Potent Anti-SARS-CoV-2 Efficacy of COVID-19 Hyperimmune Globulin from Vaccine-Immunized Plasma.

Coronavirus disease 2019 (COVID-19) remains a global public health threat. Hence, more effective and specific antivirals are urgently needed. Here, COVID-19 hyperimmune globulin (COVID-HIG), a passive immunotherapy, is prepared from the plasma of healthy donors vaccinated with BBIBP-CorV (Sinopharm COVID-19 vaccine). COVID-HIG shows high-affinity binding to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, the receptor-binding domain (RBD), the N-terminal domain of the S protein, and the nucleocapsid protein; and blocks RBD binding to human angiotensin-converting enzyme 2 (hACE2). Pseudotyped and authentic virus-based assays show that COVID-HIG displays broad-spectrum neutralization effects on a wide variety of SARS-CoV-2 variants, including D614G, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.617.1), Delta (B.1.617.2), and Omicron (B.1.1.529) in vitro. However, a significant reduction in the neutralization titer is detected against Beta, Delta, and Omicron variants. Additionally, assessments of the prophylactic and treatment efficacy of COVID-HIG in an Adv5-hACE2-transduced IFNAR-/- mouse model of SARS-CoV-2 infection show significantly reduced weight loss, lung viral loads, and lung pathological injury. Moreover, COVID-HIG exhibits neutralization potency similar to that of anti-SARS-CoV-2 hyperimmune globulin from pooled convalescent plasma. Overall, the results demonstrate the potential of COVID-HIG against SARS-CoV-2 infection and provide reference for subsequent clinical trials.

Human amniotic fluid-derived stem cells can differentiate into hepatocyte-like cells in vitro and in vivo.

Although human amniotic fluid is an attractive source of multipotent stem cells, the potential of amniotic fluid stem cells (AFSCs) to differentiate into hepatic cells has not been extensively evaluated. In this study, we examined whether human AFSCs can differentiate into a hepatic cell lineage in vitro and in vivo. After being treated with cytokines (fibroblast growth factor 4, basic fibroblast growth factor, hepatocyte growth factor, and oncostatin), AFSCs developed a morphology similar to that of hepatocytes. RT-PCR and immunofluorescence analysis showed that the treated AFSCs expressed the hepatocyte-specific markers albumin, cytokeratin 18, and alpha-fetoprotein. The differentiated cells also developed hepatocyte-specific functions, i.e., they secreted albumin, absorbed indocyanine green, and stored glycogen. When transplanted into CCl(4)-injured immunodeficient mice, undifferentiated AFSCs were integrated into the liver tissue, and they expressed markers characteristic of mature human hepatocytes. Although integration of AFSCs into the liver was limited (0.1-0.3% of hepatocytes), histological analysis showed that the recipient mice recovered more rapidly from CCl(4) injury than CCl(4)-injured mice that did not receive AFSCs. AFSCs can differentiate into hepatocyte-like cells in vitro and in vivo and can represent an easily accessible source of progenitor cells for hepatocyte regeneration and liver cell transplantation.

[Induction of hepatic specification of human adipose-derived stem cells (hADSCs) in vitro].

OBJECTIVE: To induce hepatic differentiation of human adipose-derived stem cells (hADSCs) in vitro. METHODS: hADSCs were isolated from human adipose tissue and treated with improved hepatic medium containing HGF, bFGF and FGF4. After 7 days of culture, OSM was added to the culture media. Cell growth during hepatic differentiation was evaluated by CCK8 assay. Morphology of differentiation was examined under light microscope. Liver specific genes and proteins were detected by RT-PCR analysis and immunohistochemical staining, respectively. And functional characteristics of hepatocytes were also examined. RESULTS: The number of hADSCs cultured in the improved hepatic media was increased significantly in comparison to hADSCs cultured in control media from 5 days to 21 days (t=6.59, 8.69, 15.94 and 24.64, respectively, P<0.05). The hADSCs-derived hepatocyte-like cells exhibited hepatocyte morphology, expressed hepatocyte markers, possessed hepatocyte-specific activities, such as uptake and excretion of indocyanine green, glycogen storage and albumin production. CONCLUSION: hADSCs can be induced into hepatocyte-like cells in this differentiation system. And this differentiation system promoted the growth of hADSCs.

[Effects of different culture conditions on isolation and expansion of stem cells from second-trimester amniotic fluids].

