RESUMEN
The continuous emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants poses challenges to the effectiveness of neutralizing antibodies. Rational design of antibody cocktails is a realizable approach addressing viral immune evasion. However, evaluating the breadth of antibody cocktails is essential for understanding the development potential. Here, based on a replication competent vesicular stomatitis virus model that incorporates the spike of SARS-CoV-2 (VSV-SARS-CoV-2), we evaluated the breadth of a number of antibody cocktails consisting of monoclonal antibodies and bispecific antibodies by long-term passaging the virus in the presence of the cocktails. Results from over two-month passaging of the virus showed that 9E12+10D4+2G1 and 7B9-9D11+2G1 from these cocktails were highly resistant to random mutation, and there was no breakthrough after 30 rounds of passaging. As a control, antibody REGN10933 was broken through in the third passage. Next generation sequencing was performed and several critical mutations related to viral evasion were identified. These mutations caused a decrease in neutralization efficiency, but the reduced replication rate and ACE2 susceptibility of the mutant virus suggested that they might not have the potential to become epidemic strains. The 9E12+10D4+2G1 and 7B9-9D11+2G1 cocktails that picked from the VSV-SARS-CoV-2 system efficiently neutralized all current variants of concern and variants of interest including the most recent variants Delta and Omicron, as well as SARS-CoV-1. Our results highlight the feasibility of using the VSV-SARS-CoV-2 system to develop SARS-CoV-2 antibody cocktails and provide a reference for the clinical selection of therapeutic strategies to address the mutational escape of SARS-CoV-2.
RESUMEN
Numerous mutations in the spike protein of SARS-CoV-2 B.1.1.529 Omicron variant pose a crisis for antibody-based immunotherapies. The efficacy of emergency use authorized (EUA) antibodies that developed in early SARS-CoV-2 pandemic seems to be in flounder. We tested the Omicron neutralization efficacy of an early B cell antibody repertoire as well as several EUA antibodies in pseudovirus and authentic virus systems. More than half of the antibodies in the repertoire that showed good activity against WA1/2020 previously had completely lost neutralizing activity against Omicron, while antibody 8G3 displayed non-regressive activity. EUA antibodies Etesevimab, Casirivimab, Imdevimab and Bamlanivimab were entirely desensitized by Omicron. Only Sotrovimab targeting the non-ACE2 overlap epitope showed a dramatic decrease activity. Antibody 8G3 efficiently neutralized Omicron in pseudovirus and authentic virus systems. The in vivo results showed that Omicron virus was less virulent than the WA1/2020 strain, but still caused deterioration of health and even death in mice. Treatment with 8G3 quickly cleared virus load of mice. Antibody 8G3 also showed excellent activity against other variants of concern (VOCs), especially more efficient against authentic Delta plus virus. Collectively, our results suggest that neutralizing antibodies with breadth remains broad neutralizing activity in tackling SARS-CoV-2 infection despite the universal evasion from EUA antibodies by Omicron variant.
RESUMEN
Emerging SARS-CoV-2 variants are threatening the efficacy of antibody therapies. Combination treatments including ACE2-Fc have been developed to overcome the evasion of neutralizing antibodies (NAbs) in individual cases. Here we conducted a comprehensive evaluation of this strategy by combining ACE2-Fc with NAbs of diverse epitopes on the RBD. NAb+ACE2-Fc combinations efficiently neutralized HIV-based pseudovirus carrying the spike protein of the Delta or Omicron variants, achieving a balance between efficacy and breadth. In an antibody escape assay using replication-competent VSV-SARS-CoV-2-S, all the combinations had no escape after fifteen passages. By comparison, all the NAbs without combo with ACE2-Fc had escaped within six passages. Further, the VSV-S variants escaped from NAbs were neutralized by ACE2-Fc, revealing the mechanism of NAb+ACE2-Fc combinations survived after fifteen passages. We finally examined ACE2-Fc neutralization against pseudovirus variants that were resistant to the therapeutic antibodies currently in clinic. Our results suggest ACE2-Fc is a universal combination partner to combat SARS-CoV-2 variants including Delta and Omicron.
RESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) continue to wreak havoc across the globe. Higher transmissibility and immunologic resistance of VOCs bring unprecedented challenges to epidemic extinguishment. Here we describe a monoclonal antibody, 2G1, that neutralizes all current VOCs and has surprising tolerance to mutations adjacent to or within its interaction epitope. Cryo-electron microscopy structure showed that 2G1 bound to the tip of receptor binding domain (RBD) of spike protein with small contact interface but strong hydrophobic effect, which resulted in nanomolar to sub-nanomolar affinities to spike proteins. The epitope of 2G1 on RBD partially overlaps with ACE2 interface, which gives 2G1 ability to block interaction between RBD and ACE2. The narrow binding epitope but high affinity bestow outstanding therapeutic efficacy upon 2G1 that neutralized VOCs with sub-nanomolar IC50 in vitro. In SARS-CoV-2 and Beta- and Delta-variant-challenged transgenic mice and rhesus macaque models, 2G1 protected animals from clinical illness and eliminated viral burden, without serious impact to animal safety. Mutagenesis experiments suggest that 2G1 could be potentially capable of dealing with emerging SARS-CoV-2 variants in future. This report characterized the therapeutic antibodies specific to the tip of spike against SARS-CoV-2 variants and highlights the potential clinical applications as well as for developing vaccine and cocktail therapy.
RESUMEN
@#Targeted programmed death-ligand 1 (PD-L1) and CXC chemokine receptor type 4 (CXCR4), gene sequences encoding anti-PD-L1 nanobody and anti-CXCR4 nanobody were cloned into the pET-22b (+) vector to construct recombinant expression plasmid of anti-PD-L1&CXCR4 bispecific nanobody, which was connected with 6 × His tag and transformed into E.coli BL21 (DE3). The expressed proteins were then found to exist as a soluble form in the supernatant of bacterial lysate after induction of IPTG.Three purification methods were used to obtain the target protein in order to improve the yield and purity of the bispecific nanobody.The bacterial supernatant was separated and purified by His Trap FF affinity chromatographic column.The target protein output could exceed 1 mg/L, and the product purity could reach up to 97%.Besides, the anti-PD-L1&CXCR4 bispecific nanobody shows a specific binding ability to two antigens on the cell surface, enhancing the cytotoxicity of IL-2 activated human peripheral blood mononuclear cells (PBMC) to tumor cell line AsPC-1, which lays the foundation for further evaluation of its drug efficacy in vivo.
RESUMEN
OBJECTIVE@#To explore the feasibility of remote monitoring of neonatal jaundice in newborns with ABO hemolytic disease.@*METHODS@#Forty six neonates of gestational age >35 weeks with ABO hemolytic disease admitted to Women's Hospital, Zhejiang University School of Medicine from January 20th, 2020 to February 29th, 2020 were enrolled in the study (study group). The newborns were followed up at home after discharge, the transcutaneous bilirubin (TCB) levels were measured by parents using the provided device and the results were sent to the doctor by smart phone using the installed APP. Fifty six newborns with ABO hemolytic disease admitted in 2018 who received conventional outpatient follow-up after discharge served as the control group. The demographic characteristics, total serum bilirubin (TSB) level during hospitalization, number of outpatient visit and rate of re-admission due to rebound hyperbilirubinemia were compared between the two groups.@*RESULTS@#There were no significant differences between the two groups in gestational age, birth weight, delivery mode, gender, length of the first hospitalization, TSB level before phototherapy and before discharge, and the managements during the first hospitalization (all @*CONCLUSIONS@#The remote follow-up for neonatal jaundice at home can effectively reduce the number of outpatient visits without increasing the risk of readmission and severe neonatal hyperbilirubinemia for newborns with ABO hemolytic disease.
