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Biomedical subjects

W Bessler

Publications and source records attributed to W Bessler.

At least 19 recordsLinked to original sources
PubMed2006

Role of MIF and glutathione, in association with fetal ovine globin chain (Hbgamma) and LPS, in induction of TNFalpha from cells of young and aged mice, and PBL from healthy human populations.

Previous reports from our group have established that the fetal ovine gamma globin chain (Hbgamma) and LPS can synergize in the induction of pro-inflammatory cytokines, especially TNFalpha, from mouse and human leukocytes. A fetal sheep liver extract (FSLE) which was observed to have marked immunoregulatory properties in vivo and in vitro had independently been observed to contain significant amounts of each of these molecules. However, the biological activity of this extract (hereafter FSLE) was not explained solely by its content of Hbgamma and LPS, and independent analysis confirmed also the presence of migration inhibitory factor, MIF, and glutathione in FSLE. We have investigated whether MIF and the cellular anti-oxidant glutathione can further synergize with Hbgamma and LPS in TNFalpha induction from human cells in vitro, and mouse cells activated in vivo/in vitro. Our data show that indeed there is evidence for such a synergy. Treatment or mouse cells with FSLE produced an enhanced TNFalpha production which could be inhibited independently both by anti-Hbgamma and by anti-MIF, and optimally by a combination of these reagents.

Aging↗
PubMed2005

Analysis of interaction of cloned human and/or sheep fetal hemoglobin gamma-chain and LPS in augmenting induction of inflammatory cytokine production in vivo and in vitro.

We have reported earlier that purified preparations of sheep fetal hemoglobin, but not adult hemoglobin, in concert with non-stimulatory doses of lipopolysaccharide (LPS) (lipid A), act cooperatively to regulate in vitro production of a number of cytokines, including TNFalpha, TGFbeta and IL-6 from murine and human leukocytes. Following in vivo treatment of mice with the same combination of hemoglobin and LPS, harvested spleen or peritoneal cells showed a similar augmented capacity to release these cytokines into culture supernatants. We report below that genetically cloned gamma-chain of human or sheep fetal hemoglobin, but not cloned alpha- or beta-chains, can produce this cooperative effect, as indeed can HPLC purified, heme-free, gamma-chains derived from cord blood fetal hemoglobin, and that purified haptoglobin completely abolishes the cooperative interaction.

Age Factors↗
PubMed2004

Characterization of an interaction between fetal hemoglobin and lipid A of LPS resulting in augmented induction of cytokine production in vivo and in vitro.

A previously described extract of sheep fetal liver was reported to reverse many of the cytokine changes associated with aging in mice, including an augmented spleen cell ConA-stimulated production of IL-4 and decreased production of IL-2. Similar effects were not seen with adult liver preparations. These changes were observed in various strains of mice, including BALB/c, DBA/2 and C57BL/6, using mice with ages ranging from 8 to 110 weeks. Preliminary characterization of this crude extract showed evidence for the presence of Hb gamma chain, as well as of lipid A of LPS. We show below that purified preparations of sheep fetal Hb, but not adult Hb, in concert with suboptimally stimulating doses of LPS (lipid A), cooperate in the regulation of production of a number of cytokines, including TNFalpha and IL-6, in vitro. Furthermore, isolated fresh spleen or peritoneal cells from animals treated in vivo with the same combination of Hb and LPS, showed an augmented capacity to produce these cytokines on further culture in vitro. Evidence was also obtained for a further interaction between CLP, LPS and fetal Hb itself in this augmented cytokine production. These data suggest that some of the functional activities in the fetal liver extract reported earlier can be explained in terms of a novel immunomodulatory role of a mixture of LPS (lipid A) and fetal Hb.

Animals↗
PubMed1997

Role of ADP-ribosylation in activated monocytes/macrophages.

Stimulating monocytes/macrophages with bacterial lipopolysaccharide (LPS) results in TNF-alpha, IL-1, IL-6 and nitrite (NO2-) formation. Inhibitors of poly(ADP-ribose)polymerase inhibit release of these mediators by preventing mRNA expression indicating that ADP-ribosylation plays a crucial role in the synthesis of these mediators. Furthermore we present evidence that ADP-ribosylation is involved in modifying cellular proteins. In murine macrophages a 33 kDa cytosolic protein could be identified that in response to LPS changed its state of ADP-ribosylation, and in human monocytes we showed that the inhibitor nicotinamide prevents LPS induced phosphorylation of two cytosolic proteins of 36 kDa and 38 kDa (p36/38) LPS. Taken together these data indicate that protein modification by ADP-ribosylation may control cellular processes involved in distinct steps of monocyte/macrophage activation.

