Histamine modulates the acute phase response at multiple points.
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Biomedical subjects
Publications and source records attributed to A Falus.
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Routine screening of Hungarian blood donors for anti-HCV commenced in the second half of 1992. Before this, five available anti-HCV ELISA kits were compared in pilot studies. In the first series, 831 random donor samples were tested by one of the tests and the 12 (1.4%) reactives found were retested by the other four. Six of the reactives were positive in all ELISA. In the second series, 325 samples from donors with elevated transaminase levels were tested by all five kits. Forty-four were found to be reactive by one or more of the tests and 32 (10%) were positive in all five assays. Samples concordantly reactive in the ELISA were positive in second or third generation recombinant immunoblot assay (RIBA 2 or RIBA 3); those that gave discordant results were indeterminate or negative. Eleven concordantly reactive samples from the second series were HCV RNA positive by polymerase chain reaction (PCR). In the first period of screening with Abbott ELISA 2 a repeat-reactivity rate of 0.98% was observed in 171,106 samples tested. Reactives were retested for supplementary testing by Wellcozyme anti-HCV. Donors reactive in both tests and strongly reactive (ELISA ratio (ER) = optical density/cut off > or = 2.5) in either of them were permanently deferred. Those negative in the supplementary ELISA or weakly reactive (1.0 < or = ER < 2.5) in both tests were subjected to RIBA 2. On the basis of RIBA, positive donors were permanently deferred, indeterminates were excluded for 1 year and negatives were readmitted. In 1992, 1,347 supplementary tests were completed; 824 (61%) of the respective donors were permanently deferred, 218 (16%) were deferred for 1 year and 305 (23%) were readmitted.
In order to elucidate the role of the inflammatory cytokines in regulating glucocorticosteroid binding (GCSB) and glucocorticosteroid receptor (GR) level we incubated a B-cell line (CESS), a promonocytic cell line (U937) and a hepatoma cell line (HepG2) in the presence of varying concentrations of IL-1 beta, IL-6 and TNF-alpha for 24 h. Glucocorticosteroid binding was determined by the method of 'whole cell uptake', and the cellular appearance of the glucocorticosteroid receptor was detected by immunocytochemistry. A rise in the glucocorticosteroid binding was induced by all three cytokines. The increase in level of glucocorticosteroid receptors in the cells shown by immunocytochemistry was much more pronounced. However, antagonistic effects were demonstrated by both methods between IL-6 and TNF-alpha, and between IL-1 beta and TNF-alpha when they were applied simultaneously, in U937. Present data suggest that local imbalance in the ratio of these three cytokines in different pathological cases might influence the glucocorticosteroid sensitivity of the lymphocytes, monocytes and hepatocytes as target cells.
An enhancing effect of histamine on the biosynthesis and gene expression of interleukin-6 (IL-6) by human cell lines, Epstein-Barr virus (EBV)-infected human B lymphoma line BMNH and the glioblastoma line SK-MG4 has been found. No similar effect of histamine has been detected on the IL-6 production by any other B-cell line, CESS or human peripheral monocytes. Histamine stimulates the IgM production of BMNH cells by autocrine action of IL-6 induced by histamine, since either neutralization of IL-6 by polyclonal antibody or blocking the IL-6 receptor by specific monoclonal antibody abolished the effect of histamine.
Studying the gene polymorphism of serum amyloid P a common constituent of amyloid deposits two restriction fragment length polymorphism patterns were found among Hungarian rheumatoid arthritis (RA), juvenile rheumatoid arthritis (JRA), systemic lupus erythematosus (SLE) patients and healthy controls. Although no direct connection between DNA polymorphism and the frequency of amyloidosis in three patient groups was found, a marked predominance of the heterozygosity in all studied groups has been described. Authors found close correlation between the serum levels of SAP and CRP in juvenile rheumatoid arthritis, but failed to find the same correlation in SLE and healthy controls. Moreover, the serum level of CRP of heterozygous patients were significantly higher than that of homozygous patients within the juvenile rheumatoid arthritis patient groups.
Complementology is one of the major areas of immunological research in Hungary. Here, András Falus and colleagues describe studies on the control of biosynthesis of complement components and on the nature and function of receptors in the complement system.
