Myosin IIA is required for cytolytic granule exocytosis in human NK cells

Andzelm, Milena M.; Chen, Xi; Krzewski, Konrad; Orange, Jordan S.; Strominger, Jack L.

doi:10.1083/jcb1787oia16

Cited by 44 publications

(69 citation statements)

References 23 publications

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“…17 Surprisingly, however, we found that neither blebbistatin nor ML-7 blocked activation-induced and PMAinduced FasL degranulation (Figure 3c and d).…”

Section: Resultsmentioning

confidence: 62%

“…For example we have seen that the general protein transport inhibitor brefeldin A efficiently blocks degranulation of FasL, whereas it does not affect release of CD107a (Figures 3a, 6c and 9b), or perforin and granzymes. 32 In marked contrast, myosin light chain activation, blocked by blebbistatin and ML-7, seem to be required for the release of classical cytotoxic granules 17 but not of preformed FasL (Figure 3c and d).…”

Section: Discussionmentioning

confidence: 99%

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Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

et al. 2008

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Fas (CD95/Apo-1) ligand is a potent inducer of apoptosis and one of the major killing effector mechanisms of cytotoxic T cells. Thus, Fas ligand activity has to be tightly regulated, involving various transcriptional and post-transcriptional processes. For example, preformed Fas ligand is stored in secretory lysosomes of activated T cells, and rapidly released by degranulation upon reactivation. In this study, we analyzed the minimal requirements for activation-induced degranulation of Fas ligand. T cell receptor activation can be mimicked by calcium ionophore and phorbol ester. Unexpectedly, we found that stimulation with phorbol ester alone is sufficient to trigger Fas ligand release, whereas calcium ionophore is neither sufficient nor necessary. The relevance of this process was confirmed in primary CD4 þ and CD8 þ T cells and NK cells. Although the activation of protein kinase(s) was absolutely required for Fas ligand degranulation, protein kinase C or A were not involved. Previous reports have shown that preformed Fas ligand co-localizes with other markers of cytolytic granules. We found, however, that the activationinduced degranulation of Fas ligand has distinct requirements and involves different mechanisms than those of the granule markers CD63 and CD107a/Lamp-1. We conclude that activation-induced degranulation of Fas ligand in cytotoxic lymphocytes is differently regulated than other classical cytotoxic granule proteins.

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“…17 Surprisingly, however, we found that neither blebbistatin nor ML-7 blocked activation-induced and PMAinduced FasL degranulation (Figure 3c and d).…”

Section: Resultsmentioning

confidence: 62%

Section: Discussionmentioning

confidence: 99%

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

et al. 2008

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“…In support of this, NMII inhibitors or specific knockdown of the myosin IIA heavy chain by RNA interference impaired cytotoxicity, membrane fusion of lytic granules, and granzyme secretion in natural killer cells. 48 Thus, NMII is required for cytolytic granule exocytosis in innate immune response. Moreover, accumulating evidence suggests that NMII might also have an important role in acquired immune recognition, such as B cell receptor-driven antigen processing and presentation.…”

Section: Discussionmentioning

confidence: 99%

Inhibiting nonmuscle myosin II impedes inflammatory infiltration and ameliorates progressive renal disease

Jin

Zhuang

et al. 2010

Laboratory Investigation

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The motor protein nonmuscle myosin II (NMII) through its interaction with the actin cytoskeleton constitutes the machinery of cell crawling and has an important role in driving locomotion and infiltration of immune competent cells during inflammatory response and immune reaction. Blebbistatin is a highly selective inhibitor of NMII adenosine triphosphatase. This study examined the effect of NMII inhibition by blebbistatin on inflammation. In vitro, blebbistatin markedly induced actinomyosin complex disassembly in various cultured immunocytes, and functionally impaired their motile activity and invasive capacity as assessed by the Boyden chamber motility assay and the matrigel invasion assay. In vivo, in a rat model of acute inflammation induced by tumor necrosis factor, blebbistatin obliterated renal sequestration of circulating fluorescence-labeled macrophages in a dose-dependent fashion. Moreover, in rats with progressive obstructive nephropathy, blebbistatin treatment exhibited a remarkable renoprotective effect, as evidenced by normalized kidney weight, improved gross morphology, and diminished histologic injury in the tubulointerstitium. This beneficial effect was associated with significant amelioration of renal inflammation, consistent with a primary antiinflammatory action by blebbistatin. In addition, in rats with established obstructive nephropathy, blebbistatin pretreated macrophages showed obliterated recruitment into the inflamed renal parenchyma, denoting that blebbistatin directly impedes inflammatory infiltration by immunocytes. Collectively, our findings suggest that inhibition of NMII has a potent and direct anti-inflammatory effect on the basis of impairment of the actinomyosin powered locomotive machinery, which is essential for migration and infiltration of immune competent cells.

