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1.
Nat Commun ; 13(1): 2028, 2022 04 19.
Article in English | MEDLINE | ID: covidwho-1805608

ABSTRACT

Dysfunctional immune responses contribute critically to the progression of Coronavirus Disease-2019 (COVID-19), with macrophages as one of the main cell types involved. It is urgent to understand the interactions among permissive cells, macrophages, and the SARS-CoV-2 virus, thereby offering important insights into effective therapeutic strategies. Here, we establish a lung and macrophage co-culture system derived from human pluripotent stem cells (hPSCs), modeling the host-pathogen interaction in SARS-CoV-2 infection. We find that both classically polarized macrophages (M1) and alternatively polarized macrophages (M2) have inhibitory effects on SARS-CoV-2 infection. However, M1 and non-activated (M0) macrophages, but not M2 macrophages, significantly up-regulate inflammatory factors upon viral infection. Moreover, M1 macrophages suppress the growth and enhance apoptosis of lung cells. Inhibition of viral entry using an ACE2 blocking antibody substantially enhances the activity of M2 macrophages. Our studies indicate differential immune response patterns in distinct macrophage phenotypes, which could lead to a range of COVID-19 disease severity.


Subject(s)
COVID-19 , Pluripotent Stem Cells , Humans , Lung , Macrophages , SARS-CoV-2
2.
J Virol ; 95(22): e0096621, 2021 10 27.
Article in English | MEDLINE | ID: covidwho-1561933

ABSTRACT

The high pathogenicity of SARS-CoV-2 requires it to be handled under biosafety level 3 conditions. Consequently, Spike protein-pseudotyped vectors are a useful tool to study viral entry and its inhibition, with retroviral, lentiviral (LV), and vesicular stomatitis virus (VSV) vectors the most commonly used systems. Methods to increase the titer of such vectors commonly include concentration by ultracentrifugation and truncation of the Spike protein cytoplasmic tail. However, limited studies have examined whether such a modification also impacts the protein's function. Here, we optimized concentration methods for SARS-CoV-2 Spike-pseudotyped VSV vectors, finding that tangential flow filtration produced vectors with more consistent titers than ultracentrifugation. We also examined the impact of Spike tail truncation on transduction of various cell types and sensitivity to convalescent serum neutralization. We found that tail truncation increased Spike incorporation into both LV and VSV vectors and resulted in enhanced titers but had no impact on sensitivity to convalescent serum. In addition, we analyzed the effect of the D614G mutation, which became a dominant SARS-CoV-2 variant early in the pandemic. Our studies revealed that, similar to the tail truncation, D614G independently increases Spike incorporation and vector titers, but this effect is masked by also including the cytoplasmic tail truncation. Therefore, the use of full-length Spike protein, combined with tangential flow filtration, is recommended as a method to generate high titer pseudotyped vectors that retain native Spike protein functions. IMPORTANCE Pseudotyped viral vectors are useful tools to study the properties of viral fusion proteins, especially those from highly pathogenic viruses. The Spike protein of SARS-CoV-2 has been investigated using pseudotyped lentiviral and VSV vector systems, where truncation of its cytoplasmic tail is commonly used to enhance Spike incorporation into vectors and to increase the titers of the resulting vectors. However, our studies have shown that such effects can also mask the phenotype of the D614G mutation in the ectodomain of the protein, which was a dominant variant arising early in the COVID-19 pandemic. To better ensure the authenticity of Spike protein phenotypes when using pseudotyped vectors, we recommend using full-length Spike proteins, combined with tangential flow filtration methods of concentration if higher-titer vectors are required.


