Search

This article presents abstracts of various articles and research papers presented at the XXIIIrd Meeting of the Scandinavian Society for Immunology and the Vlllth Summer School, held during May 26-31, 1992, in Oslo, Norway. Abstract of the article "Cloning and Characterization of the 5'-transcriptional Regulators Region of Human α-2'6' Sialyltransferase," summarizes a study of the expression of the individual glycosyltransferases. It describes that cellular interactions such as homing, are processes which involve cell to cell adhesion and recognition. Some of these interactions are mediated by oligosaccharide epitopes on cell surface glycoproteins and glycolipids. Abstract of the paper, entitled "Production or Aleutian Disease Virus (ADV) Encoded Structural Proteins in a Baculovirus Expression System and Its Use in Vaccination Studies," presents results of various ongoing studies of recombinant baculovirus expression system and its uses in different vaccine trials. Abstract of another article, "Endotoxin and Staphylococcus aureus Enterotoxin A Induced Different Patterns of Cytokines," summarizes the study assessing effects of S. aureus enterotoxin A and lipopolysaccharide in cytokine production at the single cell level in cells obtained from healthy blood donors.

The article presents instructions for the authors submitting manuscripts to be published in the periodical "Scandinavian Journal of Immunology." The periodical publishes papers within the various fields of cellular and molecular immunology. Manuscripts should be submitted either to one of the managing editors or to one of the editors, whose addresses are given on the second cover page of the periodical. Manuscripts must be typewritten, double-spaced throughout, on one side of the paper, with a 5 centimeters wide margin.

Cellular immune responses are important in the recovery from human cytomegalovirus (HCMV) infection. However, little is known about the CD4+ T cell response and the target antigens (Ag) recognized. In this paper, we have analysed the proliferative T cell response of healthy HCMV seropositive (HCMV+) blood donors to recombinant immediate-early proteins expressed in transfected astrocytoma cells and to total HCMV Ags expressed in infected astrocytoma cells. We found that CD4+ T cells were the major cell population that proliferated in the presence of IE or total HCMV Ags. Among healthy HCMV seropositive blood donors with anti-HCMV specific proliferative response, 33-44% also responded to IE Ags. Moreover, in high responders, the precursor frequencies of cells which proliferated in the presence of total HCMV, IE, or IE1 Ags were high (1/103 to 1/255, 1/2785 to 1/7744 and 1/5190 to 1/13531, respectively). In some donors, the anti-IE response was variable over time, whereas the anti-total HCMV Ags response remained constant, which suggests regulation of the anti-IE response in immunocompetent subjects. Our results suggest that the CD4+ anti-IE1 response represents a significant part of the anti-HCMV proliferative response, both at the population level, and within individual immune systems. [ABSTRACT FROM AUTHOR]

Thymocytes from mice with experimental Trypanosoma cruzi infection respond poorly to Con-A stimulation. However, the proliferative capacity of these cells is not impaired, as demonstrated by the fact that at high doses, exogenous rIL-2 restores thymidine uptake. This finding could be explained either by insufficient IL-2 production or by the appearance of inhibitory factors during T. cruzi infection. This paper shows that in response to Con A, IL-2 production is decreased in the model. Furthermore, the whole profile of cytokine production is modified, with a striking increase in IL-10, IFN-γ, IL-4, IL-5 and IL-6 production. The results indicate that IL-10 plus IFN-γ are responsible for the decrease in the Con A-induced proliferation since a normal proliferative response as well as normal IL-2 production can be restored if both cytokines are neutralized by adding their monoclonal antibodies (MoAbs). Evidence is provided also for an enhanced non-specific cytotoxicity of thymic cells from infected mice that might involve IL-4, IL-5 and IL-6. This is the first study demonstrating an alteration of thymic cell function by T. cruzi infection which results from overstimulation of IL-10 and IFN-γ production. [ABSTRACT FROM AUTHOR]

We have previously shown that two distinct mouse placental fractions (PF) are potent immunomodulators in vivo. A 40 kDa PF induces a marked decrease of plaque forming cell (PFC) responses, while a 60 kDa PF increases them. Both effects are specific for the priming antigen. In the present study, these two PF are assayed on a cell-mediated response to allogeneic cells, i.e. in a local graft-versus-host reaction (LGVHR). Mice were primed with allogeneic cells in the presence of various amounts of the 40 kDa or 60 kDa PF, or liver extract (LE) as control. Six days later, their spleen cells were injected into the footpads of F1 recipients. Precise dose-response curves were established and the kinetics of the GVH response were carefully followed. Parallel with the modulation of PFC responses, the 40 kDa PF caused a potent inhibition of the LGVHR, while the 60 kDa PF greatly enhanced it. Both effects were specific for the alloantigens injected with the PF. Furthermore, we showed that these modulations were observed whatever the intensity of the GVH reaction, which varied according to the number of primed spleen cells transferred. This report also demonstrates that these PF can be greatly enriched by package over affinity columns made of insolubilized lectins. The 40 kDa PF is retained on and can be eluted from columns of insolubilized concanavalin A (Con A) or wheat germ agglutinin (WGA), which indicates that it is a glycoprotein. Conversely, the 60 kDa PF does not bind to any of the above lectins and is probably not a glycoprotein. This biochemical purification step is also a good procedure for obtaining an even cleaner separation of the two fractions from each other. Thus, this paper demonstrates that both PF have important regulatory, properties on specific cellular immune responses. [ABSTRACT FROM AUTHOR]

This paper describes a technique utilizing rosette formation with sheep red blood cells as a human T lymphocyte marker, and separation of T cells by rosette sedimentation. [ABSTRACT FROM AUTHOR]

The paper describes the use of mitogens for the functional characterization of human lymphocyte subpopulations with special reference to the activation of human B lymphocytes by antibodies to β2microglobulin. [ABSTRACT FROM AUTHOR]

