Toll-like receptor pathway evolution in deuterostomes
| Autor: | Michael G. Tassia, Kenneth M. Halanych, Nathan V. Whelan |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Toll-Like Receptor Pathway Zoology Adaptive Immunity Biology Evolution Molecular Mice 03 medical and health sciences Immune system Molecular evolution Phylogenetics Animals Humans Cell Lineage Phylogeny Armadillo Domain Proteins Multidisciplinary Innate immune system Deuterostome Toll-Like Receptors Bayes Theorem Biological Sciences biology.organism_classification Acquired immune system Invertebrates Immunity Innate Cytoskeletal Proteins 030104 developmental biology Evolutionary biology Myeloid Differentiation Factor 88 Drosophila Transcriptome Cell Adhesion Molecules Signal Transduction |
| Zdroj: | Proceedings of the National Academy of Sciences. 114:7055-7060 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1617722114 |
| Popis: | Animals have evolved an array of pattern-recognition receptor families essential for recognizing conserved molecular motifs characteristic of pathogenic microbes. One such family is the Toll-like receptors (TLRs). On pathogen binding, TLRs initiate specialized cytokine signaling catered to the class of invading pathogen. This signaling is pivotal for activating adaptive immunity in vertebrates, suggesting a close evolutionary relationship between innate and adaptive immune systems. Despite significant advances toward understanding TLR-facilitated immunity in vertebrates, knowledge of TLR pathway evolution in other deuterostomes is limited. By analyzing genomes and transcriptomes across 37 deuterostome taxa, we shed light on the evolution and diversity of TLR pathway signaling elements. Here, we show that the deuterostome ancestor possessed a molecular toolkit homologous to that which drives canonical MYD88-dependent TLR signaling in contemporary mammalian lineages. We also provide evidence that TLR3-facilitated antiviral signaling predates the origin of its TCAM1 dependence recognized in the vertebrates. SARM1, a negative regulator of TCAM1-dependent pathways in vertebrates, was also found to be present across all major deuterostome lineages despite the apparent absence of TCAM1 in invertebrate deuterostomes. Whether the presence of SARM1 is the result of its role in immunity regulation, neuron physiology, or a function of both is unclear. Additionally, Bayesian phylogenetic analyses corroborate several lineage-specific TLR gene expansions in urchins and cephalochordates. Importantly, our results underscore the need to sample across taxonomic groups to understand evolutionary patterns of the innate immunity foundation on which complex immunological novelties arose. |
| Databáze: | OpenAIRE |
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