【Objective】 To analyze the basic characteristics of whole blood donors from blood stations before and after the outbreak of COVID-19. 【Methods】 After excluding invalid data, data related to the basic characteristics of whole blood donors collected from 26 blood stations in China during 2018 to 2021 were statistically analyzed, including the trend of total whole blood donors, the number of repeated blood donors, the frequency of blood donation, the average age of donors and the recruitment of first-time blood donors. 【Results】 Affected by the epidemic, 8 out of 14 indicators were with large variations, accounting for 57%. The overall growth rate of total whole blood donors during the epidemic was higher than before the epidemic (P<0.05).The number of repeated blood donors has shown an increased trend, with a higher number during the epidemic than before (P<0.05). The frequency of blood donation was lower during the epidemic than before(P<0.05).Average ages of blood donors and female blood donors fluctuated widely during the epidemic, both higher than those before the epidemic(P<0.05).The donation rate of first-time blood donors <25 years old and ≥25 years old varied widely and irregularly during the epidemic (both P<0.05). The percentage of first-time blood donors fluctuated irregularly during the epidemic, with overall percentage lower than that before the epidemic(P<0.05). 【Conclusion】 Whole blood donors from 26 blood stations increased after the outbreak of COVID-19, and some indicators in certain areas showed significant fluctuations during the epidemic.

【Objective】 To analyze the hepatitis B virus (HBV) infection data of blood donors from 18 domestic blood stations, so as to investigate the HBV infection situation of blood donors. 【Methods】 The positive rate of HBV and its distribution characteristics of regions, the percentage of HBsAg+ ELISA in first-time vs repeated blood donors, and the percentage of HBsAg-/HBV DNA+ blood donors of 18 domestic blood stations during 2017 to 2020 were collected from the Working Platform for Practice Comparison of Blood Centers, and the HBV infection among blood donors were statistically analyzed. 【Results】 From 2017 to 2020, the positive rate of HBV in blood donors among 18 domestic blood stations was 13.48/10 000-144.02/10 000, with the average HBV positive rate in eastern, central and western region at 26.14/10 000, 51.98/10 000 and 41.00/10 000, respectively. The HBsAg+ rate by ELISA among first-time and repeated blood donors was 14.55/10 000-305.39/10 000 vs 1.04/10 000-87.43/10 000 The HBsAg-/HBV DNA+ yield was 1.80/10 000-35.31/10 000. 【Conclusion】 The distribution of HBV infection in blood donors has regional characteristics, and HBV prevalence was low in repeated blood donors. HBsAg ELISA combined with HBV DNA detection can better ensure blood safety.

【Objective】 To learn the production efficient of platelet components among prefecture-level blood stations in China, to provide supporting data for those blood stations to optimize the production mode of platelet components and continuously improve production efficiency and supply capacity. 【Methods】 The data from 2017 to 2020 was obtained from 24 prefecture-level blood stations who were the members of the practice comparison network for blood institutes in China. The collection units of apheresis platelets, the number of dual-collections of apheresis platelets and plasma, the average apheresis units of one platelet apheresis procedure, the discarded rate of apheresis platelets, the amount of expired apheresis platelets and the amount of apheresis platelets issued were collected. For concentrated platelets, the prepared amount of platelet concentrates and the amount of expired platelet concentrates were collected; both the quantity of qualified and issued concentrated platelets were submitted for statistical analysis.The total output and efficiency of platelet components were calculated based on the collected data. 【Results】 The average annual growth rate of apheresis platelets collection in 24 prefecture-level blood stations was 12.23%, accounting for 99.80% of the total platelet output; the average collection unit of one platelets apheresis procedure was 1.75; from 2019 to 2020, only 5 blood stations performed dual-collection of platelet and plasma during one apheresis procedure; the discarded rate of apheresis platelets was 0.28%, of which 0.007% was due to expiration. A total of 1 621.2 therapeutic units of concentrated platelets were prepared, and 13.03% of them was discarded due to the expiration. The production efficiency of platelet components was 97.56%, of which the production efficiency of apheresis platelets was 97.61% and the production efficiency of concentrated platelets was 74.43%. 【Conclusion】 There are large regional differences in the supply capacity of platelet components in prefecture-level blood stations. Apheresis platelets are the main resource of platelet components product, and the collection capacity is increasing over the years with the characteristics of high production efficiency and low expiration scrapping rate. However, the preparation of concentrated platelets are still limited with relatively low production and high expiration discarded rate.

【Objective】 To understand the current situation of blood components distribution in domestic prefecture-level blood stations through analyzing the components distribution data of 24 prefecture-level blood stations in China. 【Methods】 The data of components distribution of 24 blood stations from 2017 to 2020 as well as the data of blood deployment of 24 blood stations from 2019 to 2020 were collected and analyzed. 【Results】 From 2017 to 2020, positive annual growth in red blood cells, plasma and cryoprecipitate was observed in 22, 19 and 15 out of the 24 blood stations, and the annual growth median rate of above three components was 5.24%, 3.80% and 3.25%, respectively. Among the 24 prefecture-level blood stations, 23 carried out the preparation of cryoprecipitate. 【Conclusion】 The distribution of red blood cells, cryoprecipitate and plasma in prefecture-level blood stations is increasing year by year. However, there is a overstock of plasma, and most blood stations need blood employment.