Asunto(s)
Femenino , Humanos , Recién Nacido , Bilirrubina , Eritroblastosis Fetal/diagnóstico , Hiperbilirrubinemia Neonatal/diagnóstico , Ictericia Neonatal/diagnóstico , Monitoreo Fisiológico/métodos , FototerapiaRESUMEN
Objectives To analyze the risk factors for transfusion in very low birth weight infants and to explore the strategies for prevention of anemia. Methods Neonates with gestational age <37 weeks and birth weight <1500 g admitted from January 2015 to June 2016 were included. The neonates were divided into blood transfusion group and non-blood transfusion group. The general conditions and complications were compared, and the risk factors of blood transfusion and the related factors were analyzed. Results One hundred fifty cases of very low birth weight infants were included, among whom 108 cases were from blood transfusion group and 42 cases were from non-blood transfusion group. Compared with the non-blood transfusion group, the gestational age and body weight of the blood transfusion group were smaller, the basic hemoglobin was lower, the parenteral nutrition time was longer, and the total volume of blood collection in hospital was higher, and these differences were all statistically significant (P all<0.05). The incidence of bronchopulmonary dysplasia (BPD), acute respiratory distress syndrome (RDS) and patent ductus arteriosus (PDA) in the blood transfusion group were higher than those in the non-blood transfusion group, and they were all statistically different (P all <0.05). Multiple linear regression analysis showed that the volume of blood transfusion was higher when the gestational age and body weight were smaller, the longer parenteral nutrition was needed, and the total volume of blood taken from the hospital was higher (P all <0.05). Conclusions The gestational age, body weight, parenteral nutrition time and the total volume of blood collection in very low birth weight infants have different effects on blood transfusion risk and transfusion volume. The incidences of BPD, RDS, and PDA in infants with blood transfusion are higher.
RESUMEN
Objective To analyze the association of postnatal weight gain proportion of very low birth weight (BW) preterm babies and the onset of severe retinopathy of prematurity,and investigate the optimal cut-off points and predictive ability of postnatal weight gain (WG) proportion for the onset of retinopathy of prematurity (ROP).Methods A retrospective cohort study.257 preterm infants underwent screening whose weight was less than 1500 g were enrolled in this study.Risk factors include BW,gestational age (GA),history of oxygen inhalation,need for blood transfusions,Apgar score in 1 to 10 minutes,embryo number,delivery mode,in vitro fertilization infants,and WG proportion within 6 weeks after birth and other systemic diseases were recorded.Their correlation with severe ROP is analyzed.Clinical outcomes were divided into severe ROP group (patients who suffered from ROP and required treatment) and mild and no ROP group (patients who suffered from ROP but do not require treatment and-patient without ROP).The severe ROP group included 18 patients and mild and no ROP group included 239 patients.Multiple logistic regression and receiver operating characteristic (ROC) curve were used to determine if the WG proportion was independently related to severe ROP development and if it was capable of predicting severe ROP.This study determines the predict value by comparing the area under the ROC curve (AUC) of independent risk factors.Results GA (t=-4.835,P＜0.001),BW(t=-5.192,P＜0.001),history of oxygen inhalation (x2=6.001,P=0.009),proportion of infants who had oxygen inhalation for more than 10 days(x2 =10.019,P=0.002),postnatal WG proportion at 1 week(t =-3.663,P＜ 0.001),postnatal WG proportion at 2 weeks(t=-3.425,P=0.001) had significant difference between two groups.Multiple logistic regression analysis revealed that GA (β =-0.858,P =0.008),BW (β =-0.005,P =0.010),postnatal WG proportion at 2 weeks (β=-8.745,P =0.035) were correlated to severe ROP significantly.And their area under the ROC were 0.836[95％ confidence interval (CI):0.752-0.920],0.826 (95％CI:0.947-0.903),0.744 (95％CI:0.598-0.891) respectively.The optimal cut-off points of GA,BW,and postnatal WG proportion at 2 weeks were 28.41 weeks,1241.96 g,12.80％ respectively.Conclusion Low WG proportion at 2 weeks of very low BW preterm babies is an important and independent risk factor for severe ROP and has certain predictive value of the onset of severe ROP.
