B7-H5 costimulates human T cells via CD28H

The B7/CD28 family has profound modulatory effects in immune responses and constitutes an important target for the development of novel therapeutic drugs against human diseases. Here we describe a new CD28 homologue (CD28H) that has unique functions in the regulation of the human immune response and...

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Bibliographic Details
Main Authors: Zhu, Yuwen, Yao, Sheng, Iliopoulou, Bettina P., Han, Xue, Augustine, Mathew M., Xu, Haiying, Phennicie, Ryan T., Flies, Sarah J., Broadwater, Megan, Ruff, William, Taube, Janis M., Zheng, Linghua, Luo, Liqun, Zhu, Gefeng, Chen, Jianzhu, Chen, Lieping
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:en_US
Published: Nature Publishing Group 2014
Online Access:http://hdl.handle.net/1721.1/84623
https://orcid.org/0000-0002-5687-6154
Description
Summary:The B7/CD28 family has profound modulatory effects in immune responses and constitutes an important target for the development of novel therapeutic drugs against human diseases. Here we describe a new CD28 homologue (CD28H) that has unique functions in the regulation of the human immune response and is absent in mice. CD28H is constitutively expressed on all naive T cells. Repetitive antigenic exposure, however, induces a complete loss of CD28H on many T cells, and CD28H negative T cells have a phenotype of terminal differentiation and senescence. After extensive screening in a receptor array, a B7-like molecule, B7 homologue 5 (B7-H5), was identified as a specific ligand for CD28H. B7-H5 is constitutively found in macrophages and could be induced on dendritic cells. The B7-H5/CD28H interaction selectively costimulates human T-cell growth and cytokine production via an AKT-dependent signalling cascade. Our study identifies a novel costimulatory pathway regulating human T-cell responses.