Deep immune profiling reveals early-stage and highly coordinated immune responses in mild COVID-19 patients

Abstract

While immunopathology has been widely studied in severe COVID-19 patients, immunoprotective factors in non-hospitalized patients have remained largely elusive. We systematically analyzed 484 peripheral immune cell signatures, various serological parameters and TCR repertoire in a longitudinal cohort of 63 mild and 15 hospitalized patients versus 14 asymptomatic and 26 control individuals. Within three days following PCR diagnosis, we observed coordinated responses of CD4 and CD8 T cells, various antigen presenting cells and antibody-secreting cells in mild, but not hospitalized COVID-19 patients. This early-stage SARS-CoV-2-specific response was predominantly characterized by substantially expanded clonotypes of CD4 and less of CD8 T cells. The early-stage responses of T cells and dendritic cells were highly predictive for later seroconversion and protective antibody levels after three weeks in mild non-hospitalized, but not in hospitalized patients. Our systemic analysis provides the first full picture and early-stage trajectory of highly coordinated immune responses in mild COVID-19 patients.

Third SARS-CoV-2 vaccination and breakthrough infections enhance humoral and cellular immunity against variants of concern

“…As a surrogate neutralization assay (34,35), multiplex serology assays V-PLEX SARS-CoV-2 Panel 23 (IgG, K15567U, Mesoscale, USA) and V-PLEX SARS-CoV-2 Panel 28 (IgG, K15614, Mesoscale, USA) were used, measuring the capability of plasma IgG to interfere with the interaction of the viral total spike-protein or RBD and the human ACE2 receptor. In total, SARS-CoV-2 variant-specific antibody inhibitory capacity (AIC) for IgG antibodies to eight spike antigens from WT and variants of SARS-CoV-2, including the (Alpha), B.1.351 (Beta), P.1 (Gamma), AY.3 (Delta), AY.4 (Delta), AY.4.2 (Delta) and BA.1 (Omicron) variants and to four RBD antigens for BA.2 (Omicron), BA.2.12.2 (Omicron), BA.3 (Omicron) and BA.4/5 (Omicron) were analyzed.…”