title: c-Rel is crucial for lymphocyte proliferation but dispensable for T cell effector function.
abstract: The TCR signals are essential for T cell activation and proliferation, primarily through the induction of cytokine and cytokine receptors. Several transcription factor families, including NF-kappaB/Rel, have been implicated in the regulation of cytokine gene expression in T cells in response to antigen, cytokine and mitogenic stimulation. In this study, we show that the mice with a null mutation in the lymphoid-specific c-Rel gene have normal development of lymphoid tissues and T cell compartment. However, T cells derived from the c-Rel knockout mice have several functional abnormalities. The c-Rel-deficient T lymphocytes fail to respond to activation and proliferation signals mediated by the TCR and mitogens in vitro. This is attributed to an impaired production of cytokines IL-2, IL-3 and granulocyte macrophage colony stimulating factor. In addition, the induction of IL-2R alpha chain is impaired in the c-Rel(-/-) T cells. The poor expression of cytokines and IL-2R alpha chain correlates with a reduced nuclear translocation of NF-kappaB components in c-Rel(-/-) T cells. Since activation is prerequisite for differentiation into effector cells, c-Rel(-/-) T cells failed to differentiate into cytotoxic T cells or Th cells without rescuing cytokines. However, upon supplement with exogenous IL-2, the c-Rel(-/-) cytotoxic T lymphocytes are able to execute cytotoxicity and the c-Rel(-/-) Th cells are capable of providing help to normal B cells. These data suggest that c-Rel is important for inducible cytokine and cytokine receptor expression, and a key regulator of early activation and proliferation in T cells.
authors.affiliation: Cornell University Medical College, Department of Medicine, New York, NY 10021, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Liou
authors.forename: Z
authors.initials: Z
authors.lastname: Jin
authors.forename: J
authors.initials: J
authors.lastname: Tumang
authors.forename: S
authors.initials: S
authors.lastname: Andjelic
authors.forename: K A
authors.initials: KA
authors.lastname: Smith
authors.forename: M L
authors.initials: ML
authors.lastname: Liou
mesh_terms: D000818:Animals; D001692:Biological Transport; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic; D018390:Gene Targeting; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D020569:Proto-Oncogene Proteins c-rel; D011519:Proto-Oncogenes; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D016207:Cytokines; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; D015375:Receptors, Interleukin-2