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Structural and Biophysical Insights into the TCR?? Complex in Chickens.

ABSTRACT: In this work, chicken HPAIV H5N1 epitope-specific TCR?? (ch-TCR??) was isolated and its structure was determined. The C? domain of ch-TCR?? does not exhibit the typical structure of human TCR??, and the DE loop extends outward, resulting in close proximity between the C? domain of ch-TCR?? and CD3??/?. The FG loop of the C? domain of ch-TCR?? is shorter. The changes in the C domains of ch-TCR?? and the difference in chicken CD3??/? confirm that the complexes formed by TCR?? and CD3??/? differ from those in humans. In the chicken complex, a positively charged cleft is formed between the two CDR3 loops that might accommodate the acidic side chains of the chicken pMHC-I-bound HPAIV epitope intermediate portion oriented toward ch-TCR??. This is the first reported structure of chicken TCR??, and it provides a structural model of the ancestral TCR system in the immune synapses between T cells and antigen-presenting cells in lower vertebrates.

SUBMITTER: Zhang L

PROVIDER: S-EPMC7711287 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature

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Structural and Biophysical Insights into the TCRαβ Complex in Chickens.

Zhang Lijie L Liu Yanjie Y Meng Geng G Liang Ruiying R Zhang Bing B Xia Chun C

iScience 20201120 12

In this work, chicken HPAIV H5N1 epitope-specific TCRαβ (ch-TCRαβ) was isolated and its structure was determined. The Cα domain of ch-TCRαβ does not exhibit the typical structure of human TCRαβ, and the DE loop extends outward, resulting in close proximity between the Cα domain of ch-TCRαβ and CD3εδ/γ. The FG loop of the Cβ domain of ch-TCRαβ is shorter. The changes in the C domains of ch-TCRαβ and the difference in chicken CD3εδ/γ confirm that the complexes formed by TCRαβ and CD3εδ/γ differ fr ...[more]

PMID: 33305184

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