Metabolic and Structural Requirements for Concanavalin A Capping in Phagocytic Cells

Williams, David A.; Lessard, James L.; Boxer, Laurence A.; Rein, Diane C.; Baehner, Robert L.

doi:10.3181/00379727-162-40613

Cited by 3 publications

(5 citation statements)

References 5 publications

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“…anaerobic glycolysis or oxidative phosphorylation and the ability of the cells to mobilize their Con A receptors. As previously indicated (Williams et al, 1979), the energy required for colchicine-induced capping differed between freshly explanted AM and PM. Exposure of fresh AM and PM to the mitochondrial poison KCN reduced colchicine-induced capping to a larger extent in AM than PM which likely reflects the greater dependence of AM on mitochondrial derived energy from aerobic metabolism.…”

Section: Capping Responsementioning

confidence: 62%

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Changes in Energy Metabolism, Structure and Function in Alveolar Macrophages under Anaerobic Conditions

et al. 1981

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To determine whether the change in energy metabolism of guinea-pig alveolar macrophages (AM) would alter their function to resemble peritoneal macrophages (PM), AM were exposed to strict anaerobic environments for 96 h. Exposure of cultivated AM to hypoxic conditions resulted in a decreased activity of cytochrome oxidase, a key enzyme in oxidative phosphorylation, whereas pyruvate kinase activity, a key enzyme in glycolysis, increased to levels observed in PM. Under hypoxic conditions the total mitochondrial structure available for respiratory activity also decreased in the glycolytic energy-dependent AM. Accompanying the shift in energy metabolism, adaptive changes in the functional responses of lectin-receptor activity occurred in the AM exposed to hypoxic conditions. Culture of AM in an anaerobic environment led to a loss in their ability to mobilize their lectin receptors in response to cytochalasin B, whereas AM maintained in an aerobic environment could mobilize their receptors in response to either cytochalasin B and D. Alterations in O2 tension affect AM metabolism, morphology and function and indicate that the AM is able to change its energy metabolism according to environmental circumstances.

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Section: Capping Responsementioning

confidence: 62%

“…Capping of cells with concanavalin A-FITC. Capping was carried out as previously described (Williams et a!, 1977(Williams et a!, , 1979. 1-2 x lo6 cells/ml were incubated for 15 min at 37°C with or without various drugs, stained for 5 min with 50 p g fluoresceinated concanavalin A (Con A-FITC) (Miles Laboratory, Elkhart, Ind.)…”

Section: Methodsmentioning

confidence: 99%

Changes in Energy Metabolism, Structure and Function in Alveolar Macrophages under Anaerobic Conditions

et al. 1981

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“…Microfilaments lose their uniform pattern of distribution beneath the plasma membrane and are -concentrated beneath the protuberance. In addition to requiring these interactions of plasma membrane and cytoskeleton, capping by N is an energy-dependent process that can be inhibited by cold temperatures and by cytochalasin B (12,17,23). Thus, an alteration in any of several cellular processes could lead to aberrant Con A capping.…”

Section: Discussionmentioning

confidence: 99%

“…Many cellular processes are involved in cap formation (12,23), and the possibility cannot be excluded that abnormalities unrelated to oxidation may contribute to aberrant capping. For example, it has been suggested in a preliminary report (5) that decreased Con A capping of infant N is a deveio~mental defect of the plasma membLAe.…”

Section: Kbmentioning

confidence: 99%

“…Several cellular Drocesses are involved in the successful ~erformance of membrane-dependent functions; the cytoskeleton is especially important (12). Concanavalin A (Con A) capping provides a technique to study the cytoskeleton and its interactions with the plasma membrane and other factors (12,23). Furthermore, abnormalities of N function may be related to aberrant Con A capping because these conditions coexist in two disorders characterized by N dysfunction, Chediak-Higashi disease (12) and glutathione synthetase deficiency (13).…”

