published: June 2006

A limiting‐dilution system was established to measure the frequency of alloreactive cytotoxic T‐lymphocyte precursors (CTL‐p) in human peripheral blood T cells. Culture medium supple mented with recombinant interleukin‐2 enabled clonal expansion of all CTL‐p stimulated by allogeneic peripheral blood or spleen cells. The range of CTL‐p frequencies in fully HLA‐mismatched responder‐stimulator combinations was 1:240 to 1:1230. Split‐well analysis of individual microwells showed that the cytotoxic T‐cell clones generated under limiting‐dilution conditions showed exquisite specificity for the stimulating alloantigens. Alloreactive CTL‐p were enriched in the OKT4 T‐cell subset. This limiting‐dilution system was highly reproduci ble and can thus be applied to investigate human cytotoxic T‐eell precursor frequencies in various clinically relevant situations.
Monoclonal Antibody‐Defined β2‐Microglobulin‐Positive Mononuclear Cells in Acquired Immune Deficiency Syndrome
Authors: GUPTA S.
Published: June 2006

In healthy heterosexuals, by means of a monoclonal antibody against β2‐microglobulin (β2m) and fluorescence‐activated cell sorter analyser (FACS analyser), we observed two populations of β2+ mononuclear cells (MNC); a large population with high‐intensity cells and a small population of relatively low‐intensity cells. Because elevated β2m levels have been shown in the sera of patients with acquired immune deficiency syndrome (AIDS), we examined the proportions of β2m+ MNC in AIDS and AIDS‐related complex (ARC). The proportions and numbers of high‐fluorescence intensity β2m+ MNC were significantly (P<0.05) decreased in AIDS and ARC when compared with those of asymptomatic homosexuals and healthy heterosexuals. The proportion and number of total β2m+ MNC (both high‐ and low‐intensity β2m+) in ARC were comparable to those of control groups; however, the numbers of total β2m+ MNC were significantly (P<0.01) reduced only in the AIDS group. This relative deficiency of highintensity β2m+ MNC appears to be due to a shift from high‐intensity β2m+ to low‐intensity β2m+ MNC. A linear correlation was observed between the deficiency of high‐intensity β2m+ cells and T helper to T suppressor phenotype cell ratios.
Augmentation of Natural Killer Cell Activity by Anti‐Host Delayed‐Type Hypersensitivity during the Graft‐versus‐Host Reaction in Mice
Authors: McI A. , MOWAT A. , BORLAND A. , PARROTT D. M. V.
Published: June 2006

During a graft‐versus‐host (GVH) reaction in unirradiated F1 hybrid mice there is a generalized activation of natural killer (NK) cells. We have examined whether the enhanced NK activity is due to an F1 resistance mechanism directed at the parental cells used to induce the GVH reaction. Spleen cells of C57BL/10 origin induce much more NK cell activation in B10F1 hybrids than the opposite parental type, despite a similar intensity of systemic GVH reactions. However, this does not correlate with in vivo resistance of mice with GVH reaction to a local challenge dose of B10 cells. NK cell activation in (CBA xBALB/c)F1 mice with GVH reaction involves both host and donor cells and is preceded by an anti‐host delayed‐type hypersensitivity (DTH) response. B10 cells have a greater ability to induce DTH in B10F1 mice than cells from the opposite parent. We propose that NK cells are one group of non‐specific effector cells recruited by DTH in a GVH reaction and may contribute to the tissue pathology.
Elimination of Trinitrophenol‐Specific Antibody Response by Antigen‐Toxin Conjugates
Authors: ARNDT R. , THIESEN H.‐J.
Published: June 2006

The aim of the experiments presented here is the selective inhibition of an antigen‐specific immune response. Antigen receptors are used as targets for conjugates of antigens and toxin to eliminate antigen‐reactive cells. The trinitrophenol (TNP)‐Specific immune response can be specifically abrogated by incubating the TNP‐keyhole limpet haemocyanin (KLH)‐primed spleen cells with TNP‐ricin or TNP‐chicken IgG‐ricin conjugates before in vitro stimulation with TNP‐KLH. The rate of elimination is dose‐dependent and related to the degree of TNP moieties bound to the toxin molecule. The specificity of the toxin conjugates is demonstrated by treating sheep erythrocyte‐primed spleen cells with TNP‐lgG‐ricin conjugates. These results may have therapeutic relevance for treating autoimmune diseases.
T and B Lymphocytes in Patients with Nickel Sensitivity
Authors: AL‐TAWIL N. G. , MARCUSSON J. A. , MÖLLER E.
Published: June 2006