This paper gives a review of the field of virus-lymphocyte interactions and virus receptors on lymphocytes as well as the use of viruses as markers for various lymphocyte populations. [ABSTRACT FROM AUTHOR]

This paper describes the assay system for two different types of lymphocyte complement receptors, the immune adherence receptor (C3b receptor) and the C3d receptor. [ABSTRACT FROM AUTHOR]

This paper describes the generation, detection and characterization of cytotoxic T lymphocyte activity in vitro and the application of this assay system to various immunological problems. [ABSTRACT FROM AUTHOR]

This paper describes lymphocyte binding of aggregated immunoglobulin, which appears to bind to B lymphocytes and the third lymphocyte-like cell population. The applications of aggregated Ig binding are also discussed, and the relation to Fc receptors and Ia-like antigens. [ABSTRACT FROM AUTHOR]

This paper deals with recent developments in the fractionation of immunocornpetent cells with different physical properties, using preparative free flow cell electrophoresis, fractionation of cells according to their size and density. [ABSTRACT FROM AUTHOR]

Immune responsiveness to the streptotoccal group polysaccharides at the clonal level can conveniently be monitored by analytical isoelectric focusing combined witb autoradiography. The parameters investigated in this paper can be summarized as follows: [l] Within the first week after injection antistreptococcal polysaccbaride responses art characterized by IgM antibodies, followed by subclass restriction in Balb/c mice to IgG2a antihodies. [2] The clonal pattern of specific IgG2a antibodies established in the second week after inimunization does not change within the following 6 weeks. [3] Persistence of a specific response pattern established within a primary immunization course holds for Balb/c mice and rabbits for as long as 12 to 13 months. [4] Repeated immunization courses in mice and rabbits maintain established clonal antibody patterns in toto. Temporal variations of clonal expression are generally quantitative rather than qualitative. B-cell memory within this system is therefore stable and long-lived. [ABSTRACT FROM AUTHOR]

The article highlights the contributions of Peter C. Doherty and Rolf M. Zinkernagel, 1996 Nobel Prize in Medicine awardees, to research on the specificity of the cell mediated immune defence and the biological function of the major histocompatibility complex (MHC) molecules. Recognition of alloantigens may be explained within the same frame as a result of their work. And the fact that susceptibility or protection against development of several diseases are associated to given human leukocyte antigen molecules follows as a consequence.

The influence of immune response on the treatment of American tegumentary leishmaniasis is pointed by several authors, and the existence of protective immunity in self-healed patients (SH) is also suggested. Thus, interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), interleukin (IL-) 10, IL-17, IL-22 and nitric oxide (NO) production was determined in PBMC culture supernatants from patients with active disease (AD) and after therapy, SH patients and healthy subjects, in response to the soluble antigen of Leishmania (Viannia) braziliensis. It was demonstrated that, during the active disease, there is a predominance of IFN-γ and TNF-α, indicating a proinflammatory phase of the response; IL-17 is also highlighted at this clinical state. Also, TNF-α was slightly increased in patients after therapy. NO secretion was noticed in SH individuals, while IL-17 appeared in low levels in these patients and seems to be regulated by NO. The presence of IL-10 was observed in all groups of patients. From this study, we can suggest that in the active disease and after clinical cure, with or without chemotherapy, specific cellular immunity takes part against Leishmania, but with some similarities between the clinical states. Thus, it indicates that the mediators herein described are necessary for the cure to occur. [ABSTRACT FROM AUTHOR]

Patients with adenosine deaminase (ADA) deficiency exhibit spontaneous and partial clinical remission associated with somatic reversion of inherited mutations. We report a child with severe combined immunodeficiency (T-B- SCID) due to ADA deficiency diagnosed at the age of 1 month, whose lymphocyte counts including CD4+ and CD8+ T and NK cells began to improve after several months with normalization of ADA activity in Peripheral blood lymphocytes (PBL), as a result of somatic mosaicism caused by monoallelic reversion of the causative mutation in the ADA gene. He was not eligible for haematopoietic stem cell transplantation (HSCT) or gene therapy (GT); therefore he was placed on enzyme replacement therapy (ERT) with bovine PEG-ADA. The follow-up of metabolic and immunologic responses to ERT included gradual improvement in ADA activity in erythrocytes and transient expansion of most lymphocyte subsets, followed by gradual stabilization of CD4+ and CD8+ T (with naïve phenotype) and NK cells, and sustained expansion of TCRγδ+ T cells. This was accompanied by the disappearance of the revertant T cells as shown by DNA sequencing from PBL. Although the patient's clinical condition improved marginally, he later developed a germinal cell tumour and eventually died at the age of 67 months from sepsis. This case adds to our current knowledge of spontaneous reversion of mutations in ADA deficiency and shows that the effects of the ERT may vary among these patients, suggesting that it could depend on the cell and type in which the somatic mosaicism is established upon reversion. [ABSTRACT FROM AUTHOR]

Memory cells are currently thought to be a major barrier to tolerance induction in transplantation. However, whether alloreactive memory cells resulting from a primary transplant have cross-reactivity in a second transplant is unclear. Here, we used skin transplantation from BALB/ c mice donors to presensitize CBL/6 (B6) mice. One month later, several strains of mice (including BALB/ c, DBA/2, NOD, C3H and B6 mice) were chosen as donors to construct a memory model of heterotopic cardiac transplantation. The higher degree of major histocompatibility complex (MHC) mismatch to sensitizing MHC resulted in longer median survival times (MSTs, BALB/ c 3.63 days versus C3H 6.08 days). After 3.5 days of cardiac transplantation, compared with the BALB/ c and DBA/2 groups, in the groups of NOD and C3H, the infiltration of inflammatory cells in the grafts, the proportion and proliferation of memory cells in spleens and the function of allogeneic antibodies decreased significantly. The varying degrees of MHC mismatch between the primary and secondary donors influenced the intensity of alloreactive memory cell function, the higher degree of MHC mismatch resulted in better tolerance during secondary transplantation, and these may be related to the changed activation, proliferation and function of the alloreactive memory cells. [ABSTRACT FROM AUTHOR]

