Article
Asymptomatic and symptomatic SARS-CoV-2 infections elicit polyfunctional antibodies

https://doi.org/10.1016/j.xcrm.2021.100275Get rights and content
Under a Creative Commons license
open access

Highlights

  • COVID-19 patient sera activate the complement system and kill infected cells by ADCC

  • Asymptomatic and symptomatic individuals harbor polyfunctional antibodies

  • Antibody levels and functions are slightly lower in asymptomatic individuals

  • Functions of anti-Spike antibodies have similar kinetics of induction and contraction

Summary

Many SARS-CoV-2-infected individuals remain asymptomatic. Little is known about the extent and quality of their antiviral humoral response. Here, we analyze antibody functions in 52 asymptomatic infected individuals, 119 mildly symptomatic, and 21 hospitalized patients with COVID-19. We measure anti-spike immunoglobulin G (IgG), IgA, and IgM levels with the S-Flow assay and map IgG-targeted epitopes with a Luminex assay. We also evaluate neutralization, complement deposition, and antibody-dependent cellular cytotoxicity (ADCC) using replication-competent SARS-CoV-2 or reporter cell systems. We show that COVID-19 sera mediate complement deposition and kill infected cells by ADCC. Sera from asymptomatic individuals neutralize the virus, activate ADCC, and trigger complement deposition. Antibody levels and functions are lower in asymptomatic individuals than they are in symptomatic cases. Antibody functions are correlated, regardless of disease severity. Longitudinal samplings show that antibody functions follow similar kinetics of induction and contraction. Overall, asymptomatic SARS-CoV-2 infection elicits polyfunctional antibodies neutralizing the virus and targeting infected cells.

Keywords

SARS-CoV-2
ADCC
complement
asymptomatic
antibody

Cited by (0)

11

These authors contributed equally

12

These authors contributed equally

13

Twitter: @virus_immunity

14

Lead contact