Interaction between CD40 and the CD40 ligand (CD40L) is required for mouse mammary tumor virus (MMTV) propagation. We found that Fas was expressed on B cells and CD40L on a small subset of viral superantigen-cognate T cells 12 h after MMTV(SW) infection. CD40L and Fas were down-regulated after 24 h. All CD4 T cells then became resistant to anti-CD3-induced CD40L induction in vitro for 2 wk. Initiation of CD40L expression and its rapid shut-off was associated with IL-12 production and was controlled by IFN-γ and shedding of soluble CD40. These results suggest that a rapid, transient CD40-CD40L interaction involving a small number of cells is sufficient for MMTV propagation. Modulation of CD40L expression may be a major mechanism regulating the balance between viral propagation and host defenses, allowing mutual survival.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of Immunology|
|State||Published - Nov 15 1998|
ASJC Scopus subject areas