{"doi":"10.3390/v16101507","title":"Redundancy in Innate Immune Pathways That Promote CD8+ T-Cell Responses in AAV1 Muscle Gene Transfer","abstract":"While adeno-associated viral (AAV) vectors are successfully used in a variety of in vivo gene therapy applications, they continue to be hampered by the immune system. Here, we sought to identify innate and cytokine signaling pathways that promote CD8+ T-cell responses against the transgene product upon AAV1 vector administration to murine skeletal muscle. Eliminating just one of several pathways (including DNA sensing via TLR9, IL-1 receptor signaling, and possibly endosomal sensing of double-stranded RNA) substantially reduced the CD8+ T-cell response at lower vector doses but was surprisingly ineffective at higher doses. Using genetic, antibody-mediated, and vector engineering approaches, we show that blockade of at least two innate pathways is required to achieve an effect at higher vector doses. Concurrent blockade of IL-1R1 > MyD88 and TLR9 > MyD88 > type I IFN > IFNaR pathways was often but not always synergistic and had limited utility in preventing antibody formation against the transgene product. Further, even low-frequency CD8+ T-cell responses could eliminate transgene expression, even in MyD88- or IL-1R1-deficient animals that received a low vector dose. However, we provide evidence that CpG depletion of vector genomes and including TLR9 inhibitory sequences can synergize. When this construct was combined with the use of a muscle-specific promoter, transgene expression in muscle was sustained with minimal local or systemic CD8+ T-cell response. Thus, innate immune avoidance/blockade strategies by themselves, albeit helpful, may not be sufficient to prevent destructive cellular responses in muscle gene transfer because of the redundancy of immune-activating pathways.","journal":"Viruses","year":2024,"id":428996,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":11,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9524,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":393004,"name":"Sandeep Kumar","orcid":"0000-0002-0533-219X","position":1,"is_corresponding":false},{"id":1231059,"name":"Di Cao","orcid":"0009-0008-5290-4120","position":2,"is_corresponding":false},{"id":663956,"name":"Maite Muñoz-Melero","orcid":null,"position":3,"is_corresponding":false},{"id":1058907,"name":"Sreevani Arisa","orcid":null,"position":4,"is_corresponding":false},{"id":1231628,"name":"Bridget A. Brian","orcid":null,"position":5,"is_corresponding":false},{"id":1231629,"name":"Calista M. Greenwood","orcid":null,"position":6,"is_corresponding":false},{"id":826655,"name":"Kentaro Yamada","orcid":"0000-0001-5454-4554","position":7,"is_corresponding":false},{"id":320631,"name":"Dongsheng Duan","orcid":"0000-0003-4109-1132","position":8,"is_corresponding":false},{"id":290766,"name":"Roland W. Herzog","orcid":"0000-0002-7213-998X","position":9,"is_corresponding":false},{"id":1231058,"name":"Ning Li","orcid":"0000-0003-4633-5781","position":0,"is_corresponding":true}],"reference_count":72,"raw_metadata":null,"created_at":"2026-07-19T01:59:06.668462Z","pmid":"39459842","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}