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Playing Favorites: Integrin αvβ5 Mediates Preferential Zika Infection of Neural Stem Cells
Cell Stem Cell
Previews human trunk neuromuscular organoids. Cell Stem Cell 26, this issue, 172–186. Marton, R.M., and Pașca, S.P. (2019). Organoid and Assembloid Technologies for Investigating Cellular Crosstalk in Human Brain Development and Disease. Trends Cell Biol., S0962-8924(19) 30200-4.
McCauley, H.A., and Wells, J.M. (2017). Pluripotent stem cell-derived organoids: using principles of developmental biology to grow human tissues in a dish. Development 144, 958–962. Tzouanacou, E., Wegener, A., Wymeersch, F.J., Wilson, V., and Nicolas, J.F. (2009). Redefining
the progression of lineage segregations during mammalian embryogenesis by clonal analysis. Dev. Cell 17, 365–376. Verschuuren, J., Strijbos, E., and Vincent, A. (2016). Neuromuscular junction disorders. Handb. Clin. Neurol. 133, 447–466.
Playing Favorites: Integrin avb5 Mediates Preferential Zika Infection of Neural Stem Cells Christine Vazquez1 and Kellie Ann Jurado1,* 1Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA *Correspondence: [email protected] https://doi.org/10.1016/j.stem.2020.01.007
The molecular basis dictating specificity of Zika virus infection in neural stem cells (NSCs) remains elusive. Two recent papers in Cell Stem Cell (Zhu et al., 2020) and Cell Reports (Wang et al., 2020) identify integrin avb5 as an internalization factor that increases susceptibility in NSCs and glioblastoma stem cells.
Zika is a mosquito-transmitted virus that primarily causes acute, febrile illness. In more rare incidences or in particular contexts, such as congenital infection, Zika infection can present with neurological manifestations. Infection studies using human brain organoids (Garcez et al., 2016) or induced pluripotent stem cells (Souza et al., 2016; Tang et al., 2016) found that Zika preferentially targets neural progenitor cells for infection. The increased susceptibility of neural progenitor cells to Zika virus remains unclear. However, in this issue of Cell Stem Cell, Zhu et al. (2020) find that Zika virus tropism for glioblastoma neural stem cells is mediated by the SOX2-integrin avb5 axis. Complementary work by Wang et al. (2020) in Cell Reports further supports a role for integrin avb5 as an internalization factor for Zika infection in neural stem cells. Glioblastoma is an extremely lethal brain cancer that is sustained through self-renewing, highly tumorigenic cancer stem-like cells. Glioblastoma stem cells (GSCs) resist current therapy and contribute to near inevitable tumor recurrence. Since Zika selectively infects and kills neural stem cells, it has been proposed as a therapeutic onco-
lytic agent for glioblastoma therapy. Promisingly, Zika infection specifically depletes patient-derived glioblastoma stem cells as opposed to differentiated tumor or neuronal cells in in vitro systems and leads to improved survival in animal models (Zhu et al., 2017). Due to safety concerns with use of wildtype Zika virus in the clinic, understanding how Zika discriminates between stem cells and differentiated neurons could largely improve oncolytic virus approaches. To define the molecular pathways used by Zika that enable increased susceptibility of GSCs, Zhu et al. (2020) investigated the functional consequences of the transcriptional regulator SOX2. SOX2 expression is important for maintenance of stem-like properties in glioblastoma and was previously found to mark Zika infected neural progenitor cells (Souza et al., 2016). The authors found that silencing of SOX2 levels in GSCs attenuated Zika virus infection and identified two mechanisms by which SOX2 contributes to GSCs selective targeting by Zika virus. First, they observed that in GSCs, SOX2 has an inverse relationship with the innate antiviral immune response suggesting that
GSCs may be less immunogenic than differentiated cells. Second, because SOX2 was found to regulate integrin av (ITGAV) expression, the authors looked at the impact of blocking integrin heterodimer partners. They found that blocking the integrin heterodimer complex avb5 specifically inhibited Zika infection through a reduction of viral internalization. In a separate study aimed at determining mediators of Zika virus entry in GSCs, Wang et al. (2020) independently identified integrin avb5 as an important mediator of Zika virus infection in GSCs through CRISPR-mediated screening. Their analysis extended beyond neoplastic stem cells to assess the functional consequence of avb5 inhibition in neurospheres made from human induced pluripotent stem cells and from primary fetal-derived neural stem cells. Wang et al. (2020) report that avb5 inhibition reduced Zika-mediated cell death in neurospheres. Since avb5 is proposed to mediate virus internalization, the impact of integrin inhibition on viral replication would be a more direct readout, but surprisingly, the authors do not report viral load in neurosphere infections. Further, given that Zhu et al.
