bluuebunny/crossref_metadata_2025 huggingface dataset:
Biology of Human Epidermal Langerhans Cells: Cell Cycle Studies
Authors: CZERNIELEWSKI J. , VAIGOT P. , BLACHON F. , DESBAS C. , DELASALLE B. , PRUNIERAS M.
Published: June 2006

Langerhans cells (LC) are considered to play an important role in the initiation of the immune response in the skin. This study was performed to analyse the kinetics of LC in normal human epidermis. Using flow cytometry (FCM), we have applied three methods to estimate LC DNA distribution: FCM DNA measurement in LC‐enriched suspensions (70‐90% purity). FCM‐correlated analysis of DNA and OKT6‐positive cells in original epidermal cell suspensions, and staining of LC‐enriched suspensions by the Feulgen technique on microscopic slides and counter labelling of contaminating keratinocytes with anti‐keratin antiserum to eliminate them from the LC DNA estimation. All three methods clearly showed that human LC are a cycling cell population, and it was suggested that LC may represent a stable, self‐reproducing cell population in normal epidermis.
Dendritic Cells and Monocytes as Accessory Cells in T‐Cell Responses in Man
Authors: GAUDERNACK G. , BJERCKE S.
Published: June 2006

A method is described for simple and rapid preparation of human dendritic cells (DC) and monocytes (Mo) from peripheral blood. The phenotype of enriched DC and Mo was determined and compared by means of a panel of monoclonal antibodies (Mab's). The distribution and quantitative expression of HLA class II molecules encoded by the subloci DP, DO, and DR were the same on the two cell types. During in vitro culture a rapid decrease of class II antigens on Mo was observed, whereas the expression of class II antigens on DC was relatively stable. The absence of monocyte markers on DC may indicate that this cell type docs not belong to the monocyte/macrophage cell lineage. The phenotypic analysis shows that peripheral blood DC also lack differentiation antigens expressed by epidermal Langerhans cells (OKT6) and lymph node follicular dendritic reticulum cells (DRC‐1). The relationship between peripheral blood DC and tissue‐localized DC thus remains unsolved. With relatively high numbers of DC now available, production of DC lineage‐specific Mab's may be approached.
Dendritic Cells and Monocytes as Accessory Cells in T‐Cell Responses in Man
Authors: BJERCKE S. , GAUDERNACK G.
Published: June 2006

The main antigen‐presenting cells (APC) of human blood are reported to be the dendritic cells (DC), whereas monocytes (Mo) are only weakly or not at all capable of inducing T‐cell immune responses to the soluble antigen purified protein derivative (PPD). In contrast, we found Mo to have a suppressive effect on the APC function of DC in vitro. Removal of Mo by adherence resulted in an increased APC activity, even though Mo produce more interleukin 1 (Il‐1) than DC. Furthermore, addition of the prostaglandin synthesis inhibitor indomethacin gave rise to increased Il‐1 production, HLA‐class II expression, and a stronger antigen‐specific T‐cell response to PPD. Taken together, our studies indicate that the superior accessory cell function of DC compared with Mo in in vitro cultures may, at least partly, be attributed to the prostaglandin E2 production by Mo and more stable expression of HLA‐class II molecules on DC.
Purine Metabolic Enzymes in Lymphocytes
Authors: KURASHIGE S. , AKUZAWA Y. , MITSUHASHI S.
Published: June 2006

Coformycin, which is an inhibitor of adenosine deaminase, significantly inhibited in vitro blastogenic responses of human lymphocytes to both phytohaemagglutinin (PHA) and pokeweed mitogen (PWM), whereas blastogenic responses to bacterial lipopolysaccharide (LPS) were rather enhanced by the addition of coformycin. Blastogenic responses of lymphocytes to PHA and PWM were markedly suppressed by the addition of adenosine, which is a substrate of adenosine deaminase. Allopurinol, which is an inhibitor of xanthine oxidase, inhibited blastogenic responses of human lymphocytes to PHA, PWM, and bacterial LPS. Inosine (a substrate of purine nucleoside phosphorylase) and hypoxanthine (a substrate of xanthine oxidase) showed no or only a small effect on blastogenic responses of human lymphocytes. These results suggest that adenosine deaminase activity is associated with the T‐cell response but not with the B‐cell response and that the impaired T‐cell response in adenosine deaminase deficiency is the result of intracellular retention of adenosine in T cells. The results also suggest that purine nucleoside phosphorylase or xanthine oxidase activity is associated with both T‐ and B‐cell responses.
Induction of Immunoglobulin Secretion by Protein A from Staphylococcus aureus in Human Blood and Bone Marrow B Cells
Authors: RINGDÉN O.
Published: June 2006

Antibody secretion was measured in vitro as plaque‐forming cells (PFC). using an indirect haemolysis‐in‐gel assay. Protein A from Staphylococcus aureus (SPA) induced 4900±1800 (mean ± from 12 individuals) IgG+A+M PFC/106 blood lymphocytes. This was comparable to responses induced by Staph. aureux Cowan 1, lipopolysaccharide, pokeweed mitogen, and purified protein derivative of tuberculin. In bone marrow, SPA induced the highest number oi PFC (36,500 ± 100/106) of all the B‐cell activators. SPA mainly induced IgG PFC and only a few IgA and IgM PFC. In blood, B cells enriched by sheep erythrocyte sedimentation gave a higher PFC response to SPA than unseparated blood lymphocytes, whereas almost no stimulation was seen in enriched T cells. In bone marrow, the highest number of PFC stimulated by SPA was often seen among the enriched T cells. After the removal of adherent and phagocytic cells, the number of PFC induced by SPA was reduced in blood and bone marrow cells. In enriched B cells from blood, the number of PFC stimulated by SPA increased in the presence of enriched T cells depleted of OKT8‐positive cells and decreased when cultured with T cells depleted of OKT4‐positive cells. It is concluded that macrophages/monocytes and T helper and suppressor cells play a role in the regulation of human B‐cell antibody secretion induced by SPA.
IgG with a Deviant Conformation in Serum and Synovial Fluid from Rheumatoid Arthritis Patients
Authors: HANSSON U.‐B. , OHLIN M. , LINDSTRÖM F. D.
Published: June 2006

