The innate immune system in allograft rejection and tolerance.

Indoleamine 2,3-Dioxygenase and Immunological Tolerance during Pregnancy

Indoleamine 2,3-dioxygenase (IDO), an enzyme involved in the catabolism of tryptophan, is expressed by a variety of cells and tissues such as macrophages, dendritic cells, cells of the endocrine system and by the placenta. IFN- γ is the main inducer of this enzyme. IDO acts as an important defense mechanism of innate immunity against pathogens. It also has tumor suppressive activity and prolong...

Dendritic Cells in Transplant Tolerance

Dendritic cells (DCs) are a heterogeneous family of professional APCs involved in priming adaptive immune responses. Donor DCs (direct pathway of allorecognition) and recipient DCs presenting processed donor major histocompatibility complex (MHC) as peptides (indirect pathway of allorecognition) participate actively in graft rejection by stimulating recipient T cell responses following organ tr...

Rejection and Tolerance The Innate Immune System in Allograft

Absence of MyD88 signaling induces donor-specific kidney allograft tolerance.

Toll-like receptors (TLRs) play a fundamental role in innate immunity and provide a link between innate and adaptive responses to an allograft; however, whether the development of acute and chronic allograft rejection requires TLR signaling is unknown. Here, we studied TLR signaling in a fully MHC-mismatched, life-sustaining murine model of kidney allograft rejection. Mice deficient in the TLR ...

Innate Immunity and Resistance to Tolerogenesis in Allotransplantation

The development of immunosuppressive drugs to control adaptive immune responses has led to the success of transplantation as a therapy for end-stage organ failure. However, these agents are largely ineffective in suppressing components of the innate immune system. This distinction has gained in clinical significance as mounting evidence now indicates that innate immune responses play important ...