Adenosine Diphosphate Ribose↗
PubMed1997

Kissing osteochondromata leading to synostoses.

Our aim was to determine the incidence of synostoses in the bones of the lower limbs in patients with multiple cartilaginous exostosis (MCE) and use the available imaging to suggest the cause and mechanism of its development. Radiographs of the lower legs of 21 patients with MCE were reviewed. With the intention of demonstrating the exact site and extent of synostoses and other bone deformities, such as bone pressure atrophy or erosions in five patients, 8 proximal and 6 distal tibiofibular joints were examined by CT scans. No synostoses were present in 11 patients and 10 patients had 1 to 4 synostoses. Of these synostoses, 14 were localized below the knee joint and 9 above the ankle joint. A growing osteochondroma arising from tibia or fibula can cause an erosion in the contagious surface of the neighbouring bone. If facing osteochondromata are present in both bones and show an interlocking growth at abutting parts, on osseous fusion can take place with formation of a synostosis in the proximal or distal tibiofibular joint region. In adult patients with MCE and abundant osteochondromata synostoses between the neighbouring bones of the lower legs are common findings; they are always caused by coalescence of "kissing" osteochondromata.

Adolescent↗
PubMed1997

Drug specific antibodies: T-cell epitope-lipopeptide conjugates are potent adjuvants for small antigens in vivo and in vitro.

To generate conventional or monoclonal antibodies for the serological detection of drugs, antibiotics, toxins and other low molecular mass substances, a suitable and effective adjuvant is needed. Lipopeptides derived from a major component of the bacterial cell wall constitute potent nontoxic and nonpyrogenic immunoadjuvants when mixed with conventional antigens. Here we demonstrate that the synthetic lipopeptide N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2R,S)-propyl]-(R)-cysteinyl- serine (P3CS) coupled to a Th-cell epitope (P3CS-Th) can efficiently enhance the specific immune response against low molecular weight compounds in different species. In the presence of the synthetic lipopeptide P3CS-Th, the peptides which are per se non-immunogenic stimulated a specific humoral immune response in mice after intraperitoneal application. Mixtures containing adjuvants without the Th sequence showed no significant antibody induction. A marked enhancement of the humoral immune response was obtained with the low molecular mass antigens Iturin AL, Herbicolin A and Microcystin (MLR) coupled to poly-l-lysin (MLR-PLL), in rabbits and in chickens. Lipopeptide-Th cell epitope conjugates also constituted adjuvants for the in vitro immunization of either human mononuclear cells or mouse B-cells with MLR-PLL; after fusion of the immunized cultures with the heteromyeloma cell lines CB-F7 or the mouse myeloma cell line SP 2/0, respectively, we observed a significantly increased yield of antibody secreting hybridomas.

Adjuvants, Immunologic↗
PubMed1997

A comparative analysis of cytokine production and tolerance induction by bacterial lipopeptides, lipopolysaccharides and Staphyloccous aureus in human monocytes.

Monocytes (MO) and macrophages (MAC) are important producers of cytokines involved in the pathophysiology of bacterial sepsis. Most studies concentrate on the effects of bacterial lipopolysaccharides (LPS) regarding the induction of cytokine gene expression and secretion in MO/MAC. Here we report that besides LPS, the synthetic lipoprotein analogue lipopeptide N-palmitoyl-S-(2,3-bis(palmitoyl)-(2RS)-propyl)-(R)-cysteinyl-alanyl- glycine (Pam3-Cys-Ala-Gly), another component of the outer membrane of Gram-negative bacteria, as well as heat-killed Staphyloccocus aureus (S. aureus/SAC) are potent stimuli for cytokines in human MO. For all three investigated stimuli we found an individual pattern of cytokine induction: LPS was most potent in inducing interleukin-6 (IL-6) synthesis, whereas for tumour necrosis factor-alpha (TNF-alpha) secretion SAC was the best stimulus. Comparable amounts of IL-8 were induced by either LPS or Pam3-Cys-Ala-Gly, with SAC being less effective even at higher concentrations. The addition of serum led to an increase in LPS-, SAC- and Pam3-Cys-Ala-Gly-stimulated TNF-alpha secretion, indicating that the presence of serum is critical not just for LPS stimulation. Furthermore, as is known for LPS, Pam3-Cys-Ala-Gly and SAC rendered MO refractory to a second bacterial stimulus. Pam3-Cys-Ala-Gly and SAC induced tolerance for itself, but LPS could partially overcome this effect. As the CD14 molecule is discussed as a common receptor for different bacterial components, we investigated whether the TNF-alpha response of MO could be blocked by anti-CD14 antibodies. MY4, a CD14 antibody, selectively blocked the TNF-alpha secretion induced by LPS but not by Pam3-Cys-Ala-Gly or SAC. In summary, we conclude that besides LPS, lipopeptide Pam3-Cys-Ala-Gly and SAC are potent stimuli for human MO, while the mechanisms of activation seem to be partially different from LPS.