Specific rabbit antisera were prepared against an IgG with a special conformation (IgG spec.) previously detected in some sera from patients with rheumatoid arthritis. The antibodies had no affinity to normal human IgG and were not anti‐idiotypic to human rheumatoid factor. The affinity of IgG spec, to the antibodies could not be explained by an antiglobulin activity to rabbit IgG. The amount of protein with affinity to immobilized specific IgG F(ab′)2 of the antibodies was determined in serum and synovial fluid from patients with various joint diseases. A relationship between the content of IgG spec, and the diagnosis of seropositive rheumatoid arthritis was found on analysis of serum samples. IgG spec, also occurred in synovial fluid from some individuals with seropositive rheumatoid arthritis. Differences in the serum content of IgG spec, could not be explained by differences in the normal IgG content. Circular dichroism analysis of isolated IgG spec, showed that in the region(s) close to tyrosine residue(s) this polyclonal protein had similarities to heat‐aggregated IgG.
Isolation of Highly Purified Lymphocyte Subsets for Functional Studies by Means of an Indirect Rosette Technique
Authors: van der GIESSEN M. , POSTMA S. , THE T. H.
Published: June 2006

An indirect rosette assay, utilizing ox erythrocytes (RBC) coupled with rabbit anti‐mouse IgG and lymphocytes sensitized with monoclonal mouse antibodies against membrane markers, was used fur purification of lymphocyte subsets that were functionally intact. Either peripheral Mood mononuclear cells (PBMC) or T lymphocytes isolated by sheep RBC rosetting could be used as starting material for obtaining pure T‐cell subsets (T4 or T8). The following steps of the method were evaluated: the procedure of coupling rabbit anti‐mouse IgG to ox RBC via the CrCl3 method, the experimental conditions for specific rosetting, and the use of Percoll for the separation of rosettes from the non‐rosetting cells. Under optimal experimental conditions the recovery of positively selected cells was 45–55% of the cells originally present in the PBMC. The purity of these cells reached a value of more than 95%. whereas the contamination of the depleted fraction was less than 3%. The functional integrity, manifesting itself as proliferation after mitogen stimulation and as regulatory influences on in vitro Ig synthesis, appeared to be unimpaired. The described technique may be applied to the purification of various cell subpopulations for functional studies, provided monoclonal antibodies against membrane antigens are available.
Functional Characterization of Hapten‐Specific Suppressor Cells
Authors: ZÖLLER M. , WIGZELL H. , ANDRIGHETTO G.
Published: June 2006

T cells From animals suppressed against a given hapten, trinitrophenyl (TNP), were analysed for their capacity to inhibit the humoral B‐cell response against the hapten and/or a complex antigen, horse erythrocytes (HRBC), coupled or not 10 the hapten. As expected, suppression of the response to HRBC in all experiments required coupling to TNP. However, the suppressing capacity of the T cells varied with the stage of the B cells, with no detectable suppression occurring if already primed carrier‐specific B cells were used. Hapten‐specific T helper cells could, however, be induced in hapten‐suppressed mice, when hapten‐carrier conjugates were used as immunogen. Under these conditions normal efficiency of induction of carrier‐specific T helper cells was observed, and this probably also applied to hapten‐specific T helper cells to the same extent. This assumption was strengthened by using the hapten‐binding capacity of the suppressor T cells and Lyt‐l/2‐specific sera to subdivide physically helper and suppressor function.
Influenza Virus‐Specific T Cells Fail to Reduce Lung Virus Titres in Cyclosporin‐Treated, Infected Mice
Authors: SCHILTKNECHT E. , ADA G. L.
Published: June 2006

Cyclosporin A (CsA) inhibited the function(s) of transferred influenza‐specific K.D‐restricted cytotoxic T cells, which led to clearance of virus in the lungs of influenza virus‐infected mice. CsA had no effect on the migration of the transferred cells to the lungs. The pattern of migration and the number of cells recovered from the lungs were similar when cells were transferred into normal, untreated, infected or CsA‐treated. infected mice. CsA had no effect on the in vitro expression of cytotoxic activity by the K.D‐rcstricted cytotoxic T cells. These findings strongly suggest that the in vivo clearance of influenza virus by K.D‐restricted cytotoxic T cells involves a lymphokine mechanism.
1,25‐Dihydroxyvitamin D3‐Differentiated Human Promyelocytic Leukaemia Cells (HL‐60) Can Kill Antibody‐Coated Tumour Cells (K562)
Authors: ESPEVIK T.
Published: June 2006

The active metabolite of vitamin D3 1α,25‐dihydroxyvitamin D3, (1,25(OH)3D3), was tested for the ability to differentiate promyelocytic leukaemia cells (HL‐60) and histocytic lymphoma cells (U937) into cytotoxic effector cells against K562 leukaemia cells. A concentration of 10‐6 M 1,25(OH)2D3 differentiated HL‐60 cells into substrate‐adherent monoeyte‐like cell with cytolytic activity against antibody‐coated K562 cells. These differentiated HL‐60 cells were not able to lyse uncoated K562 cells in an 18‐h Cr‐release assay. Similar treatment of the U937 cells with l,25(OH)2D3 did not make them cytolytic towards K562 cells. These data indicate that l,25(OH)2D3 can differentiate HL‐60 cells to mature monocytes with cytolytic activity against antibody‐coated leukaemia cells.
In Vivo Treatment of Rats with Monoclonal Anti‐T‐Cell Antibodies
Authors: HOLMDAHL R. , OLSSON T. , MORAN T. , KLARESKOG L.
Published: June 2006