RESUMEN
BACKGROUND:Rheumatoid arthritis is an autoimmune disease, and traditional treatment methods are difficult to effectively solve the patient's lack of immune tolerance mechanisms. With the development of stem cel s in regenerative medicine, stem cel therapy has become a hot spot in the treatment of autoimmune diseases. Currently, studies on cel transplantation for the treatment of rheumatoid arthritis are rarely reported. OBJECTIVE:To study the influence of umbilical cord mesenchymal stem cel therapy on the changes of Th1/Th2 and Treg in rheumatoid arthritis patients, thereby seeking new therapies for rheumatoid arthritis. METHODS:We selected 180 cases of rheumatoid arthritis, including 27 patients as control group undergoing non-steroidal anti-inflammatory drugs and anti-rheumatic drugs and 153 patients as cel treatment group undergoing intravenous infusion of 40 mL umbilical cord mesenchymal stem cel s at a density of 4×107. Dosing regimen was same in the two groups. The 76 of 153 patients accepted second cel therapy at 3-4 months after the first cel therapy. After fol ow-up of 3 and 6 months, clinical effectiveness evaluation (DAS28, HAQ, ACR20), rheumatoid factor, anti-CCP antibodies, T cel subsets, Th cytokine were detected;for patients with second cel therapy, T cel subsets and Treg were detected at 8 months after treatment. RESULTS AND CONCLUSION:(1) At 3 months after treatment, the DAS28, HAQ and ACR20 scores were significantly lower in the cel treatment group than the control group (P0.05). (5) B cel levels were significantly decreased at 6 months after treatment (P>0.05);the rheumatoid factor value was significantly decreased at 3-6 months after treatment (P<0.05). (6) There was no change in anti-CCP antibody and interleukin-17 levels at 3-6 months after treatment. These findings indicate that after treatment with umbilical cord mesenchymal stem cel s, the Th1/Th2 tends to balance and Treg level is elevated in rheumatoid arthritis patients, which are directly related to clinical trials and symptomatic relief. Therefore, standard rheumatism medication combined with umbilical cord mesenchymal stem cel transplantation can improve immune network effects, adjust the immune tolerance and prevent il ness progress in rheumatoid arthritis patients.
RESUMEN
To study the umbilical cord mesenchymal stem cells impact of inflammatory factors in rheumatoid arthritis patients.Methods:94 cases of patients with RA hospitalized in our department from April 2011 to December 2012 were treated with umbilical cord mesenchymal stem cells (MSCs) UC,during which the cell therapy scholastic ethics was committed approvally and patients′informed consents were separately signed .94 patients were directly intravenous infusion with 40 ml UC-MSCs ( 4×107 cells/ml),including 57 cases with two UC-MSCs therapy.We used multifunctional flow lattice Luminex 200 analysis to detect contents of 13 kinds of factors in serum such as TNF alpha,IFN-gamma,IL-1β,IL-4,IL-6,IL-8,IL-10,ie,and detected CPR,ESR,assessment DAS28,HAQ,and ARA.Follow-up treatments were performed after 1 week,3 months,6 months ( two cells treatment of 60 cases).Results:①DAS28,HAQ grading standards,were decreased (P<0.01) in 3 months and 6 months before the patients treatment ,2 times than one continue treatment decreased ( P<0.01 );the ESR and CRP in 1 week dropped significantly after treatment ( P<0.01),3 months,6 months before the treatment also decreased (P<0.05).②IL-6,TNF alpha were in falling levels after 1 week,3 months and 6 months treatment ,( P<0.05 ).Conclusion: We proved the inflammatory factors directly related with clinical indicators and symptoms of RA patients .94 cases of patients with other inflammatory factor (IL-17,IL-4,IL-10,etc.) also had some change,we still needed further observation.According to drug rheumatism guide at the same time , collaborative using with UC-MSCs could make RA patients improve local and systemic inflammatory response ,prevent disease progression.