Antibodies, Monoclonal↗
PubMed1994

Intraperitoneal injection of synthetic bacterial lipopeptides does not cause a rise in circulating inflammatory cytokines.

The production of TNF-alpha, IL-1 and IL-6 was measured in mice after i.p. injections of the synthetic bacterial lipopeptide Pam3Cys-Ala-Gly, a potent macrophage and B cell activator in vitro. Only minor amounts of IL-6 and no TNF-alpha were detectable in the serum of mice injected with 10 or 100 micrograms of Pam3Cys-Ala-Gly. Lipopeptide concentrations up to 1000 micrograms failed to induce IL-1, and TNF-alpha production and serum IL-6 levels were only slightly elevated. In contrast to Pam3Cys-Ala-Gly, i.p. injections of LPS were accompanied by high levels of the inflammatory cytokines TNF-alpha, IL-1 and IL-6 suggesting fundamental differences of the mode of action of these two substances when applied in vivo.

Amino Acid Sequence↗
PubMed1993

Responsiveness of cardiac Na+ channels to a site-directed antiserum against the cytosolic linker between domains III and IV and their sensitivity to other modifying agents.

Elementary Na+ currents were recorded in inside-out patches from neonatal rat heart cardiocytes to analyze the influence of a site-directed polyclonal anti-serum against the linker region between the domains III and IV (amino acids 1489-1507 of the cardiac Na+ channel protein) on Na+ channel gating and to test whether this part of the alpha-subunit may be considered as a target for modifying agents such as the (-)-enantiomer of DPI 201-106. Anti-SLP 1 serum (directed against amino acids 1490-1507) evoked, usually within 10-15 min after cytosolic administration, modified Na+ channel activity. Antiserum-modified Na+ channels retain a single open state but leave, at -60 mV for example, their conducting configuration consistently with an about threefold lower rate than normal Na+ channels. Another outstanding property of noninactivating Na+ channels, enhanced burst activity, may be quite individually pronounced, a surprising result which is difficult to interpret in terms of structure-function relations. Removal of inactivation led to an increase of reconstructed peak INa (indicating a rise in NPo) and changed INa decay to obey second-order kinetics, i.e., open probability declined slowly but progressively during membrane depolarization. The underlying deactivation process is voltage dependent and responds to a positive voltage shift with a deceleration but may operate even at the same membrane potential with different rates. Iodate-modified Na+ channels exhibit very similar properties including a conserved conductance. They are likewise controlled by an efficient, voltage-dependent deactivation process.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

Case report 726. Enchondromatosis of the left femur and hemipelvis (Ollier's disease).

A case of Ollier's disease is demonstrated. Large osteolytic lesions in the left femur and hemipelvis visible on the roentgenograms represent enchondromas. On CT and MRI studies numerous fine translucencies are demonstrated in the surrounding bone, corresponding to multiple cartilaginous foci. These findings may be considered pathognomonic for enchondromatosis (Ollier's disease). In addition, the nature of Ollier's disease and its predilection for malignant transformation are considered. The major differential diagnostic entity in this case was probably fibrous dysplasia.

Adult↗
PubMed1991

Histopathological studies on the local reactions induced by complete Freund's adjuvant (CFA), bacterial lipopolysaccharide (LPS), and synthetic lipopeptide (P3C) conjugates.