The effects of intraperitoneal injection of monoclonal anti‐rat T‐lymphocyte antibodies were evaluated immunohistochemically and functionally in normal rats and in rats with experimental allergic neuritis. In the normal animals a single injection of OX8 antibodies, reactive with suppressor/cytotoxic T cells, completely eliminated OX8‐reactive cells from peripheral lymphoid organs and from circulation, whereas the ‘pan’ T‐cell‐reactive W3/13 antibodies and the helper T‐cell‐reactive W3/25 antibodies only caused a partial elimination of their respective target cells. Injection of the W3/13 and W3/25 antibodies but not of OX8 antibodies led to a diminished responsiveness to allogeneic stimulation in vitro for spleen cells obtained from the treated rats, whereas the OX8 injection caused a complete elimination of the in vitro cytotoxic response to allogeneic cells in the mixed lymphocyte reaction‐activated spleen cell population. When Lewis rats were injected with peripheral nerve myelin and Freund's adjuvant for the induction of EAN, treatment with W3/13 antibodies completely prevented the onset of disease, whereas treatment with the OX8 antibodies exaggerated the disease symptoms.
Identification of a Cell Surface Protein Complex Mediating Phorbol Ester‐Induced Adhesion (Binding) among Human Mononuclear Leukocytes
Authors: PATARROYO M. , BEATTY P. G. , FABRE J. W. , GAHMBERG C. G.
Published: June 2006

Phorbol esters rapidly induce aggregation of human mononuclear leukocytes in vitro. Previous studies have indicated that cell surface proteins are involved. We report now that the monoclonal antibody 60.3, either as purified IgG or as Fab fragments, to an antigen common to leukocytes completely inhibited the phorbol ester‐induced intercellular adhesion (binding). No inhibition of cell aggregation was observed with monoclonal antibodies to common leukocyte antigen T 200, T‐cell‐associated antigen, monocyte‐granulocyte antigen, brain granulocyle‐T‐lymphocyte antigen, transterrin receptor, mature T‐cell antigens (mol. wt either 67,000 or 19,000/29,000). T helper/inducer cell antigen, sheep erythrocyte receptor, class I or class II antigens, or T cytotoxic/suppressor cell antigen. The antibody 60.3 did not inhibit stimulation of the cells since the characteristic phorbol ester‐induced morphological changes and phorbol ester‐enhanced cap formation of membrane glycoproteins were readily observed. Two major cell surface polypeptides with apparent molecular weights of 90,000 and 160,000 were immunoprecipitated. We conclude that this protein complex, or at least one of its components, mediates adhesion among mononuclear leukocytes.
Monoclonal Antibodies Recognizing a Neoantigen of Poly(C9) Detect the Human Terminal Complement Complex in Tissue and Plasma
Authors: MOLLNES T. E. , LEA T. , HARBOE M. , TSCHOPP J.
Published: June 2006

The terminal complement complex (TCC), consisting of C5b, C6, C7, C8, and C9, contains neoantigens that are absent from the individual native components. Neoantigens are present both in the membrane‐bound (MAC) and the fluid‐phase (SC5b‐9) complex. The present study describes production of monoclonal antibodies against neoantigens of both forms of the TCC. A convenient screening and detection system, based mainly on enzyme‐linked immunosorbent assays, crossed immunoelectrophoresis with autoradiography, and affinity chromatography with subsequent sodium dodecyl sulphate‐polyacrylamide gel electrophoresis including immunoblotting, is described in detail. Two monoclonal antibodies were specific for a neoantigen located in the poly(C9) moiety of the TCC. One of these antibodies, MCaE11, was used for immunohistochemical detection of MAC in tissue and for quantification of the fluid‐phase TCC in ethylenediaminetetraacetic acid plasma.
Isolation and Characterization of a x Amyloid Fibril Protein
Authors: GERTZ M. A. , SKINNER M. , COHEN A. S. , CONNORS L. H. , KYLE R. A.
Published: June 2006

The fibril in primary amyloidosis (AL) is composed of a monoclonal light chain or portions thereof. No unique primary structure has been identified that predisposes certain light chains to form amyloid fibrils. Currently, classification of amyloidosis is based on the biochemistry of the amyloid fibril. We determined the NH2‐terminal sequence of an amyloid fibril and found it to be of the xI immunoglobulin subgroup. No structural alterations were detected to account for the conversion of the light‐chain fragment to an amyloid fibril. Antiserum produced to the fibril protein did not react in immunodiffusion with purified LEP or MAG antigens, which are xI proteins. This antiserum may be directed to antigenic sites unique to the immunizing protein and is unable to recognize homologous proteins, rendering it unsuitable for immunochemical identification of amyloid deposits of light‐chain origin. PAG represents the 10th reported variable xI amyloid fibril protein subjeeted to partial sequence analysis. Antisera that recognize antigenic determinants present in all members of an immunoglobulin subgroup need further development.
Human Monocyte‐Released Cytotoxic Factor
Authors: KILDAHL‐ANDERSEN O. , BAKKE O‐ , NISSEN‐MEYER J.
Published: June 2006

