The Origin of Antibody‐Forming Cells Detected in the Bone Marrow after Thymus‐Independent Antigen‐Stimulation and Abnormality in Migration of B Cells of X‐Linked Immunodeficient CBA/N Mice

The anti‐TNP IgM plaque‐forming cells (PFC) were generated in the spleen and bone marrow of non‐immunodeficient normal mice after intraperitoneal administration of TNP‐LPS. Irradiation of normal mice while shielding bone marrow completely abrogated the generation of bone marrow PFC, indicating that they are derived from extramedullary sites. The bone marrow PFC response to TNP‐LPS was low in X‐linked immunodeficient CBA/N strain mice, while the spleen response was comparable to that seen in the normal mice. To further study the basis of the deficient bone marrow PFC response in CBA/N mice, spleen cells were adoptively transferred to irradiated syngeneic mice stimulated with TNP‐LPS. While spleen cells from normal mice generated high numbers of PFC in recipient bone marrow and spleen, those from CBA/N strain mice could not generate bone marrow PFC. This result was obtained regardless of whether normal or CBA/N recipients were used. These results indicate that TNP‐LPS administration normally results in the migration of B lymphocytes from the periphery into the bone marrow and that B cells from immunodeficient CBA/N strain mice bear an inherent defect in this migratory function. This migratory defect was shown to be X‐linked, as are the other previously reported B cell defects in this inbred mouse strain. The possible relationship between this migratory defect and the maturational defects of B cell lineage as reported previously in CBA/N strain mice is discussed.