Figure 3.

Receptor interaction by EtxB does not prevent T cell reactivity to CII but does reduce the anti-CII antibody response. (A) Inguinal lymph node cells were isolated 16 days after injection with collagen and were cultured either in the presence (solid symbols) or absence (open symbols) or 50 μg/ml of heat denatured bovine CII. Identical cultures were established from either EtxB-protected (triangles) or unprotected (squares) mice. Proliferation in these cultures was measured on days 2 to 6 by assay of [³H]thymidine incorporation. (B) Serum samples from mice (n = 11) injected either with CII alone or with CII plus EtxB (as indicated) were collected 15 days after immunization and assayed for the presence of anti-bovine CII antibodies. End point titers of total anti-CII IgG were calculated by linear regression analysis for each animal and are shown (□) along with the mean (bar) for the group.