Antibody landscape against SARS-CoV-2 proteome revealed significant differences between non-structural/ accessory proteins and structural proteins

Li, Y.; Xu, Z.; Lei, Q.; Lai, D.; Hou, H.; Jiang, H.; Zheng, y.; Wang, X.; Wu, J.; Ma, M.; Zhang, B.; Chen, H.; Yu, C.; Xue, J.; Zhang, N.; Qi, H.; Guo, S.; Zhang, Y.; Lin, X.; Yao, Z.; Sheng, H.; Sun, Z.; Wang, F.; Fan, X.; Tao, S.-c.

The immunogenicity of SARS-CoV-2 proteome is largely unknown, especially for non-structural proteins and accessory proteins. Here we collected 2,360 COVID-19 sera and 601 control sera. We analyzed these sera on a protein microarray with 20 proteins of SARS-CoV-2, built an antibody response landscape for IgG and IgM. We found that non-structural proteins and accessory proteins NSP1, NSP7, NSP8, RdRp, ORF3b and ORF9b elicit prevalent IgG responses. The IgG patterns and dynamic of non-structural/ accessory proteins are different from that of S and N protein. The IgG responses against these 6 proteins are associated with disease severity and clinical outcome and declined sharply about 20 days after symptom onset. In non-survivors, sharp decrease of IgG antibodies against S1 and N protein before death was observed. The global antibody responses to non-structural/ accessory proteins revealed here may facilitate deeper understanding of SARS-CoV-2 immunology.