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Effect of thioglycolate on phagocytic and microbicidal activities of peritoneal macrophages.

Brewer thioglycolate-elicited mouse peritoneal macrophages were as active as resident peritoneal macrophages in the phagocytosis of opsonized Staphylococcus epidermidis but were unable to kill ingested microorganisms. This decreased functional activity was restricted to Brewer thioglycolate-elicited macrophages, since peritoneal macrophages elicited with NIH thioglycolate, alone or supplemented with agar and methylene blue, were as active as resident peritoneal macrophages. No effect of agar on the functional activities of macrophages was observed. A defective intracellular killing by peritoneal macrophages due to Brewer thioglycolate was seen only after an intraperitoneal injection with thioglycolate, not after in vitro incubation of resident macrophages with thioglycolate. The results of this study show that, depending on the kind of thioglycolate used, the functional characteristics of elicited macrophages may alter. However, none of the forms of thioglycolate investigated induced the recruitment of activated macrophages.

Animals

Kinetics of macrophage recruitment and turnover in peritoneal inflammatory exudates induced by Salmonella or thioglycollate broth.

Kinetics of peritoneal macrophage turnover during infection of mice with Salmonella enteritidis or following injection with thioglycollate broth or other peritoneal stimulants has been studied. Single intravenous injections of tritiated thymidine were given and the cells were examined by autoradiography. Maximum labelling of small adherent peritoneal macrophages occurred when 3H-thymidine was given 1 d after Salmonella and the cells were harvested 1 d later. Labelled cells decreased at later times despite maintenance of high numbers of macrophages in the exudates. Results from experiments in which labelled peritoneal cells were reinjected indicated that small, monocyte-enriched, labelled cells were not the major source of the large macrophages. Similar labelling at 2 d was observed using heat-killed Corynebacterium parvum or lipopolysaccharide (LPS) as ip stimulants. Following injection of thioglycollate broth, labelled peritoneal macrophages were only detectable if 3H-thymidine was given before the stimulant. These labelled cells remained longer in the peritoneal cavity. Labelling of and numbers of blood monocytes were consistent with the promotion of monocytopoiesis by Salmonella but not by thioglycollate. The response to thioglycollate but not Salmonella was dependent on the age of the mice. Animals injected with thioglycollate 1 d before Salmonella also had decreased resistance to bacteria and low numbers of labelled peritoneal macrophages. We propose that thioglycollate may recruit from a subset of preformed monocytes and temporarily block monocytopoiesis or macrophage bactericidal activity.

Adjuvants, Immunologic

Thioglycolate medium decreases resistance to bacterial infection in mice.

Brewer thioglycolate medium, a bacterial culture medium which is widely used as a nonspecific in vivo macrophage stimulant, was tested for its effect on mouse resistance to bacterial infection. Mice which did or did not receive thioglycolate medium were challenged with Listeria monocytogenes. Injection of thioglycolate medium significantly decreased the ability of the host to resist infection. This decreased resistance occurred whether thioglycolate medium was injected 0 to 9 days before, or 1 to 2 h after Listeria challenge. Bacteria grew considerably better in washed adherent peritoneal cells from thioglycolate medium-injected mice than in washed adherent peritoneal cells from normal mice. Thus, thioglycolate medium may ultimately cause a decrease in macrophage function.

Animals

Dissociation of bactericidal activity from other functions of activated macrophages in exudates induced by thioglycolate medium.

Macrophages displayed increased spreading, increased Fc-receptor-mediated phagocytosis, and increased secretion of plasminogen activator when collected from the peritoneal cavities of either Listeria-immune mice challenged intraperitoneally 3 days earlier with Listeria or nonimmune mice injected intraperitoneally 3 days earlier with fluid thioglycolate medium. In contrast, macrophages from the thioglycolate-induced peritoneal exudates were severely impaired in vitro in their ability to destroy Listeria. Injection of thioglycolate markedly interfered with the destruction of sublethal intraperitoneal challenge of Listeria, which resulted in nonimmune animals dying of an overwhelming systemic infection. In animals immune to Listeria, injection of thioglycolate delayed the onset of the expression of immunity to an intraperitoneal challenge of bacteria. The thioglycolate-induced suppression of bactericidal activity was determined to be confined to the site of injection. Results of experiments indicated that the colloidal agar in thioglycolate medium was the cause of the impairment of macrophage bactericidal activity. In addition to the impairment of bactericidal activity induced by agar, additional studies showed that an intraperitoneal injection of colloidal agar (0.075% wt/vol) by itself was a sufficient inflammatory stimulus for the accumulation of a large number of host phagocytic cells.