The local concentration of histamine at sites of inflammation and immune responses is invariably high. Recent studies suggest that the biological relevance of this accumulation of histamine extends beyond its well-characterized role in mediating allergic reactions. In this article, András Falus and Katherine Merétey describe a possible function for histamine in cytokine-governed regulation of inflammatory and immune cascades.
The expression of 80 kDa interleukin-6 receptor (IL-6R) and the associated molecule gp130 has been studied on human cell lines by FACS- and Northern blot analysis. The effects of dexamethasone, dibutyric-(DB)-cAMP and phorbol-12-myristate-13-acetate (TPA) have been studied on plasmacytoma cell line U266, B cell line BMNH and monocytoid cell line U937. Our data show a definite downregulation of IL-6R and gp130 expression by TPA in U266 and BMNH at both mRNA and cell surface protein levels. In U937 TPA inhibits only the IL-6R expression, without affecting that of gp130. DB-cAMP decreases the expression of both proteins in U937, slightly inhibits the IL-6R expression in U266, but is uneffective in BMNH. Dexamethasone induces considerable upregulation of gp130 only in U266. Our findings suggest separate regulation of IL-6R and gp130 on U266, BMNH and U937 cell lines.
The effect of murine IgG isotypes on the gene expression and secretion of the third component of complement (C3) has been studied using the monocytoid cell line P388D1 and oil-elicited mouse peritoneal macrophages. It is demonstrated that the binding of IgG2a and IgG2b but not IgG1 and IgG3 augments the biosynthesis of C3 both in the presence and in the absence of the phorbol ester, phorbol myristate acetate in the case of both cell types. The multifunctional cytokine interleukin-6 (IL-6) alone reveals no effect on the gene expression of C3, but increases the effectiveness of mouse IgG2a and IgG2b. Confirming the role of Fc gamma RII, a strong up-regulation of C3 gene expression and C3 secretion was found when macrophages were cultured with the F(ab')2 fragment of the Fc gamma RII-specific monoclonal antibody 2.4G2.
Murine hepatocytes cultured in the presence of human recombinant interleukin-6 (IL-6) show increased synthesis of fibrinogen and complement component C3 by the addition of histamine. No similar effect was achieved when murine hepatocytes were treated with histamine alone or with histamine and interleukin-1 alpha together. Using histamine-1 (H1) and H2 receptor antagonists a prevalence of histamine H1 receptor in the enhancement of IL-6-induced effect is suggested.
In this study the IL-6 production was studied by synovial cells isolated from patients with either rheumatoid arthritis (RA) or osteoarthritis (OA). The kinetics of spontaneous IL-6 production differs in both groups. Furthermore, the induction of IL-6 by bacterial lipopolysaccharide (LPS) in synovial cell cultures of RA is much more rapid than in those of OA patients. On the other hand, more PGE2 was detected in culture supernatants from synovial adherent cells of OA than in those of RA patients. We also compared the IL-6 production and the amount of IL-6 mRNA in fragments derived from the areas of synovial tissue showing macroscopic signs of intensive inflammation (area A), with those from relatively intact (area B) synovial sites. In synovial fragments, but not in isolated adherent cells at area A the in vitro IL-6 production starts earlier in RA than in OA. In the area A, significantly more CD14+, CD43+ and HLA-DR+ cells were detected than in the other compartment less involved in local inflammatory events.
Interleukin 6 (IL-6), a multifunctional cytokine particularly active in regulation of the acute phase response, governs the terminal maturation of B lymphocytes and participates in early activation of T cells. IL-6 levels of synovial fluids of 153 patients with different arthritides were measured by a simple sandwich enzyme immunoassay. Highest IL-6 concentrations were detected in patients with rheumatoid arthritis (RA), particularly in those characterized by very active general symptoms and severe joint pain. High IL-6 levels were detected in patients with juvenile RA with polyarticular onset of disease and in gout. Corresponding to the suggested in vivo relevance of IL-6, dose correlation of IL-6 levels with the synovial IgM rheumatoid factor accumulation was demonstrated. The rate of the correlation between synovial IL-6 level and concentration of serum C-reactive protein in RA was inversely proportional to the dose of steroid treatment in patients with RA.