Human lymphokine‐activated monocytes release a cytotoxic protein factor (CF). The cytostatic activity of CF was potentiated by the DNA and RNA synthesis inhibitors actinomycin D, daunomycin, and mitomycin C. These inhibitors increased the sensitivity for detecting CF approximately 10‐fold, and this is of great practical value when assaying CF. The CF‐potentialing inhibitors had a similar effect on the cell cycle distribution in that they all induced an accumulation of cells in the S and G2 phases of the cell cycle. Cytolytic activity was shown to be associated with CF, and this activity was also greatly potentiated by daunomycin and actinomycin D. The two other inhibitors studied, cycloheximide and 5‐fIuorouracil (5‐FU), had an adverse effect on the cytostatic activity of CF. These two inhibitors reduced the sensitivity of the assay for CF about fivefold. Cycloheximide had no apparent effect on the relative cell cycle distribution, whereas 5‐FU induced an accumulation of cells in the G1 phase. Of the inhibitors studied, only those that induced an accumulation of cells in the S and G2 phases of the cell cycle potentiated the cytotoxic activity of CF. suggesting that CF may preferentially act in these parts of the cell cycle.
Detection of Cell‐Mediated Lympholysis Determinants Encoded by the I‐A and I‐E Genes on Ultraviolet‐Irradiated Spleen Cells
Authors: BERETTA A. , LARSSON E.‐L.
Published: June 2006

We have analysed the effects of ultraviolet (UV) irradiation on the expression, by normal splenic cell populations, of cell‐mediated lympholysis determinants encoded by the I‐A and I‐E genes of the H‐2 complex. Cytotoxic T lymphocytes specific for class II antigens could be generated from unprimed responder mice when stimulated with UV‐treated cells from I‐A‐and/or I‐E‐congenic mice in the presence of interleukin 2‐containing medium. A cytotoxic T‐cell line specific for I‐Ek antigens was obtained and maintained upon stimulation with UV‐irradiated spleen cells. Secondary la‐specific responses were obtained with UV‐irradiated stimulators in the absence of added soluble factors. The results show that the failure of UV‐irradiated cells to stimulate primary cytotoxic T‐cell responses is not due to a selective destruction of class II antigens but rather to the inactivation of a still undefined function of la‐positive cells, other than interleukin‐1 production, involved in the establishment of high‐affinity interactions between the responding T helper cells and the stimulator cells.
Second Messenger Function of Arachidonic Acid Lipoxygenation Products in Human Natural Killer Cell Lysis?
Authors: JONDAL M. , KULLMAN C. , ROSSI P. , LINDGREN J.‐A.
Published: June 2006

Human natural killer (NK) cells were tested in the presence of several fatty acid oxygenase inhibitors such as nordihydroguaiaretic acid (NDGA), 5,8,11,14‐eicosatetraynoic acid, 3‐amino‐l‐m‐(trinuoromethyl)‐phenyl‐2‐pyrazoline (BW 755C). and indomcthacin. All drugs inhibited NK lysis at the post‐target cell‐binding level at concentrations that also suppressed lipoxygenation of arachidonic acid, suggesting that such reactivity may be required for effector cell triggering. NDGA gave a 50% NK cell inhibition in the range of 10‐30 μM and also suppressed antibody‐dependent and lectin‐dependenl systems. Further evidence of the involvement of arachidonic acid lipoxygenation was found as NK activity could be reconstituled to NDGA‐suppressed effector cells with several metabolites such as LTB4. LTB4 analogues, and hydroxyeicosatetraenoic acids lipoxygenated at C‐5, C‐12, and C‐15. Cyclic nucleotides such as cGMP and cAMP could also reconstitute activity with optimal effects at approximately 10−8 M. The combined evidence is compatible with a model for triggering lysis in which lipoxygenation products have a second messenger function. Whether arachidonic acid lipoxygenation is necessary for effector cells at all different activation/differentiation stages and whether the lipoxygenation products activate guanylic cyclase, protein kinase C, or some other target molecule remain to he further investigated.
T Lymphocytes in Collagen II‐Induced Arthritis in Mice
Authors: HOLMDAHL R. , KLARESKOG L. , RUBIN K. , LARSSON E. , WIGZELL H.
Published: June 2006

Collagen type II‐spedfic long‐term cultured T helper cells, derived from the DBA/1 mouse, have been established and characterized. Clones from these T‐cell lines could he shown to recognize either species‐specific or species‐nonspecific determinants on the collagen type II molecule, including determinants on autologous mouse collagen. Induction of arthritis via transfer to both irradiated and normal syngeneic recipient mice was obtained with both collagen type II‐specific T‐cell lines and an autoreactive and collagen type II‐specific T‐cell clone. Fewer cells were needed to evoke arthritis in normal than in irradiated recipients. Cells from lines and the clone used for transfer were by immunocytochemistry shown to have T helper phenotype.
Characterization of T‐Lymphocyte Colony‐Forming Cells in the Mouse
Authors: RÖPKE C.
Published: June 2006

T‐cell colony‐forming cells (CFC), the cells from which T‐lymphocyte colonies are initiated when cells are grown in semisolid medium, have been studied. CFC have previously been shown to be more frequent in populations of rather mature thymic cells and peripheral lymphocytes than in populations of immature cortical thymocytes. We have here evaluated whether CFC in spleen and lymph nodes are confined either to newly emigrated thymocytes or to older recirculating T cells, h is shown that CFC in spleen have the same Lyt phenotype as thymic and lymph node CFC, namely Lyt‐1+ 2+, and that the peripheral complement of CFC is rather slowly built up after birth or after total body irradiation and bone marrow reconstitution. Results obtained after fluorescence‐activated cell sorting, hydrocortisone injection, or thymectomy indicate that CFC are present in a broad variety of peripheral T‐cell populations in accordance with age and thus that T‐cell colonies can be used to lest the proliferate capacity of the ‘average’ peripheral T cells of the Lyt‐1+2+ phenotype.
Proportions of Ig Classes and Subclasses in Mumps Antibodies
Authors: SARNESTO A. , JULKUNEN I. , MÄKELÄ O.
Published: June 2006

