| First Author | Tafuri A | Year | 2001 |
| Journal | Nature | Volume | 409 |
| Issue | 6816 | Pages | 105-9 |
| PubMed ID | 11343123 | Mgi Jnum | J:66702 |
| Mgi Id | MGI:1929009 | Doi | 10.1038/35051113 |
| Citation | Tafuri A, et al. (2001) ICOS is essential for effective T-helper-cell responses. Nature 409(6816):105-9 |
| abstractText | The outcome of T-cell responses after T-cell encounter with specific antigens is modulated by co-stimulatory signals, which are required for both lymphocyte activation and development of adaptive immunity. ICOS, an inducible co-stimulator with homology to CD28, is expressed on activated, but not resting T cells, and shows T-cell co-stimulatory function in vitro. ICOS binds specifically to its counter-receptor B7RP-1 (refs 5,6,7), but not to B7-1 or B7-2. Here we provide in vivo genetic evidence that ICOS delivers a co-stimulatory signal that is essential both for efficient interaction between T and B cells and for normal antibody responses to T-cell-dependent antigens. To determine the physiological function of ICOS, we generated and characterized gene-targeted ICOS-deficient mice. In vivo, a lack of ICOS results in severely deficient T-cell-dependent B-cell responses. Germinal centre formation is impaired and immunoglobulin class switching, including production of allergy-mediating IgE, is defective. ICOS-deficient T cells primed in in vivo and restimulated in vitro with specific antigen produce only low levels of interleukin-4, but remain fully competent to produce interferon-gamma. |