Agar

The oxidative metabolism of thioglycollate-elicited mouse peritoneal macrophages: the relationship between oxygen, superoxide and hydrogen peroxide and the effect of monolayer formation.

The oxygen and glucose metabolism of peritoneal macrophages harvested from untreated mice (resident cells) and mice given an i.p. injection of thioglycollate broth (thioglycollate cells) were examined. Thioglycollate cells consumed approximately 3 times as much O2 at rest and during phagocytosis as resident cells, but oxygen reduction products (superoxide and hydrogen peroxide) could be recovered in only minimal amounts despite triggering by phagocytosis or exposure to PMA. Indirect evidence for the formation of oxygen reduction products such as O2- by thioglycollate cells was obtained by observation of the major pathways for glucose oxidation and NBT dye reduction. When thioglycollate cells were allowed to adhere to a glass surface O2- and H2O2 were easily recovered in the extracellular medium with a 20-fold increase above cells in suspension exposed to PMA. This study suggests that thioglycollate-elicited macrophages have a vigorous oxidative metabolism but that recovery, and perhaps utilization, of O2 reduction products formed will depend on the conditions of incubation. These events may be significant both for the study of parameters of macrophage "activation" in vitro as well as the function of these cells in vivo.

Animals

Increased phospholipid mass with decreased arachidonoyl molecular species is associated with decreased eicosanoid synthesis and increased tumor necrosis factor synthesis by thioglycollate-elicited rat peritoneal macrophages.

Because the activation state of macrophages may alter their response to endotoxin, we compared phospholipid arachidonic acid content, and synthesis of eicosanoids and tumor necrosis factor by resident and thioglycollate-elicited rat peritoneal macrophages. Thioglycollate elicitation increased macrophage phospholipid mass twofold, increased the relative percentages of 16:0-20:4 diacylglycerophosphocholine (PtdCho) and 18:0-20:4 diacylglycerophosphoethanolamine (PtdEtn), and decreased the relative percentages of 18:0-20:4 alkenylacylglycerophosphoethanolamine (PlsEtn) and 18:0-20:4 alkylacylglycerophosphocholine (PakCho) compared with resident peritoneal macrophages. Thioglycollate-elicited macrophages synthesized significantly less thromboxane B2, 6-keto-prostaglandin F1 alpha, and prostaglandin E2 and more tumor necrosis factor (TNF) activity in response to both endotoxin and A23187 than did resident macrophages. These results suggest that thioglycollate elicitation decreases specific arachidonic acid-containing molecular species in PlsEtn and PakCho, which may, in part, explain the decrease in eicosanoid and increase in TNF synthesis by thioglycollate-elicited macrophages. The differences between resident and thioglycollate-elicited macrophages in the synthesis of the eicosanoids and TNF activity was not altered by increasing either the concentration of either stimulus or the incubation time.

Animals

Regulation of lipopolysaccharide-induced tumor necrosis factor alpha production by endogenous prostaglandin E2 in rat resident and thioglycollate-elicited macrophages.