The inflammatory reactions following subcutaneous application of adjuvants revealed characteristic pathological patterns. The injection of complete Freund's adjuvant (CFA) resulted in the formation of large lipid deposits encircled by an inflammatory reaction and concentrically arranged collagen bundles. Bacterial lipopolysaccharide (LPS) caused granulomatous aggregations of mononuclear cells with thrombotic vessel occlusions. Inoculation of the lipopeptide adjuvants induced accumulation of mononuclear cells with only minimal fibrotic changes which were resolved after day 28. Lipopeptide conjugates based on the head group tripalmitoyl-S-glyceryl-cysteinyl-serin (P3CS) can thus be used as effective immunogens and adjuvants without long-term tissue damage.

Animals↗
PubMed1991

Increase in the intracellular free calcium concentration is not an obligatory early event in lipopeptide-induced B-cell activation.

We recently showed that synthetic lipopeptides, analogues of the N-terminal region of bacterial lipoprotein, induce DNA synthesis in B lymphocytes in the absence of enhanced phosphatidylinositol 4,5-bisphosphate hydrolysis and protein kinase C translocation. Here we demonstrate that lipopeptides are capable of inducing enhanced expression of MHC class II molecules and early increases in the intracellular free calcium concentration ([Ca2+]i) in B cells. However, they do not effect T cells. The increase in [Ca2+]i seen in B cells is due primarily to Ca2+ release from intracellular stores. Since lipopeptides differ in their capability to induce early increases in [Ca2+]i and since the calcium response does not correlate with the ability of lipopeptides to induce proliferation and expression of MHC class II molecules, we suggest that this biochemical event may not be essential for lipopeptide-mediated B-cell activation.

Amino Acid Sequence↗
PubMed1990

Induction and activity of NO synthase in bone-marrow-derived macrophages are independent of Ca2+.

The aim of the present study was to analyse whether an increase in the intracellular free Ca2+ concentration ([Ca2+]i) plays a role as a signal mediating synthesis of nitric oxide (NO) in bone-marrow-derived macrophages, either by stimulating induction of NO synthase or by regulating the activity of the enzyme. Therefore we compared the effects of various synthetic analogues of bacterial lipopeptide and of lipopolysaccharide (LPS) on NO production (assessed as nitrite formation during an incubation for 24 h) and on [Ca2+]i [measured with the fluorescent probe indo-1 (1-[2-amino-5-(6-carboxyindol-2-yl)phenoxy]-2- 2-(2'-amino-5'-methylphenoxy)ethane-NNN'N'-tetra-acetic acid)]. Strongly dissociating effects were evoked on nitrite formation and on [Ca2+]i by the stimuli. LPS was preferentially effective on nitrite formation, whereas the Ca2+ ionophore ionomycin and AlF3 induced increases only in [Ca2+]i. The lipopeptides N-palmitoyl-(S)-[2,3-bis(palmitoyloxy)-(2RS)- propyl]-(R)-cysteinylalanylglycine, N-palmitoyl-(S)-[2,3-bis(palmitoyloxy)- (2RS)-propyl]-(R)-cysteinylseryl-lysyl-lysyl-lysine and (S)-(1,2- dicarboxyhexadecyl)ethyl-N-palmitoylcysteinylseryl-lysyl-lys yl-lysine stimulated both parameters, but the maximal effects on nitrite formation and the shape of the dose-response curves did not parallel the effects on [Ca2+]i. Reduction of extracellular Ca2+ with EGTA significantly inhibited increases in [Ca2+]i, but did not change nitrite formation. Furthermore, NO synthesis in the cytosolic fraction of stimulated macrophages was not affected by Ca2+ over the concentration range 10 nM-2 microM. We conclude that increases in [Ca2+]i are not required for NO production in bone-marrow-derived macrophages. Thus the cellular regulation of NO production strikingly differs from that in the vascular endothelium, brain and adrenal gland.

Aluminum↗
PubMed1990

L-arginine-dependent nitric oxide formation and nitrite release in bone marrow-derived macrophages stimulated with bacterial lipopeptide and lipopolysaccharide.

