Volume 27, Number 1—January 2021
Research
Intrafamilial Exposure to SARS-CoV-2 Associated with Cellular Immune Response without Seroconversion, France
Figure 3

Figure 3. Frequency of specific T cells directed against spike glycoprotein antigens of the 2 common cold HCoVs 229E and OC43 in study of intrafamilial exposure to SARS-CoV-2, France. A) Index patients (n = 11); B) seronegative partners of index patients (n = 11); C) unexposed healthy controls (n = 10). Spot counts of common cold human coronaviruses-specific T cells were measured by interferon-gamma ELISPOT assay. All experiments were performed in duplicate. Data are shown as means and standard deviations of spot counts of interferon-gamma–producing T cells per 1 million CD3+ cells. T-cell secretion of IFN-γ was determined in response to peptide pools spanning the N-terminal and the C-terminal regions of the spike glycoprotein of HCoV 229E (ES1 and ES2 subpools) and HCoV OC43 (OS1 and OS2 subpools). Each color corresponds to 1 antigen subpool. C, contact; HCoV, human coronavirus; HD, healthy blood donor (control); P, index patient; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.