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“…Target cells were identified by labeling with carboxyfluorescein succinimidyl ester. The staining was as in the work of Andzelm et al (11). For the reliable detection of changes in CD107a cell surface expression, strong NK cell stimuli were required, as provided by YAC-1 target cells.…”

Section: Methodsmentioning

confidence: 99%

“…Target cell contact triggers the complex polarization of primed cytolytic effectors, recruitment of cytolytic granules to the interface (10,11), cytoskeletal reorientation (12,13), and receptor clustering (14,15). Cytolytic effector polarization is likely functionally important, as key regulators of cytoskeletal dynamics, Vav and WASP, play critical roles (16)(17)(18)(19).…”

mentioning

confidence: 99%

Transience in polarization of cytolytic effectors is required for efficient killing and controlled by Cdc42

Sinai¹,

Nguyen²,

Schatzle³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Cytolytic effectors polarize toward target cells for effective killing and IFN-γ secretion. The spatiotemporal features of this polarization and their importance for cytolysis have not been resolved. In cytotoxic T cells and natural killer (NK) cells, transient polarization was consistently associated with effective killing. Polarization was regulated by Cdc42, a small Rho family GTPase universally critical for cytoskeletal dynamics. Transient accumulation of active Cdc42 at the cytolytic effector/target cell interface and focus of such accumulation on the interface center were closely related to cytolysis. Surprisingly, however, the intensity of Cdc42 activation was not. We interfered with Cdc42 activation in NK cells such that sustained polarization in long lasting nonkilling cell couples was selectively blocked. Thus the proportion of the NK cell population displaying transient polarization was increased. As a consequence, cytolytic responder frequency and IFN-γ production were enhanced upon such interference with Cdc42 activation. These data support the notion that transience in polarization is critical for cytolytic effector function, likely by preventing cytolytic effectors from becoming trapped in nonproductive target cell interactions. Each can also secrete IFN-γ to modulate adaptive immune function. To acquire effector capability, cytolytic effectors need to be primed. CTL priming occurs as the consequence of naive CD8 T cell interactions with antigen-presenting dendritic cells. NK cell priming requires cytokines generated predominantly by dendritic cells. However, the nature of the cytokines involved is less certain. IL-12 and IL-18 enable NK cells to secrete IFN-γ (1, 2) and are synergistic (3). IL-15 can promote NK cell expansion (4, 5). IL-15 needs transpresentation by the IL-15 receptor α chain (6, 7), which is induced on dendritic cells by engagement of Toll-like receptors (7). High concentrations of IL-2 effectively prime NK cells in vitro, as often used in clinical settings (8, 9). However, in vivo, IL-2 is dispensable for NK cell priming (5). To understand the role of the polarization of cytolytic effector in their function, the effect of priming conditions on NK cell polarization needs to be taken into account.Target cell contact triggers the complex polarization of primed cytolytic effectors, recruitment of cytolytic granules to the interface (10, 11), cytoskeletal reorientation (12, 13), and receptor clustering (14,15). Cytolytic effector polarization is likely functionally important, as key regulators of cytoskeletal dynamics, Vav and WASP, play critical roles (16-19). However, WASP and Vav are complex molecules with functions that may or may not require cytoskeletal regulation (20,21). The Rho family GTPases Rac and Cdc42 are the central regulators of cytoskeletal dynamics in many cell types (22). Although it has been established that Rac is required for cell coupling and polarization of cytolytic granules (16), the role Cdc42 has not been addressed. Despite the established importance of ...

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Myosin IIA is required for cytolytic granule exocytosis in human NK cells

Cited by 44 publications

References 23 publications

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

Distinct requirements for activation-induced cell surface expression of preformed Fas/CD95 ligand and cytolytic granule markers in T cells

Inhibiting nonmuscle myosin II impedes inflammatory infiltration and ameliorates progressive renal disease

Transience in polarization of cytolytic effectors is required for efficient killing and controlled by Cdc42

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