The results indicated that the percentage of IgM+ B-lymphocytes in PBLs obviously declined at 1 h (12.1%) as compared to pre-infection (0 h, 19.9%), reduced to the lowest value at 3 h (10.4%), then increased at 6 h, and reached to a relatively higher level at 12 h (15.5%) and 36 h (15.0%) but still lower than before infection (Figure 7(B1)). Here, CD40LG is linked to infection.