--- _id: '10655' abstract: - lang: eng text: "Adeno-associated viruses (AAVs) are widely used to deliver genetic material in vivo to distinct cell types such as neurons or glial cells, allowing for targeted manipulation. Transduction of microglia is mostly excluded from this strategy, likely due to the cells’ heterogeneous state upon environmental changes, which makes AAV design challenging. Here, we established the retina as a model system for microglial AAV validation and optimization. First, we show that AAV2/6 transduced microglia in both synaptic layers, where layer preference corresponds to the intravitreal or subretinal delivery method. Surprisingly, we observed significantly enhanced microglial transduction during photoreceptor degeneration. Thus, we modified the AAV6 capsid to reduce heparin binding by introducing four point mutations (K531E, R576Q, K493S, and K459S), resulting in increased microglial transduction in the outer plexiform layer. Finally, to improve microglial-specific transduction, we validated a Cre-dependent transgene delivery cassette for use in combination with the Cx3cr1CreERT2 mouse line. Together, our results provide a foundation for future studies optimizing AAV-mediated microglia transduction and highlight that environmental conditions influence microglial transduction efficiency.\r\n" acknowledged_ssus: - _id: Bio - _id: LifeSc - _id: PreCl acknowledgement: This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 715571). The research was supported by the Scientific Service Units (SSU) of IST Austria through resources provided by the Bioimaging Facility, the Life Science Facility, and the Pre-Clinical Facility, namely Sonja Haslinger and Michael Schunn for their animal colony management and support. We would also like to thank Chakrabarty Lab for sharing the plasmids for AAV2/6 production. Finally, we would like to thank the Siegert team members for discussion about the manuscript. article_processing_charge: Yes article_type: original author: - first_name: Margaret E full_name: Maes, Margaret E id: 3838F452-F248-11E8-B48F-1D18A9856A87 last_name: Maes orcid: 0000-0001-9642-1085 - first_name: Gabriele M. full_name: Wögenstein, Gabriele M. last_name: Wögenstein - first_name: Gloria full_name: Colombo, Gloria id: 3483CF6C-F248-11E8-B48F-1D18A9856A87 last_name: Colombo orcid: 0000-0001-9434-8902 - first_name: Raquel full_name: Casado Polanco, Raquel id: 15240fc1-dbcd-11ea-9d1d-ac5a786425fd last_name: Casado Polanco orcid: 0000-0001-8293-4568 - first_name: Sandra full_name: Siegert, Sandra id: 36ACD32E-F248-11E8-B48F-1D18A9856A87 last_name: Siegert orcid: 0000-0001-8635-0877 citation: ama: Maes ME, Wögenstein GM, Colombo G, Casado Polanco R, Siegert S. Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment. Molecular Therapy - Methods and Clinical Development. 2021;23:210-224. doi:10.1016/j.omtm.2021.09.006 apa: Maes, M. E., Wögenstein, G. M., Colombo, G., Casado Polanco, R., & Siegert, S. (2021). Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment. Molecular Therapy - Methods and Clinical Development. Elsevier. https://doi.org/10.1016/j.omtm.2021.09.006 chicago: Maes, Margaret E, Gabriele M. Wögenstein, Gloria Colombo, Raquel Casado Polanco, and Sandra Siegert. “Optimizing AAV2/6 Microglial Targeting Identified Enhanced Efficiency in the Photoreceptor Degenerative Environment.” Molecular Therapy - Methods and Clinical Development. Elsevier, 2021. https://doi.org/10.1016/j.omtm.2021.09.006. ieee: M. E. Maes, G. M. Wögenstein, G. Colombo, R. Casado Polanco, and S. Siegert, “Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment,” Molecular Therapy - Methods and Clinical Development, vol. 23. Elsevier, pp. 210–224, 2021. ista: Maes ME, Wögenstein GM, Colombo G, Casado Polanco R, Siegert S. 2021. Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment. Molecular Therapy - Methods and Clinical Development. 23, 210–224. mla: Maes, Margaret E., et al. “Optimizing AAV2/6 Microglial Targeting Identified Enhanced Efficiency in the Photoreceptor Degenerative Environment.” Molecular Therapy - Methods and Clinical Development, vol. 23, Elsevier, 2021, pp. 210–24, doi:10.1016/j.omtm.2021.09.006. short: M.E. Maes, G.M. Wögenstein, G. Colombo, R. Casado Polanco, S. Siegert, Molecular Therapy - Methods and Clinical Development 23 (2021) 210–224. date_created: 2022-01-23T23:01:28Z date_published: 2021-12-10T00:00:00Z date_updated: 2023-11-16T13:12:03Z day: '10' ddc: - '570' department: - _id: SaSi - _id: SiHi doi: 10.1016/j.omtm.2021.09.006 ec_funded: 1 external_id: isi: - '000748748500019' file: - access_level: open_access checksum: 77dc540e8011c5475031bdf6ccef20a6 content_type: application/pdf creator: cchlebak date_created: 2022-01-24T07:43:09Z date_updated: 2022-01-24T07:43:09Z file_id: '10657' file_name: 2021_MolTherMethodsClinDev_Maes.pdf file_size: 4794147 relation: main_file success: 1 file_date_updated: 2022-01-24T07:43:09Z has_accepted_license: '1' intvolume: ' 23' isi: 1 language: - iso: eng license: https://creativecommons.org/licenses/by/4.0/ month: '12' oa: 1 oa_version: Published Version page: 210-224 project: - _id: 25D4A630-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '715571' name: Microglia action towards neuronal circuit formation and function in health and disease publication: Molecular Therapy - Methods and Clinical Development publication_identifier: eissn: - 2329-0501 publication_status: published publisher: Elsevier quality_controlled: '1' scopus_import: '1' status: public title: Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87 volume: 23 year: '2021' ...