In vivo metabolic response of hepatic nonparenchymal cells and leukocytes to granulocyte-macrophage colony-stimulating factor

This study investigates the in vivo glucose utilization of various immune-competent cells after an intra-arterial injection of a nonlethal dose (30 micrograms/kg body weight) of murine recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF). Injection of GM-CSF resulted in a rapid but transient reduction in the number of circulating neutrophils. After 20 min the number of neutrophils returned to normal values, and by 4 h it was about 80% greater than in time-matched saline-injected controls. One hour after the treatment, neutrophils were accumulated in the livers of GM-CSF-injected animals but not in control livers. In vivo glucose utilization by circulating neutrophils and mononuclear cells and various liver cell types was investigated by combining the 2-deoxyglucose tracer technique with cell isolation procedures. GM-CSF increased the in vivo glucose utilization of circulating and infiltrating neutrophils by more than 200%. Glucose utilization by circulating mononuclear cells was also doubled. After GM-CSF injection, glucose utilization by Kupffer cells was increased by 130% and by hepatic endothelial cells was increased by 60%. Indomethacin pretreatment blunted the hyperglycemia caused by GM-CSF injection; however, it did not inhibit the increased glucose utilization by immune-competent cells. This suggests that the effect of GM-CSF on glucose utilization by these cells is not mediated by prostanoids and is at least partially independent of the mass action of elevated glucose concentration. These findings indicate that GM-CSF may be an important member of the cytokine cascade that mediates the acute in vivo metabolic response of immune-competent cells in sepsis or endotoxemia.

In vivo latex phagocytosis primes the Kupffer cells and hepatic neutrophils to generate superoxide anion

Activation of liver macrophages during clearance of endotoxins, bacteria, or other particulate materials may be accompanied by the migration of polymorphonuclear neutrophils (PMNs) into the liver and priming of the hepatic phagocytes to release toxic oxygen metabolites. In the present study we investigated the effect of in vivo administration of latex particles on the hepatic sequestration of PMNs and the release of superoxide anion (O2-) by the in situ perfused rat liver and isolated hepatic phagocytes. One hour after an intravenous injection of latex beads, a significant amount of O2- (0.7 nmol/min/g) was produced by the in situ perfused liver. Administration of latex particles into the perfused liver also elicited O2- production. Hepatic phagocytes from latex-treated rats generated large amounts of O2- (2-14 nmol/60 min/10(6) cells) when these cells were stimulated in vitro with opsonized zymosan or phorbol myristate acetate (PMA), whereas phagocytes from saline-treated rats released less than 0.8 nmol O2-. Intravenous infusion of superoxide dismutase or ibuprofen did not prevent the immigration of PMNs to the liver. However, ibuprofen inhibited the production of O2- by the perfused liver. Also, after addition of ibuprofen in vitro to isolated cells, there was more than 50% inhibition of O2- generation by Kupffer cells and hepatic PMNs treated with either zymosan or PMA. These observations suggest that arachidonic acid metabolites play a role in O2- release under these conditions. Thus, activation of the reticuloendothelial system by latex phagocytosis induces the migration of PMNs into the liver and enhances the production of toxic oxygen-derived radicals by these cells and the resident Kupffer cells. The toxic oxygen radicals may also contribute to hepatic injury.

Tumor necrosis factor-alpha stimulates superoxide anion generation by perfused rat liver and Kupffer cells

Tumor necrosis factor (TNF) has been implicated as one of the mediators of the immunologic and metabolic changes in endotoxemia. Under adverse conditions, TNF can also be cytotoxic, and its effects can ultimately contribute to organ failure. This study shows that a 30-min infusion of a nonlethal dose of TNF induced the release of superoxide anion (0.9 nmol.min-1.g-1) by the in situ perfused rat liver. TNF also primed the liver to generate more superoxide anion (2.0 nmol.min-1.g-1) in response to an in vitro challenge with phorbol 12-myristate 13-acetate (PMA). Kupffer cells are most likely responsible for the superoxide anion production under these conditions, because the isolated Kupffer cells from TNF-infused rats produced increased quantities of superoxide anion (4-8 nmol/10(6) cells) when subsequently treated in vitro with either PMA or opsonized zymosan (control less than 1 nmol/10(6) cells). Thus, under these experimental conditions, TNF in vivo primed the Kupffer cells, but not the hepatocytes, endothelial cells, and the blood or hepatic neutrophils, to release more superoxide anion. These studies indicate that during a short-term nonlethal TNF infusion, Kupffer cells are a major target of TNF action, leading to the release of toxic-oxygen metabolites that may contribute to organ failure.

