Neutralization of Omicron BA.4/BA.5 and BA.2.75 by Booster Vaccination or BA.2 Breakthrough Infection Sera

Many new Omicron sub-lineages have been reported to evade neutralizing antibody response, including BA.2, BA.2.12.1, BA.4 and BA.5. Most recently, another emerging sub-lineage BA.2.75 has been reported in multiple countries. In this study, we constructed a comprehensive panel of pseudoviruses (PsVs), including wild-type, Delta, BA.1, BA.1.1, BA.2, BA.3, BA.2.3.1, BA.2.10.1, BA.2.12.1, BA.2.13, BA.2.75 and BA.4/BA.5, with accumulate coverage reached 91% according to the proportion of sequences deposited in GISAID database since Jan 1st, 2022. We collected serum samples from healthy adults at day14 post homologous booster with BBIBP-CorV, or heterologous booster with ZF2001, primed with two doses of BBIBP-CorV, or from convalescents immunized with three-dose inactivated vaccines prior to infection with Omicron BA.2, and tested their neutralization activity on this panel of PsVs. Our results demonstrated that all Omicron sub-lineages showed substantial evasion of neutralizing antibodies induced by vaccination and infection, although BA.2.75 accumulated the largest number of mutations in its spike, BA.4 and BA.5 showed the strongest serum escape. However, BA.2 breakthrough infection could remarkably elevated neutralization titers against all different variants, especially titers against BA.2 and its derivative sub-lineages.

Preliminary evaluation of the safety and efficacy of oral human antimicrobial peptide LL-37 in the treatment of patients of COVID-19, a small-scale, single-arm, exploratory safety study

Background& AimsThe Coronavirus Disease 2019 (COVID-19) has become a global epidemic and has caused a lasting and huge loss of life security, economic development and social stability in more than 180 countries around the world. Unfortunately, there is still no specific treatment for COVID-19 till now, therefore, at this point, all potential therapies need to be critically considered. LL-37 is one of the best-studied human antimicrobial peptide (AMPs) that has a broad-spectrum activity against bacteria and viruses. The use of living, genetically modified organisms (GMOs) is an effective approach for delivery of therapeutic proteins. The aim of this study was to determine the safety and efficacy of the Lactococcus lactis which has been genetically modified to produce the therapeutic human antimicrobial peptide LL-37 (herein after referred to cas001) in the patients of COVID-19. MethodsFirstly we constructed genetically modified food-grade probiotic, Lactococcus lactis, with sequence of seven tandem repeats of mature human LL-37 under control of the nisin-inducible nisA promoter to produce the cas001. A total of 20 healthy SD rats, half male and half female (There were five male and five female in the control group, the same in treatment group) were used to observe the acute toxic reaction and death after daily administration of cas001 for three weeks, which helps to provide necessary reference basis for clinical dose selection, verificaition of toxic reaction and possible target organs. According to the estimated clinical dosage of 1 x 108CFU /kg/day, considering the conversion of body surface area, the dose for rats should be multiplied by 6.17 to 6 x 108 CFU/kg/day. We administrated 100 times higher dose at 6 x 1010 CFU/ /kg/day to rats. In order to investigate the pharmacokinetics of cas001, male SD rats (body weight 250-300g, 1 x 1010 /animal, n=3) were given oral administration of LL-37 bacteria powder. The concentration of LL-37 in the blood before and after gavage was detected by ELISA kit (Hycult biotechnology Cat# HK321). Human clinical study was approved by Ethics committee of Chinese PLA General Hospital (S2020-074-04) and a total of 11 patients with mild symptoms were enrolled in Wuhan hankou hospital and Huoshenshan hospital. They were enrolled voluntarily and all patients signed informed consent. Among them, there were 5 males and 6 females, aged 55 {+/-} 12 (36-70) years old, and the duration from onset to medication enrollment was 35 {+/-} 19 (5-68) days. 6 patients were nucleic acid positive and 5 patients were nucleic acid negative when they were enrolled. All patients received the oral drug cas001 treatment according to requirement(1 x 109 CFU/capsule, 3 capsules/time, three times a day for 3weeks), with an average follow-up time of 33 {+/-} 15 days (see table 1 for the results). O_TBL View this table: org.highwire.dtl.DTLVardef@1845d29org.highwire.dtl.DTLVardef@1004b38org.highwire.dtl.DTLVardef@4a741aorg.highwire.dtl.DTLVardef@c73d5org.highwire.dtl.DTLVardef@188b563_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable 1.C_FLOATNO O_TABLECAPTIONSerum biochemical detection in rats two weeks after gavage Serum biochemistry detection of rats at the end of two weeks (Vehicle[male] v.s. LL-37[male], n=5; Vehicle[female] v.s. LL-37[female], n=5). *represent p value<0.05. C_TABLECAPTION C_TBL FindingsWestern blot analysis shows that reasonable amount of LL-37 were induced by different concentrations of nisin, which means we have successfully constructed cas001. In the pre-clinical safety evaluation test, after three weeks administration of cas001, no adverse effects were observed on the rats body weight, food and water intake, hematological or serum biochemical parameters. The results showed that the LD50 of cas001 was higher than that of the 100 times of the expected clinical dose of 6 x 1010 CFU/day. These results showed that cas001 could be safe in animal experiments. In addition, rat pharmacokinetics results showed that the serum concentration of LL-37 reached peak 2 hours after gavage of cas001 and returned to basal level 6 hours after gavage. During study period, the volunteers did not feel any discomfort while taking the cas001 capsules, and two hours after oral administration, the concentration of LL-37 were increased in healthy volunteers. cas001 shows definite effect in the improvement of gastrointestinal symptoms and is possible to have effects in improving the systemic symptoms and respiratory symptoms and may play a role in the improvement of results of nucleic acid test and lung CT test. 11 patients enrolled showed good compliance, tolerance, subjective feeling and actively interacted with the doctors. None of the patients had any adverse reactions. ConclusionsBased on above observations, we conclude here that as an oral anti-viral agent, cas001 displayed good safety profiles. It is very hard to reach conclusion of clinical outcomes related to the cas001, although changes of several symptoms indicate encouraging findings.