Prostaglandin E2 (PGE2) is generally accepted to be a negative feedback effector of tumor necrosis factor alpha (TNF alpha) production. However, we have observed that a cyclooxygenase inhibitor had different effects on TNF alpha production by resident and thioglycollate-elicited rat peritoneal macrophages. Indomethacin coordinately reduced PGE2 production and increased TNF alpha production in lipopolysaccharide (LPS)-stimulated resident macrophages, whereas indomethacin reduced PGE2 production without affecting TNF alpha production in thioglycollate-elicited macrophages. PGE2 production and arachidonate release were much less in thioglycollate-elicited macrophages than in resident macrophages. However, exogenously added PGE2 suppressed TNF alpha production to the same extent in the two macrophage populations. The addition of free arachidonic acid to cultures of LPS-stimulated, thioglycollate-elicited macrophages elevated PGE2 production and suppressed TNF alpha production in a manner similar to that observed with LPS-stimulated resident macrophages. These results indicate that the differential effects of indomethacin treatment on TNF alpha production observed between the two macrophage populations are not due to the differences in arachidonate contents, PGE2 productivities, nor to their capacities to respond to PGE2. Instead, the inability of indomethacin to increase TNF alpha production by thioglycollate-elicited versus resident macrophages appears to result from an inability to release arachidonate efficiently and a lower initial level of cyclooxygenase, in thioglycollate-elicited macrophages.

Animals

The use of thioglycolate to distinguish between 3' AP (apurinic/apyrimidinic) endonucleases and AP lyases.

Addition of thioglycolate and DEAE-Sephadex chromatography were used to analyze the cleavage of the C(3')-O-P bond 3' to AP (apurinic/apyrimidinic) sites in DNA and to distinguish between a mechanism of hydrolysis (which would allow the nicking enzyme to be called 3' AP endonuclease) or beta-elimination (so that the nicking enzyme should be called AP lyase). For this purpose, DNA labelled in the AP sites was first cleaved by rat-liver AP endonuclease, then with the 3' nicking catalyst in the presence of thioglycolate and the reaction products were analyzed on DEAE-Sephadex: deoxyribose-5-phosphate (indicating a 3' cleavage by hydrolysis) and the thioglycolate:unsaturated sugar-5-phosphate adduct (indicating a cleavage by beta-elimination) are well separated allowing to eventually easily discard the hypothesis of a hydrolytic process and the appellation of 3' AP endonuclease. We have shown that addition of thioglycolate to the unsaturated sugar resulting from nicking the C(3')-O-P bond 3' to AP sites by beta-elimination is an irreversible reaction. We have also shown that the thioglycolate must be present from the beginning of the reaction with the nicking catalyst to prevent the primary 5' product of the beta-elimination reaction from undergoing other modifications that complicate the interpretation of the results.

Animals

Thioglycollate elicited macrophages demonstrate enhanced virus replication and depressed bacterial killing.

Thioglycollate elicited peritoneal macrophages of Balb/c mice exhibited minimal antibacterial activity against Listeria monocytogenes but were fully permissive for the replication of ectromelia virus. By comparison, resident and LPS elicited macrophages did not exhibited depressed antibacterial activity nor did they support viral replication. The thioglycollate effects were demonstrated in macrophages cultured in vitro and also in intact Balb/c mice. Mice given thioglycollate intraperitoneally and challenged by the same route suffered overwhelming virus and bacterial infections as a result of early local proliferation within peritoneal macrophages with subsequent spread to the liver. Balb/c mice challenged intravenously with similar doses of the virus of bacterial pathogen after administration of thioglycollate by the i.p. route did not succumb to either infection. Thus the ability of thioglycollate to compromise cellular host defenses against the infectious agents appears to be site specific; i.e. restricted to the peritoneal cavity where exudate macrophages and challenge inocula first come into contact.

Animals

The effect of thioglycolate on intermediate filaments and membrane translocation in rat urothelium during the expansion-contraction cycle.

