Wortmannin delays transfer of human rhinovirus serotype 2 to late endocytic compartments

Brabec, Marianne; Blaas, Dieter; Fuchs, Renate

doi:10.1016/j.bbrc.2006.07.125

Cited by 29 publications

(32 citation statements)

References 37 publications

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“…Using a different experimental approach, we demonstrate that (i) endogenous LC3 and LAMP-2 are unchanged in cells actively replicating HRV2 and (ii) these markers do not colocalize with viral proteins, but on the other hand, (iii) infection is affected neither by induction of autophagy by tamoxifen or by rapamycin acting via different signaling pathways nor by inhibition of autophagy by 3-MA, and finally, (iv) viral yield and virus release into the medium are not increased by tamoxifen treatment. These results are in line with previous data demonstrating that the phosphatidylinositol 3-kinase and autophagy inhibitor wortmannin (8) does not modify viral yield (1). Thus, at least this particular rhinovirus serotype does not induce the synthesis of LAMP-2-and LC3-positive compartments, nor does modification of autophagy result in increased viral synthesis.…”

supporting

confidence: 92%

Induction of Autophagy Does Not Affect Human Rhinovirus Type 2 Production

Brabec-Zaruba¹,

Berka²,

Blaas

et al. 2007

J Virol

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Induction of autophagy has been shown to be beneficial for the replication of poliovirus, a phenomenon that might also apply for other picornaviruses. We demonstrate that de novo synthesis of human rhinovirus type 2 (HRV2), an HRV of the minor receptor group, is unaffected by tamoxifen, rapamycin, and 3-methyladenine (3-MA), drugs either stimulating (tamoxifen and rapamycin) or inhibiting (3-MA) autophagic processes. Furthermore, LC3-positive vesicles (i.e., autophagosomes) are not induced upon infection. Therefore, multiplication of this particular picornavirus is not dependent on autophagy.Human rhinoviruses (HRVs) are responsible for roughly 50% of respiratory tract infections. As picornaviruses, they are nonenveloped, with a positive-sense RNA genome (12). Of the 99 HRV serotypes, 12 (the minor group) use members of the low-density lipoprotein receptor family and 87 (the major group) use intercellular adhesion molecule 1 for cell entry (13). The prototype minor-group virus HRV2 is internalized and routed to late endosomes, where RNA uncoating occurs (2, 9). Subsequently, viral protein synthesis is initiated and followed by RNA replication. Finally, infective viruses are assembled and released from the host cell. Replication has been most extensively studied for the closely related poliovirus, and Schlegel and coworkers found double-membraned vesicles in infected cells. These compartments could be immunoisolated with an antibody against viral protein 2C and contained markers of the secretory pathway and lysosomal membrane protein 1 (LAMP-1), indicative of an autophagic origin (11). Furthermore, induction of autophagy by tamoxifen and rapamycin increased poliovirus yield (6). Based on immunofluorescence colocalization of green fluorescent protein (GFP)-microtubule-associated protein light chain kinase 3 (LC3) (an autophagosome marker) and LAMP-1 as well as staining with monodansylcadaverine (MDC), autophagosomes were also observed after infection with HRV2 and the major-group virus HRV14. Focusing on HRV2, we therefore investigated whether replication of this rhinovirus is also affected by modulators of autophagy.Autophagosomes are induced by treatment with tamoxifen in cells expressing the estrogen receptor. In accordance with Bursch et al. (3), 1 M tamoxifen was sufficient to induce autophagy in all HeLa-H1 cells after 48 h. MDC and LAMP-2

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supporting

confidence: 92%

Induction of Autophagy Does Not Affect Human Rhinovirus Type 2 Production

Brabec-Zaruba¹,

Berka²,

Blaas

et al. 2007

J Virol

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“…On the other hand, HRV2, used as a control, completely overlapped with transferrin at the plasma membrane and in early endosomes (44; also data not shown) although their intracellular pathways separated thereafter (6). A more direct proof for clathrin-independent entry via ICAM-1 was obtained by using a GFP-tagged clathrin light chain.…”

Section: Vol 84 2010 Hrv14 Entry 3985mentioning

confidence: 96%

Human Rhinovirus 14 Enters Rhabdomyosarcoma Cells Expressing ICAM-1 by a Clathrin-, Caveolin-, and Flotillin-Independent Pathway