Comparison of DNA extraction methods from four Chinese traditional medical herbs / 中国生化药物杂志

Objective To establish an optimum DNA extraction method for Chinese traditional medical herbs in order to meet necessary for DNA barcoding research.Methods Four Chinese traditional herbs, Glycyrrhiza uralensis Fisch, Phellodendron Chinensis Cortex, Cistanche tubulosa Wight and Cistanche deserticola Ma were chosen as the experimental materials, the DNA was extracted by 6 different kinds of DNA extraction method, including the improved method of high-salt combined low-pH,the improved method of SDS,CTAB method,PVP method,PlantZol Kit and Ezup Kit, the quality of DNA was investigated by ultraviolet spectrophotometry,agarose gel electrophoresis and PCR amplification by using specific primers of ITS2 and psbA-trnH. ResuIts The quality of the DNA was better than other four kinds of methods by the improved method of high-salt combined low-pH and Ezup Kit, the value of OD260/OD280 was between 1.7 ~1.9,the yield of DNA was the highest by the PlantZol kit , followed by the improved method of high-salt combined low-pH( P <0.05 ) , but the purity of DNA was poor by the PlantZol kit.The DNA electrophoresis tests showed that the DNA integrity of Glycyrrhiza uralensis Fisch and Cistanche tubulosa Wight were better with the improved method of high-salt combined low-pH, the improved SDS method, the CTAB method and the PlantZol kit.The DNA of Phellodendron Chinensis Cortex and Cistanche deserticola Ma were extracted by the six methods appeared diffuse status in the lanes.But only the improved method of high-salt combined low-pH could make the PCR amplification of the success rate 100% by using specific primers of ITS2 and trnH-psbA.ConcIusion The DNA extraction method of high-salt combined low-pH can be used to establish the Chinese DNA barcoding which has the advantages of lower cost, simpler procedure and less time.

Construction and function detection of EMMPRIN glycosylation mutantion plasimid / 吉林大学学报(医学版)

Objective To construct in the extracellular matrix metalloproteinase inducer (EMMPRIN)glycosylation single point mutation plasmid,and to explore its relationship with tumor cell proliferation.Methods PCR point mutantion technology was used to construct the mutantion plasimid of EMMPRIN glycosylation single point.After successful mutation, the function of mutantion plasmids were detected. Western blotting was used to detect the expression of EMMPRIN protein,immunofluorescence method was used to detemine the morphological changes of the cells,and MTT assay was performed to detect the relationship between mutantion pasmid and tumor cell proliferation.Results Confirmed by restriction enzyme digestion and sequencing,the 44th,the 152th,and the 186th Asn were successfully mutated to Gln in the sequence of EMMPRIN;EMMPRIN/GFP (N44Q), EMMPRIN/GFP(N152Q),and EMMPRIN/ GFP (N186Q)glycosylation single point mutation plasmids were constructed.Compared with wild-type,thel morphology of the cells was significantly changed,the core division of mutant-type cells was significantly reduced, the number of filopodia was reduced. The results of MTT assay showed that the survival rate of the cells in wild-type group were significantly increased compared with control group (P<0.05 );the survival rates of the cells in EMMPRIN (N44Q) group, EMMPRIN (N152Q) group and EMMPRIN(N186Q)were significantly decreased compared with wild-type group(P<0.05).Conclusion Mutant-type EMMPRIN can inhibit the proliferation of tumor cells;with the duration increasing, the inhibitory effect is weakened.There is a correlation between EMMPRIN glycosylation and proliferation of tumor cells.