Cellular immune response and delayed-type hypersensitivity reactions are considered to play a major role in the immunopathogenesis of pulmonary tuberculosis (PTB). But the exact mechanism is still to be clarified. Th1 cells are mainly involved in cellular immune responses in PTB and provide a normal healing process with minimal or no sequela whereas Th2 cell and CD8+ T lymphocyte responses may lead to more severe type of disease. In this study, we investigated the peripheral blood immune responses in PTB. The study group consisted of acid fast positive young male soldiers with PTB and a negative HIV serology. The control group included healthy young volunteer male soldiers without a history of PTB. Intracytoplasmic cytokine content of CD8+ T cells and lymphocytes, including IL-2, IL-4, IL-5, IL-10 and IFN-γ were determined by flow cytometry, and IL-2, IL-4, IL-5, IL-10, IFN-γ and TNF-α serum levels were measured by cytometric bead array (CBA). No difference was observed between the percentages of T, B, NK cells and HLA-DR expression in both groups, however, the number of CD3+HLA-DR+ activated T cell percentages was higher in PTB group as compared to healthy subjects. IL-2, IL-4, IL-5, IL-10 contents of lymphocytes and IFN-γ+CD8+ T cells were found to be significantly lower in PTB patients when compared with healthy subjects, and in parallel, serum IL-2, IL-4, IL-5 and TNF-α levels were also significantly lower in PTB patients. In conclusion we suggest that, CD8+ T cells producing both Th1 and Th2 type cytokines, may play important role in the peripheral immune response to mycobacteria. [ABSTRACT FROM AUTHOR]

Interleukin (IL)-21 and IL-15 belong to the common γ-chain receptor family. IL-15 represents a novel therapeutic target in rheumatoid arthritis (RA), whereas less is known about the role of IL-21 in human inflammatory diseases. We have analysed the effects of blocking IL-21 and IL-15 on spontaneous production of pro-inflammatory cytokines in RA synovial cell cultures. RA synovial membrane cells were cultured in the presence of an IL-21R-Fc chimera or a neutralizing IL-15 antibody and production of tumour necrosis factor (TNF)α, IL-6 and IL-1β was measured by enzyme-linked immunosorbent assay (ELISA). Expression of IL-21 and IL-15 in RA synovium was measured by RT-PCR and ELISA. mRNA for IL-21 and IL-21R was detected in the culture cell lysates. Protein for IL-15 was found at detectable levels in the cell lysates. Both the IL-21R-Fc chimera and anti-IL-15 antibody inhibited cytokine release, although substantially more IL-21R-Fc was needed. IL-21R-Fc at the highest dose (100 μg/ml) significantly reduced TNFα production by 50%, IL-6 by 57% and IL-1β by 81%. Anti-IL-15 antibody (5 μg/ml) significantly inhibited TNFα release by 51%, IL-6 by 37% and IL-1β by 82% in line with previous published observations. The data confirm that IL-15 plays a role in RA and suggests that IL-21 is also involved in driving the pro-inflammatory cytokine response in RA. [ABSTRACT FROM AUTHOR]

To describe how peripheral immune-parameters reflect the inflammatory alterations of the atherosclerotic plaques in coronary atherosclerosis. We measured general inflammatory markers C-reactive protein (CRP) and granulocyte activity, lymphocyte subpopulations and their state of activation, evaluated circulating Th1/Th2-type cytokines, and specific intracytoplasmic cytokines. We investigated the association of immune-parameters with disease outcome and mortality. Thirty-three patients with acute coronary syndrome (ACS), 62 with stable coronary artery disease (CAD) and 58 healthy controls were studied. Peripheral blood lymphocyte subgroups were quantified by flow cytometry, soluble cytokines and autoantibodies were assessed using enzyme-linked immunosorbent assay (ELISA), while intracellular cytokine levels were measured by flow cytometry after intracellular staining. We found elevated levels of CRP and granulocyte activity in ACS versus CAD ( P < 0.001, P = 0.017, respectively). Natural killer (NK) cell percentages were elevated, while percentage of T cells to the total lymphocyte count was slightly decreased in ACS compared to controls (P < 0.0001, P = 0.012, respectively). Both forms of coronary atherosclerosis showed significantly higher percentages of activated T cells than controls when stained for the activation markers HLA-DR3 and CD69+ (ACS: P < 0.0001, P = 0.002, CAD: P < 0.0001, P = 0.018, respectively). IL-1, IL-4 and IL-10 proved significantly higher in ACS versus controls ( P = 0.036, P = 0.01, P < 0.0001 respectively). Th1 to Th2 ratio shifted towards a Th1 dominance in both diseases. Both general proinflammatory markers and activated T cells signify CAD. The orchestrated proinflammatory cascade eventually leads to the development of the disease. [ABSTRACT FROM AUTHOR]

Sixty-five healthy adult volunteers were immunized four times at 1-week intervals with an inactivated whole-virus influenza vaccine based on the strain A/New Caledonia/20/99 (H1N1) without adjuvant. The vaccine was administered as nasal spray with a newly developed device to secure intranasal delivery (OptiMist™, OptiNose AS, Oslo, Norway), as regular nasal spray, nasal drops or as an oral spray. Significant IgA-antibody responses in nasal secretions were induced in volunteers immunized intranasally but not after oral spray immunization. In saliva, IgA antibodies were only marginally amplified even after oral spray immunizations. At least 73% of the volunteers belonging to any group of vaccine delivery reached serum haemagglutination inhibition titres of 40 or higher, considered protective against influenza, after only two vaccine doses. Those who had the vaccine delivered intranasally also showed evidence from in vitro secretion of granzyme B that cytotoxic T cells had been stimulated. Although immunization with the breath-actuated OptiMist™ device and nasal drops were superior with respect to both mucosal and systemic immune responses, oral spray immunization might still be considered for studies of mucosal adjuvants that are not yet acceptable for intranasal use. [ABSTRACT FROM AUTHOR]

