{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,25]],"date-time":"2026-07-25T03:26:01Z","timestamp":1784949961122,"version":"3.55.0"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"17","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1991,9]]},"abstract":"<jats:p>We investigated whether staphylococcal exotoxins (SEs), in addition to their capacity to induce T-cell activation restricted by the T-cell receptor (TCR) beta-chain variable region, can deliver an activation signal to human T-cell clones through major histocompatibility complex (MHC) class II molecules. Eleven human T-cell clones (9 alpha beta TCR and 2 gamma delta TCR clones) of different antigenic specificities were tested for their capacity to proliferate in response to toxic shock syndrome toxin 1 (TSST-1) and two SEs, SEA and SEB. In the absence of accessory cells, only 4 alpha beta TCR clones were stimulated to proliferate, each by a single SE, and to mobilize intracellular free Ca2+ in response to that SE, events indicative of TCR engagement and, presumably, recognition restricted by the beta-chain variable region. In the presence of accessory cells, each of the 11 T-cell clones was stimulated to proliferate by any one of the three SEs tested. This apparently TCR-unrestricted SE-mediated polyclonal proliferation of T-cell clones occurred in the absence of an increase in intracellular free Ca2+ and was not dependent on the presence of MHC class II expression on accessory cells. In contrast, SE-mediated polyclonal proliferation did not occur in 3 alpha beta TCR clones derived from an MHC class II-deficient patient. Furthermore, all of the three SEs induced the proliferation of 4 natural-killer-cell clones, suggesting that expression of TCR\/CD3 complex is not essential for SE-mediated polyclonal proliferation of activated lymphocytes. These results indicate that MHC class II molecules transduce activation signals to human T- and natural-killer-cell clones.<\/jats:p>","DOI":"10.1073\/pnas.88.17.7533","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T07:44:17Z","timestamp":1149061457000},"page":"7533-7537","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":39,"title":["Staphylococcal exotoxins deliver activation signals to human T-cell clones via major histocompatibility complex class II molecules."],"prefix":"10.1073","volume":"88","author":[{"given":"F","family":"Spertini","sequence":"first","affiliation":[{"name":"Division of Allergy and Immunology, Children's Hospital, Boston, MA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H","family":"Spits","sequence":"additional","affiliation":[{"name":"Division of Allergy and Immunology, Children's Hospital, Boston, MA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R S","family":"Geha","sequence":"additional","affiliation":[{"name":"Division of Allergy and Immunology, Children's Hospital, Boston, MA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1991,9]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.88.17.7533","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T13:15:35Z","timestamp":1649855735000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.88.17.7533"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,9]]},"references-count":0,"journal-issue":{"issue":"17","published-print":{"date-parts":[[1991,9]]}},"alternative-id":["10.1073\/pnas.88.17.7533"],"URL":"https:\/\/doi.org\/10.1073\/pnas.88.17.7533","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,9]]},"assertion":[{"value":"1991-09-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}