Interspecies brain antigen detected by naturally occurring mouse anti-brain autoantibody.

Normal mouse sera contain naturally occurring antibodies that are cytotoxic in the presence of rabbit complement for NB1, a cell line derived from a neuroblastoma adrenal metastasis of a spontaneous ovarian teratoma. The anti-NB1 antibodies can be specifically removed from normal mouse sera by absorption of the sera with homogenized brain tissue of mouse, rat, guinea pig, chicken, and man and by homogenized kidney tissue of mouse and man. The antigen recognized by anti-NB1 naturally occurring autoantibodies, designated mouse brain antigen-2 (MBA-2), is not present on other normal tissues or tumor cell lines tested. MBA-2 is distinct from previously described mouse brain antigens.