Modulation of Interleukin-15-Induced Human Neutrophil Responses by the Plant Lectin Viscum album Agglutinin-I

Pelletier, Martin; Lavastre, Valérie; Savoie, Anik; Ratthé, Claude; Saller, Reinhard; Hostanska, Katarina; Girard, Denis

doi:10.1006/clim.2001.5105

Cited by 22 publications

(29 citation statements)

References 37 publications

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“…The lectin does not appear to induce phosphorylation events (16,52) and this correlates well with the absence of a receptor-induced apoptosis pathway. The lectin needs to be internalized and its ability to inhibit protein synthesis is linked to the induction of apoptosis.…”

Section: Discussionmentioning

confidence: 55%

“…This correlates well with our previous observation that VAA-I does not induce tyrosine phosphorylation (16), a situation that occurs after receptor binding. Recently, we found that in addition to tyrosine phosphorylation, VAA-I does not induce threonine or serine phosphorylation events in human neutrophils (52). Taken together, these results strongly suggest that VAA-I does not induce phosphorylation events to mediate its proapoptotic effect.…”

Section: Discussionmentioning

confidence: 64%

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Mechanisms Involved in Spontaneous and Viscum album Agglutinin-I-Induced Human Neutrophil Apoptosis: Viscum album Agglutinin-I Accelerates the Loss of Antiapoptotic Mcl-1 Expression and the Degradation of Cytoskeletal Paxillin and Vimentin Proteins Via Caspases

Lavastre

Pelletier

Saller

et al. 2002

The Journal of Immunology

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137

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Viscum album agglutinin-I (VAA-I) is a plant lectin that possesses interesting potential therapeutic properties and immunomodulatory activities. We have recently found that VAA-I is a potent inducer of human neutrophil apoptosis, but the mechanism(s) involved require further elucidation. In this study, we found that VAA-I alters mitochondrial transmembrane potential and increases intracellular levels of reactive oxygen species (ROS). Despite these observations, treatment with the mitochondrial stabilizer, bongkrekic acid, or with catalase, known to degrade H2O2, fails to reverse VAA-I-induced apoptosis. Moreover, VAA-I was found to induce apoptosis in PLB-985 cells deficient in gp91phox, indicating that the lectin acts via an ROS-independent mechanism. Pretreatment of neutrophils with brefeldin A, an inhibitor of vesicular transport, was found to reverse VAA-I-induced apoptosis. Protein expression of Mcl-1 was decreased by VAA-I. The role of caspases in the degradation of cytoskeletal proteins during both spontaneous and VAA-I-induced neutrophil apoptosis was also investigated. Paxillin and vimentin were markedly degraded by VAA-I when compared with neutrophils that undergo spontaneous apoptosis, but not vinculin or α- and β-tubulin. Caspases were involved in cytoskeletal protein degradation because preincubation with the pan-caspase inhibitor N-benzyloxycarbonyl-V-A-D-O-methylfluoromethyl ketone was found to reverse protein cleavage. We conclude that VAA-I needs to be internalized to mediate apoptosis and that its activity is not dependent on a cell surface receptor-mediated pathway. Also, we conclude that VAA-I induces apoptosis by ROS-independent and Mcl-1-dependent mechanisms and that caspases are involved in cytoskeletal protein degradation in both spontaneous and VAA-I-induced neutrophil apoptosis.

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Section: Discussionmentioning

confidence: 55%

Section: Discussionmentioning

confidence: 64%

Mechanisms Involved in Spontaneous and Viscum album Agglutinin-I-Induced Human Neutrophil Apoptosis: Viscum album Agglutinin-I Accelerates the Loss of Antiapoptotic Mcl-1 Expression and the Degradation of Cytoskeletal Paxillin and Vimentin Proteins Via Caspases

Lavastre

Pelletier

Saller

et al. 2002

The Journal of Immunology

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137

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“…Interactions between receptors and their ligands trigger the formation of phagopodes and ultimately lead to the complete uptake of the particle. Several soluble mediators are known to enhance phagocytosis in human macrophages or neutrophils, including the cytokines GM-CSF, IL-4, and IL-15 (31,43,50), but the mechanisms underlying this biological response remain unclear. However, it has been demonstrated that Src proteins and Syk are essential for signal transduction leading to cytoskeleton remodeling and phagocytosis (51,52).…”