Cell Stem Cell 26, February 6, 2020 ª 2020 Elsevier Inc. 133
Cell Stem Cell
Previews
(2020) found a role for integnon-cancer settings. This rin avb5 in the viability and warrants inquiry into the capacity for self-renewal in immunogenic status or GSCs, it will be important distinct ISG expression to know whether avb5 pattern in non-neoplastic inhibition alone influences neural stem cells in order to neurosphere size in nonunderstand how Zika is able cancer neural stem cells. to achieve infection in Wang et al. (2020) further these cells. investigated the impact of In summary, through analavb5 inhibition during a Zika ysis of Zika virus infection of infection in wild-type mice. GSCs, two independent While more in vivo analysis groups identify integrin avb5 of integrin avb5 blockade is as an internalization factor required, the data presented used by Zika that contributes by Wang et al. (2020) suggest to its tropism for neural stem a decrease of Zika virus replicells. Overall, two mechacation in the brain, with a nistic features underlying lower number of neural stem Zika virus targeting of GSCs cells infected. Further experiwere established and can be ments are required to deterfurther leveraged to improve mine whether the observed targeting approaches for decrease in viral load is neural glioblastoma oncolytic viral stem cell specific or just a therapy (Figure 1). consequence of lower virus replication in all susceptible REFERENCES organs/cell types. These auGarcez, P.P., Loiola, E.C., Madeiro thors also demonstrate that da Costa, R., Higa, L.M., Trindade, exogenous expression of Figure 1. SOX2-Integrin b5 Axis Mediates Zika Virus Tropism for P., Delvecchio, R., Nascimento, Glioblastoma Stem Cells avb5 in a non-permissive cell J.M., Brindeiro, R., Tanuri, A., and Rehen, S.K. (2016). Zika virus imData from Zhu et al. (2020) and Wang et al. (2020) support a model for Zika line (Jurkat cells) renders the pairs growth in human neurospheres virus-selective targeting of glioblastoma stem cells for infection through two cell line susceptible to Zika viand brain organoids. Science 352, mechanisms. (1) Zika virions binds to integrin avb5 on glioblastoma stem cells 816–818. rus infection. Wang et al. for internalization. (2) Transcription factor SOX2 represses expression of interferon-stimulated genes (ISGs) and regulates expression of integrin avb5. (2020) claim that altogether Hastings, A.K., Yockey, L.J., Jagger, Illustration created with biorender. B.W., Hwang, J., Uraki, R., Gaitsch, their data suggest that integH.F., Parnell, L.A., Cao, B., rin avb5 serves as an essenMysorekar, I.U., Rothlin, C.V., et al. tial internalization factor for Zika virus Cas9-based gene editing data of Axl in (2017). TAM Receptors Are Not Required for Zika infection, but further experiments are human neural progenitor cells (Wells Virus Infection in Mice. Cell Rep. 19, 558–568. needed to clarify the physiological signifi- et al., 2016), brain organoid (Wells et al., cance of integrin avb5 in vivo since integ- 2016), and in animal models (Hastings Nowakowski, T.J., Pollen, A.A., Di Lullo, E., Sandoval-Espinosa, C., Bershteyn, M., and rin b5 knockout cells are still capable of et al., 2017) have called the physiological Kriegstein, A.R. (2016). Expression Analysis supporting Zika infection. significance of Axl as a Zika virus entry