Although antibody escape is observed in emerging severe acute respiratory syndrome coronavirus 2 variants, T cell escape, especially after the global circulation of BA.2.86/JN.1, is unexplored. Here we demonstrate that T cell evasion exists in epitope hotspots spanning BA.2.86/JN.1 mutations. The newly emerging Q229K at this conserved nucleocapsid protein site impairs HLA-A2 epitope hotspot recognition. The association between HLA-A24 convalescents and T cell immune escape points to the spike (S) protein epitope S 448-456 NYNYLYRLF, with multiple mutations from Delta to JN.1, including L452Q, L452R, F456L, N450D and L452W, and N450D, L452W and L455S. A cliff drop of immune responses was observed for S 448-456 NYNYRYRLF (Delta/BA.5.2) and S 448-456 NYDYWYRSF (JN.1), but with immune preservation of S 448-456 NYDYWYRLF (BA.2.86). Structural analyses showed that hydrophobicity exposure determines the pronounced escape of L452R and L455S mutants, which was further confirmed by T cell receptor binding. This study highlights the characteristics and molecular mechanisms of the T cell immune escape for JN.1 and provides new insights into understanding the dominant circulation of variants, from the viewpoint of cytotoxic T cell evasion.
Organizational Affiliation: 
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.
Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China.
School of Ophthalmology & Optometry, Wenzhou Medical University, Wenzhou, China.
Collaborative Innovation Centre of Regenerative Medicine and Medical BioResource Development and Application Co-constructed by the Province and Ministry, Guangxi Medical University, Nanning, China.
Beijing Ditan Hospital, Capital Medical University, Beijing, China.
Beijing Institute of Infectious Diseases, Beijing, China.
Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China.
CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. zhaoyz@ivdc.chinacdc.cn.
NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. zhaoyz@ivdc.chinacdc.cn.
Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China. zhaoyz@ivdc.chinacdc.cn.
The Fifth Hospital of Shijiazhuang, Shijiazhuang, China. 13933880581@163.com.
Beijing Ditan Hospital, Capital Medical University, Beijing, China. songruii@hotmail.com.
NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. gaof@im.ac.cn.
School of Ophthalmology & Optometry, Wenzhou Medical University, Wenzhou, China. gaof@im.ac.cn.
Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China. gaof@im.ac.cn.
CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, China. gaof@im.ac.cn.
The D. H. Chen School of Universal Health, Zhejiang University, Hangzhou, China. gaof@im.ac.cn.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. liujun@ivdc.chinacdc.cn.
NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China. liujun@ivdc.chinacdc.cn.
School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China. liujun@ivdc.chinacdc.cn.
Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, Beijing, China. liujun@ivdc.chinacdc.cn.