The catecholamine cytokine balance: interaction between the brain and the immune system.

Cytokines are involved both in various immune reactions and in controlling certain events in the central nervous system (CNS). In our earlier studies, it was shown that monoamine neurotransmitters, released in stress situations, represent a tonic sympathetic control on cytokine production and on the balance of proinflammatory/anti-inflammatory cytokines. Basic and clinical studies have provided evidence that the biophase level of monoamines, determined by the balance of their release and uptake, is involved in the pathophysiology and treatment of depression, while inflammatory mediators might also have a role in its etiology. In this work, we studied the role of changes in norepinephrine (NE) level on the lipopolysaccharide (LPS) evoked tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 response both in the plasma and in the hippocampus of mice. We demonstrated that the LPS induced TNF-alpha response is in direct correlation with the biophase level of NE, as it is significantly higher when the release of NE of vesicular origin was completely inhibited in an animal model of depression (reserpine treatment) and it is significantly lower in the case of increasing biophase levels of NE by genetic (NET-KO) or chemical (desipramine) disruption of NE reuptake. IL-10 was changed inversely to TNF-alpha levels only in the desipramine-treated animals. Our results showed that depression is related both to changes in peripheral and in hippocampal inflammatory cytokine production and to monoamine neurotransmitter levels. Since several anti-inflammatory drugs also have antidepressant effects, we hypothesized that antidepressants are also able to modulate the LPS-induced inflammatory response, which might contribute to their antidepressant effect.

Interactions of haemoglobin with erythrocyte membrane phospholipids in monomolecular lipid layers.

The role of red cell membrane lipids in the membrane-haemoglobin interaction was studied by measuring the surface potential and surface pressure of monomolecular lipid layers interacting with haemoglobin. Lipids of the outer and inner half of the red cell membrane were compared in respect to their haemoglobin-binding capacity. It was shown, that haemoglobin molecules interacted readily with the inner layer lipid film in acidic pH regions. This interaction is reduced as pH is increasing but still exists in the physiological pH range. It is in contrast with the increasing but still exists in the physiological pH range. It is in contrast with the findings for the outer layer lipid film, where only a partial interaction could be shown at pH 4, which was reduced to zero reaching the physiological pH range. It can be concluded from titration experiments that the process of haemoglobin binding as reflected in the measured parameters is irreversible. The result of this model experiments support the hypothesis on phosphatidylserine binding sites for haemoglobin in the inner side of red cell membrane.

Oxidation and denaturation of hemoglobin encapsulated in liposomes.

A study was made of the in vitro stability of hemoglobin-containing liposomes ('hemosomes') prepared from phosphatidylcholines, equimolar cholesterol and red cell lysate by the hand-shaking and ether-injection methods. Absorption spectra indicated hemichrome formation in 'hemosomes' prepared by the ether-injection technique, and increased oxidation of hemoglobin in hand-shaken 'hemosomes'. The denaturation of hemoglobin in ether-injection 'hemoglobin' was increased if the initial methemoglobin content of the hemolysate, or the temperature of preparation was elevated. It was slower if liposomes were prepared under either N2 or CO, or if the radical scavenger 1,3-diphenylisobenzofuran was added with the ether. Egg phosphatidylcholine and synthetic saturated phospholipids gave the same results. With hand-shaken 'hemosomes' the oxidized product was primarily methemoglobin, and oxidation could be inhibited by using saturated phosphatidylcholines instead of egg phosphatidylcholine. Lysophosphatidylcholine levels were higher and arachidonic acid levels lower in egg phosphatidylcholine 'hemosomes' than in equivalent liposomes containing no hemolysate. The 'hemosome' seems to be a suitable model for the study of hemoglobin-lipid membrane interactions and the resulting hemoglobin denaturation process.

TCR gamma/delta bearing lymphocytes in peripheral blood of allogenic bone marrow transplanted patients.

The presence of two distinct T-cell receptors (TCR) alpha/beta and gamma/delta dimers as well as of the activated T cells was analysed in peripheral blood mononuclear cells from seventeen recipients of allogeneic bone marrow transplants for leukemia and for severe aplastic anemia. Nine of seventeen recipients expressed an elevated percentage of T cells bearing TCR gamma/delta receptors in their peripheral blood. Seven out of nine cases having elevated gamma/delta positive cells showed chronic graft-versus-host (GVH) disease; one patient was treated with Cyclosporin A, and one patient was asymptomatic. In the twelve patients with GVH or other clinical symptoms, activated T cells (CD3+/HLA-DR+) were elevated indicating an autoreactive or alloreactive cell population. Our results confirmed earlier in vitro data showing that TCR-gamma/delta-bearing lymphocytes may be an activated T-cell population, and this T cell subset might be involved in mediating GVH disease, or in prolonging immunodeficiency after transplantation.

