The administration of a high dose of IL-12 into the mice resulted in the induction of splenomegaly. From the flow cytometry analysis of cellularity in an enlarged spleen, it was demonstrated that Thy1.2-CD45RB-c-Kit+Sca- 1+Lin- hematopoietic progenitor cells markedly increased in IL-12- administered mouse spleen compared with untreated mouse spleen. The IL-12- induced hematopoietic progenitor cells showed a greatly enhanced colony- forming activity in CFU-granulocyte/macrophage (CFU-GM), blast-forming units- erythroid (BFU-E) and CFU-spleen (CFU-S) assay. Moreover, it was initially demonstrated that the transfer of IL-12-induced splenic hematopoietic progenitor cells into immunodeficient RAG2(-/-) mice caused a complete reconstitution of their immune functions including T- and B-cell-mediated immunity. Thus, the evidence that IL-12 has a capability of inducing hematopoietic progenitor cells possessing stem cell-like activity in vivo, indicated another important immunomodulating activity of IL-12 in immunotherapy.
ASJC Scopus subject areas
- Immunology and Allergy