Highlights AXL as a Candidate Zika Virus Entry Receptor in Neural Stem Cells. Cell Stem Cell 18, The search for exclusive host factors factor into question. As such, the physio- 591–596. involved in flavivirus entry and internaliza- logical relevance of integrin avb5 in a Zika tion has historically been a challenge for virus infection necessitates further Souza, B.S., Sampaio, G.L., Pereira, C.S., Campos, G.S., Sardi, S.I., Freitas, L.A., the field. The identification of host factors investigation. initially ascertained to be essential for Interestingly, in GSCs, SOX2 expres- Figueira, C.P., Paredes, B.D., Nonaka, C.K., Azevedo, C.M., et al. (2016). Zika virus infection infection of West Nile virus and Dengue vi- sion is inversely correlated with the anti- induces mitosis abnormalities and apoptotic cell rus in in vitro models have had physiolog- viral immune response. This finding high- death of human neural progenitor cells. Sci. Rep. 6, 39775. ical relevance later called into question lights an intriguing conundrum. Stem upon in vivo investigation or in cellular cells are known to resist virus infection Tang, H., Hammack, C., Ogden, S.C., Wen, Z., contexts of complete host factor compared to differentiated cell progeny Qian, X., Li, Y., Yao, B., Shin, J., Zhang, F., knockout. This pattern has continued to due to baseline expression of interferon- Lee, E.M., et al. (2016). Zika Virus Infects hold true for Zika virus. Axl, a TAM recep- stimulated genes (ISGs), with different tis- Human Cortical Neural Progenitors and Attenuates Their Growth. Cell Stem Cell 18, tor, was initially highlighted as an entry re- sue stem cells having distinct ISG expres- 587–590. ceptor for Zika based on cell culture sion patterns (Wu et al., 2018). Zika virus models and correlative expression pat- replication is highly sensitive to antiviral Wang, S., Zhang, Q., Tiwari, S.K., Lichinchi, G., Yau, E.H., Hui, H., Li, W., Furnari, F., and Rana, terns with Zika-susceptible cells (Nowa- ISGs, yet it selectively targets and estab- T.M. (2020). Integrin avb5 internalizes Zika virus kowski et al., 2016). However, CRISPR- lishes infection in neural stem cells in during neural stem cells infection and provides 134 Cell Stem Cell 26, February 6, 2020
Cell Stem Cell
Previews a promising target for antiviral therapy. Cell Rep. 30, this issue, 221–233. Wells, M.F., Salick, M.R., Wiskow, O., Ho, D.J., Worringer, K.A., Ihry, R.J., Kommineni, S., Bilican, B., Klim, J.R., Hill, E.J., et al. (2016). Genetic Ablation of AXL Does Not Protect Human Neural Progenitor Cells and Cerebral Organoids from Zika Virus Infection. Cell Stem Cell 19, 703–708.
Wu, X., Dao Thi, V.L., Huang, Y., Billerbeck, E., Saha, D., Hoffmann, H.H., Wang, Y., Silva, L.A.V., Sarbanes, S., Sun, T., et al. (2018). Intrinsic Immunity Shapes Viral Resistance of Stem Cells. Cell 172, 423–438.e25. Zhu, Z., Gorman, M.J., McKenzie, L.D., Chai, J.N., Hubert, C.G., Prager, B.C., Fernandez, E., Richner, J.M., Zhang, R., Shan, C., et al. (2017). Zika virus
has oncolytic activity against glioblastoma stem cells. J. Exp. Med. 214, 2843–2857. Zhu, Z., Mesci, P., Bernatchez, J.A., Gimple, R.C., Wang, X., Schafer, S.T., Wettersten, H.I., Beck, S., Clark, A.E., Wu, Q., et al. (2020). Zika Virus Targets Glioblastoma Stem Cells through a SOX2Integrin avb5 Axis. Cell Stem Cell 26, this issue, 294–294.
