| First Author | Chamoto K | Year | 2004 |
| Journal | Immunol Lett | Volume | 95 |
| Issue | 1 | Pages | 5-11 |
| PubMed ID | 15325792 | Mgi Jnum | J:92591 |
| Mgi Id | MGI:3054108 | Doi | 10.1016/j.imlet.2004.04.012 |
| Citation | Chamoto K, et al. (2004) NKT cells act as regulatory cells rather than killer cells during activation of NK cell-mediated cytotoxicity by alpha-galactosylceramide in vivo. Immunol Lett 95(1):5-11 |
| abstractText | Administration of NKT cell ligands, alpha-galactosylceramide (alpha-GalCer) resulted in the activation of both cytokine production and natural killing. These responses were abolished in both CD1d-deficient mice and Valpha14NKT-deficient mice. Therefore, NKT cells have been considered to be responsible cells for both cytokine production and natural killing. Here, we reevaluated a critical role of NKT and NK cells at early time after alpha-GalCer administration. Intracellular staining experiments demonstrated that NKT cells were the earliest source of both IL-4 and IFN-gamma production after alpha-GalCer administration in vivo. However, these alpha-GalCer-activated NKT cells exhibited no significant natural killing activity. In contrast, isolated NK1.1+CD3- classical NK cells exhibited greatly enhanced natural killing activity 6 h after alpha-GalCer administration. NKT cells, however, exhibited a strong cytotoxicity when they were activated and expanded with alpha-GalCer plus IL-2 in vitro. These results indicated that NKT cells act as regulatory cells via production of cytokines for activation of NK cell-mediated cytotoxicity in vivo at early phase after alpha-GalCer administration. Thus, NK cells rather than NKT cells may be a crucial early activated killer induced by alpha-GalCer in vivo. |