Characterization of a new 120 kDa microtubule-associated protein (MAP) of rat brain

A novel protein was identified in rat brain microtubules using a monoclonal antibody. The immunoreactive protein is a microtubule-associated protein (MAP) by the criteria of co-purification with tubulin through repeated cycles of microtubule polymerisation in vitro. It belongs to the class of thermostable MAPs and runs as a closely spaced polypeptide doublet of 120 kDa on SDS-PAGE gels. MAP-120 kDa is brain- and neuron-specific and is localized predominantly in Purkinje cell bodies and dendrites in the cerebellum and in dendritic compartments of pyramidal and granule neurons in the hippocampus and dentate gyrus. During postnatal brain development, MAP-120 kD levels increase about 3 to 4-fold.

Tumor necrosis factor increases in vivo glucose uptake in hepatic nonparenchymal cells

This study aims to elucidate the in vivo metabolic response of different liver cells following a short-term (30 min) infusion of a nonlethal dose of human recombinant tumor necrosis factor (TNF). In vivo glucose uptake of different tissues and isolated liver cells was determined by a sequential double-labeling version of the tracer 2-deoxyglucose technique. Following TNF administration glucose uptake was increased in the liver, lung, spleen, and skin while it was not changed in muscle and testis. In response to TNF infusion neutropenia developed which was sustained for 40 min. The number of lymphocytes in the blood was also decreased after the termination of TNF infusion. This short-term infusion of TNF, however, was not accompanied by marked sequestration of leukocytes into the liver. In vivo glucose uptake in response to TNF was doubled in the Kupffer cells and increased by 56% in hepatic endothelial cells. Glucose uptake of parenchymal cells was not significantly affected. The prompt increase of glucose uptake in the reticuloendothelial cells of the liver, primarily in the Kupffer cells, following TNF administration suggests that a similar metabolic response of these cells to sepsis may be mediated at least in part by TNF. It is suggested that the increased glucose uptake by the hepatic nonparenchymal cells is a reflection of the immunomodulatory effect of TNF.

Upregulation of glucose metabolism by granulocyte-monocyte colony-stimulating factor

Alterations of glucose metabolism were investigated for 6 hours following an intraarterial injection of murine recombinant granulocyte-monocyte colony-stimulating factor (GM-CSF) (30 micrograms/kg body weight). GM-CSF resulted in a transient elevation of plasma glucose. The rate of whole body glucose appearance, as measured by infusion of [6-3H] glucose, was increased by about 10% between 0.5 and 3 hours following GM-CSF injection. In vivo glucose utilization of individual tissues was investigated by the tracer 2-deoxyglucose technique. At 30 min, GM-CSF increased glucose utilization by 80-90% in liver and lung, and 50-60% in skin and spleen. At 3 and 6 hours, glucose utilization by these tissues returned toward control levels except for lung. There was a 40-50% increase in glucose utilization by skeletal muscle 30 min after GM-CSF which was sustained for 6 hours. Glucose utilization of testis, ileum and kidney did not change significantly. Plasma concentrations of insulin, glucagon and tumor necrosis factor were not altered in response to GM-CSF. These findings indicate that some of the acute metabolic effects of a short-term administration of GM-CSF are observed in macrophage-rich tissues, and suggest that GM-CSF may be involved in the metabolic upregulation of immunologically active tissues.

