title: Spontaneous breakdown of T cell tolerance in the mouse IgG2ab-suppression model despite long-term tolerogenesis since the perinatal period.
abstract: T cell-induced IgG2ab allotype suppression provides a physiological model for the study of T cell responsiveness or tolerance to this Ig allotype. Normal, untreated mice of the Igha haplotype possess a basic and easily amplifiable T cell reactivity against the expression of IgG2ab, while their Ighb congenic mice produce substantial levels of this Ig and thereby are tolerant to this self-protein antigen. Therefore, the involved TCR repertoire in Igha and Ighb congenic mice is different. We have previously shown, in Ighb and Igha/b mice perinatally deprived of IgG2ab expression, that T lymphocytes bearing anti-IgG2ab TCR can emerge and induce an autoimmune suppression of IgG2ab. Correlatively, full and IgG2ab-specific T cell tolerance can be induced in Igha mice by their perinatal exposure to this Ig allotype. In this physiological model, which involves neither superantigens nor TCR-transgenic T cells, the responsive or tolerant state in Igha mice is assessed in vivo by the capacity to induce or not a T CD8(+)-dependent suppression of IgG2ab allotype production in Igha/b recipients of these cells. Taking advantage of this system, we were able to demonstrate here that, over the long term, this perinatally induced, IgG2ab-specific T cell tolerance was not definitively acquired, and that a spontaneous and total tolerance breakdown was observed by the age of 6 months. Furthermore, we showed that perinatal followed by prolonged tolerogen treatments up to 3, 6 and even 9 months of age were no longer sufficient to assure definitive T cell tolerance acquisition to IgG2ab, as the T cell suppression-induction capacity of Igha mice was partially and then entirely restored 3-6 months after the end of the tolerogen administration.
authors.affiliation: Unité d'Immunophysiologie Moléculaire, Institut Pasteur, Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Majlessi
authors.forename: N
authors.initials: N
authors.lastname: Rujithamkul
authors.forename: C
authors.initials: C
authors.lastname: Sellier
authors.forename: G
authors.initials: G
authors.lastname: Bordenave
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D007108:Immune Tolerance / Q000187:drug effects* / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology* / Q000494:pharmacology*; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D013601:T-Lymphocytes / Q000187:drug effects*
chemical_list: D007074:Immunoglobulin G