Subject(s)
Genetic Vectors/physiology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Animals , Antibodies, Neutralizing/immunology , Cell Line , Genetic Vectors/genetics , Genetic Vectors/immunology , Humans , Lentivirus/genetics , Mutation , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vesicular stomatitis Indiana virus/genetics , Viral Load/genetics
3.
Ann Surg ; 275(2): 242-246, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1522450

ABSTRACT

OBJECTIVE: To assess the association between the timing of surgery relative to the development of Covid-19 and the risks of postoperative complications. SUMMARY BACKGROUND DATA: It is unknown whether patients who recovered from Covid-19 and then underwent a major elective operation have an increased risk of developing postoperative complications. METHODS: The risk of postoperative complications for patients with Covid-19 undergoing 18 major types of elective operations in the Covid-19 Research Database was evaluated using multivariable logistic regression. Patients were grouped by time of surgery relative to SARS-CoV-2 infection; that is, surgery performed: (1) before January 1, 2020 ("pre-Covid-19"), (2) 0 to 4 weeks after SARS-CoV-2 infection ("peri-Covid-19"), (3) 4 to 8 weeks after infection ("early post-Covid-19"), and (4) ≥8 weeks after infection ("late post-Covid-19"). RESULTS: Of the 5479 patients who met study criteria, patients with peri-Covid-19 had an elevated risk of developing postoperative pneumonia [adjusted odds ratio (aOR), 6.46; 95% confidence interval (CI): 4.06-10.27], respiratory failure (aOR, 3.36; 95% CI: 2.22-5.10), pulmonary embolism (aOR, 2.73; 95% CI: 1.35-5.53), and sepsis (aOR, 3.67; 95% CI: 2.18-6.16) when compared to pre-Covid-19 patients. Early post-Covid-19 patients had an increased risk of developing postoperative pneumonia when compared to pre-Covid-19 patients (aOR, 2.44; 95% CI: 1.20-4.96). Late post-Covid-19 patients did not have an increased risk of postoperative complications when compared to pre-Covid-19 patients. CONCLUSIONS: Major, elective surgery 0 to 4 weeks after SARS-CoV-2 infection is associated with an increased risk of postoperative complications. Surgery performed 4 to 8 weeks after SARS-CoV-2 infection is still associated with an increased risk of postoperative pneumonia, whereas surgery 8 weeks after Covid-19 diagnosis is not associated with increased complications.


Subject(s)
COVID-19/diagnosis , Elective Surgical Procedures/adverse effects , Postoperative Complications/diagnosis , Time-to-Treatment , COVID-19 Testing , Humans , Pneumonia/diagnosis , Pulmonary Embolism/diagnosis , Respiratory Insufficiency/diagnosis , Risk Factors , SARS-CoV-2 , Sepsis/diagnosis , United States
4.
PLoS One ; 15(10): e0241329, 2020.
Article in English | MEDLINE | ID: covidwho-895073

ABSTRACT

OBJECTIVE: To investigate the blood coagulation function in COVID-19 patients, and the correlation between coagulopathy and disease severity. METHODS: We retrospectively collected 147 clinically diagnosed COVID-19 patients at Wuhan Leishenshan Hospital of Hubei, China. We analyzed the coagulation function in COVID-19 patients through the data including thrombin-antithrombin complex (TAT), α2-plasmininhibitor-plasmin Complex (PIC), thrombomodulin (TM), t-PA/PAI-1 Complex (t-PAIC), prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombin time (TT), D-Dimer (DD), and platelet (PLT). RESULT: The levels of TAT, PIC, TM, t-PAIC, PT, INR, FIB, and DD in COVID-19 patients were higher than health controls (p<0.05), and also higher in the patients with thrombotic disease than without thrombotic disease (p<0.05). What's more, the patients with thrombotic disease had a higher case-fatality (p<0.05). TAT, PIC, TM, t-PAIC, PT, INR, APTT, FIB, DD, and PLT were also found correlated with disease severity. Meanwhile, we found that there were significant difference in TAT, TM, t-PAIC, PT, INR, APTT, DD, and PLT in the death and survival group. Further using univariate and multivariate logistic regression analysis also found that t-PAIC and DD were independent risk factors for death in patients and are excellent predicting the mortality risk of COVID-19. CONCLUSION: Most COVID-19 patients with inordinate coagulation systems, dynamic monitoring of coagulation parameters might be a key in the control of COVID-19 death.