Cell Stem Cell 26, February 6, 2020 135
Previews human trunk neuromuscular organoids. Cell Stem Cell 26, this issue, 172–186. Marton, R.M., and Pașca, S.P. (2019). Organoid and Assembloid Technologies for Investigating Cellular Crosstalk in Human Brain Development and Disease. Trends Cell Biol., S0962-8924(19) 30200-4.
McCauley, H.A., and Wells, J.M. (2017). Pluripotent stem cell-derived organoids: using principles of developmental biology to grow human tissues in a dish. Development 144, 958–962. Tzouanacou, E., Wegener, A., Wymeersch, F.J., Wilson, V., and Nicolas, J.F. (2009). Redefining
the progression of lineage segregations during mammalian embryogenesis by clonal analysis. Dev. Cell 17, 365–376. Verschuuren, J., Strijbos, E., and Vincent, A. (2016). Neuromuscular junction disorders. Handb. Clin. Neurol. 133, 447–466.
Playing Favorites: Integrin avb5 Mediates Preferential Zika Infection of Neural Stem Cells Christine Vazquez1 and Kellie Ann Jurado1,* 1Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104, USA *Correspondence: [email protected] https://doi.org/10.1016/j.stem.2020.01.007
The molecular basis dictating specificity of Zika virus infection in neural stem cells (NSCs) remains elusive. Two recent papers in Cell Stem Cell (Zhu et al., 2020) and Cell Reports (Wang et al., 2020) identify integrin avb5 as an internalization factor that increases susceptibility in NSCs and glioblastoma stem cells.
Zika is a mosquito-transmitted virus that primarily causes acute, febrile illness. In more rare incidences or in particular contexts, such as congenital infection, Zika infection can present with neurological manifestations. Infection studies using human brain organoids (Garcez et al., 2016) or induced pluripotent stem cells (Souza et al., 2016; Tang et al., 2016) found that Zika preferentially targets neural progenitor cells for infection. The increased susceptibility of neural progenitor cells to Zika virus remains unclear. However, in this issue of Cell Stem Cell, Zhu et al. (2020) find that Zika virus tropism for glioblastoma neural stem cells is mediated by the SOX2-integrin avb5 axis. Complementary work by Wang et al. (2020) in Cell Reports further supports a role for integrin avb5 as an internalization factor for Zika infection in neural stem cells. Glioblastoma is an extremely lethal brain cancer that is sustained through self-renewing, highly tumorigenic cancer stem-like cells. Glioblastoma stem cells (GSCs) resist current therapy and contribute to near inevitable tumor recurrence. Since Zika selectively infects and kills neural stem cells, it has been proposed as a therapeutic onco-
lytic agent for glioblastoma therapy. Promisingly, Zika infection specifically depletes patient-derived glioblastoma stem cells as opposed to differentiated tumor or neuronal cells in in vitro systems and leads to improved survival in animal models (Zhu et al., 2017). Due to safety concerns with use of wildtype Zika virus in the clinic, understanding how Zika discriminates between stem cells and differentiated neurons could largely improve oncolytic virus approaches. To define the molecular pathways used by Zika that enable increased susceptibility of GSCs, Zhu et al. (2020) investigated the functional consequences of the transcriptional regulator SOX2. SOX2 expression is important for maintenance of stem-like properties in glioblastoma and was previously found to mark Zika infected neural progenitor cells (Souza et al., 2016). The authors found that silencing of SOX2 levels in GSCs attenuated Zika virus infection and identified two mechanisms by which SOX2 contributes to GSCs selective targeting by Zika virus. First, they observed that in GSCs, SOX2 has an inverse relationship with the innate antiviral immune response suggesting that
GSCs may be less immunogenic than differentiated cells. Second, because SOX2 was found to regulate integrin av (ITGAV) expression, the authors looked at the impact of blocking integrin heterodimer partners. They found that blocking the integrin heterodimer complex avb5 specifically inhibited Zika infection through a reduction of viral internalization. In a separate study aimed at determining mediators of Zika virus entry in GSCs, Wang et al. (2020) independently identified integrin avb5 as an important mediator of Zika virus infection in GSCs through CRISPR-mediated screening. Their analysis extended beyond neoplastic stem cells to assess the functional consequence of avb5 inhibition in neurospheres made from human induced pluripotent stem cells and from primary fetal-derived neural stem cells. Wang et al. (2020) report that avb5 inhibition reduced Zika-mediated cell death in neurospheres. Since avb5 is proposed to mediate virus internalization, the impact of integrin inhibition on viral replication would be a more direct readout, but surprisingly, the authors do not report viral load in neurosphere infections. Further, given that Zhu et al.
