Figure 5.

SpA or MSpA induces persistent loss of natural IgM anti-PC antibodies, whereas natural IgM anti-α1–3 dextran antibodies are nonspecifically increased. Neonatal BALB/c mice were treated with control proteins or different forms of SpA for the first 2 wk of life, and natural IgM antibody levels were quantitated 3–5 mo later. For groups of four mice, serial dilutions of antibody reactivities in ELISA are indicated with mean ± SEM.