Section: S100a9 Induces Phosphorylation Events In Human Neutrophilsmentioning

confidence: 99%

Damage-Associated Molecular Pattern S100A9 Increases Bactericidal Activity of Human Neutrophils by Enhancing Phagocytosis

Simard

Simon

Tessier

et al. 2011

The Journal of Immunology

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The damage-associated molecular-pattern S100A9 is found at inflammatory sites in infections and various autoimmune diseases. It is released at very high concentrations in the extracellular milieu by activated neutrophils and monocytes in response to various agents. This proinflammatory protein is found in infected mucosae and tissue abscesses where it acts notably as a potent neutrophil activator. In this study, we examined the role of S100A9 in the control of infections. S100A9 was found to increase human neutrophil bactericidal activity toward Escherichia coli. Although S100A9 induced the accumulation of reactive oxygen species over time through the activation of NADPH oxidase, its antimicrobial activity was mediated mainly by enhancing the efficiency of neutrophil phagocytosis. Interestingly, S100A9 did not act by increasing cell surface expression of CD16, CD32, or CD64 in neutrophils, indicating that its biological effect in FcR-mediated phagocytosis is independent of upregulation of FcγR levels. However, S100A9-induced phagocytic activity required the phosphorylation of Erk1/2, Akt, and Syk. Taken together, our results demonstrate that S100A9 stimulates neutrophil microbicidal activity by promoting phagocytosis.

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“…The plant lectin Viscum album agglutinin-I (VAA-I) can modulate some, but not all, IL-15-induced neutrophil responses and acts independent of phosphorylation events [10] . But for our case, even if IL-15 has multiple pathways to delay neutrophil apoptosis [9] , it is highly possible that TNFα involves into IL-15-associated phosphorylation events due to the decrease of Bcl-Xl expression in neutrophils.…”

Section: Discussionmentioning

confidence: 99%

“…In the latter instance, IL-15 delays human neutrophil apoptosis by intracellular events (preventing loss of the anti-apoptotic Mcl-1 protein expression, involving of different signal transduction pathways) and not via extracellular factors [8,9] . LIU It was reported that IL-15-induced neutrophil responses could be modulated by the plant lectrin Viscum album agglutinin-I [10] . In this study, it was found that TNFα could strongly block IL-15-induced suppression of neutrophil apoptosis.…”

mentioning

confidence: 99%

Modulation of interleukin-15-induced suppression of human neutrophil apoptosis by TNFα

Liu

Xiong

et al. 2007

J. Huazhong Univ. Sc. Technol.

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Human interleukin-15 (IL-15) is a proinflammatory cytokine to suppress neutrophil apoptosis, which is a potential therapeutic agent. The modulatory effect of TNFalpha was investigated in IL-15-induced suppression of human neutrophil apoptosis. TNFalpha was shown to reverse the ability of IL-15 to delay neutrophil apoptosis within certain time course. Moreover, this reverse effect by TNFalpha might be associated with a reduction of the expression of the anti-apoptotic Bcl-Xl protein detected by Western blotting. It is concluded that TNFalpha can be used to modulate IL-15-induced suppression of neutrophil apoptosis within certain time course.

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Modulation of Interleukin-15-Induced Human Neutrophil Responses by the Plant Lectin Viscum album Agglutinin-I

Cited by 22 publications

References 37 publications

Mechanisms Involved in Spontaneous and Viscum album Agglutinin-I-Induced Human Neutrophil Apoptosis: Viscum album Agglutinin-I Accelerates the Loss of Antiapoptotic Mcl-1 Expression and the Degradation of Cytoskeletal Paxillin and Vimentin Proteins Via Caspases

Mechanisms Involved in Spontaneous and Viscum album Agglutinin-I-Induced Human Neutrophil Apoptosis: Viscum album Agglutinin-I Accelerates the Loss of Antiapoptotic Mcl-1 Expression and the Degradation of Cytoskeletal Paxillin and Vimentin Proteins Via Caspases

Damage-Associated Molecular Pattern S100A9 Increases Bactericidal Activity of Human Neutrophils by Enhancing Phagocytosis

Modulation of interleukin-15-induced suppression of human neutrophil apoptosis by TNFα

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