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Based on our earlier data on the enhancing effect of histamine on the action of interleukin-6 (IL-6), we have studied the molecular mechanisms of these interactions. The effect of histamine was investigated on the binding of 125I-IL-6 by B lymphoma cell line CESS, monocytoid cell line U937 and hepatoma cell line HepG2. Histamine increases the IL-6 binding by CESS cells and inhibits that by U937 and HepG2 cells. Using H1 receptor (cetirizin and loderix) and H2 receptor (cimetidine and ranitidine) specific antagonists, an H1-dependent stimulation of IL-6 binding by CESS cells was found. In contrast, down-regulation of IL-6 binding by histamine was clearly mediated through H2 receptors. On U937 cells, using a monoclonal antibody reacting with the 80 kd chain of the human IL-6 receptor, and H2-receptor mediated inhibition of IL-6 receptor expression was found by FACS analysis.
The effect of incandescent light treatment on the density of 3H-imipramine binding sites (Bmax) was investigated in 17 patients with seasonal affective disorder, in eight patients with non-seasonal depression and in six healthy volunteers. A significant increase in mean Bmax value parallel to a marked improvement of the depressive symptoms was found only in patients with SAD. No effect was observed either on mean Bmax value or on clinical symptoms in patients with non-SAD and on mean Bmax value in healthy volunteers.
While preformed BSA-anti-BSA immune complexes (PIC) bind efficiently to human RBC after their interaction with human complement, nascent BSA-anti-BSA immune complexes (NIC) formed in the presence of complement do not bind to autologous RBC. The same results were obtained with tetanus toxoid-anti-tetanus toxoid PIC and NIC. In order to elucidate the causes of this marked difference between the RBC-binding properties of PIC and NIC, the profile of complement activation induced by them was compared using haemolytic assays and sensitive ELISA tests. BSA-anti-BSA NIC activated C1 more efficiently than PIC. This was reflected in a higher C4 content of the isolated NIC and higher C1 INH-C1s and lower C1q-fibronectin complex level in the NIC-treated serum as compared to the PIC-treated ones. Although isolated NIC contained more C3 than isolated PIC did, there was no significant difference in the AP activation. These findings suggest that the failure of NIC to bind to RBC is not due to a lack of C4-binding, or C3-binding and/or activation, but rather to the special structure of this type of complex.
The effect of conditioned media of 3-day cultures of blast cells from peripheral blood of 5 patients with acute myeloid leukemia (CM-AML) was studied on the synthesis of C2, factor B (Bf) and C1 esterase inhibitor (C1-INH) by human monocyte-macrophage cultures and HepG2 hepatoma cell line. The level of C2 in the culture supernatants was measured by immune hemolysis, those of Bf and C1-INH by ELISA. CM-AML was added to the monocyte cultures on day 3 and replaced by culture fluid on day 6. Compared to the control cultures, CM-AML significantly increased C2 and Bf levels and slightly decreased C1-INH levels in the culture fluids on day 6. On day 9, Bf synthesis enhancement still could be observed but C2 and C1-INH levels did not significantly differ from those of the control. CM-AML significantly increased the synthesis of factor B by the HepG2 cells too. A strong correlation was found between the results of the Bf protein and RNA determinations, which means that the supernatants of AML blasts affect the gene expression of factor B at a pretranslational level. The selective complement synthesis modifying effect of CM-AML was not due to interferons (IFN) because neither IFN-alpha nor IFN-gamma could be detected in these conditioned media. The present findings indicate that the hypercomplementemia observed in AML patients can be due to unknown factor(s) produced by leukemic blast cells.
C1 inhibitor (C1inh), a member of the serine protease inhibitor gene superfamily, is a glycosylated plasma protein inhibiting the proteolytic activities of C1r and C1s and involved in the regulation of coagulation, fibrinolysis and kinin-releasing systems. In this study, the in vitro effect of androgen hormones, dehydroepiandrosterone (DHEA), testosterone (TEST) and recombinant human gamma-interferon (gamma-IFN), has been determined on the production of C1inh in human cell lines. In both human monocytoid/histiocytoid cell line U937 and in hepatoma derived cell line HepG2, DHEA and TEST upregulated the gene expression and secretion of C1inh. The most pronounced effect was detected in the concn range 10(-7)-10(-9) M of the hormones. Under the same conditions DHEA and TEST had no detectable effect on the biosynthesis of C3, C2 and factor B by these cells, but DHEA at higher concn (10(-4) M) slightly increased that of C4 in HepG2 cells. Both in U937 and in HepG2 cells recombinant gamma-IFN markedly increased the gene expression and secretion of C1inh. This effect of gamma-IFN was abolished by histamine.