The functional role of cytokeratin intermediate filaments in the translocation of asymmetric membrane plaques between cytoplasm and surface of apical urothelial cells was investigated during contraction and expansion of rat urinary bladders. A stereological investigation of electron micrographs provided estimations of surface area, volume, and number of discoidal vesicles and infoldings per unit volume of urothelial apical cell cytoplasm. Contracted and distended bladders incubated in 0.01 M sodium bicarbonate were compared to identical preparations experimentally incubated in 5 mM thioglycolic acid. The latter reagent disrupts the intermediate filament network by reducing sulfhydryl bridges. Densities of discoidal vesicles in cells contracted after incubation in thioglycolate were similar to density estimations in cells expanded under control conditions. Similarly, densities of vesicles in cells expanded after exposure to thioglycolate were comparable in number to those in normally contracted cells. Thus, membrane translocation to and from the luminal surface was blocked by thioglycolate treatment. The lack of normal membrane transfer at the luminal surface induces apical cells exposed to experimental conditions to undergo extraordinary adjustments in response to external pressures of bladder contraction and distension. During contraction, the apical-intermediate cell interface unfolded while the luminal surface ballooned out into the lumen. In distended bladders, large intercellular spaces formed between apical cells along their lateral margins. The results support a model published earlier implicating the filament network as a critical mediator of membrane translocation.

Animals

Reductive and nucleophilic activation products of dynemicin A with methyl thioglycolate. A rational mechanism for DNA cleavage of the thiol-activated dynemicin A.

The reaction products of methyl thioglycolate with dynemicin A, dynemicin H and dynemicin S, were isolated by HPLC purification and identified spectroscopically. The major product, dynemicin H (C30H23NO9), was determined to be a C-8 hydrogen analogue of dynemicins L and N in which the enediyne core is aromatized. The minor product, dynemicin S (C33H27No11S), is an adduct of methyl thioglycolate at the C-8 position. By using NADPH instead of methyl thioglycolate, the reaction with dynemicin A also gives the same major product (dynemicin H). The nucleotide-specific cleavage of dynemicin A induced by addition of methyl thioglycolate is remarkably similar to that induced by addition of NADPH, whereas dynemicins H and S show no DNA cleavage activities. The formation of dynemicins H and S provides a rationale for the reductive and nucleophilic activations of dynemicin A.

Alkenes

Apoprotein E is synthesized and secreted by resident and thioglycollate-elicited macrophages but not by pyran copolymer- or bacillus Calmette-Guerin-activated macrophages.

Macrophages are active secretory cells that display functionally distinct phenotypes that are regulated by inflammation. We have found that apoprotein E (ApoE), a component of plasma lipoproteins, was synthesized and secreted by resident and nonspecifically stimulated macrophages elicited with thioglycollate broth, but not by activated macrophages obtained from mice treated with bacillus Calmette-Guerin, pyran copolymer, whole Corynebacterium parvum, or bacterial endotoxin. ApoE represented approximately 1% of the newly synthesized protein and approximately 10% of secreted protein of resident and thioglycollate-elicited macrophages. ApoE from thioglycollate-elicited macrophages was indistinguishable from ApoE in mouse plasma lipoproteins, as determined by immunoreactivity, peptide mapping, and molecular weight. When specific antibodies were used to localize cell-associated ApoE, strong immunofluorescence was seen in the Golgi region of resident and thioglycollate-elicited macrophages immediately after removal from the peritoneal cavity, as well as after culture for up to 7 d. In contrast, activated macrophages did not synthesize or secrete ApoE to an appreciable extent and had no immunocytochemically detectable intracellular ApoE. When activated macrophages were cultured in medium containing serum, their activated state, as judged by production of H2O2, declined within 48-72 h in parallel with the induction of synthesis and secretion of ApoE and detection of intracellular ApoE by immunofluorescence. During prolonged culture the rate of synthesis and secretion of ApoE increased in both resident and activated macrophages. Therefore, the synthesis and secretion of ApoE may serve as markers for the functional state of macrophages.

Animals

Limitations of thioglycolate broth as a sterility test medium for materials exposed to gaseous ethylene oxide.