Cell Stem Cell 26, February 6, 2020 ª 2020 Elsevier Inc. 133
Cell Stem Cell
Previews
(2020) found a role for integnon-cancer settings. This rin avb5 in the viability and warrants inquiry into the capacity for self-renewal in immunogenic status or GSCs, it will be important distinct ISG expression to know whether avb5 pattern in non-neoplastic inhibition alone influences neural stem cells in order to neurosphere size in nonunderstand how Zika is able cancer neural stem cells. to achieve infection in Wang et al. (2020) further these cells. investigated the impact of In summary, through analavb5 inhibition during a Zika ysis of Zika virus infection of infection in wild-type mice. GSCs, two independent While more in vivo analysis groups identify integrin avb5 of integrin avb5 blockade is as an internalization factor required, the data presented used by Zika that contributes by Wang et al. (2020) suggest to its tropism for neural stem a decrease of Zika virus replicells. Overall, two mechacation in the brain, with a nistic features underlying lower number of neural stem Zika virus targeting of GSCs cells infected. Further experiwere established and can be ments are required to deterfurther leveraged to improve mine whether the observed targeting approaches for decrease in viral load is neural glioblastoma oncolytic viral stem cell specific or just a therapy (Figure 1). consequence of lower virus replication in all susceptible REFERENCES organs/cell types. These auGarcez, P.P., Loiola, E.C., Madeiro thors also demonstrate that da Costa, R., Higa, L.M., Trindade, exogenous expression of Figure 1. SOX2-Integrin b5 Axis Mediates Zika Virus Tropism for P., Delvecchio, R., Nascimento, Glioblastoma Stem Cells avb5 in a non-permissive cell J.M., Brindeiro, R., Tanuri, A., and Rehen, S.K. (2016). Zika virus imData from Zhu et al. (2020) and Wang et al. (2020) support a model for Zika line (Jurkat cells) renders the pairs growth in human neurospheres virus-selective targeting of glioblastoma stem cells for infection through two cell line susceptible to Zika viand brain organoids. Science 352, mechanisms. (1) Zika virions binds to integrin avb5 on glioblastoma stem cells 816–818. rus infection. Wang et al. for internalization. (2) Transcription factor SOX2 represses expression of interferon-stimulated genes (ISGs) and regulates expression of integrin avb5. (2020) claim that altogether Hastings, A.K., Yockey, L.J., Jagger, Illustration created with biorender. B.W., Hwang, J., Uraki, R., Gaitsch, their data suggest that integH.F., Parnell, L.A., Cao, B., rin avb5 serves as an essenMysorekar, I.U., Rothlin, C.V., et al. tial internalization factor for Zika virus Cas9-based gene editing data of Axl in (2017). TAM Receptors Are Not Required for Zika infection, but further experiments are human neural progenitor cells (Wells Virus Infection in Mice. Cell Rep. 19, 558–568. needed to clarify the physiological signifi- et al., 2016), brain organoid (Wells et al., cance of integrin avb5 in vivo since integ- 2016), and in animal models (Hastings Nowakowski, T.J., Pollen, A.A., Di Lullo, E., Sandoval-Espinosa, C., Bershteyn, M., and rin b5 knockout cells are still capable of et al., 2017) have called the physiological Kriegstein, A.R. (2016). Expression Analysis supporting Zika infection. significance of Axl as a Zika virus entry Highlights AXL as a