SARS-CoV-2 has been identified as the causative agent of a global outbreak of
respiratory tract disease (COVID-19). In some
patients the
infection results in moderate to severe
acute respiratory distress syndrome (ARDS), requiring invasive
mechanical ventilation. High
serum levels of
IL-6 and an immune hyperresponsiveness referred to as a
cytokine storm have been associated with poor clinical outcome. Despite the large numbers of cases and deaths,
information on the
phenotype of
SARS-CoV-2-specific
T-cells is scarce. Here, we detected
SARS-CoV-2-specific CD4+ and CD8+
T cells in 100% and 80% of COVID-19
patients, respectively. We also detected low levels of
SARS-CoV-2-reactive
T-cells in 20% of the healthy controls, not previously exposed to
SARS-CoV-2 and indicative of cross-reactivity due to
infection with
common cold coronaviruses. Strongest
T-cell responses were directed to the
surface glycoprotein (spike, S), and
SARS-CoV-2-specific
T-cells predominantly produced effector and Th1
cytokines, although Th2 and Th17
cytokines were also detected. Collectively, these data stimulate further studies into the
role of
T-cells in COVID-19, support
vaccine design and facilitate the evaluation of
vaccine candidate immunogenicity. SummaryCOVID-19 is associated with
lymphopenia and
cytokine storm, but there is a scarcity of
information on specific
cellular immune responses to
SARS-CoV-2. Here, we characterized
SARS-CoV-2-specific CD4+ and CD8+
T-cells in
patients hospitalized with
acute respiratory distress syndrome (ARDS).