A naturally occurring antibody in New Zealand mice cytotoxic to dissociated cerebellar cells.

A spontaneously occurring antibody cytotoxic to dissociated cells of the neonate mouse cerebellum was found in the sera of some New Zealand (NZ) mice. No significant activity was found in the sera of six non-autoimmune mouse strains. The degree of cytotoxicity was similar towards both allogeneic and syngeneic cells. Absorption of the cytotoxic sera with brain and kidney homogenates removed the reactivity, while liver removed less reactivity. Absorptions with thymocytes and several other tissue homogenates and cells had no effect on the cytotoxicity levels, nor was there a correlation between the levels of thymocytotoxicity and cerebellar cell cytotoxicity. The antibody cytotoxic for cerebellar cells could not be demonstrated in the cerebrospinal fluid (CSF) of any mice examined, including a mouse with high serum cytotoxic levels. Gel filtration of reactive sera indicated that the antibody is of the IgM class.