Peripheral blood mononuclear cells from altogether 45 nickel‐sensitive patients and 37 controls were assayed for various T and B cell variables. All the patients, but none of the controls, fulfilled our in vitro criteria for a positive response to nickel sulphate (NiSO4). We report normal T and B lymphocyte counts, normal spontaneous plaque‐forming cell (PFC) numbers, normal serum immunoglobulin levels, and no demonstrable specific cytotoxic T lymphocyte activity associated with nickel sensitivity. We could detect only a slight increase in the number of PFC and in the number of cytoplasmic immunoglobulin positive (cIg+) cells following stimulation of the patients' cells with NiSO4 for 6 days in culture. A part from a transient increase in the [3H] thymidine uptake by patients' cells stimulated with NiSO4 in vitro, and a transient drop in the OKT4/OKT8 ratio, there were no major differences in the values of the above variables before and after in vivo challenge of 3 patients with NiSO4. Blood from only 2 of the latter 3 patients was tested in the DNA synthesis test. We conclude that apart from the DNA synthesis test, none of these tests is of any use as an aid to diagnosis in patients with nickel sensitivity. A careful attitude towards patch testing should be maintained.
Lymphocyte Activation in Rheumatoid Arthritis Synovial Fluid in Vivo
Authors: KONTTINEN Y. , BERGROTH V. , NYKÄNEN P.
Published: June 2006

Monoclonal antibodies were used in avidin‐biotin‐peroxidase complex staining for activation marker analysis of rheumatoid synovial fluid cells. Although Ia expression indicates T cell activation, cells displaying receptors for interleukin 2 (Tac)‐and transferrin receptor (T9)‐ positive proliferating cells were relatively few. Similarly, activated terminal effector cells of suppressor/cytotoxic nature were scarce in rheumatoid synovial fluid, as suggested by a low expression of Tac and 4F2 markers. The in vivo situation in the rheumatoid arthritic (RA) joint does not seem to be due to the inability of synovial fluid lymphocytes to become activated, because mitogen stimulation in vitro, in spite of a low proliferative response, induced expression of all the activation markers studied. The relevance of the present observations to the down‐regulation of the active, inflammatory‐immune response in situ is speculative, but the data show that in spite of T‐cell activation and Ia expression, activated terminal effector cells of suppressor/cytotoxic nature are few in the RA joint in vivo.
HLA Control of the Proliferative T Lymphocyte Response to Antigenic Determinants on Mumps Virus
Authors: BRUSERUD Ø. , THORSBY E.
Published: June 2006

The proliferative T lymphocyte responses to two different mumps antigen preparations, S (nucleocapsid) and V (viral envelope), were characterized. Eight patients with Type 1 (insulin‐dependent) diabetes mellitus were all found to be responders to S and V mumps antigen. Among the 64 healthy individuals. 52 were classified as responders to the S antigen and 50 as responders to the V antigen. No difference was found between T lymphocytes from Type 1 diabetic patients and those from healthy individuals as regards the effeet of indomethacin on the mumps‐specific response. The majority of the mumps‐specific T lymphocytes seemed to he restricted by epitopes on the HLA‐DR molecules. The frequency of mumps antigen‐reactive T lymphocytes (ARTL) was found to be low when the response was restricted by DR3‐associated elements, and high when it was restricted by DR4‐associated elements, compared to the frequency of ARTL when other DR‐associated elements restricted the mumps‐specific response. For the majority of the individuals tested, the DR‐associated hypo‐ and hyper‐responsiveness was found with both the S andthe V mumps antigens.
A Possible Self‐Regulating Mechanism Mediated by C3b‐Acceptor‐Bound C3b Generated by Stimulated Macrophages
Authors: FÁBRY Zs. , ERDEI A. , GERGELY J.
Published: June 2006