RESUMEN
Objective To test the effects of restuscitation with air or oxygen on the blood gas and cerebral superoxide dismutase (SOD) concentration in neonatal rats with experimental intrauterine asphyxia. Method Seventy-seven neonatal rats were randomly (random number) divided into three experimental groups: sham operation group (SHAM), air resuscitation group (AR), and oxygen resuscitation group (OR). In groups AR and OR, animal models of intrauterine asphyxia were established and then resuscitated with air (AR) or oxygen (OR) for 30min. Comparison was made between groups including the mortality 0 hour after resuscitation, and the levels of blood gas and cerebral SOD concentrations 0 h, 6 h and 24 h after resuscitation. Results Mortality of neonatal rats in SHAM group, AR group and OR group were 0 (0/24), 0 (0/26) and 3.7% (1/27), respectively (P ＞0.05). The average levels of blood PaO2 in OR group and AR group 0 h after resuscitation were (69.2 ± 8.2)mmHg and (55.5±10.3) mmHg,respectively (P=0.004). Blood pH and PaCO2 and BE levels in OR group 0 h after resuscitation were not significantly different from those in AR group (P＞0.05). Blood pH, PO2, PCO2and BE levels in OR group were also not significantly different from those in AR group 6 h and 24 hours after resuscitation. The average concentrations of cerebral SOD in OR group 0 h and 6 hours after resucitation were (38.3±9.8) U/mgprot and (8.6±3.6) U/mgprot, and those in AR group were (53.8± 10.6) U/mgprot and (13.0±4.6) U/mgprot, respectively (P = 0.003, 0.04). The cerebral SOD concentration in OR group 24 hours after resuscitation was not significantly different from that in AR group (P＞0.05). The cerebral SOD concentrations in SHAM group 0 h,6 h and 24 hours after resuscitation were much higher than those in OR group and AR group (P＜0.05). Conclusions Resuscitation with air is as good as pure oxygen in neonatal resuscitation, in respect of early mortality and improvement of acidosis in neonatal rats after intrauterine asphyxia. Resuscitation with air will generate less radical oxygen species than pure oxygen in neonatal rats after intrauterine asphyxia.
RESUMEN
Four phthalocyanines (iron tetracarboxylphthalocyanine, copper tetracarboxylphthalocyanine, manganese tetracarboxylphthalocyanine, cobalt tetracarboxylphthalocyanine) were used as dual functional mimic enzymes of superoxide dismutase (SOD) and catalase (CAT). The first function, eliminating O2－, was proved by using riboflavine-methionine photoreduction method in the concentration range of 10－5 to 10－6 mol/L. The second function, clearing out H2O2, was demonstrated by means of spectrophotometry with the decomposing percentage being increased with the increase of the concentration of the imitating compounds. Measurements of metal phthalocyanines, SOD and CAT by the liver homogenate technique of mice showed that they had obvious action of decreasing the lipid peroxidation.
RESUMEN
Four phthalocyanines (iron tetracarboxylphthalocyanine, copper tetracarboxylphthalocyanine, manganese tetracarboxylphthalocyanine, cobalt tetracarboxylphthalocyanine) were used as dual functional mimic enzymes of superoxide dismutase (SOD) and catalase (CAT). The first function, eliminating O2－, was proved by using riboflavine-methionine photoreduction method in the concentration range of 10－5 to 10－6 mol/L. The second function, clearing out H2O2, was demonstrated by means of spectrophotometry with the decomposing percentage being increased with the increase of the concentration of the imitating compounds. Measurements of metal phthalocyanines, SOD and CAT by the liver homogenate technique of mice showed that they had obvious action of decreasing the lipid peroxidation.
