Vaccine. 2016 Apr 12;34(17):2008-14. doi: 10.1016/j.vaccine.2016.02.063. Epub 2016 Mar 5.

Memory T cell responses targeting the SARS coronavirus persist up to 11 years post-infection.

Ng OW¹, Chia A², Tan AT², Jadi RS¹, Leong HN³, Bertoletti A⁴, Tan YJ⁵.

Author information

1: Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore.
2: Program Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore.
3: Singapore General Hospital, Singapore.
4: Program Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore; Viral Hepatitis Laboratory, Singapore Institute for Clinical Sciences, Agency of Science Technology and Research (A*STAR), Singapore.
5: Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore; Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore. Electronic address: Yee_Joo_TAN@NUHS.edu.sg.

Abstract

Severe acute respiratory syndrome (SARS) is a highly contagious infectious disease which first emerged in late 2002, caused by a then novel human coronavirus, SARS coronavirus (SARS-CoV). The virus is believed to have originated from bats and transmitted to human through intermediate animals such as civet cats. The re-emergence of SARS-CoV remains a valid concern due to the continual persistence of zoonotic SARS-CoVs and SARS-like CoVs (SL-CoVs) in bat reservoirs. In this study, the screening for the presence of SARS-specific T cells in a cohort of three SARS-recovered individuals at 9 and 11 years post-infection was carried out, and all memory T cell responses detected target the SARS-CoV structural proteins. Two CD8(+) T cell responses targeting the SARS-CoV membrane (M) and nucleocapsid (N) proteins were characterized by determining their HLA restriction and minimal T cell epitope regions. Furthermore, these responses were found to persist up to 11 years post-infection. An absence of cross-reactivity of these CD8(+) T cell responses against the newly-emerged Middle East respiratory syndrome coronavirus (MERS-CoV) was also demonstrated. The knowledge of the persistence of SARS-specific celullar immunity targeting the viral structural proteins in SARS-recovered individuals is important in the design and development of SARS vaccines, which are currently unavailable.