The spike protein of the SARS-CoV-2 virus is the foremost target for the designing of vaccines and therapeutic antibodies and also acts as a crucial antigen in the assessment of COVID-19 immune responses. The enveloped viruses; such as SARS-CoV-2, Human Immunodeficiency Virus-1 (HIV-1) and influenza, often hijack host-cell glycosylation pathways and influence pathobiology and immune selection. These glycan motifs can lead to either immune evasion or viral neutralization by the production of cross-reactive antibodies that can lead to antibody-dependent enhancement (ADE) of infection. Potential cross-protection from influenza vaccine has also been reported in COVID-19 infected individuals in several epidemiological studies recently; however, the scientific basis for these observations remains elusive. Herein, we show that the anti-SARS-CoV2 antibodies cross-reacts with the Hemagglutinin (HA) protein. This phenomenon is common to both the sera from convalescent SARS-CoV-2 donors and spike immunized mice, although these antibodies were unable to cross-neutralize, suggesting the presence of a non-neutralizing antibody response. Epitope mapping suggests that the cross-reactive antibodies are targeted towards glycan epitopes of the SARS-CoV-2 spike and HA. Overall, our findings address the cross-reactive responses, although non-neutralizing, elicited against RNA viruses and warrant further studies to investigate whether such non-neutralizing antibody responses can contribute to effector functions such as antibody-dependent cellular cytotoxicity (ADCC) or ADE.
【저자키워드】 SARS-CoV2, Neutralizing antibodies, Influenza, cross-reactivity, HIV-1, Glycan dependent, 【초록키워드】 COVID-19, SARS-CoV-2, Vaccine, cross-protection, antibody, Antibody-dependent enhancement, Human, Infection, immune, Spike protein, Antigen, Protein, immune evasion, immune responses, sera, therapeutic, hemagglutinin, ADCC, viral neutralization, RNA virus, convalescent, ADE, epitope, function, antibody-dependent cellular cytotoxicity, Donor, cross-neutralize, cross-reactive, cross-reactive antibody, observation, Epidemiological study, immunized mice, motif, responses, reported, contribute, elicited, cross-react, Potential, COVID-19 infected individual, glycosylation pathway, non-neutralizing antibody, non-neutralizing antibody response, the SARS-CoV-2, the SARS-CoV-2 virus, 【제목키워드】 SARS CoV-2, Influenza virus, glycan, polyclonal antibody,