ABSTRACT
BackgroundTimely diagnosis of SARS-CoV-2 infection is the prerequisite for treatment and preventive quarantine. The serology characteristics and complement diagnosis value of antibody test to RNA test needs to be demonstrated. MethodA patient cohort study was conducted at the first affiliated hospital of Zhejiang University, China. Serial plasma of COVID-19 patients and were collected and total antibody (Ab), IgM and IgG antibody against SARS-CoV-2 were detected. The antibody dynamics during the infection were described. ResultsThe seroconversion rate for Ab, IgM and IgG in COVID-19 patients was 98.8% (79/80), 93.8% (75/80) and 93.8% (75/80), respectively. The first detectible serology marker is total antibody and followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 day post exposure (d.p.e) or 9, 10 and 12 days post onset, separately. The antibody levels increased rapidly since 6 d.p.o and accompanied with the decline of viral load. For patients in the early stage of illness (0-7d.p.o),Ab showed the highest sensitivity (64.1%) compared to the IgM and IgG (33.3% for both, p<0.001). The sensitivities of Ab, IgM and IgG detection increased to 100%, 96.7% and 93.3% two weeks later, respectively. ConclusionsTypical acute antibody response is induced during the SARS-CoV-2 infection. The serology testing provides important complementation to RNA test for pathogenic specific diagnosis and helpful information to evaluate the adapted immunity status of patient. It should be strongly recommended to apply well-validated antibody tests in the clinical management and public health practice to improve the control of COVID-19 infection. Take-Home MessageAntibody responses are induced after SARS-CoV-2 infection and complement diagnosis value of antibody test to RNA test was observed. Antibody tests are critical tools in clinical management and control of SARS-CoV-2 infection and COVID-19.
ABSTRACT
SOCS3, a feedback inhibitor of the JAK/STAT signal pathway, negatively regulates axonal regrowth and inflammation in the central nervous system (CNS). Here, we demonstrated a distinct role of SOCS3 in the injured spinal cord of the gecko following tail amputation. Severing the gecko spinal cord did not evoke an inflammatory cascade except for an injury-stimulated elevation of the granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon gamma (IFN-γ) cytokines. Simultaneously, the expression of SOCS3 was upregulated in microglia, and unexpectedly not in neurons. Enforced expression of SOCS3 was sufficient to suppress the GM-CSF/IFN-γ-driven inflammatory responses through its KIR domain by attenuating the activities of JAK1 and JAK2. SOCS3 was also linked to GM-CSF/IFN-γ-induced cross-tolerance. Transfection of adenovirus overexpressing SOCS3 in the injured cord resulted in a significant decrease of inflammatory cytokines. These results reveal a distinct role of SOCS3 in the regenerating spinal cord, and provide new hints for CNS repair in mammals.
ABSTRACT
In order to study T-bet function in mouse cells, a novel retroviral vector expressing mouse T-bet and reporter gene Thy1.1 was constructed. Retrovirus particles were then produced by transfection of the recombinant retroviral plasmid into a packaging cell line Platinum-E. The recombinant retrovirus played considerable infection ability. T-bet expression was then identified by FACS after infection of CD4+ primary T cells from T-bet knockout mouse with recombinant retrovirus. To determine if exogenous expressing T-bet has normal function, we checked the expression level of T-bet target gene, Ifng. IFN-y expression was upregulated in the T-bet knockout T cells infected with recombinant retrovirus. In conclusion, we successfully constructed an effective mouse T-bet recombinant retroviral vector.
Subject(s)
Animals , Mice , Cell Line , Genetic Vectors , Interferon-gamma , Metabolism , Mice, Knockout , Recombinant Proteins , Retroviridae , T-Box Domain Proteins , T-Lymphocytes , Metabolism , TransfectionABSTRACT
Aim To study the effect of CSE ( cigarette smoke extract ) on the single-molecule interactional force between thrombomodulin and thrombin by live-cell single-molecule force spectroscopy. Methods CSE was prepared by a previously reported method. The plasmid of TM-GFP was constructed and transfect-ed in COS-7 cells. The expression of TM-GFP was de-tected by fluorescence microscopy and laser scanning confocal microscopy. The transfected COS-7 cells were grouped ( 1 ) GFP -thrombin group ( 2 ) TM-thrombin group ( 3 ) CSE-TM-thrombin group ( 4 ) CSE- GFP-thrombin group. Force measurements with the thrombin modified AFM tips on the living cell surface were car-ried out on PicoSPM II with a Pico-Scan 3000 control-ler and a larger scanner. The force curves measured in living cells were recorded by PicoScan 5 software and analyzed by MATLAB R2009aMetlab. Results The single-molecule binding force of thrombomodulin and thrombin ( TM-Thr ) was determined ( 60. 90 ± 0. 82 ) pN. The binding probability for TM-Thr was about (22. 58 ± 3. 95)%. Antibody blocking binding proba-bility for TM-Thr was ( 2. 58 ± 2. 0 )%. The binding probabilities for GFP-Thr group, CSE-TM-Thr group and CSE-GFP-Thr group were significantly decreased compared with TM-Thr group ( P<0. 05 ) . The mean value of the most probable single molecular interaction force of thrombin/TM-ECD was determined as ( 45. 30 ± 1. 37 ) pN, the binding probability of thrombin and TM-ECD was ( 23. 25 ± 7. 02 )%. When the binding was blocked with the TM-MAb solution, the binding probability decreased to ( 4. 64 ± 2. 31 )%. The bind-ing probability was ( 8. 31 ± 1. 06 )% in the CSE-TM-thr-S group. When further blocked with TM-MAb, the binding probability was ( 5. 17 ± 2. 96 )%. Conclusion CSE significantly decreases the binding probability for TM-Thr to induce intravascular thrombosis.
