As T cell immunity depends critically on peptide presentation by MHC, Wei and Yewdell leave no stone unturned by compiling evidence that an alternative translational system may exist which plays a significant role in generating the peptide targets of immune surveillance. They cite multiple examples of non-canonical translation (alternative start codons, nuclear intron translation, nonsense-mediated decay) and ribosome heterogeneity (distinct subunit composition and post-translational modifications), and posit that Ribo-Seq may provide much needed clarity.

The MHC class I antigen presentation pathway enables T cell immunosurveillance of cancer cells, viruses and other intracellular pathogens. Rapidly degraded newly synthesized proteins (DRiPs) are a major source of self-, and particularly, viral antigenic peptides. A number of findings support the idea that a substantial fraction of antigenic peptides are synthesized by "immunoribosomes", a subset of translating ribosomes that generate class I peptides with enhanced efficiency. Here, we review the evidence for the immunoribosome hypothesis.

Author Info: (1) Cellular Biology Section, Laboratory of Viral Diseases, NIAID, Bethesda, MD, United States. (2) Cellular Biology Section, Laboratory of Viral Diseases, NIAID, Bethesda, MD, United

Author Info: (1) Cellular Biology Section, Laboratory of Viral Diseases, NIAID, Bethesda, MD, United States. (2) Cellular Biology Section, Laboratory of Viral Diseases, NIAID, Bethesda, MD, United States. Electronic address: jyewdell@nih.gov.

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