Macrophages have been shown to produce C3 and to hear Fc receptors (FcR). and besides The various C3 receptors, they possess C3b acceptors (C3bA) as well as surface proteases capable of cleaving C3. Using the immune adherence method, we demonstrated that the amount of covalently fixed (i.e., C3bA‐bound) C3h is markedly increased upon cell stimulation by phorbol myristate acetate or aggregated IgG. even in the absence of C3. The enhancement of nascent C3b (C3bx) binding to C3bA on these cells could be reversed by inhibiting the process at different stages, using either cycloheximide. phenyl‐methyl‐sulphonyl‐fluoride, salycil hydroxamic acid, or methylamine. On the basis of our present results and earlier results, we propose a self‐regulatory mechanism by which activated. C3‐producing macrophages cleave C3 by their surface proteases. C3bx generated in this way fixes covalently to C3bA of the producer cells, resulting in the inhibition of FcR on these cells.
Calcium Ionophore A23187 Induces Interleukin 2 Reactivity in Human T Cells
Authors: CLEVERS H. C. , HOEKSEMA M. , GMELIG‐MEYLING F. H. J. , BALLIEUX R. E.
Published: June 2006

In the present study the activation of purified human T lymphocytes by the calcium ionophore A23187 was analysed in the light of current concepts of receptor‐linked inositol lipid metabolism. It was found that A23187 was only slightly mitogenic, with a narrow optimum at 400‐500 nM. The proliferation could be blocked by anti‐Tac ascites at 10‐3 dilution, suggesting an interleukin 2 (IL‐2)‐dependent pathway of activation. However, an unexpectedly large proportion of A23187‐stimulated cells expressed the IL‐2 receptor. Reculturing the cells with exogenous IL‐2 after removal of A23187 resulted in strongly enhanced proliferation. Phorbol myristic acetate (PMA) at non‐mitogenic concentrations exerted an extremely strong synergistic effect on A23187‐induced cell proliferation, which was, again, mediated via an IL‐2‐dependent pathway. Supernatants of A23187‐stimulated T cells did not contain detectable amounts of IL‐2. Combination of PMA and A23187 resulted in considerable IL‐2 production. It is concluded that A23187 induces the expression of IL‐2 receptors without concurrent stimulation of IL‐2 production, thus allowing only low levels of proliferation. Addition of exogenous IL‐2 or of PMA restores the imbalance between the occurrence of IL‐2 and its receptor and results in high rates of proliferation.
Amino Acid Sequence of a λ VI Primary (AL) Amyloid Protein (WLT)
Authors: DWULET F. E. , STRAKO K. , BENSON M. D.
Published: June 2006

It has been observed that monoclonal immunoglobulin proteins of the λ VI subgroup have a high propensity to form amyloid deposits. To ascertain whether λ VI proteins have unique structure determinants that would account for self association and resultant fibril formation, we have determined the complete amino acid sequence of the AL amyloid protein WLT. This protein, isolated from the spleen of a patient with AL amyloid, has 134 amino acid residues and contains the entire variable region, the joining segment, and the first tryptic peptide of the constant region. Comparison of the structure of this protein with the 3 completely sequenced λ VI proteins reveals that they are highly homologous and contain a 2‐residue insertion at positions 68 and 69. Phylogenetic comparisons of the variable domain of all λ VI proteins reveal that the 3 amyloid proteins WLT, SUT, and AR are all more closely related to each other than to the myeloma protein NIG48. Separating the variable domains into framework (FR) and complementarity‐determining regions (CD) and recalculating the phylogenetic comparisons, we identify major substitutions in the FR regions of NIG48 in relation to the amyloid proteins. This supports the hypothesis that the formation of AL amyloid is a result of the secondary structure of the FR regions of the precursor molecules.
Rabbit Anti‐Human β2 Microglobulin Antibodies: A T‐Cell Mitogen
Authors: HAMMARSTRÖM L. , SMITH C. I. E.
Published: June 2006

Rabbit anti‐β2 microglobulin antibodies have been described as a potent mitogen for human B lymphocytes. However, when fractionated after activation, only the T‐cell enriched population is actively dividing. The induction of proliferation in purified T cells requires the presence of non‐T cells. Daudi cells (which do not express β2 microglobulin on their cell surface) were shown to produce ‘macrophage replacing factors’ which supported anti‐β2‐induced T cell division. Non‐T cells could be effectively replaced by addition of interleukin 2 containing cell supernatants, 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA), or teleocidin B. Thus, anti‐β2 appears to selectively activate T cells. In contrast to other T cell mitogens, anti‐β2 microglobulin antibodies did not induce secondary immunoglobulin production in B cells from peripheral blood or spleen.
An Assessment of the Extent of Antigenic Analogy between Physiologically Bound C3 and C3 Denatured by Sodium Dodecyl Sulphate
Authors: NILSSON B. , NILSSON U. R.
Published: June 2006

