AUTHOR=Johnson Deborah K. , Magoffin Wyatt , Myers Sheldon J. , Finnell Jordan G. , Hancock John C. , Orton Taylor S. , Persaud Stephen P. , Christensen Kenneth A. , Weber K. Scott TITLE=CD4 Inhibits Helper T Cell Activation at Lower Affinity Threshold for Full-Length T Cell Receptors Than Single Chain Signaling Constructs JOURNAL=Frontiers in Immunology VOLUME=11 YEAR=2021 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.561889 DOI=10.3389/fimmu.2020.561889 ISSN=1664-3224