{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T16:16:22Z","timestamp":1772208982742,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,3,1]],"date-time":"2021-03-01T00:00:00Z","timestamp":1614556800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["18H04018, 16K15160, and 19H05552"],"award-info":[{"award-number":["18H04018, 16K15160, and 19H05552"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008667","name":"SENSHIN Medical Research Foundation","doi-asserted-by":"publisher","award":["Grant-in-Aid"],"award-info":[{"award-number":["Grant-in-Aid"]}],"id":[{"id":"10.13039\/501100008667","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Takeda Research Support 2019","award":["Grant-in-Aid"],"award-info":[{"award-number":["Grant-in-Aid"]}]},{"DOI":"10.13039\/100007449","name":"Takeda Science Foundation","doi-asserted-by":"publisher","award":["Grant-in-Aid"],"award-info":[{"award-number":["Grant-in-Aid"]}],"id":[{"id":"10.13039\/100007449","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"publisher","award":["JP20am0101084 and JP20am0101123"],"award-info":[{"award-number":["JP20am0101084 and JP20am0101123"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>T cells that are genetically engineered to express chimeric antigen receptor (CAR) have a strong potential to eliminate tumor cells, yet the CAR-T cells may also induce severe side effects due to an excessive immune response. Although optimization of the CAR structure is expected to improve the efficacy and toxicity of CAR-T cells, the relationship between CAR structure and CAR-T cell functions remains unclear. Here, we constructed second-generation CARs incorporating a signal transduction domain (STD) derived from CD3\u03b6 and a 2nd STD derived from CD28, CD278, CD27, CD134, or CD137, and investigated the impact of the STD structure and signaling on CAR-T cell functions. Cytokine secretion of CAR-T cells was enhanced by 2nd STD signaling. T cells expressing CAR with CD278-STD or CD137-STD proliferated in an antigen-independent manner by their STD tonic signaling. CAR-T cells incorporating CD28-STD or CD278-STD between TMD and CD3\u03b6-STD showed higher cytotoxicity than first-generation CAR or second-generation CARs with other 2nd STDs. The potent cytotoxicity of these CAR-T cells was not affected by inhibiting the 2nd STD signals, but was eliminated by placing the STDs after the CD3\u03b6-STD. Our data highlighted that CAR activity was affected by STD structure as well as by 2nd STD signaling.<\/jats:p>","DOI":"10.3390\/ijms22052476","type":"journal-article","created":{"date-parts":[[2021,3,1]],"date-time":"2021-03-01T10:25:18Z","timestamp":1614594318000},"page":"2476","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Structure of the Signal Transduction Domain in Second-Generation CAR Regulates the Input Efficiency of CAR Signals"],"prefix":"10.3390","volume":"22","author":[{"given":"Kento","family":"Fujiwara","sequence":"first","affiliation":[{"name":"Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Masaki","family":"Kitaura","sequence":"additional","affiliation":[{"name":"Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ayaka","family":"Tsunei","sequence":"additional","affiliation":[{"name":"Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hotaka","family":"Kusabuka","sequence":"additional","affiliation":[{"name":"Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erika","family":"Ogaki","sequence":"additional","affiliation":[{"name":"Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8414-0622","authenticated-orcid":false,"given":"Naoki","family":"Okada","sequence":"additional","affiliation":[{"name":"Project for Vaccine and Immune Regulation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1507","DOI":"10.1056\/NEJMoa1407222","article-title":"Chimeric antigen receptor T cells for sustained remissions in leukemia","volume":"371","author":"Maude","year":"2014","journal-title":"N. 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