Bone marrow as the major site of antierythrocyte autoantibody production in NZB mice.

By use of a hemolytic plaque assay, it has been determined that most cells secreting the clinically important (anti-X) erythrocyte autoantibody of NZB mice are located in the bone marrow. There was evidence of excessive polyclonal B cell activation in NZB spleen but not in bone marrow, despite the role of marrow as the major source of erythrocyte autoantibody. These findings suggest that polyclonal activation of B cells within the marrow does not lead to erythrocyte autoantibody production. Small but significant numbers of antierythrocyte autoantibody producing cells were detected in the bone marrow but not in the spleens of normal mice, indicating that tolerance to erythrocytes may be less absolute in the bone marrow than in the spleen, or that the bone marrow serves as a repository for autoantibody secreting cells generated elsewhere.