This study shows that stimulating bone marrow-derived macrophages with either lipopolysaccharide (LPS) or the lipopeptide N-palmitoyl-S-(2,3-bis(palmitoyloxy)-(2RS)-propyl)-(R)- cysteinyl-alanyl-glycine (Pam3Cys-Ala-Gly), a synthetic analogue of the N-terminal part of bacterial lipoprotein, leads to the formation of nitric oxide (NO) and nitrite (NO2-), a stable analogue of NO. NO was detected by applying the chemiluminescence method and by measuring the activity of exogenously added soluble guanylate cyclase (GC), which is strongly and selectively activated by NO. Synthesis of NO and NO2- occurs via activation of the L-arginine and NADPH-dependent enzyme(s) present in the cytosol of bone marrow-derived macrophages. No produced by this non-constitutive L-arginine pathway is thought to be responsible for the cytostatic and killing properties of macrophages (Stuehr & Nathan, 1989). Macrophages stimulated either with LPS or Pam3Cys-Ala-Gly exhibited a 6-hr lag time before engaging in nitrite synthesis, a time at which expression of the NO-forming enzyme had already reached its maximum. The regulation of NO and NO2- synthesis during macrophage development seems to differ from that of cytokine synthesis. Whereas cytokine release varies during a culture period up to 20 days, NO synthesis and expression of the NO-forming enzyme remain unaltered. These studies show that, similar to LPS, Pam3Cys-Ala-Gly is a potent activator of 'the oxidative L-arginine pathway' in bone marrow-derived macrophages. Whether both stimuli use the same signal transfer mechanism to induce this pathway and whether NO synthesized by this pathway is involved in the activation of the enzyme guanylate cyclase in macrophages requires clarification.

Animals↗
PubMed1989

B cell activation by synthetic lipopeptide analogues of bacterial lipoprotein bypassing phosphatidylinositol metabolism and proteinkinase C translocation.

Synthetic analogues of bacterial lipoprotein induce proliferation of murine small resting B lymphocytes. We investigated the role of proteinkinase C (PKC) activation in lipopeptide-induced B cell stimulation. Using a standardized extraction procedure, there was no change in membrane bound and soluble PKC activity upon stimulation with lipopeptide. However, omitting Ca2+ chelators from the standard extraction medium resulted in a decrease of membrane bound PKC activity after stimulation. Lipopeptide failed to induce phosphoinositide degradation and the generation of the two second messengers cAMP and cGMP. To test whether guanosinetriphosphate-binding proteins are involved in lipopeptide-induced signal transfer we investigated the effect of LiCl, choleratoxin and pertussistoxin on B lymphocyte proliferation. LiCl and pertussistoxin did not inhibit cell activation, whereas choleratoxin reduced the proliferation rate at concentrations higher than 0.5 micrograms/ml. Similar results were observed when LPS was used as mitogen, whereas the anti-immunoglobulin-induced B cell activation was inhibited by all three compounds. Our results show, that B cell activation by bacterial lipopeptides bypasses phosphatidylinositol metabolism and PKC translocation.

Amino Acid Sequence↗
PubMed1988

Modulation of protein kinase C activity by NaF in bone marrow derived macrophages.

Stimulation of murine bone marrow derived macrophages with NaF, prelabeled with [1-14C]oleate and [3H]inositol, increased the production of inositol phosphates and the release of 1,2-[14C]diacylglycerol (DAG). Moreover, NaF also induced activation of protein kinase C. These results indicate that bone marrow derived macrophages exhibit a phosphatidyl-4,5-bisphosphate phospholipase C activity, sensitive to NaF, which might be modulated by G-proteins. Activation of protein kinase C could have been mediated by NaF-induced release of DAG.

Animals↗
PubMed1988

Distinction between HIV-1 and HIV-2 infection using novel synthetic lipopeptide conjugates as antigens in enzyme immunoassays.

A novel immunoassay technique using synthetic lipopeptide (Pam3Cys-Ser) linked to immunodominant peptide domains of HIV-1 and HIV-2 envelope proteins as an antigen adsorbent has been developed. Attachment of peptides to microtiter plates can be considerably improved with this method by employing the hydrophobic properties of lipopeptide. From the sera of 121 HIV-1 infected patients 117 reacted with Pam3Cys-Ser-[HIV-1(598-609)cyclic disulfide]. Five of 5 HIV-2 positive sera were positive with Pam3Cys-Ser-[HIV-2(593-603)cyclic disulfide]. Control sera failed to react with these conjugates.

Acquired Immunodeficiency Syndrome↗