First Author | Johnson TR | Year | 2008 |
Journal | J Leukoc Biol | Volume | 84 |
Issue | 3 | Pages | 748-59 |
PubMed ID | 18519743 | Mgi Jnum | J:138168 |
Mgi Id | MGI:3804381 | Doi | 10.1189/jlb.0907621 |
Citation | Johnson TR, et al. (2008) Pulmonary eosinophilia requires interleukin-5, eotaxin-1, and CD4+ T cells in mice immunized with respiratory syncytial virus G glycoprotein. J Leukoc Biol 84(3):748-59 |
abstractText | Severe illness, type 2 cytokine production, and pulmonary eosinophilia are adverse immune responses resulting from respiratory syncytial virus (RSV) challenge of vvGs-immunized mice. We have shown IL-4 and IL-13 activity must be simultaneously inhibited to reduce disease severity. We now address the contributions of IL-5, eotaxin-1, and CD4+ and CD8+ T cells to the induction of disease-enhancing immune responses. Depletion of CD4+ T cells during immunization prevented IL-4, IL-13, and eotaxin-1 production, diminished eosinophilia, and reduced weight loss. Conversely, CD8+ T cell depletion did not decrease eosinophilia, weight loss, or type 2 cytokines but did dramatically reduce mucus production and increase eotaxin production. Anti-IL-5 administration at immunization or challenge significantly decreased pulmonary eosinophilia. Strikingly, there were not concomitant decreases in weight loss. Following RSV challenge eotaxin-1-deficient mice immunized with vvGs exhibited significantly less eosinophilia without decreased weight loss or type 2 cytokine production. We conclude CD4+ T cell production of IL-5 and induction of eotaxin-1 are required for vvGs-induced eosinophilia following RSV challenge, while CD8+ T cells appear to down-regulate eotaxin-1 and mucus production. In summary, we demonstrate that pulmonary eosinophilia 1) is a by-product of memory CD4+ T cell activation, 2) does not necessarily correlate with mucus production, and, most importantly, 3) is not required for the RSV G-induced illness in mice. These findings have important implications for the evaluation of candidate RSV vaccines. |