Search results for "Radiation Chimera"

T cell-mediated cytotoxic immune responsiveness of chimeric mice bearing a thymus graft fully allogeneic to the graft of lymphoid stem cells

1980

Fully allogeneic, chimeric mice were established by adult thymectomy of (A × B) F1animals, grafting parental A-type thymus under the kidney capsula, followed by lethal (900 rd) irradiation and reconstitution with B parental-type bone marrow cells treated with xenogeneic anti-T cell antiserum plus complement. Following in vivo sensitization with inactivated Sendai virus (SV) suspensions, no virus-specific T cells could be detected within the spleen cells of the mice. Upon stimulation with third-party allogeneic cells in a primary mixed lymphocyte culture, spleen cells of all animals generated alloreactive cytotoxic T lymphocytes (CTL). More interestingly, upon secondary in vitro stimulation …

A non-redundant role for OX40 in the competitive fitness of Treg in response to IL-2.

2010

OX40 stimulation is known to enhance activation of effector T cells and to inhibit induction and suppressive function of Treg. Here we uncovered a novel role of OX40 in sustaining Treg competitive fitness in vivo, during repopulation of lymphopenic hosts and reconstitution of BM chimeras. Defective expansion of OX40-null Treg diminished their ability to suppress inflammation in a model of lymphopenia-driven colitis. OX40-mediated promotion of Treg fitness spanned beyond lymphopenic environments, as endogenous Treg in OX40-null mice showed decreased accumulation during thymic development, enhanced susceptibility to antibody-mediated depletion and defective turnover following thymectomy. In v…

Impact of thymus on the generation of immunocompetence and diversity of antigen-specific MHC-restricted cytotoxic T-lymphocyte precursors.

1981

Intrathymic tolerance induction: determination of tolerance to class II major histocompatibility complex antigens in maturing T lymphocytes by a bone…

1987

Two new experimental approaches were established to analyse the influence of the thymus on tolerance induction to major histocompatibility complex (MHC) antigens: The aim of the first experiment was to perform successful transplantation of adult allogeneic thymus tissue into nude mice, an attempt that has been unsuccessful in the past. Tolerance for the MHC genotype of a prospective thymus graft recipient (A) was induced in mice of strain B by injection of (A X B) splenocytes during the neonatal period. Adult thymic tissue obtained from these allogeneic donors (B) were grafted into the nude mice of strain A. The allogeneic thymus was accepted by the nude mice and immunoreconstitution was ac…

MAPK3 deficiency drives autoimmunity via DC arming.

2010

DC are professional APC that instruct T cells during the inflammatory course of EAE. We have previously shown that MAPK3 (Erk1) is important for the induction of T-cell anergy. Our goal was to determine the influence of MAPK3 on the capacity of DC to arm T-cell responses in autoimmunity. We report that DC from Mapk3(-/-) mice have a significantly higher membrane expression of CD86 and MHC-II and--when loaded with the myelin oligodendrocyte glycoprotein--show a superior capacity to prime naive T cells towards an inflammatory phenotype than Mapk3(+/+) DC. Nonetheless and as previously described, Mapk3(-/-) mice were only slightly but not significantly more susceptible to myelin oligodendrocyt…

Human interleukin-6 facilitates hepatitis B virus infection in vitro and in vivo.

2000

Abstract Background and aim. Research on hepatitis B virus (HBV) infection in vivo has been limited due to the absence of a suitable animal model. We have developed a human–mouse radiation chimera in which normal mice, preconditioned by lethal total body irradiation and radioprotected with SCID mouse bone marrow cells, are permissive for engraftment of human hematopoietic cells and solid tissues. This resulting human–mouse model, which comprises three genetically disparate sources of tissue, is therefore termed Trimera. This study was aimed at assessing the effect of human IL-6 on HBV infection in vivo in Trimera mice. Methods. Trimera mice were transplanted with human liver tissue fragment…