Disseminated fungal infections are increasing. However, the interactions between the body's largest population of tissue macrophages, the Kupffer cells and the fungal pathogens are scarcely understood. The aim of this study was to examine the involvement of Toll-like receptor 4 (TLR4) signalling in cytokine production, using primary cultures of rat and murine Kupffer cells exposed to Aspergillus fumigatus and Candida albicans hyphae and conidia. All fungal components induced the release of tumour necrosis factor-α (TNF-α), but with delayed kinetics compared with lipopolysaccharide (LPS). Candida albicans was the most potent inducer of TNF-α protein and mRNA and the only inducer of interleukin-10 (IL-10) in rat Kupffer cells. All fungal components induced enhanced mRNA levels of macrophage inhibitory protein-2 (MIP-2) in the cells, similar to LPS. Inhibitors of Src tyrosine kinases added to cells prior to stimulation led to attenuation in the release of both TNF-α (60%, P < 0.05) and IL-10 (70%, P < 0.05) induced by C. albicans conidia but did not influence the LPS-mediated cytokine release. Murine Kupffer cells (C57BL/10J) also released TNF-α as well as the chemokines keratinocyte-derived chemokine (KC) and MIP-2 in response to fungal component. Surprisingly, Kupffer cells from TLR4-deficient C57BL/ScCr mice exhibited significantly enhanced production of KC and MIP-2 upon stimulation by fungal components compared with control littermates ( P < 0.05). Our study demonstrates that Aspergillus and Candida components induce cytokine production in rat Kupffer cells and that the response to C. albicans conidia involves Src tyrosine kinases. The experiments with TLR4-deficient Kupffer cells suggest that the cytokine response in these cells to fungal component is not mediated by TLR4. [ABSTRACT FROM AUTHOR]

An ideal immune system should provide each individual with rapid and efficient responses, a diverse repertoire of recognition and effector molecules and a certain flexibility to match the changing internal and external environment. It should be economic in cells and genes. Specific memory would be useful. It should not be autoreactive. These requirements, a mixture of innate and adaptive immunity features, are modulated in function of the dominant mode of selection for each species of metazoa during evolution (K or r). From sponges to man, a great diversity of receptors and effector mechanisms, some of them shared with plants, are articulated around conserved signalling cascades. Multiple attempts at combining innate and adaptive immunity somatic features can be observed as new somatic mechanisms provide individualized repertoires of receptors throughout metazoa, in agnathans, prochordates, echinoderms and mollusks. The adaptive immunity of vertebrates with lymphocytes and their specific receptors of the immunoglobulin superfamily, the major histocompatibility complex, developed from innate immunity evolutionary lines that can be traced back in earlier deuterostomes. [ABSTRACT FROM AUTHOR]

Despite improvements in allogeneic stem cell transplantation, acute graft-versus-host disease (GVHD) remains a significant problem after transplantation, and it is still a major cause of post-transplant mortality. Disease progression is characterized by the differentiation of alloreactive T cells to effector cells leading to tissue damage, recruitment of additional inflammatory cell populations and further cytokine dysregulation. To make the complex process of acute GVHD more explicit, the pathophysiology of acute GVHD is often divided into three different phases. This review summarizes the mechanisms involved in the three phases of acute GVHD. [ABSTRACT FROM AUTHOR]

In this work, the authors analysed T and B lymphocyte subsets and cytokine production in the spleen of BALB/c mice during polyclonal lymphocyte activation (primary infection) and parasite-specific response to Plasmodium chabaudi chabaudi (secondary infection). The secondary response was evaluated in fully immunoprotected animals, 60 days after a chloroquine-cured infection. The authors observed that in polyclonal lymphocyte activation antibody-secreting cells of all isotypes increased, with predominance of IgG2a and IgG3 classes. At that time, IFN-γ was largely produced, but IL-4/IL-5 were just slightly enhanced. In mice re-infected after 60 days, the Ig-isotype pattern was restricted to IgG1 and only IL-4/IL-5 were produced. In both responses, however, the levels of IL-2 were greatly reduced, while those of IL-10 were enhanced to similar levels. The different involvement of Th1 and Th2 cells in both responses was confirmed through analysis of CD45RB expression by CD4+ cells. The authors observed that CD45RBhigh cells were the major CD4+ subpopulation in primary infected mice, while CD45RBlow cells predominated in 60 days re-infected animals. Moreover, the great majority of activated (large) CD4+ cells in the primary infection belonged to the CD45RBhigh subset, while alter re-infection most of the CD4+ large had a CD45RBlow phenotype. [ABSTRACT FROM AUTHOR]

Induction of anti-tumour immunity in syngeneic mice by LBC cell line derived from a non-immunogenic T cell leukaemia was studied. The immunization of BALB/c mice with LBC irradiated cells induced in them anti-tumour spleen cells, cytotoxic T lymphocytes and anti-LBC antibodies. The anti-LBC antibodies reacted with components of 14, 16 and 27 kDa present on LB tumour cells, LBC cell line and normal thymocytes, but not with normal lymph node cells. Furthermore, immunization of the autologous hosts with LBC cells partially protected them against subsequent challenge with the original LB leukaemic cells. These findings demonstrate that culture conditions induced modifications in the antigenic properties of the leukaemic cells, allowing LBC cells to stimulate an immune response directed against components expressed at early stages during T cell maturation. These results also suggest that the immune response is responsible for the prolongation of the survival time of the mice inoculated with the parental leukaemic cells. [ABSTRACT FROM AUTHOR]

