Antigenic cross-reactivity among rodent brain tissues and stem cells.

Previous studies have shown that antisera prepared in rabbits against mouse brain (RAMB) contains activity in vitro against the mouse bone marrow colony-forming unit (CFU) or hematopoietic stem cell. In the present study, in vitro treatment of mouse bone marrow with antisera prepared in rabbits against brain tissue from rats (BARB) or hamsters (RAHB) also reduced the CFU content of the mouse marrow. Prior absorption of the RAMB serum with fetal liver tissues from rats or hamsters as well as mice reduced the anti-CFU activity of the RAMB preparation. In addition, absorption of the RAMB preparation with brain tissue from any of the rodents reduced the activity of the antiserum for the mouse stem cell. It appears that the determinants previously shown to be shared by the brain tissue and stem cells of mice are cross-reactive with determinants present on the stem cells and brain tissue of rats and hamsters.