Mumps antibodies of 34 human beings were studied, 12 patients with natural mumps infection, 15 subjects vaccinated with a live mumps vaccine, and seven subjects vaccinated with an inactivated vaccine. Small amounts of antibodies reacting with mumps antigen were found in the prevaccination sera. An immunization with either the live or the killed vaccine caused an increase in the mumps antibodies (range, from 1.1‐fold to more than 50‐fold; geometric mean, approximately sevenfold). IgG1 was the major isotype in all post‐vaccination sera; the averag share was 61%. Next came IgM (28%), followed by IgA (9%), and IgG3 (2% of total). The patient samples had 10 (acute phase) or 20 times (convalescent phase) more mumps antibodies than the prevaccination samples. IgGl was the predominant isotype in the acute phase sera (average 42% of all antibodies). Next came IgM (41%) followed by IgA (13%), and IgG3 (4%). In convalescent sera IgGl was also the predominant isotype (average 67%), followed by IgM (19%). The minor isotypes in the second samples were IgA (12%) and IgG3 (3%). Small amounts of IgG2 antibodies were found in 1 patient and 1 vaccinee. IgG4 antibodies were not detected.
Turnover of Dendritic Cells in Rat Heart
Authors: LESZCZYNSKI D. , RENKONEN R. , HÄYRY P.
Published: June 2006

Taking advantage of the high class II (I‐region‐associaled) antigen content of the tissue dendritic cells and monoclonal antibodies directed in ihc backbone determinants of the bone marrow donor strain, we have investigated the location and analysed the turnover rate of tissue dendritic cells in rat heart. Low numbers of class II‐expressing, factor VII‐negative, nonphagocytic cells with dendritic appearance were observed between the heart muscle fibres. After irradiation with 960 rad, these cells were no longer visible but they reappeared (in lower numbers) on day 20. indicating that they are relatively radioresistant but the antigen expression is radiosensitive. Transplantation of allogeneic bone marrow demonstrated that similar cells appeared from the transplanted bone marrow on day 10, and that these cells populated the heart at a maximum of 20‐25 days after transplantation. This indicates a relatively rapid turnover rate, comparable with the turnover rate of dendritic cells in rat kidney and mouse lymphoid tissue.
Production of Interleukin 1 but not of Procoagulant Activity by Large Granular Lymphocytes
Authors: RAMBALDI A. , ALESSIO G. , ROSSI V. , DONATI M. B. , SEMERARO N. , MANTOVANI A.
Published: June 2006

Large granular lymphocytes (LGL) share phenotypic and functional properties with monocytes. We have investigated the production of procoagulant activity (PCA), so far attributed to cells of the monocyte‐macrophage lineage, by LGL. Endotoxin triggered interleukin (I L‐1) release and PCA activity by highly purified monocyte preparations. In contrast, LGL exposed to endotoxin produced IL‐1 but had no PCA activity. Similarly ineffective in inducing PCA in LGL were other stimuli that either triggered monocyte PCA or stimulated the natural killer cytotoxicity of LGL. Thus, although LGL share properties with monocytes such as the capacity to produce IL‐1, PCA is confined, among circulating leukocytes, to cells of the monocyte lineage.
Consequences of Cyclophosphamide Treatment in Murine Lymphocytic Choriomeningitis: Evidence for Cytotoxic T Cell Replication in Vivo
Authors: ALLAN J. E. , DOHERTY P. C.
Published: June 2006

Administration of a large dose (400 mg/kg) of Cyclophosphamide (Cy) prior to infection with lymphocytic choriomeningitis virus (LCMV) suppresses the virus‐immune cytotoxic T lymphocyte (CTL) response. Treatment with 150 mg/kg of Cy before, at the time of, or on the day after LCMV infection has little effect on CTL function. In contrast, when given on 2‐7 days after LCMV, this dose profoundly depresses the day‐8 CTL response and delays the onset of neurological disease. Administration of as little as 50 mg/kg of Cy has a marked effect on CTL activity when given 5 days after virus. Therefore it seems likely that CTL are replicating for 5 or 6 days during this primary response. Multiplication of these T cells is apparently completed by day 8, since inoculation of 150 mg/kg of Cy at this time has little effect on the level of CTL activity measured on day 9. The CTL activity is not reconstituted by in vitro culture with added helper factors. The interpretation that CTL are replicating in vivo following inoculation of LCMV is in accord with other analyses of virus‐specific precursor frequency in primed and naive mice.
Enhancement of Cytotoxic Activity of Natural Killer Cells by Interleukin 2, and Antagonism between Interleukin 2 and Adenosine Cyclic Monophosphate
Authors: CHUN M. , KRIM M. , GRANELLI‐PIPERNO A. , HIRST J. A. , HOFFMANN M. K.
Published: June 2006

Two cytokines. Interferon (IFN) and interleukin 2 (IL‐2). activate murine natural killer (NK) cells in vitro. Together both factors synergize considerably. Antibody against IFN eliminates the response of N K cells to IFN as well as to IL‐2, whereas antibody againt IL‐2 blocks the effect of IL‐2 but not of IFN. These findings as well as previous observations imply that both factors act on the same cell but have different roles. We suggest that IFN induces NK cell activation and IL‐2 enhances this effect. Further studies revealed that besides inducing cytotoxicity in NK cells IFN induces the production of prostaglandin E (PGE) which inhibits NK cell activation. We propose therefore that IFN has a dual effect on NK cells: it induces NK cells to become cytotoxic and initiates a negative feedback by increasing the production of PGE. IL‐2, which synergizes with IFN in the activation of NK cells, ceases to do so when the negative feedback (PGE‐mediated) is blocked with indomethacin. We infer that IL‐2 enhances NK cell activity by interfering with the negative Feedback rather than by aiding NK cell activation.
Proliferating Cells in the Synovial Fluid in Rheumatic Disease
Authors: BERGROTH V. , KONTTINEN Y. T. , NYKÄNEN P. , ESSEN R. VON , KOOTA K.
Published: June 2006

