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Cytotoxic Lymphocyte-Monocyte Complex Reflects the Dynamics of Coronavirus Disease 2019 Systemic Immune Response
Jiajia Lin1,2, Shiyu Bai2, Liheng He1
1Department of Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine.
Abstract:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes a variety of clinical manifestations, many of which originate from altered immune responses, either locally or systemically. Immune cell cross-talk occurs mainly in lymphoid organs. However, systemic cell interaction specific to coronavirus disease 2019 has not been well characterized. Here, by employing single-cell RNA sequencing and imaging flow cytometry analysis, we unraveled, in peripheral blood, a heterogeneous group of cell complexes formed by the adherence of CD14+ monocytes to different cytotoxic lymphocytes, including SARS-CoV-2-specific CD8+ T cells, γδ T cells, and natural killer T cells. These lymphocytes attached to CD14+ monocytes that showed enhanced inflammasome activation and pyroptosis-induced cell death in progression stage; in contrast, in the convalescent phase, CD14+ monocytes with elevated antigen presentation potential were targeted by cytotoxic lymphocytes, thereby restricting the excessive immune activation. Collectively, our study reports previously unrecognized cell-cell interplay in the SARS-CoV-2-specific immune response, providing new insight into the intricacy of dynamic immune cell interaction representing antiviral defense.
Insights
Researchers discovered unique cell interactions in the blood of COVID-19 patients. Cytotoxic lymphocytes attach to monocytes, influencing immune responses during infection and recovery, revealing new insights into antiviral defense.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to diverse clinical outcomes driven by immune dysregulation.
- While immune cell communication is known in lymphoid organs, systemic interactions in coronavirus disease 2019 (COVID-19) remain poorly understood.
Purpose of the Study:
- To characterize previously unrecognized systemic cell-cell interactions in COVID-19 patients.
- To investigate the role of these interactions in the immune response to SARS-CoV-2.
Main Methods:
- Single-cell RNA sequencing
- Imaging flow cytometry analysis of peripheral blood
Main Results:
- Identified heterogeneous cell complexes in peripheral blood, comprising CD14+ monocytes adhered to cytotoxic lymphocytes (including SARS-CoV-2-specific CD8+ T cells, γδ T cells, and natural killer T cells).
- Observed enhanced inflammasome activation and pyroptosis in CD14+ monocytes during the progression stage of infection.
- Found cytotoxic lymphocytes targeting CD14+ monocytes with increased antigen presentation potential during the convalescent phase, mitigating excessive immune activation.
Conclusions:
- Reported novel cell-cell interplay within the SARS-CoV-2-specific immune response.
- Provided new insights into the dynamic immune cell interactions critical for antiviral defense.
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