title: Massive and destructive T cell response to homeostatic cue in CD24-deficient lymphopenic hosts.
abstract: In response to a lymphopenic cue, T lymphocytes undergo a slow-paced homeostatic proliferation in an attempt to restore T cell cellularity. The molecular interaction that maintains the pace of homeostatic proliferation is unknown. In this study, we report that in lymphopenic CD24-deficient mice, T cells launch a massive proliferation that results in the rapid death of the recipient mice. The dividing T cells have phenotypes similar to those activated by cognate antigens. The rapid homeostatic proliferation is caused by a lack of CD24 on dendritic cells (DCs). Interestingly, although CD24 expression in T cells is required for optimal homeostatic proliferation in the wild-type (WT) host, mice lacking CD24 on all cell types still mount higher homeostatic proliferation than the WT mice. Thus, a lack of CD24 in the non-T host cells bypassed the requirement for T cell expression of CD24 in homeostatic proliferation in the WT host. Our data demonstrate that CD24 expressed on the DCs limits T cell response to homeostatic cue and prevents fatal damage associated with uncontrolled homeostatic proliferation.
authors.affiliation: Division of Cancer Immunology, Department of Pathology, The Ohio State University Medical Center, Columbus, OH 43210, USA.
authors.forename: Ou
authors.initials: O
authors.lastname: Li
authors.forename: Xing
authors.initials: X
authors.lastname: Chang
authors.forename: Huiming
authors.initials: H
authors.lastname: Zhang
authors.forename: Ergun
authors.initials: E
authors.lastname: Kocak
authors.forename: Cheng
authors.initials: C
authors.lastname: Ding
authors.forename: Pan
authors.initials: P
authors.lastname: Zheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D051927:CD24 Antigen / Q000235:genetics*; D049109:Cell Proliferation; D002478:Cells, Cultured; D006706:Homeostasis / Q000235:genetics / Q000276:immunology*; D008212:Lymphocyte Depletion; D008231:Lymphopenia / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000473:pathology* / Q000637:transplantation
chemical_list: D051927:CD24 Antigen