The subtype of the proliferating cells in the synovial fluid of patients with rheumatoid arthritis (RA), ankylopoietic spondylarthrosis (SPA), and osteoarthritis (OA) was studied with auto‐radiography‐immunoperoxidase double staining. Of all spontaneously proliferating synovial fluid cells in chronic arthritis, 59±4% displayed T8 differentiation marker, whereas T4 (21±4%) and B (2±1%) cells were few. Of all T4+ and all T8+ lymphocytes, 0.55±0.1% and 0.90±0.1%, respectively, incorporated [3H]thymidine. The [3H]thymidine labelling index for B cells was 0.30±0.1%. This was in contrast to OA, in which no proliferating lymphocytes were observed in the synovial fluid. Our findings suggest that the predominance of proliferating T8+ cells in the synovial fluid reflects an underlying chronic inflammation. Because RA and SPA synovium is a site of intense immunoglobulin production, our finding of the predominance of activated, proliferating T8+ cells may also reflect a dissociation between phenotype and function as a reason for the chronicity of the joint inflammation.
Murine and Human T Cell Factors that Induce the Differentiation of Normal Mouse Lymphocytes into Cytotoxic Cells Copurify with Interleukin 2
Authors: DENIZOT F. , RUBIN B.
Published: June 2006

Fetal calf serum (FCS)‐specific T promoter cell lines (line 12), clones, or lymphomas produce lymphocyte promoter factors (LPF). These factors are defined as T‐cell supernatant activities that induce polyclonal differentiation of normal experimentally unprimed mouse lymphocytes into antibody‐forming cells (B‐LPF) or into cytotoxic cells (T‐LPF). The cytotoxic cells thus induced lysed a broad range of target cells including syngeneic and allogeneic tumour cells and lymphoblasts. We have investigated whether T cell tumours (mouse or human) other than FCS‐specific T promoter cell lines (line 12), clones, or lymphomas produce T‐LPF activity, and whether T‐LPF activity is related to interleukin 2 (IL‐2) activity. We found that the EL4 thymoma cells were high producers of T‐LPF and IL‐2 activity. When EL4 cells and T‐LPF + line 12 lymphomas were cloned, all T‐LPF high‐producer clones were also high IL‐2 producers. In addition, the human Jurkat T tumour cells produced both T‐LPF and IL‐2 activity which could he detected on both mouse and human lymphocytes. By using biochemical fractionation (size fractionation or chromatofocusing fractionation) and absorption techniques, we could not separate T‐LPF and IL‐2 activity. Thus, the present data may indicate that the T‐LPF and IL‐2 activities studied in the present systems are borne by the same molceule(s) (=IL‐2?). These results are discussed in relation to current hypotheses on the cellular and molecular requirements for the generation of cytotoxic T cells.
Mycobacterium leprae‐Induced Alterations in Macrophage Fc Receptor Expression and Monocyte‐Lymphocyte Interaction in Familial Contacts of Leprosy Patients
Authors: MISTRY N. F. , BIRDI T. J. , MAHADEVAN P. R. , ANTIA N. H.
Published: June 2006

Macrophage Fc receptor expression and monocyte‐lymphocyte interaction in the presence of Mycobacterium leprae were examined in familial contacts of leprosy patients. Defective Mφ functions similar to those of borderline and lepromatous patients could he observed in approximately 71% of consanguineous contacts and 43% of of spouses of index patients. Although the values in the latter group were markedly lower than those of the consanguineous contacts, they tended to be higher than those of normal individuals (20%). These in vitro Mφ functions were independent of age, sex, and age at onset of exposure and were only weakly associated with duration of exposure. The outcome of the monocyte‐lymphocyte interaction lest paralleled to a large extent the in vivo Mitsuda lepromin response. Four contacts with defective Mφ functions also showed signs of leprosy. The value of these in vitro tests as markers of ‘susceptibility’ could therefore prove significant.
Serum Immunoglobulin‐Lipid Complexes in Plasma Cell Dyscrasia
Authors: MANASTER J. , AVIRAM M. , SILVIAN I. , CHEZAR J. , SPIRA G.
Published: June 2006

Immunoglobulin‐lipid complexes (SILC) are found in the serum of all patients with monoclonal gammopathy. Fractionation by density gradient ultracentrifugalion. Sephadex G‐200 chromatography and Sepharose protein A affinity, followed by extensive immunoassaying for immunoglohulins and lipoproteins, does not confirm the accepted assumption that SILC are immune complexes between monoclonal immunoglobulins and lipoproteins. Lipid extraction of monoclonal fractions isolated on protein A columns followed by thin‐layer chromatography shows a lipid pattern characteristic of the one found in cellular membranes. It is proposed that SILC are hydrophobic complexes between immunoglobulins and lipids, as described in membranes of B lymphocytes.
Natural Killer Cell Activity of Human Fetal Liver Cells after Allogeneic Stimulation
Authors: UKSILA J. , LASSILA O. , HIRVONEN T. , TOIVANEN P.
Published: June 2006

Cells isolated from the liver of human fetuses were confronted with mitomycin C‐treated adult allogeneic cells. After this mixed leukocyte culture (MLC)‐type reaction, the cytotoxic activity of fetal cells was tested against K562 cell line in a 4‐h 51Cr release assay. Three of the seven fetuses tested (8 to 11 weeks of gestational age) expressed marginal cytotoxic activity before cultivation. Cells from one 8‐week‐old and one 9‐week‐old fetus were slightly more cytotoxic when cultured in the presence of allogeneic cells than when cultured in the medium only. Production of gamma interferon (IFN‐γ) was not detected in these cultures. Cells of one 18‐week‐old fetus expressed strong cytotoxic activity against K562 cells after MLC. Thymocytes from the same fetus were not cytotoxic, either before or after MLC against K562 cells. The results indicate that the ‘prethymic’ human liver contains cytotoxic cells able to spontaneously kill natural killer (NK)‐sensitive target cells. Generation of strong NK‐like cytotoxicity from noncytotoxic precursor cells was observed only after the thymus becomes lymphoid, suggesting that thymus‐processed cells may regulate the generation of NK‐like cytotoxic activity. The results suggest a different ontogenity of spontaneous and MLC‐induced NK‐like cells in the human fetus.
HLA‐DR Expression on Cytotoxic T Lymphocytes
Authors: RESS S. R. , STRASSMANN G. , BACH F. H.
Published: June 2006

