CD24 expression on T cells is required for optimal T cell proliferation in lymphopenic host.
It is well established that T lymphocytes undergo homeostatic proliferation in lymphopenic environment. The homeostatic proliferation requires recognition of the major histocompatibility complex on the host. Recent studies have demonstrated that costimulation-mediated CD28, 4-1BB, and CD40 is not required for T cell homeostatic proliferation. It has been suggested that homeostatic proliferation is costimulation independent. Here, we report that T cells from mice with a targeted mutation of CD24 have a remarkably reduced rate of proliferation when adoptively transferred into syngeneic lymphopenic hosts. The reduced proliferation cannot be attributed to abnormal survival and homing properties of the CD24-deficient T cells. T cell proliferation in allogeneic hosts is less affected by this mutation. These results demonstrate a novel function of CD24 expressed on T cells. Thus, although distinct costimulatory molecules are involved in antigen-driven proliferation and homeostatic proliferation, both processes can be modulated by costimulatory molecules.
Division of Cancer Immunology, Department of Pathology, Ohio State University Medical Center, Columbus, OH 43210, USA.
Ou
O
Li
Pan
P
Zheng
Yang
Y
Liu
D019264:Adoptive Transfer; D000818:Animals; D015703:Antigens, CD / Q000032:analysis / Q000502:physiology*; D051927:CD24 Antigen; D007371:Interferon-gamma / Q000096:biosynthesis; D019041:L-Selectin / Q000032:analysis; D008213:Lymphocyte Activation; D008231:Lymphopenia / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000032:analysis / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology*
D015703:Antigens, CD; D051927:CD24 Antigen; C497890:Cd24a protein, mouse; D008562:Membrane Glycoproteins; D019041:L-Selectin; D007371:Interferon-gamma