title: Lack of transglutaminase 2 diminished T-cell responses in mice.
abstract: Transglutaminase 2 (TG2) has been reported to play a role in dendritic cell activation and B-cell differentiation after immunization. Its presence and role in T cells, however, has not been explored. In the present study, we determined the expression of TG2 on mouse T cells, and evaluated its role by comparing the behaviours of wild-type and TG2(-/-) T cells after activation. In our results, naive T cells minimally expressed TG2, expression of which was increased after activation. T-cell proliferation, expression of activation markers such as CD69 and CD25, and secretions of interleukin-2 and interferon-γ were suppressed in the absence of TG2, presumably due, in part, to diminished nuclear factor-κB activation. These effects on T cells seemed to be reflected in the in vivo immune response, the contact hypersensitivity reaction elicited by 2,4-dinitro-1-fluorobenzene, with lowered peak responses in the TG2(-/-) mice. When splenic T cells from mice immunized with tumour lysate-loaded wild-type dendritic cells were re-challenged ex vivo with the same antigen, the profile of surface markers including CD44, CD62L, and CD127 strongly indicated lesser generation of memory CD8(+) T cells in TG2(-/-) mice. In the TG2(-/-)  CD8(+) T cells, moreover, Eomes expression was markedly decreased. These results indicate possible roles of TG2 in CD8(+) T-cell activation and CD8(+) memory T-cell generation.
authors.affiliation: Department of Anatomy, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jin-Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Jun Man
authors.initials: JM
authors.lastname: Hong
authors.forename: Eui Man
authors.initials: EM
authors.lastname: Jeong
authors.forename: Wang Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Hang-Rae
authors.initials: HR
authors.lastname: Kim
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Kang
authors.forename: In-Gyu
authors.initials: IG
authors.lastname: Kim
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Hwang
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D019204:GTP-Binding Proteins / Q000172:deficiency / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases / Q000172:deficiency / Q000276:immunology / Q000378:metabolism*
chemical_list: D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins
keywords: CD8+ T cells; Eomes; T-cell activation; transglutaminase 2