title: IL-7/anti-IL-7 mAb complexes restore T cell development and induce homeostatic T Cell expansion without lymphopenia.
abstract: IL-7, a member of the common gamma-chain family of cytokines, is essential for B and T lymphocyte development and homeostasis of mature T cell subsets. Thus, naive and memory T cells are both dependent on IL-7 for survival and homeostatic proliferation under lymphopenic conditions. In line with prior findings with IL-2, we show in this study that the biological activity of IL-7 in vivo is greatly increased by association with anti-IL-7 mAb. Under in vivo conditions, IL-7/mAb complexes displayed 50- to 100-fold higher activity than free IL-7 and induced massive expansion of pre-B cells. IL-7/mAb complexes also increased thymopoiesis in normal mice and restored thymopoeisis in IL-7-deficient mice. For mature T cells, IL-7/mAb complexes induced marked homeostatic proliferation of both naive and memory CD4(+) and CD8(+) cell subsets even under normal T cell-replete conditions. Finally, IL-7/mAb complexes were able to enhance the magnitude of the primary response of Ag-specific naive CD8(+) cells. The strong stimulatory activity of IL-7/mAb complexes could be useful for treatment of immunodeficiency and cancer.
authors.affiliation: Department of Immunology, Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Onur
authors.initials: O
authors.lastname: Boyman
authors.forename: Chris
authors.initials: C
authors.lastname: Ramsey
authors.forename: David M
authors.initials: DM
authors.lastname: Kim
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sprent
authors.forename: Charles D
authors.initials: CD
authors.lastname: Surh
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D049109:Cell Proliferation; D006706:Homeostasis; D007156:Immunologic Memory; D015851:Interleukin-7 / Q000276:immunology* / Q000378:metabolism; D008231:Lymphopenia / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism
chemical_list: D000936:Antigen-Antibody Complex; D015851:Interleukin-7; D011994:Recombinant Proteins