A supply of iron is of vital importance if lymphocyte proliferation is to proceed successfully and two major sources of iron are available, intracellular stores and serum transferrin. We have investigated the relative importance to the human T lymphocyte of these two sources of iron by depleting them of intracellular iron with the chelator desferrioxamine and by culturing them in medium completely depleted of transferrin iron. The chelator decreased mitogen-stimulated proliferation of human peripheral blood T cells, in a dose-dependent manner, in the absence of extracellular transferrin-iron. By culturing the cells in iron-depleted medium, we found that normal lymphocytes proliferated, to a degree, in the absence of extracellular transferrin-iron. We also observed that transferrin receptor mRNA expression was sustained in mitogen-stimulated, iron-deprived lymphocytes, compared with untreated cells suggesting that up-regulation of transferrin receptor may occur in these cells through stabilization of the mRNA. We propose that intra- and extra-cellular iron may contribute to early and late activation processes and that a low level of intracellular iron in lymphocytes, chronically activated in the iron-deficient environment associated with chronic inflammatory diseases such as rheumatoid arthritis, may be a factor in the abnormal cell-mediated immunity associated with such diseases. [ABSTRACT FROM AUTHOR]

The lymphocyte transformation test was used to evaluate the cellular immune response in 31 adult patients with MCNS in comparison with 30 normal control and 49 patient (CRF, FSGN, MGN) control groups. The results showed that the stimulation indices of the lymphocytes in MCNS group were significantly lower than those of the normal control and patient control groups with the exception of CRF group. In cross studies, lymphocytes obtained from normal individuals were incubated in homologous serum obtained from MCNS patients in relapse, and lymphocytes from MCNS patients in relapse were incubated in normal homologous AB serum. In both circumstances there was a depressed lymphocyte function which indicates that there is a defect in lymphocyte itself as well as a serum inhibitory factor(s) during the active stage of the MCNS. This depressed cellular immune response returned to normal level during remission of the patients with MCNS. [ABSTRACT FROM AUTHOR]

Insertion of various cDN As in the genome of the vaccinia virus (VV) enables the in vivo and in vitro study of the functional role and/or the immunogenicity of the virally encoded recombinant proteins. We have prepared a recombinant VV expressing the cDNA of the human cytokine HILDA/LTF (human interleukin for DA cells/leukaemia inhibitory factor), and used this virus to immunize mice against this protein, which is very homologous to its murine counterpart (&ap; 80% homology). We also constructed and expressed by the same system a chimeric gene encoding the HILDA/LIF protein fused to the 37 COOH-terminal amino-acids of the human decay accelerating factor (DAF). This sequence proved to be sufficient for the targeting of the fusion protein to the cell membrane, where it is linked to the phosphatidylinositols. Both recombinant VVs induced cytokine-specific antibodies in mice as analysed with an FLISA where the recombinant HILDA/LIF was plastic-coated and a cytonuorometric assay where the LIF-DAF molecule was present at the cell surface of stably transfected PSI 5. In the latter case HILDA/LIF remained biologically active suggesting that it was expressed in its native form. The LIFDAF fusion protein was found to exhibit a better capacity to elicit an antibody response against the native form of the cytokine as detected in cytofluorometric assays. Whatever the recombinant virus used to immunize the mice, the MoAbs obtained were positive either in the ELISA or in the cytofluorometric assays but one, which suggested that the plastic coating induced a conformational change of HILDA/LIF. [ABSTRACT FROM AUTHOR]

We are interested in cellular responses to antigens of parasites to which the cell donor has not been previously exposed and how such responses may influence parasite establishment. In order to characterize such responses we have used cells from unexposed healthy donors and analysed the lymphoproliterative response to various Leishmania aethiopica antigen preparations and the cytokines produced in the process. Peripheral blood lymphocytes were stimulated with SDSPAGE separated L., aethiopica antigen coupled to nitrocellulose particles. Fifteen of the 16 unexposed individuals tested had proliferative responses to either the whole or and the antigen-bearing nitrocellulose fractions (NC fractions). Although the degree of response to the fractionated antigen varied in individuals, major stimulatory fractions were found in the high molecular weight region of 110 80 kDa (fractions 3 6) and low molecular weight region of 46-18 kDa (fractions 12 16). Substantial amounts of interferon gamma (IFN-γ) and interleukin 2 (IL-2) were present in the supernatants of cells stimulated with the whole unfractionated antigen. The potential relevance of such responses in resistance to Leishmania infection is discussed. [ABSTRACT FROM AUTHOR]

The various cytokine responses associated with stimulation by parasites is discussed with emphasis on Leishmania parasites. Cells from normal individuals can respond to Leishmania antigens in vitro but the state of the antigen used for stimulation influences the outcome. We have used cells from non-Leishmania exposed donors and stimulated them in vitro with variously treated promastigotes of L. aethiopica. The levels of some cytokines released into the supernatant were measured. All the Leishmania preparations tested induced high levels of IL-6, whereas IFN-γ production to the different stimuli was variable in the individual donors. The ability of these supernatants to inhibit intracellular forms of L. aethiopica was sometimes stronger in L. aethiopica-induced than in PHA-induced cultures. Such strong non-Leishmania specific responses, if they exist in vivo, may influence whether disease is established when the host encounters Leishmania parasites. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the cytokine production and cytokine responsiveness of the first T-cell receptor (TcR) positive cells that appear in the murine fetal thymus, namely TcR Vγ3 cells. It is shown that IL-2-cultured fetal TcR Vγ3 thymocytes were capable of producing IL-3, GM-CSF, TNF-α and IFN-γ upon TcR triggering, IL-2, IL-4, IL-5 and IL-6 could not be detected. With regard to cytokine responsiveness, TcR Vγ3 cells proliferated to a high extent when high concentrations of rIL-2 were added, rIL-4 or rIL-7 alone, but not rIL-1 alone, were capable of inducing a modest proliferation of TcR Vγ3 thymocytes. When combined with low concentrations of IL-2, a synergistic effect could be observed with IL-1, IL-4 or IL-7. It is shown that the synergistic effect of IL-2 with IL-4 was mainly due to induction of IL-2 receptor expression. The synergistic effect of IL-2 and IL-7 on the proliferation of TcR Vγ3 cells could only be partially inhibited by anti-IL-2 receptor MoAb, and this antibody had no effect on the IL- 2+IL-1 cultures. These observations can explain the extensive proliferation of TcR Vγ3 thymocytes during fetal life and they indicate that TcR Vγ3 thymocytes have the potential to play a functional role during fetal thymus development. [ABSTRACT FROM AUTHOR]

The article explores various dimensions of the immune system. The immune system was considered to be the set of components within the body that produced antibodies in response to certain external stimuli. Subsequently, observations of immune phenomena not mediated by antibodies led to the idea of a cell-mediated as well as a humoral arm within the immune system. Emphasis then shifted to the nature of these two functional subsystems and the relationship between them. It became apparent that additional modules were required and further, that other systems, such as the reticuloendothelial and haemopoietic systems, also had an impact on immune functions.

