Ndfip1 mediates peripheral tolerance to self and exogenous antigen by inducing cell cycle exit in responding CD4⁺T cells

Abstract

The NDFIP1 (neural precursor cell expressed, developmentally downregulated protein 4 family-interacting protein 1) adapter for the ubiquitin ligase ITCH is genetically linked to human allergic and autoimmune disease, but the cellular mechanism by which these proteins enable foreign and self-antigens to be tolerated is unresolved. Here, we use two unique mouse strains-an Ndfip1-YFP reporter and an Ndfip1-deficient strain-to show that Ndfip1 is progressively induced during T-cell differentiation and activation in vivo and that its deficiency causes a cell-autonomous, Forkhead box P3-independent failure of peripheral CD4+ T-cell tolerance to self and exogenous antigen. In small cohorts of antigen-specific CD4 + cells responding in vivo, Ndfip1 was necessary for tolerogen-reactive T cells to exit cell cycle after one to five divisions and to abort Th2 effector differentiation, defining a step in peripheral tolerance that provides insights into the phenomenon of T-cell anergy in vivo and is distinct from the better understood process of Bcl2-interacting mediator of cell death-mediated apoptosis. Ndfip1 deficiency precipitated autoimmune pancreatic destruction and diabetes; however, this depended on a further accumulation of nontolerant anti-self T cells from strong stimulation by exogenous tolerogen. These findings illuminate a peripheral tolerance checkpoint that aborts T-cell clonal expansion against allergens and autoantigens and demonstrate how hypersensitive responses to environmental antigens may trigger autoimmunity.immunological tolerance | allergy | T lymphocyte | Interleukin-4 | Aire (Autoimmune Regulator)

The Ubiquitin Ligase Adaptor NDFIP1 Selectively Enforces a CD8+ T Cell Tolerance Checkpoint to High-Dose Antigen

“…Bystander CD8 + T cell activation confounds analysis of any CD8 + T cell-intrinsic role of NDFIP1 in Ndfip1 kru/km mice homozygous for an NDFIP1-truncating null mutation (Altin et al, 2014). Activated or effector CD44 hi CD8 + T cell accumulation was reduced in Ndfip1 kru/kru mice bearing a rearranged TCR transgene encoding OT-I, an ovalbumin (OVA)-specific major histocompatibility complex class I (MHC class I)-restricted TCR, and was abolished in Rag1 −/− OT-I Ndfip1 kru/kru mice in which no other TCRs can be expressed (Figure S1A).…”

“…NDFIP1, a Golgi and intracellular vesicle localized transmembrane protein, plays a selective checkpoint role within CD4 + T cells (Altin et al, 2014; Oliver et al, 2006). NDFIP1 binds to and activates HECT-type E3 ubiquitin ligases (Mund and Pelham, 2009; Riling et al, 2015), thereby triggering ubiquitin-medi- ated degradation of key T cell differentiation regulators, including JUNB, RORγt, and JAK1 (Layman et al, 2017b; O’Leary et al, 2016; Oliver et al, 2006).…”

“…In T cells, NDFIP1 primarily recruits and activates the HECT-type E3 ligase ITCH (Oliver et al, 2006). Ndfip1 -deficient CD4 + T cells resist both in vitro anti- CD3 induced anergy and in vivo tolerance to low or high antigen levels because of excessive interleukin (IL)-2 production, a failure to exit the cell cycle, and aberrant differentiation into T helper (Th) 2 or Th17 cells (Altin et al, 2014; Layman et al, 2017b; Oliver et al, 2006; Ramos-Hernández et al, 2013). Mice lacking NDFIP1 develop a fatal T cell-mediated inflammatory disease associated with T cell activation, regulatory T cell dysfunction, and Th2-mediated organ pathology (Altin et al, 2014; Beal et al, 2011; Layman et al, 2017a; Oliver et al, 2006).…”

“…Ndfip1 -deficient CD4 + T cells resist both in vitro anti- CD3 induced anergy and in vivo tolerance to low or high antigen levels because of excessive interleukin (IL)-2 production, a failure to exit the cell cycle, and aberrant differentiation into T helper (Th) 2 or Th17 cells (Altin et al, 2014; Layman et al, 2017b; Oliver et al, 2006; Ramos-Hernández et al, 2013). Mice lacking NDFIP1 develop a fatal T cell-mediated inflammatory disease associated with T cell activation, regulatory T cell dysfunction, and Th2-mediated organ pathology (Altin et al, 2014; Beal et al, 2011; Layman et al, 2017a; Oliver et al, 2006). NDFIP1 likely plays similar roles in humans, because NDFIP1 polymorphisms and ITCH deficiency are associated with inflammatory and autoimmune diseases (Ferreira et al, 2011; Franke et al, 2010; Hu et al, 2011; International Multiple Sclerosis Genetics et al, 2011; Lohr et al, 2010; Ramon et al, 2011).…”

“…Despite elevated activated effector CD8 + T cells in Ndfip1 −/− mice and high Ndfip1 expression in CD8 + T cells (Altin et al, 2014), CD8 + T cell activation in Ndfip1 −/− mice is largely an indirect consequence of excessive IL-4 production by Ndfip1 mutant CD4 + T cells (Altin et al, 2014; Kurzweil et al, 2014). However, excessive bystander inflammation in Ndfip1 −/− mice may mask a CD8 + T cell-intrinsic role for NDFIP1.…”