Neonatal ingestion of IgG-containing milk increases the survival of adoptively transferred B-lineage cells in B cell-deficient mice

This study shows that neonatal ingestion of immunoglobulin-containing milk increases the survival of adoptively transferred B-lineage cells in non-irr adiated B cell-deficient (mu (-/-)) mice. Neonatal mu (-/-) mice were eithe r transferred to lactating mu (+/+) foster dams, allowing them to suckle Ig G-containing milk, or were kept with their mu (-/-) darns, without IgG in t he milk. After adoptive transfer of spleen cells as adults, serum-IgG level s, numbers of plasma cells, T and B cells in spleen and bone marrow were de termined. The results showed that the mice which had received milk-IgG had significantly higher levels of serum-IgG and splenic B cells, as well as a higher number of Ig-secreting cells in spleen and bone marrow. This indicat es that the mice might have been tolerised against IgG as neonates, if allo wed to ingest Ig-containing milk. There is, however, a possibility that B c ells in the milk may also contribute to the observed tolerising effect. In summary, the results suggest that 'cross-fostering' could be a suitable met hod to facilitate the long-term reconstitution of B- and plasma cell number s in non-irradiated B cell-deficient mice. (C) 2001 Elsevier Science Irelan d Ltd. All rights reserved.