Origins of the RAG Transposome and the MHC.

Origins of the RAG Transposome and the MHC. Trends Immunol. 2020 May 25;: Authors: Tsakou-Ngouafo L, Paganini J, Kaufman J, Pontarotti P Abstract How innate immunity gave rise to adaptive immunity in vertebrates remains unknown. We propose an evolutionary scenario beginning with pathogen-associated molecular pattern(s) (PAMPs) being presented by molecule(s) on one cell to specific receptor(s) on other cells, much like MHC molecules and T cell receptors (TCRs). In this model, mutations in MHC-like molecule(s) that bound new PAMP(s) would not be recognized by original TCR-like molecule(s), and new MHC-like gene(s) would be lost by neutral drift. Integrating recombination activating gene (RAG) transposon(s) in a TCR-like gene would result in greater recognition diversity, with new MHC-like variants recognized and selected, along with a new RAG/TCR-like system. MHC genes would be selected to present many peptides, through multigene families, allelic polymorphism, and peptide-binding promiscuity. PMID: 32467030 [PubMed - as supplied by publisher]
Source: Trends in Immunology - Category: Allergy & Immunology Authors: Tags: Trends Immunol Source Type: research