Candidate Zika Virus Entry Receptor in Neural Stem Cells. Cell Stem Cell 18, The search for exclusive host factors factor into question. As such, the physio- 591–596. involved in flavivirus entry and internaliza- logical relevance of integrin avb5 in a Zika tion has historically been a challenge for virus infection necessitates further Souza, B.S., Sampaio, G.L., Pereira, C.S., Campos, G.S., Sardi, S.I., Freitas, L.A., the field. The identification of host factors investigation. initially ascertained to be essential for Interestingly, in GSCs, SOX2 expres- Figueira, C.P., Paredes, B.D., Nonaka, C.K., Azevedo, C.M., et al. (2016). Zika virus infection infection of West Nile virus and Dengue vi- sion is inversely correlated with the anti- induces mitosis abnormalities and apoptotic cell rus in in vitro models have had physiolog- viral immune response. This finding high- death of human neural progenitor cells. Sci. Rep. 6, 39775. ical relevance later called into question lights an intriguing conundrum. Stem upon in vivo investigation or in cellular cells are known to resist virus infection Tang, H., Hammack, C., Ogden, S.C., Wen, Z., contexts of complete host factor compared to differentiated cell progeny Qian, X., Li, Y., Yao, B., Shin, J., Zhang, F., knockout. This pattern has continued to due to baseline expression of interferon- Lee, E.M., et al. (2016). Zika Virus Infects hold true for Zika virus. Axl, a TAM recep- stimulated genes (ISGs), with different tis- Human Cortical Neural Progenitors and Attenuates Their Growth. Cell Stem Cell 18, tor, was initially highlighted as an entry re- sue stem cells having distinct ISG expres- 587–590. ceptor for Zika based on cell culture sion patterns (Wu et al., 2018). Zika virus models and correlative expression pat- replication is highly sensitive to antiviral Wang, S., Zhang, Q., Tiwari, S.K., Lichinchi, G., Yau, E.H., Hui, H., Li, W., Furnari, F., and Rana, terns with Zika-susceptible cells (Nowa- ISGs, yet it selectively targets and estab- T.M. (2020). Integrin avb5 internalizes Zika virus kowski et al., 2016). However, CRISPR- lishes infection in neural stem cells in during neural stem cells infection and provides 134 Cell Stem Cell 26, February 6, 2020
Cell Stem Cell
Previews a promising target for antiviral therapy. Cell Rep. 30, this issue, 221–233. Wells, M.F., Salick, M.R., Wiskow, O., Ho, D.J., Worringer, K.A., Ihry, R.J., Kommineni, S., Bilican, B., Klim, J.R., Hill, E.J., et al. (2016). Genetic Ablation of AXL Does Not Protect Human Neural Progenitor Cells and Cerebral Organoids from Zika Virus Infection. Cell Stem Cell 19, 703–708.
Wu, X., Dao Thi, V.L., Huang, Y., Billerbeck, E., Saha, D., Hoffmann, H.H., Wang, Y., Silva, L.A.V., Sarbanes, S., Sun, T., et al. (2018). Intrinsic Immunity Shapes Viral Resistance of Stem Cells. Cell 172, 423–438.e25. Zhu, Z., Gorman, M.J., McKenzie, L.D., Chai, J.N., Hubert, C.G., Prager, B.C., Fernandez, E., Richner, J.M., Zhang, R., Shan, C., et al. (2017). Zika virus
has oncolytic activity against glioblastoma stem cells. J. Exp. Med. 214, 2843–2857. Zhu, Z., Mesci, P., Bernatchez, J.A., Gimple, R.C., Wang, X., Schafer, S.T., Wettersten, H.I., Beck, S., Clark, A.E., Wu, Q., et al. (2020). Zika Virus Targets Glioblastoma Stem Cells through a SOX2Integrin avb5 Axis. Cell Stem Cell 26, this issue, 294–294.
Cell Stem Cell 26, February 6, 2020 135