New threats posed by the emerging circulating variants of SARS-CoV-2 highlight the need to find conserved neutralizing epitopes for therapeutic antibodies and efficient vaccine design. Here, we identified a receptor-binding domain (RBD)-binding antibody, XG014, which potently neutralizes β-coronavirus lineage B (β-CoV-B), including SARS-CoV-2, its circulating variants, SARS-CoV and bat SARSr-CoV WIV1. Interestingly, antibody family members competing with XG014 binding show reduced levels of cross-reactivity and induce antibody-dependent SARS-CoV-2 spike (S) protein-mediated cell-cell fusion, suggesting a unique mode of recognition by XG014. Structural analyses reveal that XG014 recognizes a conserved epitope outside the ACE2 binding site and completely locks RBD in the non-functional "down" conformation, while its family member XG005 directly competes with ACE2 binding and position the RBD "up". Single administration of XG014 is effective in protection against and therapy of SARS-CoV-2 infection in vivo. Our findings suggest the potential to develop XG014 as pan-β-CoV-B therapeutics and the importance of the XG014 conserved antigenic epitope for designing broadly protective vaccines against β-CoV-B and newly emerging SARS-CoV-2 variants of concern.
Angiotensin-Converting Enzyme 2 ; Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19 ; Epitopes ; Humans ; SARS-CoV-2/genetics* ; Spike Glycoprotein, Coronavirus/genetics*

Objective:To clarify the differences of host immune responses at different stages of HBV infection. Methods:We constructed three HLA-A*0201/HBV tetramers with immunodominant epitopes of core18-27,polymerase 575-583 and envelope 335-343,and analyzed antigen specific CD8+ T cells and the expression of CD127 in peripheral blood mononuclear cells ( PBMCs) from patients infected with HBV using these HLA-A*0201/HBV tetramers. Results: The frequencies and expansion ability of antigen specific CD8+ T cells in most self-limited HBV infected individuals were higher than that in chronically HBV infected patients. In low copy period the frequencies of antigen specific CD8+ T cells were similar to those in immune clearance phase at a high viral load and liver damage and in immune clearance phase, which had no significant correlation with virus quantitation and ALT level. In chronic infection the ability of antigen specific CD8+ T cells proliferation was inversely proportional to the viral titer. In most self-limited HBV infected individuals the IFN-γsecretion functions of antigen specific CD8+ T cells were higher than in chronic infection,but in immune tolerance phase these cells lost the ability. HBsAg level was different at different stages after HBV infection:it was highest in immune tolerance phase,but in immune clearance phase,activity period and low copy period the correlation with HBV DNA replication gradually declined. The frequency of CD8+ CD127+ T cells in chronic HBV infection was lower than the control group and self-limited infection group,especially in immune tolerance with HBeAg+ and immune clearance phase. Conclusion: The frequencies of antigen specific CD8+ T cells are not the main determinant of immune-mediated protection in chronic HBV infection,memory antigen specific CD8+ T cells are not clear or missing,which provides the possibility for therapeutic vaccines and immunization therapy.

Objective To analyze the clinical application of HLA donor specific antibodies (DSAs) detected by Luminex single antigen beads,and to discuss the impact of early intervention on renal function.Method In 64 cases of living-relative renal transplantation,DSA was detected using a Luminex single antigen assay before and after transplantation.The positive recipients were given large doses of intravenous irnmunoglobulin (IVIG) and increased doses of mycophenolate mofetil (MMF).The relationship between DSA and renal function was analyzed.Result DSA was negative in all recipients before transplantation.Ten cases of DSA positive recipients were found in HLA mismatch after transplantation.After the intervention,two cases of DSA positive recipients became negative,immunofluorescence intensity was decreased by more than 50％ in 6 cases,and no significant reduction was found in the other two cases.Antibody-mediated rejection (AMR) occurred in two cases of intervention ineffective recipients after 3 to 6 months and the renal function was impaired.Conclusion Dynamic monitoring of DSA using Luminex single antigen beads may timely predict changes of renal function.Early application of large doses of IVIG and increasing doses of MMF can reduce the incidence of AMR.

This study investigated the expression profiles of IL-10 gene in three human hepatoma cell lines including Huh7, HepG2, and HepG2 transfected with a plasmid containing hepatitis B virus (HBV) named HepG2.2.15. RT-PCR analysis demonstrated that IL-10 message RNA was absent in HepG2 and Huh7 cells, whereas it was present in HepG2.2.15 cells, which was consistent with ELISA result. Furthermore, except for lamivudine other antiviral treatments did not significantly decrease the HBV DNA level in HepG2.2.15 cells, while they had different effects on the expression of IL-10 protein, although stimulation by LPS had no significant effect. In addition, except for poly(I:C), the other treatments decreased the expression of IL-10 protein to different degrees, but had no significant effects on the expression of NF-κB and MyD88. Meanwhile, all treatments we used had effect on the expression of STAT1. In conclusion, IL-10 was expressed in HepG2.2.15 cells and STAT1 pathway might be involved in the regulation of IL-10 expression in HepG2.2.15 cells, but it was not the sole pathway, the exact mechanism warrants further study.

This study investigated the expression profiles of IL-10 gene in three human hepatoma cell lines including Huh7,HepG2,and HepG2 transfected with a plasmid containing hepatitis B virus (HBV) named HepG2.2.15.RT-PCR analysis demonstrated that IL-10 message RNA was absent in HepG2 and Huh7 cells,whereas it was present in HepG2.2.15 cells,which was consistent with ELISA result.Furthermore,except for lamivudine other antiviral treatments did not significantly decrease the HBV DNA level in HepG2.2.15 cells,while they had different effects on the expression of IL-10 protein,although stimulation by LPS had no significant effect.In addition,except for poly(I:C),the other treatments decreased the expression of IL-10 protein to different degrees,but had no significant effects on the expression of NF-κB and MyD88.Meanwhile,all treatments we used had effect on the expression of STAT1.In conclusion,IL-10 was expressed in HepG2.2.15 cells and STAT1 pathway might be involved in the regulation of IL-10 expression in HepG2.2.15 cells,but it was not the sole pathway,the exact mechanism warrants further study.