Effect of pepsin treatment on the HIV envelope and core antigens.

In order to clarify whether HIV-1 core and env antigens are destroyed during pepsin treatment, used previously for detecting HIV-1 core and env antibodies hidden in circulating immune complexes, purified recombinant env and core antigen preparations were treated with pepsin. Core antigen was found to be extremely sensitive to this enzyme. By contrast, the antigenicity of the purified env antigen was not destroyed and was even increased after pepsin treatment, performed under identical conditions. These findings suggest that after pepsin digestion the core-anti-core immune complexes do not reconstitute because of the loss of antigenicity of the core antigen. By contrast, the lack of binding after neutralization to the env antigen of the F(ab')2 fragment of the anti-env antibody, cleaved by pepsin from the immune complexes, is probably due to other factors.

Differential involvement of sympathetic nervous system and immune system in the modulation of TNF-alpha production by alpha2- and beta-adrenoceptors in mice.

In the present study, the regulation of tumor necrosis factor-alpha (TNF-alpha) production by alpha2- and beta-adrenoceptors located on noradrenergic nerve terminals and on macrophages was studied in endotoxaemic mice. We found that reduction of the sympathetic outflow by reserpine dramatically increased the lipopolysaccharide (LPS)-induced TNF-alpha production, demonstrating that the release of endogenous noradrenaline (NA), controlled by presynaptic alpha2-adrenoceptors, was a determinant factor in this model. By using alpha2- and beta-adrenergic drugs (clonidine, CH-38083, isoproterenol, propranolol) we provided the first in vivo evidence that, beside the dominance of neuronal alpha2- and macrophage beta-adrenoceptors, the alpha2-adrenoceptors on macrophages were also involved in the modulation of LPS-induced TNF-alpha production. Since adrenergic drugs are widely used in the clinical practice, our findings may have therapeutical implications.

Changes in the cholinergic system of lymphocytes due to mitogenic stimulation.

A significant increase in acetylcholinesterase (AChE) activity and muscarinic-type cholinergic receptor (mAChR) expression was demonstrated in normal human peripheral blood lymphocytes as an early response to various stimuli. AChE activity of lymphocytes from T-cell acute lymphoid leukemia patients, and that of leukemic cell lines was enhanced or increased only slightly, in good accordance with their significantly decreased response to mitogenic stimuli. The higher initial AChE activity of cultured leukemic cell lines probably reflects their permanently activated state. AChE activity and mAChR expression in these cases could only be increased by a differentiation-inducing agent. Based on these observations, the possible role of the cholinergic modulation in thymic lymphocyte maturation is assumed.

Enhanced tumor necrosis factor-alpha-specific and decreased interleukin-10-specific immune responses to LPS during the third trimester of pregnancy in mice.

It is increasingly apparent that there is a bidirectional interaction between the maternal immune system and the reproductive system during pregnancy. Pregnancy is associated with a suppression of maternal specific immune responses, which process underlies the protection of fetal tissues expressing paternally inherited alloantigens. However, recent evidence indicates that the suppression of specific, lymphocyte-mediated immune responses during pregnancy is accompanied by activation of the non-specific arm of the maternal immune response. In the present study, we have investigated the effect of pregnancy on the non-specific immune response induced by bacterial lipopolysaccharide (LPS, endotoxin) in mice. Pregnancy enhanced the LPS-induced production of proinflammatory cytokines, including tumor necrosis factor-alpha, interleukin (IL)-6, and interferon-gamma. On the other hand, LPS-induced levels of the anti-inflammatory cytokine IL-10 were suppressed in pregnant mice. These alterations in cytokine production correlated with an increased susceptibility for endotoxemic mortality in the pregnant mice. Although adrenergic receptors are important regulators of cytokine production in non-pregnant mice, the alpha(2)- and the beta-adrenoceptor-mediated modulation of cytokine production ceases to operate during pregnancy associated with severe endotoxemia. These data may explain how excessive activation of the non-specific immune responses during pregnancy can contribute to the increased severity of some maternal diseases, including septic shock, and can be an important pathophysiological factor in disseminated intravascular coagulation or preeclampsia.

Acetylcholinesterase (AchE) activity of lymphocytes in chronic lymphoid leukemia (CLL).

The specific AchE (EC 3.1.1.7) activity of lymphocytes from the peripheral blood of normal donors was determined. On Leukopak filter the isolated T lymphocytes showed activity, whereas in stepwise Percoll gradient, population TLD displayed enzyme activity. The THD and B cells were inactive. [Szelényi J. G., Bartha E. & Hollán S. R. (1982) Br. J. Haemat. 50, 241]. A mixed cell population derived from CLL patients had significantly lower enzyme activity than normal. With the progress of B-cell proliferation AchE activity decreased in parallel with the number of T cells. The sp. act. of TLD population isolated from CLL patients was the same as that of normal donors whereas their B cells were inactive.