Section: Speculationmentioning

confidence: 99%

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Spontaneous and Drug-Induced Concanavalin A Capping of Neutrophils from Human Infants and Their Mothers

Strauss

Hart

1981

Pediatr Res

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SummaryWe investigated concanavalin A capping that occurred either spontaneously (neutrophils incubated only with buffer) or was drug induced (neutrophils with colchicine or diamide) using neutrophils obtained from the blood of newborn infants and their mothers. A greater proportion of infant and maternal neutrophils than controls formed caps spontaneously ( P < 0.01). The percent of capped neutrophils (mean f S.E.) for 24 infants and their mothers was 23 + 3 and 39 + 4, respectively, versus 13 + 2 for 26 controls.Spontaneous capping was significantly decreased when neutrophils were incubated with catalase and superoxide dismutase to suggest that it was related, at least in part, to oxidation. Drug-induced capping of infant and maternal neutrophils was decreased when compared to controls (P < 0.05). Colchicine increased capping of control neutrophils 11.76-fold above the spontaneous value, whereas capping of infant and maternal cells was increased only 2.35-and 1.65-fold. Corresponding values for diamide were 11.94, 2.27-, and 2.49-fold for control, infant, and maternal neutrophils, respectively. Many cellular processes are involved in capping, and the mechanisms responsible for aberrant capping of infant neutrophils remain undefined. However, this is another property that distinguishes infant neutrophils from those of older individuals. SpeculationFunctions of infant neutrophils that have been found most consistently to be abnormal are those related to plasma membrane integrity. Aberrant concanavalin A capping suggests abnormal interactions between the plasma membrane, cytoskeleton, and several metabolic processes of infant neutrophils. Further investigations of mechanisms responsible for aberrant concanavalin A capping may help identify causes of the dysfunctions of infant neutrophils.Serious infections occur frequently in newborn infants. Although several abnormalities of the body defense mechanisms of infants have been described (6), results have been contradictory, and opinion is divided regarding the relative importance of each abnormality. Neutrophils (N) obtained from infant blood differ in many respects from those of adults (19), particularly when N functions dependent on plasma membrane integrity are studied such as mig;ation, deforhability, and phagocyksis (9). Several cellular Drocesses are involved in the successful ~erformance of membrane-dependent functions; the cytoskeleton is especially important (12). Concanavalin A (Con A) capping provides a technique to study the cytoskeleton and its interactions with the plasma membrane and other factors (12, 23). Furthermore, abnormalities of N function may be related to aberrant Con A capping because these conditions coexist in two disorders characterized by N dysfunction, Chediak-Higashi disease (12) and glutathione synthetase deficiency (13). We investigated Con A capping of N isolated from the venous blood of newborn infants to further define mechanisms that may be responsible for the dysfunction of infant N. MATERIALS AND METHODSStudies were approved b...

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Concanavalin A receptors and capping in control and activated macrophages

1983

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Macrophages activated in vivo with Corynebacterium parvum and asbestos showed an increased sub-population of cells which capped spontaneously on incubation with fluoresceinated Concanavalin A compared to saline-induced control macrophages. This capping was unaffected by colchicine but was inhibited by cytochalasin B. The spontaneous capping of activated macrophages did not appear to be directly related to the total number of Concanavalin A receptors as measured by specific 125I-labelled Concanavalin A binding to activated and control macrophages. Capping also did not appear to be related to the position of Concanavalin A receptors as judged by trypsin accessibility of bound 125I-labelled Concanavalin A.

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Metabolic and Structural Requirements for Concanavalin A Capping in Phagocytic Cells

Cited by 3 publications

References 5 publications

Changes in Energy Metabolism, Structure and Function in Alveolar Macrophages under Anaerobic Conditions

Changes in Energy Metabolism, Structure and Function in Alveolar Macrophages under Anaerobic Conditions

Spontaneous and Drug-Induced Concanavalin A Capping of Neutrophils from Human Infants and Their Mothers

Concanavalin A receptors and capping in control and activated macrophages

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