Although ethylene oxide is a reliable sterilizer, the process may be limited by diffusion. Thus, situations may exist where microorganisms are protected from the sterilizing gas. It is possible that the exterior of a substance may be sterilized, whereas the interior is not. We investigated three general types of materials in which this limitation of diffusion could occur: the bore of glass and plastic tubing, the center of cotton balls, and plastic adhesive film/paper backing interface. These materials were contaminated as close to their geometric center as possible with Bacillus subtilis var. niger spores occluded in crystals of sodium chloride. After exposure of the contaminated materials (except aluminum foil) to ethylene oxide, thioglycolate broth (a standard sterility-test medium) indicated sterility, whereas Trypticase Soy Broth indicated nonsterility. It is likewise possible that aerobic microorganisms, surviving in or on material after exposure to dry heat or steam sterilization processes, would not be recovered by thioglycollate broth. Entrapped aerobic organisms will probably not grow out in the low oxygen tension zone of an anaerobic medium such as thioglycollate broth. It is recommended than an aerobic medium such as Trypticase Soy Broth be used concurrently with thioglycolate broth for sterility testing.

Bacillus subtilis

Changes in spores of Bacillus megaterium treated with thioglycolate at a low pH and restoration of germinability and heat resistance by cations.

Spores of Bacillus megaterium QM B1551 treated with thioglycolate (0.4 m, pH 2.6) at 50 C for 30 min remained refractile, but they became stainable, lysozymesensitive, and nonviable, and they lost dipicolinic acid (DPA). The loss of DPA and of viability were functions of the time and temperature of exposure to thioglycolate. Spores treated with thioglycolate at a lower temperature and for a shorter time (30 C, 5 min) retained DPA, viability, and nonstainability. Although these spores also retained their resistance to gamma radiation and to lysozyme, they lost thermo-resistance. Their percentage of germination over a 2-hr period in glucose was markedly reduced. Germinability and heat resistance were restored by exogenous cations, suggesting that the thioglycolate treatment (30 C, 5 min) resulted in the loss of spore ions essential for normal germination in glucose and for heat resistance.

Bacillus megaterium

Effect of thioglycollate on macrophage lysosomal enzymes.

Mice peritoneal macrophages obtained after i.p. injection of a medium containing thioglycollate (Institut Pasteur, Paris) have increased levels of beta glucuronidase and acid phosphatase, when compared with macrophages obtained without previous thioglycollate injection. The maximum increase is observed between 7 and 10 days after injection and reaches up to 3 to 4 times the normal activity. When using separately the various components of the medium, the same phenomenon may be observed but never to the same degree. The injection of thioglycollate also produces: a) an increase in total number of peritoneal cells, and b) an increase in the percentage of macrophages among these cells. Kinetic studies suggest that thioglycollate injection first induces an increase in the number of peritoneal macrophages and subsequently macrophage modifications resulting in lysosomal enzyme increase.

Acid Phosphatase

Thioglycollate stimulus modifies lymphocyte metabolism and proliferation. A comparison with lymphocyte activation by Walker 256 tumour implantation.

Key enzyme activities of glycolysis, the pentose-phosphate pathway, the Krebs' cycle and glutaminolysis were measured in lymphocytes obtained from the control (CC), thioglycollate-injected (TG) and Walker 256 tumour-implanted (WT) groups, non-immune and immune inflammatory stimuli, respectively. The rates of incorporation of [2-14C]-thymidine and [5-3H]-uridine into cultured lymphocytes were also determined. The results indicated that the rates of both [2-14C]-thymidine and [5-3H]-uridine incorporation were enhanced in lymphocytes obtained from thioglycollate-injected (by an average of 80 per cent) and tumour-implanted animals (by 2.4-fold) as compared to control rats. Lymphocyte hexokinase activity diminished both in the TG (23 per cent) and WT (61 per cent) groups, whereas glucose 6-phosphate dehydrogenase activity was not altered due to the non-immune inflammatory stimulus, being reduced (23 per cent) in WT rats as compared to CC. The activity of lymphocyte citrate synthase was lowered by thioglycollate (39 per cent) and tumour-implantation (46 per cent). In contrast, glutaminase activity was augmented in lymphocytes from the TG (41 per cent) and was not modified in the WT groups. Taken as a whole, the presence of the Walker 256 tumour did not affect the capacity for glutamine utilization but depressed glucose metabolism in these cells. On the other hand, the non-immune inflammatory stimulus suppressed the activities of glycolysis and the Krebs' cycle and enhanced that of glutaminolysis in lymphocytes.

Animals