Defective V-to-J recombination of T cell receptor gamma chain genes in scid mice

The status of T cell receptor gamma chain genes (TcR gamma) in 11 spontaneous T cell lymphomas from mice with severe combined immune deficiency (scid) was analyzed. We found that as a result of large abnormal deletions accompanying attempted site-specific V-to-J recombinations, 36 of 47 rearranged TcR gamma genes lacked the variable (V) and/or joining (J) region gene segment involved in this attempted recombination. No such deletions were found in T cell lymphomas from normal mice. We interpret our data as indicating a defective V-to-J recombination in scid lymphocytes consistent with our earlier observation of faulty D-to-J recombination in transformed scid lymphocytes (Schuler et al., Cell 1986. 46: 963). The present results further support the hypothesis that the scid mutation affects a component of the VDJ-recombinase system used in common by B and T cells to assemble antigen receptor genes.

Elevated muscle tissue oxygen tension in short-term insulin-dependent diabetes mellitus

In order to assess hemodynamic changes in early phases of insulin-dependent diabetes mellitus, muscle tissue oxygen tensions were determined in 7 newly diagnosed insulin-dependent diabetic patients and in 6 healthy control subjects matched for sex, age and weight. Muscle tissue oxygen tension was measured by polarrographic needle probes while breathing ambient air and oxygen enriched air with an oxygen concentration of 40 per cent as well. Three times during the experiment, heart rates, blood pressures, blood glucose concentrations, and capillary oxygen tensions were obtained. Heart rate, blood pressure, peripheral and autonomic nerve functions did not differ between the 2 groups studied. While breathing ambient air, muscle tissue oxygen tensions were significantly (p = 0.025) higher in the diabetic patients than in the control subjects. In contrast to the control subjects, diabetic patients did not increase muscle tissue oxygen tensions after inhalation of oxygen enriched air despite of an equal increase in capillary oxygen tensions (2p less than 0.05). Local tissue hypoxia does not seem to be a leading cause of hemodynamic abnormalities in the early phases of diabetes.

[Surgical correction of bronchial stenosis: increased somatic development following elimination of the stenosis]

A 5 year old girl suffered from nearly total stenosis of the bronchus intermedius and exspiratory collaps of both main bronchi. Because of preterm birth she was postnatally intubated and mechanically ventilated for 6 weeks. Her somatic development was significantly retarded in comparison with the monozygotic twin, and pulmonary impairment increased again in the last preoperative year. By the combination of latest surgical technics (pericardial patch, interposition of a costal segment, fibrine glue) the bronchial abnormalities could be corrected successfully. In the first year after surgery catch-up growth was observed in the girl.

Transcription of unrearranged antigen receptor genes in scid mice

The scid mouse mutant is severely deficient in lymphocytes; cells of the B or T lymphocyte lineage cannot be detected by either serological or functional assays. However, as shown here, germ-line transcripts of B cell immunoglobulin (Ig) constant and variable region genes and of T cell receptor (TCR) genes are detectable in lymphopoietic tissues of scid mice, as well as B and T lineage-specific lambda 5 and T3 delta transcripts. We conclude that B and T lineage-committed cells do arise in scid mice and that their Ig and TCR genes are accessible to enzymes involved in their recombination. This suggests that scid impairs lymphopoiesis at the stage at which antigen receptor genes normally undergo rearrangement.

[Prenatal toxoplasmosis: diagnosis and prevention]

Sera of six children, clinically suspected of having congenital toxoplasmosis, and of their mothers were examined for specific antibodies. In four, prenatal infection was established shortly after birth by significant titre differences between the neonatal and maternal sera. In three neonates, toxoplasma-specific IgM antibodies were demonstrated. In two children, aged seven and 16 months, postnatal infection could not be absolutely excluded, although both they and their mothers had high toxoplasma antibody titres.