Three previously defined antigenic subsets of C3 (C3(S), C3(D)α and C3(D)β clearly distinguish native C3 from C3 that has been denatured in the presence of sodium dodecyl sulphate (C3‐SDS): C3‐SDS expresses antigens of all 3 subsets, while native C3 only expressed C3(S) antigens. The radioimmunometric assessment performed in this study revealed that 90% of the C3(S) and C3(D)α and 70% of the C3(D)β antigens demonstrable in C3‐SDS also was expressed by physiologically hound C3b on sheep erythrocytes. The antigenic properties of bound C3b were not shared by soluble C3b, which (like soluble C3) only expressed C3(S) antigens, nor did soluble C3b ‘spontaneously’ released from complement‐treated larget cells express antigens other than C3(S). We therefore conclude that the expression of C3(D) antigens, under physiological conditions of activation, reflects a conformatonal modification unique for bound C3b and occurring to an extent comparable to that of C3 in the presence of a strong denaturant. Additional studies further revealed that the antigenic profile of bound C3b is determined by a heterogeneous population of molecules differing in their relative expression of the C3(S), C3(D)α and C3(D)β subsets.
The Use of Interleukin 1+ and Interleukin 1− Cell Lines to Dissociate Signals Involved in the Induction of Cytolytic T Cells
Authors: SMITH L. A. , COHEN D. A. , KAPLAN A. M.
Published: June 2006

The availability of paired homogeneous la+ tumour cell lines (P388AD, interleukin (IL)‐l+ and P388NA. IL‐1). which differ in inducibility for IL‐l, provided it unique opportunity to assess directly the role of Ia and IL.‐1 in the induction of cytolytic T cells (CTL) to trintrophenol (TNP)‐modified self. TNP‐P388AD but not TNP‐P388NA consistently induced Unrestricted, hapten‐specific CTL. However, in the presence of an exogenous source of IL‐l. TNP‐P388NA was able to induce CTL of the magnitude seen with TNP‐P388AD. Both Ia expression and IL‐l secretion were necessary in that when TNP‐modified purified T cells were utilized as stimulators, CTL activity was not demonstrated even if IL‐1 was added, but was only seen when unmodified. P388AD. or spleen cells were added to the cultures.
Graft‐versus‐Host Disease in the Rat: Cellular Changes and Major Histocompatibility Complex Antigen Expression in the Liver
Authors: STET R. J. M. , THOMAS C. , KOUDSTAAL J. , HARDONK M. J. , HULSTAERT C. E. , NIEUWENHUIS P.
Published: June 2006

Cellular changes in the liver were studied during an acute lethal graft‐versus‐host (GVH) disease in relation to the expression of major histocompatibility complex (MHC) antigens on different liver cells‐ Screening for MHC antigen expression revealed that control livers contained very few Ia+ cells: mainly cells in the portal tract interstitium and and a small percentage of the Kupffer cells. The changes during an ongoing GVH reaction could he separated into those related to the sinusoid‐associated cells, including the liver parenchyma, and those related to the portal‐tract‐associated cells, including periportal hepalocytes In the sinusoids an increase in the number of Kupffer cells was seen, mm all expressing Ia+ antigens No damage to hepatocytes or other sinusoid‐associated cells was observed 1l is postulated that the increase in both number and Ia+ expression of the Kupffer cells is most probably due to an increased phagocytic uptake of Mood‐borne cellular debris and is not a result of extensive damage to hepatocytes. In the portal tracts expanding infiltrates were found composed of Ia+ T ceils and macrophages (ratio 2:1). These infiltrates are probably due to a local accumulation of lymphocytes and macrophages as a result of an interaction of migrating donor‐type alloreactive T cells with recipient type Ia+ cells present in the portal tract interstitium. which also interfered with normal recipient lymphocyte and macrophage traffic. Damage to portal‐tract‐associated cells was slight and confined to bile duct epithelial cells, which now expressed Ia+ antigens, and to periportal hepatocytes. In conclusion, these data do not indicate that damage to liver parenchyma plays a major role in the pathogenesis of an acute GVH reaction.
The Human Cell Surface Glycoprotein Complex (gp 120,200) Recognized by Monoclonal Antibody K20 is a Component Binding to Phytohaemagglutinin on T Cells
Authors: AMIOT M. , BERNARD A. , TRAN H.C. , LECA G. , KANELLOPOULOS J. M. , BOUMSELL L.
Published: June 2006