OBJECTIVE: To investigate the effects of different culture conditions on the isolation and expansion of stem cells from second-trimester amniotic fluids. METHODS: Amniotic fluids were obtained from 15 pregnant women undergone amniocenteses for medical indications between 16 - 24 gestation weeks by transabdominal amniocenteses from September 2007 to June 2008. Amniotic fluids (10 - 20 ml) samples were collected and each was cultured under different conditions or groups. (1) Low-glucose DMEM (LD) medium supplemented with 10% of fetal bovine serum (group of 10%FBS); (2) LD medium with 20% of FBS (group of 20%FBS); (3) LD medium with 15% of FBS and 4 ng/ml of basic fibroblast growth factor (group of bFGF); (4) LD medium with 10% of FBS as well as the culture plate coated with gelatin (group of gelatin). The effects of different conditions were evaluated by comparing the number of primary colonies, the cell morphology and the ability of expansion. The isolated stem cells were identified by flow cytometry, RT-PCR and differentiation ability to adipocyte. RESULTS: (1) The success rates of primary culture of the group of 10%FBS, 20%FBS, bFGF and gelatin were 60%, 73%, 73% and 60% respectively (P > 0.05). The numbers of colonies were 0.9 +/- 0.5, 2.6 +/- 1.5, 2.9 +/- 1.5, 1.1 +/- 0.8 (P < 0.01 when group of 10%FBS and gelatin compared with group of 20%FBS and bFGF); among the primary colonies, fibroblast-like colonies accounted for 46%, 49%, 64%, 44% respectively (P > 0.05). (2) The second passage cells obtained from all of these four groups could differentiate into adipocyte after induction. (3) In the group of bFGF, stem cells were isolated from 5 samples and expanded to nearly 10(7) cells after 5 passages (P < 0.01 compared with other groups). (4) Karyotype were normal in all samples. (5) Stem cells from bFGF group showed positive expression of SSEA-4, Oct-4 and Nanog gene detected by flow cytometry and RT-PCR. CONCLUSION: Stem cells can be isolated from second-trimester amniotic fluids; moderate serum concentration and supplementation of bFGF can improve the efficiency of isolation and expansion of amniotic fluid of stem cells.

[Protective effect of sodium pyruvate on ischemia/reperfusion injury of rats subjected to hemorrhagic shock].

AIM: To study the protective effect of sodium pyruvate on ischemia/reperfusion injury following hemorrhagic shock. METHODS: Rat models of hemorrhagic shock were built up. When the shed blood was infused, the rats were also randomly provided by one of normal saline, glutathione and sodium pyruvate. Rats were killed 3 hours after the reperfusion, the activity of plasma lactate dehydrogenase (LDH) and glutamic-oxaloacetic transaminase (GOT), the level of tissue malondialdehyde (MDA) and the activity of tissue myeloperoxidase (MPO) were detected. Biopsy specimens were obtained to investigate morphological changes of the myocardial, hepatic, lung and renal tissue. RESULTS: The activity of plasma LDH and GOT, the level of MDA of hepatic, lung and renal tissue and the activity of MPO of myocardial, lung and renal tissue decreased remarkably in group given sodium pyruvate compared with group given normal saline, and the effect of group given sodium pyruvate was more remarkable than group given glutathione. CONCLUSION: These data support the view that sodium pyruvate shows protective effect on ischemia/reperfusion injury following hemorrhagic shock. It is possibly relevant to scavenging of oxygen free radicals, reduction of neutrophil, and anti-inflammatory response.

[Differentiation of bone marrow derived Thy-1+ beta2M- cells into liver cells in AA induced liver injury micro-environment].

OBJECTIVE: To investigate the differentiation of bone marrow derived Thy-1+ beta2M- cells (BDTCs) into liver cells in allyl alcohol (AA) induced liver injury micro-environment. METHODS: BDTCs of male F344 rats were isolated by two-step magnetic separation system (MACS) technique, and infused intraportally into female recipients after labeling with PKH26. Thirty recipients were divided randomly into 3 groups: (1) AA-injured liver + BDTCs infusion, (2) normal liver + BDTCs infusion and (3) AA-injured liver + NS infusion (control). Blood biochemical examination, fluorescence labeled cellular localization, Y-chromosome sry gene in-situ hybridization and immunohistochemistry were carried out to evaluate BDTCs distribution, differentiation and proliferation in recipients's livers after different intervals. RESULTS: Fluoromicroscopy and in situ hybridization suggested that BDTCs of donors were interspersed in pieces and cords among the necro-periportals induced by AA; immunohistochemistry indicated that those implanted cells expressed OV-6, AFP, CK19 and albumin successively, while positive cells were hardly seen in the normal liver + BDTCs infusion group. Compared with the controls, the blood biochemical restitution was more rapid in group (1), (9.8 d +/- 3.1 d vs. 13.7 d +/- 4.2 d). CONCLUSION: The injury micro-environment induced by AA facilitates BDTCs integration with hepatic cell plates and differentiation into mature liver cells. BDTCs differentiation into liver cells might accelerate endogenous liver cell regeneration and reparation.

[The expression of fusion protein GST-GP302 in E.coli and its preparation of rabbit anti-serum].

AIM: To express fusion protein of GST and vWf binding domain(GP302) of platelet GPIbalpha in E.coli and its preparation of rabbit anti-serum. METHODS: GP302 gene was inserted into pGEX-4T-1. The recombinant vector was identificated by restriction endonuclease digestion analysis. Fusion protein GST-GP302 was expressed in E.coli via IPTG induction. The rabbit antibody against GST-GP302 was prepared by using renatured GST-GP302 as immuneogen and the specificity of polyclonal antibody was identified by Western blot. RESULTS: The restriction endonuclease digestion analysis of recombinant plasmid demonstrated that the GP302 gene had been exactly inserted into pGEX-4T-1. SDS-PAGE analysis showed that the ralative molecular mass(M(r)) of the fusion protein was about 59 000. ELISA analysis proved that the titer of rabbit serum against GST-GP302 was 10(-5). The polyclonal antibody specifically bound to purified platelet GPIbalpha. CONCLUSION: The preparation of polyclonal antibody against GP302 peptide provides an usefal reagent for the detection of platelet GPIbalpha.