Abstract
Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection induces elevated levels of inflammatory cytokines, which are mainly produced by the innate response to the virus. The role of NK cells, which are potent producers of IFN-γ and cytotoxicity, has not been sufficiently studied in the setting of SARS-CoV-2 infection. We confirmed a different distribution of NK cell subsets in hospitalized COVID-19 patients despite their NK cell deficiency. The impairment of this innate defense is mainly focused on the cytotoxic capacity of the CD56dim NK cells. On the one hand, we found an expansion of the CD56dimCD16neg NK subset, lower cytotoxic capacities, and high frequencies of inhibitory 2DL1 and 2DL1/S1 KIR receptors in COVID-19 patients. On the other hand, the depletion of CD56dimCD16dim/bright NK cell subsets, high cytotoxic capacities, and high frequencies of inhibitory 2DL1 KIR receptors were found in COVID-19 patients. In contrast, no differences in the distribution of CD56bright NK cell subsets were found in this study. These alterations in the distribution and phenotype of NK cells might enhance the impairment of this crucial innate line of defense during COVID-19 infection.
Highlights
Published: 28 December 2021Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has continued as a worldwide pandemic since December 2019 [1,2]
NKfunction cell subtypes the killerinfection immunoglobulin-like receptors (KIRs) thatThe regulate their during and SARS-CoV-2 is still under investigation, since that regulate their function during SARS-CoV-2 infection is still under investigation, since research has been mainly focused on the adaptive immune responses
Impaired natural killer (NK) cell counts and functionality [18], as well as deficits in other members of the innate immunity research has been mainly focused on the adaptive immune responses
Summary
Published: 28 December 2021Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has continued as a worldwide pandemic since December 2019 [1,2]. Most infected patients recover spontaneously with mild symptoms, but others develop symptoms that require hospitalization, including acute respiratory distress syndrome, multiorgan failure, and death [4]. Immune responses to this disease have been extensively studied, but the role of innate immunity remains unclear [5,6]. The major subset of innate lymphocytes that plays an important role in early protection against viruses is natural killer (NK) cells [7,8,9] These are important in the regulation of the humoral and cellular adaptive immune responses. NK cells can be subdivided into subsets based on their relative surface expression of CD56 and CD16 receptors: the CD56dim CD16pos cell subset is considered to be the cytolytic cell subset, the CD56bright CD16neg cell subset includes the cytokine-producing cells, and the unconventional CD56dim CD16neg cell subset has been reported to expand in several clinical conditions [10,11,12]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