Monoclonal antibody K2H recognizes a human glycoprotein complex that is not rcstricted in haematopoietic lineages but is preferentially expressed on early haematopoietic cells, T cells, and monocytes This glycoprotein complex is made of constant ini 120,000–140,000 M1, subunitnoncovalently associated at the cell surface with subunits of higher M1. ranging from 150,000 to 200,000 on different cell types. Internal labelling with [35S]methionine and pulse‐chase experiments revealed that in the cell the 120,000 M, glycoprotein of this complex is also noncnvalently associated with a 100,000 Mt glycoprotein, and that both glycoproteins are independently biosynthesized. This glycoprotein complex is shown by immunoprecipitation by lectin plus antilectin antibodies and by sequential immunoprecipitation to be one one of the cell surface structures bound by phytohaemagglutinin on the surface of normal T cells.
Separation of Human B Lymphocytes on Helix pomatia A Haemagglutinin into Two Major Fractions Differing in Responsiveness to T‐dependent Mitogen (Pokeweed Mitogen) or Antigen (Tetanus Toxoid)
Authors: ROBERTSSON E.‐S. , HELLSTRÖM U. , AXELSSON B. , PERLMANN P.
Published: June 2006

A B‐cell fraction consisting of 70% of cells carrying the B‐cell‐associated B1 antigen, 15–20% of M1+ non‐B cells, and less than 3% of T cells was prepared from the peripheral blood of healthy human donors, previously vaccinated with tetanus toxoid (TT). As assessed by immunofluorescence after treatment with neuraminidase, approximately 40–50% of the B cells had surface structures binding to Helix pomatia A haemagglutinin (HP). The cells were separated into three fractions by affinity chromatography on HP conjugated to Sepharose (P, non‐retained cells; EI, cells eluted with 0.1 mg/ml N‐acetyl‐D‐galactosamine (D‐GalNac); EII, cells eluted with 1 mg D‐GalNac/ml). The majority of B cells in fraction EII were HP+ and were rich in cells expressing the B2 differentiation antigen. Sixty per cent of the B cells in this fraction also expressed the major HP‐binding glycoprotein, gp 150. In the presence of autologous T cells, these B cells were strongly responsive to activation by either pokeweed mitogen (PWM) or antigen (TT), as reflected by differentiation into plasma cells, secretion of polyelonal IgG and IgM, or IgG anti‐TT antibodies. In contrast, fraction P, which contained more than 90% HP‐ B cells, and which was partially depleted of B2+ cells, responded poorly or not at all to both PWM and TT. Fraction El was a mixed fraction that responded in an intermediate fashion. When the preparations were depleted of contaminating non‐B cells carrying the monocyte or large granular lymphocyte associated M1 antigen, their response to the two stimulating agents did not alter. The results suggest that HP+ B cells differ from HP− B cells in their responsiveness to T‐cell signals. Fractionation on unsolubilized HP offers a simple and efficient way of separating B cells into at least two subsets differing in their responsiveness to T‐cell‐derived differentiation and maturation signals.
Lymphokine Production in Ty Lymphoproliferative Disorders
Authors: RAMBALDI A. , ROSSI V. , ALLAVENA P. , INTRONA M. , LANDOLFO S. , BASSAN R. , BARBUI T. , MANTOVANI A.
Published: June 2006

We have studied five patients with chronic lymphoeytosis consisting of large granular lymphocytes (LGL). The increased numbers of LGL in these patients had little or no natural killer activity, mediated antibody‐dependent cellular cytotoxicity, and were induced to kill tumour lines after culture for 3 days with interleukin 2 (IL‐2). Patients' LGL showed considerable reactivity with HNK‐1 and AB8.28 monoclonal antibodies (MoAb), whereas positivity for OKM1 and N901 was found m only two subjects, and only one patient reacted with B73.1. No appreciable reactivity has been found with anti‐Tac MoAb in the four patients tested. In the absence of stimulation, the patients’ LGL produced no IL‐2 and only minimal amounts of IL‐1 and interferon (IFN). On stimulation with lipopolysaccharides (for IL‐1) or phytohaemag‐glutinin A (PHA) (for IL‐2 and IFN), they produced IL‐1 and IFN in amounts similar to those produced by normal lymphocytes, but only modest levels of IL‐2. These results indicated that proliferating LGL, like normal LGL, have a secretory capacity. The lack of constitutive lymphokine production, the lack of Tac receptor expression, and the defect in IL‐2 production after PHA stimulation do not support the hypothesis of an autocrine proliferation sustained by a known growth factor.
Quantitation of Blood Lymphocytes Secreting Antibodies to Pneumococcal Polysaccharides after in Vivo Antigenic Stimulation
Authors: HEILMANN C. , PEDERSEN F. K.
Published: June 2006

