CD40LG and infection: As previously reported [25], the 7D4 (IgM, anti-CD25) antibody substantially reduced the proportion of splenic CD25+ CD4 cells within 3 days (i.e day of infection) but CD25+ cells recovered to normal levels by day 4 pi (results not shown) and 7D4 treatment had no significant effect on the frequency of CD4+Foxp3+ve cells (results not shown).