title: Truncated form of TGF-βRII, but not its absence, induces memory CD8+ T cell expansion and lymphoproliferative disorder in mice.
abstract: Inflammatory and anti-inflammatory cytokines play an important role in the generation of effector and memory CD8(+) T cells. We used two different models, transgenic expression of truncated (dominant negative) form of TGF-βRII (dnTGFβRII) and Cre-mediated deletion of the floxed TGF-βRII to examine the role of TGF-β signaling in the formation, function, and homeostatic proliferation of memory CD8(+) T cells. Blocking TGF-β signaling in effector CD8(+) T cells using both of these models demonstrated a role for TGF-β in regulating the number of short-lived effector cells but did not alter memory CD8(+) T cell formation and their function upon Listeria monocytogenes infection in mice. Interestingly, however, a massive lymphoproliferative disorder and cellular transformation were observed in Ag-experienced and homeostatically generated memory CD8(+) T cells only in cells that express the dnTGFβRII and not in cells with a complete deletion of TGF-βRII. Furthermore, the development of transformed memory CD8(+) T cells expressing dnTGFβRII was IL-7- and IL-15-independent, and MHC class I was not required for their proliferation. We show that transgenic expression of the dnTGFβRII, rather than the absence of TGF-βRII-mediated signaling, is responsible for dysregulated expansion of memory CD8(+) T cells. This study uncovers a previously unrecognized dominant function of the dnTGFβRII in CD8(+) T cell proliferation and cellular transformation, which is caused by a mechanism that is different from the absence of TGF-β signaling. These results should be considered during both basic and translational studies where there is a desire to block TGF-β signaling in CD8(+) T cells.
authors.affiliation: Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Harumichi
authors.initials: H
authors.lastname: Ishigame
authors.forename: Munir M
authors.initials: MM
authors.lastname: Mosaheb
authors.forename: Shomyseh
authors.initials: S
authors.lastname: Sanjabi
authors.forename: Richard A
authors.initials: RA
authors.lastname: Flavell
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D007156:Immunologic Memory / Q000276:immunology*; D008088:Listeriosis / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008232:Lymphoproliferative Disorders / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D017346:Protein Serine-Threonine Kinases / Q000276:immunology* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000378:metabolism
chemical_list: D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II