Khan

Pickl‐Herk

Gajdzik

et al. 2010

J Virol

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Intercellular adhesion molecule 1 (ICAM-1) mediates binding and entry of major group human rhinoviruses (HRVs). Whereas the entry pathway of minor group HRVs has been studied in detail and is comparatively well understood, the pathway taken by major group HRVs is largely unknown. Use of immunofluorescence microscopy, colocalization with specific endocytic markers, dominant negative mutants, and pharmacological inhibitors allowed us to demonstrate that the major group virus HRV14 enters rhabdomyosarcoma cells transfected to express human ICAM-1 in a clathrin-, caveolin-, and flotillin-independent manner. Electron microscopy revealed that many virions accumulated in long tubular structures, easily distinguishable from clathrin-coated pits and caveolae. Virus entry was strongly sensitive to the Na ؉ /H ؉ ion exchange inhibitor amiloride and moderately sensitive to cytochalasin D. Thus, cellular uptake of HRV14 occurs via a pathway exhibiting some, but not all, characteristics of macropinocytosis and is similar to that recently described for adenovirus 3 entry via ␣ v integrin/CD46 in HeLa cells.

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“…This effect indicated the contribution of the lysosomal pathway to FITC-CsNP exocytosis; however, no significant difference was observed between the VAL group and the negative control group at 24 h, suggesting the presence of a compensatory action of other pathways. When WOT was used to inhibit exocytosis, exocytosis was significantly and almost completely inhibited within 24 h. WOT was able to prevent not only the transport of endosomes to lysosomes but also MVB biogenesis ( Figure 9A); 44,45 thus, the complete inhibitory effect of WOT indicated the importance of the MVB pathway in NP excretion and that it could compensate for exocytosis when the lysosomal pathway was prevented. In the current study, golgicide (GOL) and PRQ were used as inhibitors of golgi 25 and recycling endosomes, 26 and no inhibition effects occurred, suggesting that the exocytosis could not be attributed to golgi and recycling endosomal pathways.…”

Section: Exocytosis Mechanismsmentioning

confidence: 99%

Intracellular disposition of chitosan nanoparticles in macrophages: intracellular uptake, exocytosis, and intercellular transport

Jiang¹,

Wang²,

Webster³

et al. 2017

IJN

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Biodegradable nanomaterials have been widely used in numerous medical fields. To further improve such efforts, this study focused on the intracellular disposition of chitosan nanoparticles (CsNPs) in macrophages, a primary cell of the mononuclear phagocyte system (MPS). Such interactions with the MPS determine the nanoparticle retention time in the body and consequently play a significant role in their own clinical safety. In this study, various dye-labeled CsNPs (about 250 nm) were prepared, and a murine macrophage cell line (RAW 264.7) was selected as a model macrophage. The results showed two mechanisms of macrophage incorporation of CsNPs, ie, a clathrin-mediated endocytosis pathway (the primary) and phagocytosis. Following internalization, the particles partly dissociated in the cells, indicating cellular digestion of the nanoparticles. It was proved that, after intracellular uptake, a large proportion of CsNPs were exocytosed within 24 h; this excretion induced a decrease in fluorescence intensity in cells by 69%, with the remaining particles possessing difficulty being cleared. Exocytosis could be inhibited by both wortmannin and vacuolin-1, indicating that CsNP uptake was mediated by lysosomal and multivesicular body pathways, and after exocytosis, the reuptake of CsNPs by neighboring cells was verified by further experiments. This study, thus, elucidated the fate of CsNPs in macrophages as well as identified cellular disposition mechanisms, providing the basis for how CsNPs are recognized by the MPS; such information is crucial to numerous medical applications of CsNPs.

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Wortmannin delays transfer of human rhinovirus serotype 2 to late endocytic compartments

Cited by 29 publications

References 37 publications

Induction of Autophagy Does Not Affect Human Rhinovirus Type 2 Production

Induction of Autophagy Does Not Affect Human Rhinovirus Type 2 Production

Human Rhinovirus 14 Enters Rhabdomyosarcoma Cells Expressing ICAM-1 by a Clathrin-, Caveolin-, and Flotillin-Independent Pathway

Intracellular disposition of chitosan nanoparticles in macrophages: intracellular uptake, exocytosis, and intercellular transport

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