RESUMEN
Objective To study the effect of hypoxia ischemia on cysteinyl aspartate specific proteinases (caspase 3) activity in cerebral tissue of neonatal rat and probe into its significance Methods To induce hypoxic ischemic brain damage (HIBD), the left carotid artery of rats at day 7 was ligated and animals were exposed to 8% oxygen for 2 hours 0 5,12,24,and 48 hours after HIBD, both ipsilateral and contralateral cerebral tissue were ditected and homogenized caspase 3 activity was measured by cleavage of the colorimetric substrate DEVD pNA Results Caspase 3 activity in ipsilateral cerebral tissue increased gradually after HIBD and peaked at 24 hours, and then decreased significantly at 48 hours( P 0 05) Conclusions Significant activation of caspase 3 after cerebral hypoxia ischemia strongly suggests that apoptosis is involved in HIBD Application of caspase inhibitors or other anti apoptotic agents may become a new therapeutics of HIBD
RESUMEN
Objective To study the effect of hypoxia-ischemia on cysteinyl aspartate-specific proteinases (caspase-3) activity in cerebral tissue of neonatal rat and probe into its significance. Methods To induce hypoxic-ischemic brain damage (HIBD), the left carotid artery of rats at day 7 was ligated and animals were exposed to 8% oxygen for 2 hours. 0.5,12,24,and 48 hours after HIBD, both ipsilateral and contralateral cerebral tissue were ditected and homogenized. caspase-3 activity was measured by cleavage of the colorimetric substrate DEVD-pNA. Results Caspase-3 activity in ipsilateral cerebral tissue increased gradually after HIBD and peaked at 24 hours, and then decreased significantly at 48 hours（P<0.001）. There were no significant changes in caspase-3 activity in the contralateral tissue at all time points (P>0.05）. Conclusions Significant activation of caspase-3 after cerebral hypoxia-ischemia strongly suggests that apoptosis is involved in HIBD. Application of caspase inhibitors or other anti-apoptotic agents may become a new therapeutics of HIBD.
RESUMEN
Objective:To investigate the negative effect of the IL-10 on monocyte-derived DC maturation and differation iv vitro,and the potentiation of the TNF-? or sCD40L to inhibit or reverse the IL-10′s inhibitory effect on monocyte-derived DC.Methods:The expression of the surface molecules on DC was detected by FACS analysis.The potentiation to stimulate T cell proliferation was assayed by 3H-TdR incorporation,and IL-12 secretion in the DC supernatant measured by ELISA.Results:In vitro DC-inducing system IL-10 had an obviously negative effect on the maturation as well as the potentiation to stimulate the T cell proliferation and IL-12 secretion of the immature monocyte-derived DC,and IL-10 could drive monocyte-derived DC differentiate into the macrophages.The negative effect was also correlative to the concentration of the added IL-10;The results also showed that IL-10 hadn′t any negative effect on mature DC induced by sCD40L,but to some extent could reduce the mature DC induced by TNF-? to produce IL-12;Furthermore the inhibitory effect of IL-10 can′t be reversed by adding TNF-? or sCD40L after IL-10 was added to the DC-inducing culture system for three days.Interesting by adding sCD40L not TNF-? to the DC-inducing culture system with IL-10 at the same time can inhibit the negative effect of IL-10 completely.Conclusion:IL-10 is an important biological factor produced in tumor microenvironment for escaping the attack of the immune system by repressing maturation,potentiation to costimulate the T cells and IL-12 secretion of the immature monocyte-derived DC.The reverse effect of TNF-? and sCD40L on IL-10 negative effect on monocyte-derived was different.All together suggested that CD40 signal has important values to obtain the therapeutic DC for the tumor immune intervention.