Rearrangement of antigen receptor genes is defective in mice with severe combined immune deficiency

A process unique to lymphocyte differentiation is the rearrangement of genes encoding antigen-specific receptors on B and T cells. A mouse mutant (C.B-17scid) with severe combined immune deficiency, i.e., that lacks functional B and T cells, shows no evidence of such gene rearrangements. However, rearrangements were detected in Abelson murine leukemia virus-transformed bone marrow cells and in spontaneous thymic lymphomas from C.B-17scid mice. Most of these rearrangements were abnormal: approximately 80% of Igh rearrangements deleted the entire Jh region, and approximately 60% of TCR beta rearrangements deleted the entire J beta 2 region. The deletions appeared to result from faulty D-to-J recombination. No such abnormal rearrangements were detected in transformed tissues from control mice. The scid mutation may adversely affect the recombinase system catalyzing the assembly of antigen receptor genes in developing B and T lymphocytes.

Immune response against the T-independent antigen alpha (1----3) dextran. II. Occurrence of B gamma memory cells in the course of immunization with the native polysaccharide is T cell dependent

The immune response of BALB/c mice against the bacterial antigen dextran B1355S [alpha (1----3)dextran] (Dex), a class 2 T cell-independent antigen, is largely restricted to IgM class antibody production. However, despite the fact that Dex fails to give rise to enhanced IgG responses upon repeated immunization, the development of Dex-specific B gamma memory cells, i.e. resting B cells committed to the production of specific IgG antibodies, is observed upon immunization with Dex. These B gamma memory cells, albeit not activated to IgG production in situ, can be activated upon adoptive transfer into irradiated congenic BALB Ighb mice. This mouse strain is a nonresponder strain to Dex. The expression of adoptively transferred Dex-specific B gamma memory cells is T cell-independent as T cell depletion of spleen prior to cell transfer into BALB.Ighb recipients does not abolish the IgG response. Dex-primed athymic BALB/c nude mice, in contrast to euthymic mice, give a pronounced primary IgG response but do not develop Dex-specific B gamma memory cells. Yet, they do so when reconstituted with syngenic T cells prior to immunization. This indicates that the formation of Dex-specific B gamma memory cells requires the presence of functional T cells. The pronounced primary IgG anti-Dex response of nude mice is greatly impaired by T cell reconstitution. Thus, with regard to T cell dependence, there is an inverse relationship between the formation of B gamma memory cells and the capacity to produce IgG anti-Dex. Dex-specific B gamma memory cells from BALB/c mice are expressed in congenic BALB.Ighb recipients (nonresponder to Dex) but not when transferred into identically treated syngenic hosts. This also applies to memory cells from Dex-primed female (CBA/N X BALB/c)F1 [NBF1] or from (BALB/c X CBA/N)F1 hybrids. Dex-specific B gamma memory cells from these donors are demonstrable upon adoptive transfer into BALB.Ighb mice, but they are not expressed when transferred into syngenic recipients, including male NBF1 hybrids. NBF1 males, albeit possessing the VH-Dex+ allele, do not mount humoral responses to Dex, a deficiency which is ascribed to an X chromosome-linked B cell defect. The apparent absence of Dex-specific antibodies in NBF1 males provides an opportunity to examine whether B gamma memory cell expression is inhibited in syngenic recipients by anti-Dex or autologous anti-idiotype antibodies.(ABSTRACT TRUNCATED AT 400 WORDS)

Evidence of the juvenile hormone methyl(2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate(JH-3) in insects of four orders

With the help of radioactive dilution analysis allowing the qualitative and quantitative deter­mination of all three presently known juvenile hormones (JH-1 to 3) the following seven species of four orders were investigated in the adult stage: Coleoptera: Tenebrio molitor, Leptinotarsa decemlineata; Orthoptera: Schistocerca gregaria; Blattodea: Blatta orientalis, Leucophaea maderae, Nauphoeta cinerea; Hymenoptera: Apis mellifera.

In all these species of the 3 known juvenile hormones only m ethyl (2E ,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate (JH-3) was found, in an amount of 0.5 to 11 ng per gram of body weight. The results of the chemical analyses were confirmed biologically by the Galleria wax test.

The results demonstrate the wide spread occurrence of JH-3 in insects of different orders.