A DR‐null and DO‐null mutant lymphoblastoid cell line (LCL) was used to generate cytotoxic T cells (CTL) to investigate DR expression on CTL. Effector T cells generated in human allogeneic mixed Ivmphocyte culture (MLC) were separated on a fluorescence‐activated cell sorter (FACS) into DR‐positive and DR‐negative subsets. The great majority of delectable cytolytic activity, anti‐class 1 and anti‐class II (presumably anti‐DP) CTL, as well as natural killer (NK)‐like activity, resided within the DR‐positive population.
Cytotoxic Capabilities of Lymphocytes from Patients with the Acquired Immunodeficiency Syndrome
Authors: GERSTOFT J. , DICKMEISS E. , MATHIESEN L.
Published: June 2006

Lymphocytes from 16 AIDS patients were tested in the cell‐mediated lympholysis assay (CML). The ability to produce alloreactive cytotoxic lymphocytes in vitro was found to be substantially reduced when compared with concomitantly investigated normal controls. Addition of interleukin 2 (IL‐2) to the inducer cultures increased the cytotoxic activity, but not to normal levels. The CML response did not correlate wilh the relative or absolute number of Leu 3+ ceils or the proliferation in effector suspensions. The ability to produce cytotoxtc cells in CML. and the degree of potentialion by IL‐2. was positively correlated with the absolute number of Leu 2+ cells in peripheral blood of the patients, which was below normal in 56% of the patients. It is suggested thai the tow CML m AIDS patients is primarily caused by defective T‐cell help In addition patients wilh decreased absolute numbers of Leu 2+ cells may have a reduced number of CTL precursors. The natural killer (NK) activity of AIDS lymphocytes was reduced, but could be improved by incubation with IL‐2 in vitro. The mononuclear cells from the patients showed a decreased ability to respond and 10 stimulate in the mixed lymphocyte culture. In one of the AIDS patients, the CML was found lo induce autoreactivity in vitro.
Lymphokine‐Activated Killer Cells in Mouse Bone Marrow Chimaeras The Relationship to Natural Killer Cells and to Alloreactive Cytotoxic T Cells
Authors: SIHVOLA M.
Published: June 2006

Spleen cells from mouse bone marrow chimaeras were cultured in vitro in mixed lymphocyte cultures (MLC) or in the presence of interleukin 2 (IL‐2) without the added alloantigen. Precursors for the nonspecific cytotoxic cells (in this study: lymphokine‐activated killer (LAK) cells) lysing natural killer (N K) cell‐sensitive YAC‐1 lymphoma could be found 10–12 days after the bone marrow reconstitution, simultaneously with the appearance of the NK activity. The ability of LAK cells to lyse NK‐resistant tumour targets as well was demonstrated using the P 815 mastocytoma cell line; reactivity against this target was demonstrable 1 week later than the appearance of YAC‐1 lysing cells. Phenotypically LAK cells derived from spleen cell cultures of bone marrow chimaeras did not differ from LAK cells derived from normal spleen cell cultures: precursors resided within the Thy 1‐. asialo‐GM1+ cell population, and effectors expressed both of these antigens. Splenic N K cells of early bone marrow chimaeras (up to 14–18 days after the bone marrow reconstitution) were Thy 1+ cells, and thus LAK cells of bone marrow chimaeras were not derived from these Thy 1+ NK cells. The treatment of effector cells with anti‐Thy 1 antibody plus complement (C) abolished the lytic activity totally. However, these cells were not cytotoxic T cells, since alloreactiviiy, as an indication of the T‐cell cytotoxicity, could not be demonstrated until 4–5 weeks after the bone marrow reconstitution.
Similar Effects of Treatment with α Interferon on the Protein Synthesis of Human Large Granular Lymphocytes, T Cells, and Monocytes
Authors: GUSTAFSSON Å. , NY T. , LUNDGREN E.
Published: June 2006

Preparations of human large granular lymphocytes (LGL), T cells, and monocytes (MC) were obtained through centrifugation on Percoll gradients and preparative E‐rosetting. The different preparations contained more than 80% of the appropriate cell type, as judged by their ability to lyse 51Cr‐labelled K562 cells, cell morphology, and the presence of cell surface structures recognized by the OKT3, OKT10, Leu 7 and OKM1 monoclonal antibodies. The protein synthesis in unstimulated and α interferon (IFN‐α)‐treated cells of the different types was studied by subjecting 35S‐methionine‐labelled cell extracts to two‐dimensional gel electrophoresis. The general pattern of protein synthesis in LGL and T cells was virtually identical, whereas at least 7 major proteins were synthesized at a higher rate in monocytes. The effects of IFN‐α on the protein synthesis of LGL and T cells were identical. IFN‐α increasing the rate of synthesis of 9 proteins. These proteins were also expressed, but not always IFN‐augmentable, in monocytes. No additional, cell‐type associated, IFN‐inducible proteins were found. This suggests that the augmenting effect of IFN‐α on the cytotoxic capacity of LGL, T cells, and monocytes may be to affect common steps in their lytic machineries.
The Role of Serologically Defined Epitopes on Mumps Virus HN‐Glycoprotein in the Induction of Virus‐Dependent Cell‐Mediated Cytotoxicity
Authors: ALSHEIKHLY A.‐R. , ÖRVELL C. , ANDERSSON T. , PERLMANN P.
Published: June 2006

