Cross-reactivity of IgM- and IgG-secreting B cells in autoimmune mice.

OBJECTIVE

To determine the frequency with which in vivo-activated B cells secrete cross-reactive antibodies in lupus-prone mice.

METHODS

Analysis of freshly isolated splenic lymphocytes by chamber enzyme-linked immunospot assay.

RESULTS

Young New Zealand black, New Zealand black x New Zealand white, and MRL/lpr mice expressed repertoires in which 16-20% of IgM-secreting cells and 0-2% of IgG-secreting cells were cross-reactive. By comparison, 21-31% of IgM- and 4-14% of IgG-secreting cells in adult animals with active lupus were cross-reactive (P < 0.01).

CONCLUSION

Cross-reactive B cells constitute an abnormally large proportion of the repertoire expressed in mice with active autoimmune disease.