FIGURE 5.

B cell epitope spread to other β₂GPI domains occurs in the presence of a β₂GPI-specific T cell response. Sera from β₂GPI/LPS-immunized mice were tested by ELISA for antibodies to human β₂GPI (native protein), recombinant protein fragments of human β₂GPI (GP-1, GP-2, and GP-3), or MalBP (control fusion protein). The data shown for C57BL/6, C.B10, BALB/c, and B6.C mice are post-third immunization (black circles), whereas the data for all C3H/HeN mice and two 129S1 mice are post-second immunization (white circles) (see “Mice and Immunization”). Each circle represents the mean IgG binding (A₄₀₅ ± S.E.) of duplicate samples (1:1000 dilution, except for C57BL/6, with a 1:100 dilution) for an individual mouse (n = three to four mice/group), and the data shown are representative of three independent experiments.