Contribution of differently localized alpha 2- and beta-adrenoceptors in the modulation of TNF-alpha and IL-10 production in endotoxemic mice.

Evidence is presented that the immune response to endotoxemia is under tonic control of the sympathetic nervous system. Adrenergic agents may influence the immune response both directly through alpha- and beta-adrenergic receptors expressed by immunologically competent cells and indirectly via alteration of the endogenous NA level by influencing the activity of release-regulating presynaptic alpha 2-adrenoceptors located on the sympathetic nerve terminals. In the immunomodulatory effect of NA/adrenergic drugs, their action on beta-adrenoceptors was dominant, but the considerable role of alpha-adrenoceptors on macrophages was also demonstrated. According to our findings, regulation of the ascending wing of the inflammatory response, that is, TNF-alpha production, is more sensitive to the adrenoceptor effect, whereas modulation of its deregulation by IL-10 production also involves some other determining factors.

Opposite role of alpha2- and beta-adrenoceptors in the modulation of interleukin-10 production in endotoxaemic mice.

Our aim was to investigate the role of adrenoceptors in the modulation of in vivo interleukin-10 (IL-10) production in lipopolysaccharide (LPS)-treated mice. The effect of different adrenergic drugs on plasma concentration of IL-10 was measured by ELISA 90 min after LPS injection. Our results confirmed the involvement of beta-adrenoceptors since the beta-agonist isoproterenol significantly increased the IL-10 production in response to LPS stimulation, whereas the beta-antagonists propranolol decreased it. In contrast, the alpha2-agonists UK-14304, clonidine and xylazine significantly decreased the IL-10 plasma level, whereas the alpha2-antagonists CH-38083, prazosine and WB-4101 increased it. Our results provide the first in vivo evidence that, in addition to beta-adrenoceptors; alpha-adrenoceptors play also a very important role in the regulation of IL-10 production under endotoxaemic conditions.

Altered lymphocyte acetylcholinesterase activity in patients with senile dementia.

Reductions in the acetylcholinesterase (AChE) activity of certain brain areas in patients with senile dementia of Alzheimer type (SDAT) have been found to correlate with the severity of the disease, suggesting a central cholinergic lesion. Since AChE is expressed on the surface of various blood cells too, the AChE activity of lymphocytes and erythrocytes was determined to test the possibility whether the cholinergic lesion is also reflected on these readily available cells. The AChE activity of lymphocytes in SDAT and in alcoholic dementia (AD) were significantly lower as compared to those of the age-matched healthy volunteers. In contrast, there was no significant difference in the activity of lymphocyte AChE between age-matched healthy controls and patients with multi-infarct dementia of vascular origin (MID). No changes could be demonstrated in the erythrocyte AChE activities of the patients studied, and the age-matched healthy individuals, when comparing them to the healthy blood donors. The AChE activity of lymphocytes may thus be a useful marker to follow the alterations in the metabolism of acetylcholine (ACh) in the central nervous system (CNS) of different types of dementia.

Cytokines and the central nervous system.

Cytokines are involved both in the immune response and in controlling various events in the central nervous system, that is, they are equally immunoregulators and modulators of neural functions and neuronal survival. On the other hand, cytokine production is under the tonic control of the peripheral and the central nervous system and the cytokine balance can be modulated by the action of neurotransmitters released from nonsynaptic varicosities [131]. The neuroimmune interactions are therefore bidirectional-cytokines and other products of the immune cells can modulate the action, differentiation, and survival of neuronal cells, while the neurotransmitter and neuropeptide release play a pivotal role in influencing the immune response. Cytokines and their receptors are constitutively expressed by and act on neurons in the central nervous system, in both its normal and its pathological state, but cytokine overexpression in the brain is an important factor in the pathogenesis of neurotoxic and neurodegenerative disorders. Accordingly, it can be accepted that the peripheral and central cytokine compartments appear to be integrated, and their effects might synergize or inhibit each other; however, it should always be taken into account that they are spatiotemporally differentially regulated. New concepts are reviewed in the regulation of relations between cytokine balance and neurodegeneration, including intracellular receptor-receptor, cell-cell, and systemic neuroimmune interactions that promote the further elucidation of the complexities and cascade of the possible interactions between cytokines and the central nervous system.

Myocardial systolic alterations of insulin-dependent diabetics in rest.

