SARS Coronavirus Fusion Peptide-Derived Sequence Suppresses Collagen-Induced Arthritis in DBA/1J Mice

Shen, Zu T.; Sigalov, Alexander B.

The severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) is the etiological agent of SARS that represents the life-threatening disease associated with a mortality of about 10% 1 . Lymphopenia is observed in most SARS patients with T-helper (CD4 + ) and T-cytotoxic/suppressor (CD8 + ) cell levels reduced in 100% and 87% of the patients, respectively 2 . Most of these patients have reduced CD4 + and CD8 + cell counts during the early phase of the disease with the lowest cell count values on day 5 and 7 from disease onset 3, 4 . Like other enveloped viruses encoding class I viral fusion proteins such as human immunodeficiency virus (HIV) 5 and Ebola and avian sarcoma viruses 6 , SARS-CoV is presumed to use membrane fusion mechanisms for viral entry 7, 8 . It has been shown that the SARS-CoV viral spike protein 2 (S2) is a class I viral fusion protein that is responsible for driving viral and target T cell membrane fusion 9 . The putative SARS-CoV fusion peptide (FP) has been identified at the N terminus of the SARS-CoV S2 subunit 10 . The fusogenic activity of this peptide has been shown to depend on its amino acid sequence 10 .