An indirect plaque‐forming cell assay detecting B cells secreting IgM, IgG and IgA antibodies against pneumococcal polysaccharides (PPS) is described. The numbers of anti‐PPS‐secreting cells (SC) and Ig‐SC in the blood of normal persons immunized with a polyvalent PPS vaccine were quantitated. Anti‐PPS‐SC were recorded from the fourth to the twelfth post‐vaccination day, and the maximum number was found between days 6 and 9. Quantitatively IgA anti‐PPS‐SC outnumbered the IgM and IgG anti‐PPS‐SC. Concomitant with the increase in the numbers of antibody‐SC an increase in polyclonally activated IgM‐,IgG‐ and IgA‐SC was recorded. The specific anti‐PPS‐antibody‐SC constituted 20–80% of the total numbers of Ig‐SC from the sixth to the ninth postvacination day.
Suppression by Alpha‐Fetoprotein of Murine Natural Killer Cell Activity Stimulated in Vitro and in Vivo by Interferon and Interleukin 2
Authors: COHEN B. L. , ORN A. , CRONVIK K.‐O. , GIDLUND M. , WIGZELL H. , MURGITA R. A.
Published: June 2006

Natural killer (NK) cells are'spontaneously’ cytotoxic cells thought to be involved in surveillance against tumour cells, rejection of virally infected cells, and refulation of haematopoietie stem cell differentiation and antibody systhesis. Fetus‐derived alpha‐fetoprotein (AFP) has been shown to regulate certain T cell‐mediated immune reactionsin vitro and in vivo. The lack of NK activity in newborn mice with high endogenous levels of AFP, together with the presence of cells expressing NK surface markers, also suggests that AFP may regulate NK activity. In this study we compared the effects of AFP on spontaneous versus activated murine NK activity. The lytic abnility of both freshly prepared splenic NK cells and those arising after incubation for 24 h with interferon, Poly I: C, or T‐cell growth factor (TCGF) was not affected by AFP if the latter was present only during the killing phase. However, if AFP was added at the beginning and retained for the duration of the 24‐h in vitro lymphokine stimulation, the subsequent NK activity induced by interferon. Poly I:C, and TCGF was found to be significantly suppressed. This inhibition is both dose‐and time‐dependent. Delayed addition experiments showed that when AFP is present during the first 6 h of in vitro stimulation it will suppress interferon and TCGF‐boosted NK activity by 50–80%. The AFP‐mediated inhibitory effect on lymphokinestimulated NK activity is not the result of increased death of effector cells not, in the case of interferon and polyribonucleotides, of non‐specific binding of AFP to the enhancing agents. In vivo injections of Poly I:C of TCGF failed to invrease neonatal NK function., while administration of interferon did cause slightly higher levels of NK activity. However, spleen cells from newborn animals cultured for 24 h in the presence of lymphokines resulted in markedly elevated NK function and this in vitro activation in newborns with high endogenous levels of AFP was very similar to that of adult NK stimulation in vitro when exogenous AFP was added.
Suppressor Factors Generated from Human Mononuclear Cells by Means of Purified Myeloma Proteins
Authors: WANGEL A. G. , KONTIAINEN S. , ARVILOMMI H. , NUUTINEN M. , KOISTINEN J.
Published: June 2006

Peripheral blood mononuclear cells (PBMC) from normal human donors were cultured in Marbrook flasks in the presence of purified IgG or IgA myeloma proteins. The culture supernatants were tested for their ability to suppress pokeweed mitogen (PWM)‐ or Epstein‐Barr virus (EBV)‐driven Ig synthesis by normal PBMC, Two supernatants from PBMC cultured with IgG and one from PBMC cultured with IgA were tested and suppressed PWM‐driven Ig synthesis as measured by a reverse haemolytic plaque assay and by quantitation of the Ig secreted into the culture medium of the PWM‐driven cells. This suppression was not restricted to the Ig isotype of the ‘inducing’ myeloma protein, but was extended to IgG, IgA, and IgM, The suppressive effect could be absorbed out with human IgG.