To clarify the significance of basic fetoprotein (BFP) in lymphocytes, we investigated whether BFP is produced in lymphocytes during blastic transformation. Peripheral blood lymphocytes obtained from 14 adults were cultured under the stimulation of lectins. The concentration of BFP in the culture medium (exvtracellular BFP) was estimated serially. The incorporation of [6-3H]-thymidine was assayed simultaneously. The intracellular BFP was measured by dual flow cytometry for DNA and BFP. A lymph node was studied immunohistochemically. Serum BFP was measured in four cases of lymphocytic leukaemia. In two cases, dual staining was performed. The intracellular BFP of the mitogen-stimulated lymphocytes was increased within 24 h. The extracellular BFP was increased exponentially from 72 h. The extracellular BFP at 96 h did not correlate with the [3H]-thymidine incorporation. The intracellular BFP increase began in G1 phase. Immunostaining showed that the B cells also produced BFP. The serum BFP level in leukaemia was high in 1 of 4 cases and the leukaemic cells in two cases showed high intracellular BFP content. These observations indicate that BFP is produced in activated human lymphocytes and in lymphoeytic leukaemic cells. The production of BFP during blastic transformation will be a useful new in vitro model for studying the biological role of BFP, and BFP labelling may offer some new possibilities for the study of lymphocytes. [ABSTRACT FROM AUTHOR]

This article details developments in the field of histocompatibility studies. The major histocompatibility complex (MHC) is a group of closely linked loci present in similar form in all mammals and perhaps in all vertebrates. It plays an important role in immune phenomena. However, its immunological role is still imperfectly understood. The MHC was originally discovered because of its role in the rejection of transplants made between incompatible individuals. Genes competent to play this role in the appropriate experimental or surgical context are called histocompatibility or H. genes. The author shares his own experiences working in the field of cellular immunology. Based on a project in radiation genetics, which the author had pursued, two methods of locus identification appeared possible. The first was the use of visible marker genes to tag chromosome segments carrying a single or, at most, a few H. genes. The second was the transfer, by appropriate crosses, of an H-bearing chromosome segment from one strain onto the inbred background of another.

The effect of serum amyloid A (SAA)on fever induced by recombinant interleukin-Iβ(rTL-1β)or recombinant tumour necrosis factor D: (rTNFα) was studied in mice. Serum amyloid A is an acute phase protein whose rise in pathological events is induced by the cytokines IL-1, IL-6 and TNF, Administration of human serum amyloid A to mice inhibited fever induced by rlL-lβ or rTNFα in vivo, while the addition of human serum amyloid A to mice liypothalamic slices inhibited IL-1β- or TNFα-induced prostaglandin E; (PGE2) production in vitro. Since serum amyloid A did not affect body temperature or hypothalmic PGE2 levels when administered alone, it may represent a specific servo-mechanism for fever regulation in acute events, and it suggests, for the first time, a possible feedback relationship between serum amyloid A and the immunoregulatory cytokines. [ABSTRACT FROM AUTHOR]

Interieukin-1β (IL-1β) is a cytokine produced mainly by activated monocytes though the mechanism by which it is released is still unknown. Elevation of intracellular cyclic adenosine monophosphate (cAMP) is considered an important down-regulative signal in the production of IL-lβ in lipopolysaccharide (LPS)-induced monocytes. In this study we show that in LPS activated human monocytes, elevated cAMP concentrations (induced by either prostaglandin E2, forskolin or dibutyrylcyclic AMP) affected specifically secretion of IL-1β; the amount of secreted IL-1β was clearly reduced whereas the cell-associated level remained unchanged. TNF-α a normal secretary protein, was used as a control. Cyclic AMP also inhibited TNF production by monocytes, but the decrease was of the same magnitude in the extracellular and intracellular compartments. Thus, the down-regulative effect of cAMP on the production of these monokines is clearly different. [ABSTRACT FROM AUTHOR]

Specific inhibitors of the membrane-bound dipeptidyl peptidase IV (DP IV) and polyclonal antibodies against this enzyme were used to investigate the relationships between DP IV activity and the production and action of T cell-derived lymphokines. Production of interleukin 2 (IL-2) and gamma interferon by mitogen plus phorbol ester-stimulated mononuclear cells from human blood was found to be reduced in the presence of N-Ala-Pro-O-(nitrobenzoyl-)-hydroxylamine, epsilon-(4′nitro) benzoxycarhonyl-Lys-Pro, and anti-(DP IV) immunoglobulin in a dose-dependent manner. Moreover, the proliferative response of mitogen-stimulated mononuclear cells to IL-2 is impaired in the presence of DP IV inhibitors. Therefore it is suggested that the membrane peptidase DP IV is involved in the induction and activation of cytokines controlling lymphocyte proliferation. [ABSTRACT FROM AUTHOR]