Left ventricular systolic function was tested in 27 insulin-dependent diabetic patients by measuring the systolic time intervals. In diabetics longer pre-ejection period, and higher PEP/LVET quotient were found showing a good correlation with the values of glycosylated haemoglobin. These findings emphasize the importance of metabolic control in the development of cardiac dysfunction.

[Study of the origin of hyperglycemia in acute myocardial infarct]. / A heveny myocardialis infarctust kísérö hyperglykaemia eredetének vizsgálata.

In order to clarify the origin of hyperglycaemia, blood glucose, glycated haemoglobin (GHb) and protein-corrected serum fructosamine (SFA) values were simultaneously determined at admission of 65 patients with acute myocardial infarction while oral glucose tolerance test was performed later at discharge. In 29 patients no alterations in carbohydrate metabolism were found (blood glucose: 5.2 +/- 0.1 mmol/l, GHb: 4.4 +/- 0.1%, SFA: 2.20 +/- 0.08 mmol/l) while in 9 patients diabetes was already recorded in the medical history (blood glucose: 11.5 +/- 1.1 mmol/l, GHb: 7.9 +/- 0.9%, SFA: 3.36 +/- 0.31 mmol/l, p < 0.001). Undiagnosed diabetes was documented in 8 patients (blood glucose: 11.8 +/- 1.3 mmol/l, GHb: 7.3 +/- 0.6%, SFA: 3.51 +/- 0.24 mmol/l) while stress-hyperglycaemia was found in 19 patients (blood glucose: 8.4 +/- 0.3 mmol/l, GHb: 4.5 +/- 0.1%, SFA: 2.55 +/- 0.17 mmol/l). Undiagnosed diabetes could be recorded in one seventh while stress-hyperglycaemia could be found in one third of non-diabetic patients with acute myocardial infarction. Due to overlapping values SFA is not suitable to distinguish between stress-hyperglycaemia and undiagnosed diabetes in patients with acute myocardial infarction.

[Genetic traits in the area of Bodrogköz]. / Genetikai jellegek vizsgálata a Bodrogközben.

In 1984 a late malaria endemic area, called Bodrogköz was studied. This was a reexamination of the population genetic work performed by Walter, Nemeskéri. In six villages of Bodrogköz 328 persons were tested for AB0, Rh blood groups, haptoglobins, haemoglobin concentration, haematocrit, erythrocyte amount, the MCV, the MCH and the G-6-PD were analyzed. The quantitative determination of HbF and HbA2, red cell osmotic resistance and thalassemia were measured as well. Thalassemia heterozygote carriers and an increased level of HbF were revealed. The frequency of G-6-PD deficiency was 0.39%. In Bodrogköz the frequencies of AB0, Rh and haptoglobin types were similar in the present and all previous studies. The background of this similarity might be the genetic similarity between two following generations. On the basis of these facts, the Hb0 Arab and partially DNA work we suggested an alternative hypothesis that these mutant genes got into Bodrogköz by the rather later migration than with ancient Hungarian people during the period of conquest of Hungary.

[T gamma-lymphoproliferative disease]. / T gamma-lymphoproliferatív betegség.

The case of a rare type of T-cell malignant lymphomas, clinically with a relatively favorable course, a T gamma-lymphoproliferative disease (T gamma-cell chronic lymphocytic leukaemia) was presented. The cytomorphological, cytochemical, immuncytochemical and cytogenetical markers and functional tests of the peripheral blood lymphocytes from the patient were tested. The leukaemic cells with light- and electron microscopy showed the so called LGL (large granular lymphocyte) morphology with multifocal reactions of acid hydrolase enzymes. These cells also expressed IgG-Fc-receptor, CD 8 monoclonal antibody positivity and a monoclonally rearranged T-cell receptor gen expression. Functionally the patient's lymphocytes developed a blastic response to the T-cell mitogen Concanavalin A (ConA), they suppressed the immunoglobulin production of B-lymphocytes in co-cultures and had a normal NK-activity but decreased ADCC values. The patient was diagnosed by blood, bone marrow and lymph node examination and does not need any therapy. This case was published because of it's diagnostic, immunological and prognostical interests.

[Gene rearrangement in leukemia]. / Génátrendezödés leukaemiákban.

In this report we summarize our experiences based on the gene rearrangement study of 111 leukaemic patients of different kind. The lymphocyte DNA of the patients was studied for rearrangement of the immunoglobulin light chain constant-, the heavy chain joining- and the T cell receptor beta chain constant region. Our data have well supplemented the results of the monoclonal antibody experiments. In 33 cases the DNA study was in good agreement with the immunological data. In 42 our data helped in gave different results, immunological results. In 11 cases evaluating the DNA and immunological data indicating the necessity of further investigation. The results were inconclusive in 25 cases. As a conclusion we consider the gene rearrangement study to be useful for diagnostic purposes.