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

Figure 2. Example of IFN-γ ELISPOT images corresponding to couple 2 (P2 and C2) in a study of intrafamilial exposure to SARS-CoV-2, France. T-cell–specific response was evaluated using peptide pools spanning SARS-CoV-2 structural protein (spike glycoprotein: N-terminal region = S1, C-terminal region = S2; N, M, and E proteins); SARS-CoV-2 accessory proteins (3A, 7A, 8, and 9B); and the N-terminal and C-terminal regions of the spike glycoprotein of common cold human coronaviruses 229 (ES1 and ES2) and OC43 (OS1 and OS2). All experiments were performed in duplicate with 4 wells of negative controls (cells with culture medium only) and 2 wells of positive controls (phytohemagglutinin) for each individual. P2 was reactive to all antigens tested except for SARS-CoV-2 proteins E and 8, whereas C2 was reactive to 1 SARS-CoV-2 protein only (S2) and to ES1, ES2, and OS2. C, contact; E, envelope small membrane protein; HCoV, human coronavirus; IFN-γ, interferon gamma; M, membrane protein; N, nucleoprotein; P, index patient; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.