The role of HLA class I subunits in class II-restricted immune responses was investigated by means of a panel of monoclonal antibodies (MoAb) recognizing HLA-A, B, C heavy chain and different β2 microglobulin (β2m) epitopes. MoAb against either class I subunit strongly inhibited mixed lymphocyte cultures, generation of cytotoxic T lymphocyte cultures, generations of cytotoxic T lymphocytes or natural killer-like activity, and lymphoproliferation in response to soluble or particulate microbial antigens derived from Candida albicans. In general, anti-β2m MoAb were more efficient inhibitors than anti-HLA-A, B, C heavy chain MoAb. The inhibitory effects were specific, in that the parental myeloma ascitic fluid or a low-affinity MoAb against β2m, or MoAb directed against non-HLA surface structures did not affect any of the immune responses studied. The MoAb-induced inhibition could not be attributed to nonspecific toxic effects, since PHA-induced blastogenesis and IL-2-dependent proliferation of mixed lymphocyte culture (MLC) blasts were not inhibited. Furthermore, exogenous IL-2 did not reverse the block of MLC and microbial antigen-induced proliferative responses by MoAb. Taken together, these data suggests an involvement of both subunits of class I antigens in class II-restricted immune reponses. [ABSTRACT FROM AUTHOR]

Glycopeptides were prepared from proteolytically digested human and guinea pig α1- microglobulin (α1-m) by gel chromatography on Sephadex G-100 and affinity chromatogra- phy on concanavalin A-Sepharose. Amino acid analysis showed that the average gly- copeptide was a tripeptide containing the amino acids aspanic acid/asparagine, isoleucine, and serine and/or threonine. It has earlier been shown that human α1-m carries two or three N-glycosidically linked oligosaccharides of the high-mannose type. These preparations of glycopeptides inhibited the proliferative response of peripheral human blood leucocytes to the antigen purified protein derivative. The dose-response relationship of the inhibitions showed a greater specific activity of the glycopeptides than of whole α1-m. Mild alkali treatment of human α1-m did not affect its specific inhibitory activity, suggesting that the peptide backbone is of little importance for the immunosuppressive effect of α1-m. No difference in inhibitory activity was seen between human and guinea pig native α1-m or α1-m glycopeptides. Human asialo α1-m exerted a suppressive effect on the antigen-specific leucocyte proliferation similar to that of native α1-m. [ABSTRACT FROM AUTHOR]

Induction of suppressor cells specific for guanosine in C57BL/6 mice with syngeneic spleen cells coupled with guanosine was demonstrated. Spleen cells from mice that had been tolerized by the injection of guanosine-coupled syngeneic spleen cells (G-SC) were repeatedly stimulated with mitomycin C-treated G-SC (MMC-G-SC) in vitro. These cells effectively suppressed the secondary in vitro response to guanosine-keyhole limpet haemocyanin (G-KLH) but did not suppress the response to sheep erythrocytes (SRBC). From these cell populations a long-term-cultured suppressor T-cell line specific for guanosine was established by using interleukin-2 and MMC-G-SC. This cell line suppressed the response to G-KLH but did not suppress the response to trinitrophenyl-KLH and SRBC. The suppressive effect was completely eliminated by treatment with anti-Thy 1.2 and complement. [ABSTRACT FROM AUTHOR]

After 3–5 days of in vitro culture, peritoneal cells from untreated C3H mice produce autoantibodies specific for autoantigens in the membranes of mouse erythrocytes. The autoantigens are exposed in vitro by treating mouse erythrocytes with the proteolytic enzymc bromelain. Limiting-dilution cell culture techniques were used to determine the frequency of the autoreactive B cells. Cells were cultured in Terasaki trays at 10–200 cells/well. Autoantibody production was assayed with an in situ plaque-forming cell (PFC) assay. On average, one autoantibody precursor cell was detected for every 150–200 peritoneal cells cultured. This precursor frequency was increased to 1 in 50 by the addition of lipopolysaccharide (LPS) and dextran sulphate (DS) to the culture medium. The addition of a culture supernatant from an EL4 lymphoma subline also induced a high proportion of the peritoneal cells to secrete autoantibodies. However, it was not possible to determine the frequency of PFC accurately because at limiting numbers of peritoneal cells the effects of EL4 affected more than one limiting variable. Significant cell division was observed in cultures to which LPS/DS had been added, in contrast to untreated cultures to which EL4 supernatant was added. The results show that high numbers of autoreactive B cells committed to self antigens are present in the peritoneal cavity and that these cells under the influence of appropriate cytokines can differentiate in vitro, even without proliferation, into autoantibody secretors. The cell type or types releasing the cytokines remain to be identified. [ABSTRACT FROM AUTHOR]

An in vitro system is described which supports the primary induction of T cells able to help in the induction of delayed-type hypersensitivity. This system is used to demonstrate that hapten-Ficoll conjugates induce potent hapten-specific T cells with this function. These type-II ‘thymus-independent’ antigens are thus able to induce specific regulatory T cells. These helper T cells are similar to those induced by classical thymus-dependent antigens in that they are specific for antigen rather than idiotype and act by a linked mechanism. [ABSTRACT FROM AUTHOR]

The control of the autoimmune response to modified self-antigens was explored, using immunodeficient mice injected with syngeneic trinitrophenylated spleen cells (TNP-SC) as an experimental model system. X-irradiated (250 rad) A mice injected with TNP-SC and footpad-challenged 7 to 14 days later with syngeneic lymphoblasts generated a delayed-type hypersensitivity (DTH) response that was expressed by footpad swelling measured 24 h, 48 h and 72 h later. Histopathological examination showed massive inflammatory infiltration in the soft tissues the lymphoblast challenge only. The immunological activity was transferred from the X-irradiated TNP-SC-immunized mice to naive recipients by T cells (Lyt-1+) and not by serum, thus excluding the possibility that the inflammatory reaction is mediated by antibodies. We have previously presented evidence that the differentiation status of the lymphoblasts, and not contaminants from the incubation media, was the determinant factor eliciting the DTH were able to elicit the DTH response of immunodeficient mice injected with syngeneic TNP-SC, we suggested that immunological activity was directed against self-antigens, thus expressing an autoimmune reactivity. The ability of immunodeficient mice to generate syngeneic DTH was not restricted to the TNP hapten or to inbred A-strain mice. X-irradiated BALB/c mice injected with syngeneic penicillinated spleen cells and challenged with syngeneic lymphoblasts generated a significant DTH response, in contrast to X-irradiated BALB/c mice exposed to the challenge dose only. X-irradiated A mice injected with syngeneic TNP-SC and simultaneously reconstituted with syngeneic splenocytes failed to generate a DTH response after the lymphoblast challenge, indicating that the syngeneic DTH response is controlled by normal suppressor cells. The suppressor cells were characterized as T cells carrying I-Jk, Lyt-1+, Lyt-2+ and Lyt-3+ antigenic markets. The suppressor cells abrogated the syngeneic DTH response of immunodeficient mice injected with TNP-SC, even when transferred a few days after the induction of immunological activity, but not when transferred 1 h before the lymphoblast challenge, indicating that even the established immunological activity can be restrained. Various immunological aspects of these observations and the significance of the findings in illuminating human autoimmune disorders are considered. [ABSTRACT FROM AUTHOR]

