Fig. 1.

IgM controls MHV CNS infection and prevents demyelinating disease. B6 or aicda^−/− mice were i.n. infected with 5 × 10⁴ pfu of MHV A59. (A–D) Serum samples were obtained at days 6, 10, 20, and 60 after infection, and virus-binding IgM (A) and IgG (B) and neutralizing IgM (C) and IgG (D) were determined. Values indicate mean ± SEM (n = 5 mice per group and time point). (E and F) IgM-specific antibody-secreting cells were enumerated in CNS, CLN, spleen (SPL), and bone marrow (BM) at days 10 (E) and 30 (F) after infection. (G) Weight loss was recorded during the indicated time period after infection. Values indicate mean percentage of the initial weight ± SEM (n = 8 mice per group). (H) Spinal cord sections from i.n. infected aicda^−/− mice were analyzed on day 40 using Luxol fast blue staining. The statistical analyses in E and F were performed using Student's t test. *P < 0.05; **P < 0.01; ***P < 0.001.