The importance of virus structural proteins for the induction of virus‐dependent cellular cytotoxicity (VDCC) was studied by means of monoclonal antibodies raised in mice against mumps virions. Antibodies against the viral glycoprotein bearing the haemagglutination and neuraminidase activities (HN) inhibited VDCC but not the natural cytotoxicity (NK) displayed by the lymphocytes in the absence of virus. Antibodies to the fusion factor, the membrane protein or the nucleoprotein were inactive. These results confirmed our previous conclusion, that the only viral component required for VDCC induction is the HN protein. To clarify the role of this protein in VDCC further, the inhibitory activity of 13 HN‐specific monoclonals, all of IgG isotype and directed against 9 distinct determinants, was studied in detail. Seven antibodies reacting with 3 different determinants of the peptide moiety of the HN protein were strongly inhibitory. The remaining antibodies, specific for 5 additional peptide epitopcs, had intermediate or weak inhibitory effects. One carbohydrate specific anti‐HN antibody was inactive although its antigen‐binding capacity was of the same magnitude as that of a good inhibitory antibody. The anti‐HN antibodies inhibited VDCC regardless of their IgG subclass. Moreover, VDCC inhibition was not correlated with the capacity of the antibodies to inhibit haemagglutination, haemolysis, neuraminidase activity, or the infectivity of the virus. These results suggest that full expression of VDCC requires the interaction of more than one of the serologically defined structures of the HN polypeptide with virus receptors on the lymphocytes and probably also on the target cells. These structures may be different at least in part from those involved in other known biological activities of the virus. Treatment of lymphocytes with virus increases both the number of target‐binding cells (TBC) and the number of cytotoxic effector cells. However, when treated under conditions which gave optimal VDCC inhibition, none of the inhibitory antibodies reduced the virus‐mediated increase in TBC. This indicates either that the anti‐HN antibodies decreased the efficiency of effector–target cell interaction necessary for VDCC induction, or that they blocked a post‐binding step required for triggering of cytotoxicity.
Direct Binding of Monomeric Anti‐DNA Antibodies to Raji Cells
Authors: FAABER P. , BROEK M. F.V.D. , RIJKE T. P. M. , CAPEL P. J. A. , BERDEN J. H. M.
Published: June 2006

The Raji‐cell test is one of the most widely used methods for the detection and quantitation of immune complexes. Immune complexes and not 7 S IgG bind via C3 to complement receptors on the cell membrane of the Raji cell. During sucrose gradient fractionation of human and murine systemic lupus erythematosus sera, with a high Raji cell‐binding activity, we could not demonstrate immune complexes in these sera. Subsequent analysis showed that the major part of the Raji cell binding was used by 7 S IgG with an anti‐DNA specificity. Blocking experiments wilh complement‐bearing aggregated IgG revealed that complement and Fc receptors were not involved in the binding of these anti‐DNA antibodies to Raji cells. We conclude that the Raji cell test is not suitable for the detection and quantitation of immune complexes in sera containing anti‐DNA antibodies.
Ligands of Surface Ig Raise Cytoplasmic Free Ca++ in Human B Cells
Authors: CLEVERS H. C. , BLOEM A. C. , GMELIG‐MEYLING F. , BALLIEUX R. E.
Published: June 2006

With the use of the fluorescent Ca++ indicator Quin‐2, we have measured changes in intracellular calcium levels in human B cells in response to anti‐Ig antibodies, to Staphylococcus aureus (Staph) or to protein A. Cells of an Epstein‐Barr virus‐transformed μλ‐carrying B‐cell line, AZU‐1, increased free cytosolic calcium after addition of anti‐μ or anti‐μ antibodies: F (ab′)2 fragments with anti‐μ specificity were equally effective. Fab fragments of sheep anti‐Ig antibodies only induced a rise in calcium levels after addition of a second anti‐sheep Ig antiserum. Cross‐linking of non‐Ig surface determinants did not influence calcium homeostasis. The calcium channel blockers verapamil (100 μM). nifedipine (20 μM). and LaCl3 (200 μM) inhibited the anti‐μ‐induced calcium influx. Peripheral blood B cells reacted in essentially the same way in response to anti‐μ antibodies. The B cell mitogens protein A and Staph also induced a rise in intracellular calcium. These observations indicate that Ca++ may play a role as a messenger in the activation of human B cells via surface Ig.
The Involution of the Ageing Human Thymic Epithelium is Independent of Puberty
Authors: STEINMANN G. G. , KLAUS B. , MÜLLER‐HERMELINK H.‐K.
Published: June 2006

One hundred and thiriy‐six thymuses completely removed; il autopsy from persons suffering a sudden death were examined by stereological and morphomelrical meihods. Adding biopsy material from immunologically healthy cardiac patients we obtained relative volumes from 204 persons ranging in age from 1 month to 107 years. The size of the human thymus remains unchanged during ageing under normal physiological conditions (median: 19.5cm3). Individual maximum size (range: 5‐70 cm3) is reached in the first year of life. Early histological changes are in the enlargement of the peri vascular space, the Hassall's hodies, and the connective tissue. This begins in the first year of life, reaches a maximum from 10 to 25 years, then declines again. Adipose tissue replaces the lymphocytic pcrivascular space and the connective tissue only. This occurs extensively after the age of 15 years. When defined by the silver impregnation technique, the volumes of the thymic epithelium (cortex and medulla), show a continuous involution from the first year to the end of life. The curve can be approximated to simple negative logarithmic functions The velocity and nature of involution of the thymic epithelium do not change under the influence of the changing hormonal balance due to puberty. Since important thymic functions (T lymphopoiesis and T‐cell differentiation are located in the epithelial space. Ihe age‐related involution of the human thymlis is not related to puberty.