Murine cytomegalovirus infection model in Balb/c mice. 3. Immunoglobulin production during infection.

In mice infected with a lethal dose of murine cytomegalovirus (MCMV) the serum immunoglobulin (Ig) levels and the Ig-bearing cells in the spleen dropped to barely detectable levels 2 days after infection. In mice with acute but non-lethal MCMV infection, the serum IgM was twice and the IgG 32 times that of the uninfected controls by Day 8 of infection; the numbers of spleen cells bearing IgM and the IgG subclasses (IgG1, IgG2a, IgG2b, IgG3) were also greatly increased. In the asymptomatically infected group, serum IgM remained unchanged but the IgG increased to 16 times that of uninfected controls by Day 11 of infection; the numbers of spleen cells bearing IgM and IgG subclasses were also increased, although to a lesser extent than in the acute, non-lethally infected mice. In the latter two groups, serum IgA and IgA-bearing cells in the spleen did not alter significantly. Complement-requiring neutralizing antibodies to MCMV were detected 8 days post infection.