Transcriptomic Characteristics and Impaired Immune Function of Patients Who Retest Positive for SARS-CoV-2 RNA (preprint)

Background: The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has gradually become a global public health crisis. Some patients who have recovered from COVID-19 subsequently tested positive again for SARS-CoV-2 after discharge (retesting-positive, RTP). However, the underlying mechanism is unknown.Methods: Here, 30 RTP patients, 20 convalescent patients, and 20 healthy controls were enrolled for analysis of the immunological characteristics of their peripheral blood mononuclear cells (PBMCs). Furthermore, we sought to comprehensively characterize the transcriptional changes in the three groups by transcriptome sequencing.Findings: It was found that the absolute numbers of CD4+ T cells, CD8+ T cells, and NK cells were not decreased remarkably, while the expression of activation markers on these cells was significantly decreased in RTP patients. Furthermore, the percentage of granzyme B-producing T cells was also decreased in RTP patients compared with that in convalescent patients. Moreover, the high expression of inhibitor of differentiation-1 (ID1) and the low expression of IFITM10 may be associated with the insufficient activation of immune cells and RTP occurrence.Interpretation: Our findings provide insights into the impaired immune function and pathogenesis of RTP occurrence in COVID-19, which may contribute to the development of immunotherapy for RTP patients.Funding Statement: This work was supported by China National Center for Biotechnology Development (2020YFC0843800 and 2020YFC0846800), Ministry of Science and Technology of China (2020TFC0844100), and China Postdoctoral Science Foundation (2020T130112ZX).Declaration of Interests: The authors declare no potential conflict of interest.Ethics Approval Statement: The studies were approved by the Ethics Committee of the First Affiliated Hospital of the University of Science & Technology of China (2020-XG(H)-005) and Peking University First Hospital (2020-Research-112) for Emerging Infectious Diseases. Experiments were conducted in accordance with the ethical guidelines of the 1975 Declaration of Helsinki, the Principles of Good Clinical Practice, and the guidelines of China’s regulatory requirements.

Aberrant pathogenic GM-CSF+ T cells and inflammatory CD14+CD16+ monocytes in severe pulmonary syndrome patients of a new coronavirus (preprint)

Pathogenic human coronavirus infections, such as severe acute respiratory syndrome CoV (SARS-CoV) and Middle East respiratory syndrome CoV (MERS-CoV), cause high morbidity and mortality 1,2. Recently, a severe pneumonia-associated respiratory syndrome caused by a new coronavirus was reported at December 2019 (2019-nCoV) in the city Wuhan, Hubei province, China3-5, which was also named as pneumonia-associated respiratory syndrome (PARS)6. Up to 9th of February 2020, at least 37, 251 cases have been reported with 812 fatal cases according to the report from China CDC. However, the immune mechanism that potential orchestrated acute mortality from patients of 2019-nCoV is still unknown. Here we show that after the 2019-nCoV infection, CD4+T lymphocytes are rapidly activated to become pathogenic T helper (Th) 1 cells and generate GM-CSF etc. The cytokines environment induces inflammatory CD14+CD16+ monocytes with high expression of IL-6 and accelerates the inflammation. These aberrant and excessive immune cells may enter the pulmonary circulation in huge numbers and play an immune damaging role to causing lung functional disability and quick mortality. Our results demonstrate that excessive non-effective host immune responses by pathogenic T cells and inflammatory monocytes may associate with severe lung pathology. Therefore, we suggest that monoclonal antibody that targets the GM-CSF or interleukin 6 receptor may potentially curb immunopathology caused by 2019-nCoV and consequently win more time for virus clearance.

Pathogenic T cells and inflammatory monocytes incite inflammatory storm in severe COVID-19 patients

Pathogenic human coronavirus infections, such as severe acute respiratory syndrome CoV (SARS-CoV) and Middle East respiratory syndrome CoV (MERS-CoV), cause high morbidity and mortality1, 2 . Recently, a severe pneumonia-associated respiratory syndrome caused by a new coronavirus (SARS-CoV-2) was reported at December 2019 in the city Wuhan, Hubei province, China3, 4, 5, which was also named as pneumonia-associated respiratory syndrome (PARS)6 and can cause coronavirus disease 2019 (COVID-19) to seriously endanger human health. Up to 24th of February 2020, at least 77779 cases have been reported with 2666 fatal cases according to the report from China CDC. However, the immune mechanism that potential orchestrated acute mortality from COVID-19 patients is still unknown. Here we show that after the SARS-CoV-2 infection, CD4+ T lymphocytes are rapidly activated to become pathogenic T helper (Th) 1 cells and generate GM-CSF etc. The cytokines environment induces inflammatory CD14+CD16+ monocytes with high expression of IL-6 and accelerate the inflammation. Given that large amount of inflammatory cells infiltrations have been observed in lungs from severe COVID-19 patients7, 8, these aberrant pathogenic Th1 cells and inflammatory monocytes may enter the pulmonary circulation in huge numbers and play an immune damaging role to causing lung functional disability and quick mortality. Our results demonstrate that excessive non-effective host immune responses by pathogenic T cells and inflammatory monocytes may associate with severe lung pathology. Thus, we suggest that monoclonal antibodies targeting GM-CSF or interleukin 6 may be effective in blocking inflammatory storms and, therefore, be a promising treatment of severe COVID-19 patients