Focuses on the concept of cell surface receptors for antigen and its description in the clonal selection theory. Indication of some studies made on the involvement of the binding of anti-immunoglobulin to B cells; Radiolabeling of membrane proteins from lymphoid cells from various sources; Inhibition of the cell function through the presence of clone-specific molecule on the surface of functional T-cell lines and antibodies.

The cell-mediated immune responses of 39 patients with common variable immunodeficiency (CVI) were studied in vitro, using Staphylococcus aureus and Escherichia coli prepared as whole cells and Candida albicans extract. These microbial activators were found to require intact B-lymphocyte function for normal proliferative response. The patient group was observed to have significantly depressed lymphocyte responses compared with those of controls studied in parallel (P<0.01). Negative lymphocyte response to one activator and strongly positive response to another were found in individual patients. Examination of patients' lymphocyte response to S. aureus and E. coli in association with serum IgG levels demonstrated that a rough correlation could be drawn, showing that patients with serum IgG < 125 mg/dl had markedly lower (P<0.01) lymphocyte responses than those with serum IgG > 300 mg/dl. No similar correlation with phytohaemagglutinin activation was observed. Since depressed lymphocyte responses did not correlate with reduced B-cell number in these patients, intrinsic B-lymphocyte deficiency was indicated. These preparations of microbial activators are potentially useful tools in exploring lymphocyte subpopulation functions in primary immunodeficiency diseases. [ABSTRACT FROM AUTHOR]

We have studied two patients with common variable immunodeficiency (CVID), impaired cell-mediated immunity, and high percentages of monocytes in their peripheral blood. Removal of monocytes from cultures of peripheral blood mononuclear cells from both patients increased the in vitro responses to phytohaemagglutinin (PHA) and concanavalin A (Con A) but not to purified protein derivative (PPD), as measured by [³H]thymidine uptake. Similarly, supernatants of monocyte cultures from both patients, unlike supernatants of normal monocytes, suppressed the in vitro responses to PHA and Con A but enhanced the response to PPD by cultured mononuclear cells from the patients and form normal donors. Addition of unfractionated mononuclear cells from both patients to normal mononuclear cells suppressed both pokeweed mitogen (PWM) simulation and IgG production: this effect was abrogated by removal of monocytes from the patients' mononuclear cell populations. The effect of thymosin on both patients' mononuclear cells was assayed in vitro. Thymosin was ineffective in vitro with cells from the first patient; for the other patient, [³H]thymidine uptake by mononuclear cells stimulated with PPD increased, wheareas uptake by Con A-Stimulated cells decreased, as did the percentage of E rosette-forming cells, providing further evidence of heterogeneity of the CVID syndrome. The effects of thymosin were also dependent on monocytes. [ABSTRACT FROM AUTHOR]

The kinetics of the footpad response of bacillus Calmette-Guérin (BCG)-infected mice to soluble BCG antigens were compared in two strains of mice with different degrees of susceptibility of Mycobacterium lepraemurium. For the first 21 days the responses of the 'high-resistant' C57BL and the 'low-resistant' BALB/c to the nonpathogenic BCG were similar to that produced when the pathogenic mycobacterium was used. After 4 weeks the kinetics of the BALB/c mice changed and resembled that of the C57BL mice. The change in kinetics was compared with circulating antimycobacterial antibody levels and the response of draining lymph node cells in the antigen-specific lymphocyte transformation test. A dissociation was found between the kinetics of the delayed footpad response and the lymphocyte transformation response. Since both strains of mice are equally resistant to BCG, it appears that the delayed footpad response cannot be used as an indicator of host resistance in all mycobacterial infections. [ABSTRACT FROM AUTHOR]

Discusses studies on macrophage migration stimulation factor (MIF). Measurement of migration inhibition; Problems with MIF assay; Biological role of lymphokines; Testing of recipients of related donor allografts for cellular immunity to donor antigens by the direct migration inhibition assay.

The immunoglobulin class of the complement-dependent cytotoxic antibodies in serum from D23 hepatoma-bearing rats (D23 TBS) for D23 hepatoma cells was analysed. When studied by affinity chromatography with concanavalin A, protamine, or staphylococcal protein A conjugated to Sepharose, the cytotoxic activity bound to the former two but not to protein A. The binding fractions were further characterized by column chromatography on Sepharose CL-4B. The cytotoxic activitywas recovered exclusively in the high molecular weight fractions corresponding to human IgM. Monitoring with IgG- or IgM-specific rabbit antibodies indicated that these high molecular weight cytotoxic fractions contained both IgG and IgM. However, fractionation of D23 TBS at low pH suggested that cytotoxicity was due to IgM antibodies rather than to immune-complexed IgG antibodies. This was supported by the findings that rabbit anti-rat IgM antibodies inhibited the cytotoxicity of TBS completely when added at high dilutions. [ABSTRACT FROM AUTHOR]