We reveal TAPBPR is a peptide exchange catalyst which restricts the peptide repertoire presented by MHC I on cells, a finding which has important implications for all aspects of immune recognition.

The recently discovered peptide editor TAPBPR binds to UDP-glucose:glycoprotein glucosyltransferase 1 to provide quality control in the antigen presentation pathway by facilitating the reglucosylation of the glycan on MHC class I molecules.

The number of different peptides presented by major histocompatibility complex class I molecules to the immune system's T lymphocytes is inversely correlated with cell surface expression and is strongly associated with the response to infectious disease.

Immunopeptidomics in combination with novel cell-based assays that assess peptide exchange reveal a critical role for the K22-D35 loop of TAPBPR in mediating peptide dissociation and peptide selection on MHC I.

Downregulation of mitochondrial activity by immunosuppressive tumor-derived soluble factors leads to systemic unresponsiveness to the PD-1 blockade therapy.

A generally applicable two-hybrid assay demonstrates that MHC class I heavy chains devoid of beta-2 microglobulin associate within and across allotypes, with implications for endocytosis and autoimmunity.

A dedicated structural element facilitates chaperone and antigenic peptide selector function of TAP-associated glycoprotein, a major quality assurance auditor in adaptive immunity.

MR1T cells are human polyclonal T cells endowed with diverse effector functions in response to endogenous antigens presented by MHC-class 1-related molecule, MR1.

A near-complete flux balance analysis model of a minimal cell demonstrates the high essentiality of its metabolic genes, agrees well with experimental essentiality data and suggests some further gene removals.

A recently discovered contagious cancer in the Tasmanian devil has the potential to become widespread in the population due to the loss of histocompatibility antigens that are allogeneic to its hosts.