| First Author | Bertram EM | Year | 2002 |
| Journal | Eur J Immunol | Volume | 32 |
| Issue | 12 | Pages | 3376-85 |
| PubMed ID | 12432568 | Mgi Jnum | J:80851 |
| Mgi Id | MGI:2447282 | Doi | 10.1002/1521-4141(200212)32:12<3376::AID-IMMU3376>3.0.CO;2-Y |
| Citation | Bertram EM, et al. (2002) Role of ICOS versus CD28 in antiviral immunity. Eur J Immunol 32(12):3376-85 |
| abstractText | The costimulatory protein ICOS is inducibly expressed on activated T cells. Previous results have shown that ICOS(-/-) mice are defective in germinal center formation, antibody (Ab) production and class switch as well as Th1 and Th2 cytokine production in response to protein or parasite antigens. However, ICOS-Ig failed to block antiviral Ab responses. To date the immune response to viruses has not been examined in ICOS(-/-) mice. In this report we compared antiviral Ab responses to LCMV, VSV and influenza virus in ICOS(-/-) versus wild-type mice. Our results show that ICOS is important in the Ab response to all three viruses, with greater effects on primary as compared to secondary responses. Although ICOS(-/-) mice are impaired in some immune responses following influenza infection, the effects were less severe than for CD28(-/-) mice. There was no defect in initial influenza-specific CD8 T cell expansion in ICOS(-/-) mice or in cytotoxic effector function. However, ICOS was important in maintaining CD4 cytokine production and CD8 T cell numbers late in the primary response. Upon secondary infection, ICOS(-/-) mice show wild-type levels of influenza-specific CD8 T cells, whereas CD28(-/-) mice show greatly impaired secondary CD8 T cell expansion. Overall, our results show that ICOS plays a clear role in the primary response to viruses at the level of Ab production, germinal center formation and Th cytokine production, but has diminished effects following secondary viral challenge. |