Subject(s)
Blood Coagulation , Coronavirus Infections/blood , Pneumonia, Viral/blood , Adult , Aged , Betacoronavirus , Blood Coagulation Disorders/virology , Blood Coagulation Tests , COVID-19 , Case-Control Studies , China , Female , Humans , Male , Middle Aged , Pandemics , SARS-CoV-2
5.
Res Sq ; 2020 Aug 20.
Article in English | MEDLINE | ID: covidwho-729814

ABSTRACT

Dysfunctional immune responses contribute critically to the progression of Coronavirus Disease-2019 (COVID-19) from mild to severe stages including fatality, with pro-inflammatory macrophages as one of the main mediators of lung hyper-inflammation. Therefore, there is an urgent need to better understand the interactions among SARS-CoV-2 permissive cells, macrophage, and the SARS-CoV-2 virus, thereby offering important insights into new therapeutic strategies. Here, we used directed differentiation of human pluripotent stem cells (hPSCs) to establish a lung and macrophage co-culture system and model the host-pathogen interaction and immune response caused by SARS-CoV-2 infection. Among the hPSC-derived lung cells, alveolar type II and ciliated cells are the major cell populations expressing the viral receptor ACE2 and co-effector TMPRSS2, and both were highly permissive to viral infection. We found that alternatively polarized macrophages (M2) and classically polarized macrophages (M1) had similar inhibitory effects on SARS-CoV-2 infection. However, only M1 macrophages significantly up-regulated inflammatory factors including IL-6 and IL-18, inhibiting growth and enhancing apoptosis of lung cells. Inhibiting viral entry into target cells using an ACE2 blocking antibody enhanced the activity of M2 macrophages, resulting in nearly complete clearance of virus and protection of lung cells. These results suggest a potential therapeutic strategy, in that by blocking viral entrance to target cells while boosting anti-inflammatory action of macrophages at an early stage of infection, M2 macrophages can eliminate SARS-CoV-2, while sparing lung cells and suppressing the dysfunctional hyper-inflammatory response mediated by M1 macrophages.

6.
Med. J. Wuhan Univ. ; 4(41): 517-520, 20200715.
Article in Chinese | WHO COVID, ELSEVIER | ID: covidwho-617504

ABSTRACT

Objective: To compare the chemiluminescence and colloidal gold method in the detection of 2019 novel Coronavirus (2019-nCoV, or SARS-CoV-2) specific antibody and to evaluate the importance in the diagnosis and treatment of COVID-19. Methods: A total of 191 cases of diagnosed and suspected COVID-19 patients admitted in Febrary 2020 in Wuhan Leishenshan Hospital were included. The patients were divided into 2019-nCoV continuous positive group, 2019-nCoV positive to negative group, and 2019-nCoV suspect group according to the results of pharyngeal swab 2019-nCoV nucleic acid detection. In addition, 27 patients without COVID-19 were set as control group to test the specificity. The serum samples were collected, and colloidal gold and chemiluminescence method were used to detect total antibodies (IgM+IgG) and IgM. SPSS 24.0 was used to compare the difference in antibody detection rates between the two methods. Results: The specificity of total antibodies (IgM+IgG) and IgM detection was 100%. Two methods of total antibody detection had no significant difference in continuous positive group (P=1.00). In positive to negative group and suspect group, the positive detection rate of chemiluminescence method was significantly higher than colloidal gold method (95.2% vs 76.2% and 94.9% vs 70.5%, respectively, both P<0.05). The chemiluminescence method showed no significant difference between the three groups in IgM detection (P>0.05). Conclusion: The detection of 2019-nCoV specific antibody can be an important supplemental method to pharyngeal swab 2019-nCoV nucleic acid detection during the diagnosis and treatment of COVID-19. The chemiluminescence method is better than colloidal gold method in the detection of total antibody. The IgM detection using chemiluminescence method is suitable for all stages of the disease.

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