Growth phenotypes and biosafety profiles in poliovirus-receptor transgenic mice of recombinant oncolytic polio/human rhinoviruses

The use of oncolytic recombinant polioviruses has an important therapeutic potential in the treatment of human gliomas. This study was carried out to assess parameters of the utility of the oncolytic poliovirus/human rhinovirus type 2 chimeras (PV/HRV2). The prototype PV/HRV2 chimera was constructed containing the complete genome of wild-type PV type 1 (Mahoney) [PV1(M)] in which the cognate IRES was replaced with that of HRV2 [called PV1(RIPO)]. A derivative of PV1(RIPO) is PV1(RIPOS) in which the capsid coding region (P1) was replaced with the capsid-coding region of the PV type 1 (Sabin) [PV1(S)] vaccine strain. In addition, a third PV/HRV2 chimera was constructed containing the complete genome of PV1(S) in which the cognate IRES was replaced with that of HRV2 [termed PVS(RIPO)]. To analyze the growth phenotypes of PV/HRV2 recombinants [PV1(RIPO), PV1(RIPOS), PVS(RIPO)], one-step growth experiments were performed in four human cell lines at three different temperatures. To address the safety profile, PVS(RIPO) was injected into the brain of CD155 tg mice at the dose 10(7) PFU. Then, clinical signs, persistence of the virus in the CNS and genetic stability of PVS(RIPO) replicating in the CNS were evaluated. The data obtained in the present study suggest (i) a correlation between temperature-sensitive (ts) phenotype in both neuronal and non-neuronal cell lines and neuroattenuation in experimental animals, (ii) that PVS (RIPO) is genetically stable on replication in the CNS of poliovirus-susceptible mice. These findings highlight the safety of intracerebral inoculation of PVS(RIPO) for the treatment of human glioma.     

基于斑马鱼模型的鳗弧菌减毒活疫苗的生物安全性评价

利用疫苗对养殖鱼类进行疾病预防正得到逐步应用,而减毒活疫苗通过浸泡方式也能使鱼体获得较高的免疫保护力。利用模式动物斑马鱼对鳗弧菌减毒活疫苗MVAV6203的生物安全性进行了评价。首先进行了疫苗对斑马鱼毒性实验,每条鱼注射免疫的半致死量为9.26×104 CFU;其次分析了鳗弧菌在水体中的存活情况,菌体浓度在1.0×106 CFU/mL条件下,10 d后水体基本检测不到鳗弧菌;最后考察了其在鱼体内的存活情况,注射或浸泡免疫3 d后,鱼体组织匀浆物未检测到该菌,表明鳗弧菌减毒活疫苗具有较好的生物安全性。     

Efficacy of recombinant Marek’s disease virus vectored vaccines with computationally optimized broadly reactive antigen (COBRA) hemagglutinin insert against genetically diverse H5 high pathogenicity avian influenza viruses

The genetic and antigenic drift associated with the high pathogenicity avian influenza (HPAI) viruses of Goose/Guangdong (Gs/GD) lineage and the emergence of vaccine-resistant field viruses underscores the need for a broadly protective H5 influenza A vaccine. Here, we tested experimental vector herpesvirus of turkey (vHVT)-H5 vaccines containing either wild-type clade 2.3.4.4A-derived H5 inserts or computationally optimized broadly reactive antigen (COBRA) inserts with challenge by homologous and genetically divergent H5 HPAI Gs/GD lineage viruses in chickens. Direct assessment of protection was confirmed for all the tested constructs, which provided clinical protection against the homologous and heterologous H5 HPAI Gs/GD challenge viruses and significantly decreased oropharyngeal shedding titers compared to the sham vaccine. The cross reactivity was assessed by hemagglutinin inhibition (HI) and focus reduction assay against a panel of phylogenetically and antigenically diverse H5 strains. The COBRA-derived H5 inserts elicited antibody responses against antigenically diverse strains, while the wild-type-derived H5 vaccines elicited protection mostly against close antigenically related clades 2.3.4.4A and 2.3.4.4D viruses. In conclusion, the HVT vector, a widely used replicating vaccine platform in poultry, with H5 insert provides clinical protection and significant reduction of viral shedding against homologous and heterologous challenge. In addition, the COBRA-derived inserts have the potential to be used against antigenically distinct co-circulating viruses and future drift variants.     

Protection of White Leghorn chickens by recombinant fowlpox vector vaccine with an updated H5 insert against Mexican H5N2 avian influenza viruses

Despite decades of vaccination, surveillance, and biosecurity measures, H5N2 low pathogenicity avian influenza (LPAI) virus infections continue in Mexico and neighboring countries. One explanation for tenacity of H5N2 LPAI in Mexico is the antigenic divergence of circulating field viruses compared to licensed vaccines due to antigenic drift. Our phylogenetic analysis indicates that the H5N2 LPAI viruses circulating in Mexico and neighboring countries since 1994 have undergone antigenic drift away from vaccine seed strains. Here we evaluated the efficacy of a new recombinant fowlpox virus vector containing an updated H5 insert (rFPV-H5/2016), more relevant to the current strains circulating in Mexico. We tested the vaccine efficacy against a closely related subcluster 4 Mexican H5N2 LPAI (2010 H5/LP) virus and the historic H5N2 HPAI (1995 H5/HP) virus in White Leghorn chickens. The rFPV-H5/2016 vaccine provided hemagglutinin inhibition (HI) titers pre-challenge against viral antigens from both challenge viruses in almost 100% of the immunized birds, with no differences in number of birds seroconverting or HI titers among all tested doses (1.5, 2.0, and 3.1 log₁₀ mean tissue culture infectious doses/bird). The vaccine conferred 100% clinical protection and a significant decrease in oral and cloacal virus shedding from 1995 H5/HP virus challenged birds when compared to the sham controls at all tested doses. Virus shedding titers from vaccinated 2010 H5/LP virus challenged birds significantly decreased compared to sham birds especially at earlier time points. Our results confirm the efficacy of the new rFPV-H5/2016 against antigenic drift of LPAI virus in Mexico and suggest that this vaccine would be a good candidate, likely as a primer in a prime-boost vaccination program.     

四种消毒剂应用于DUWLs微生物污染控制的生物安全性评价

目的　评价四种不同消毒剂应用于牙科治疗椅水路系统(Dental Unit Waterlines, DUWLs)微生物污染控制的生物安全性。方法 通过CCK-8法研究四种不同的消毒剂：过氧化氢纳米银离子消毒剂（Sanosil）、次氯酸钠消毒剂（NaClO）、过氧化氢消毒剂(H2O2)和洗必泰（Chlorhexidine,CHX）在不同浓度时在体外对人口腔黏膜上皮细胞细胞毒性,比较不同消毒剂使用的生物安全性。结果 四种消毒剂在常用的消毒浓度下与人口腔上皮黏膜细胞作用一定时间下均可产生细胞毒性,但0.2%过氧化氢纳米银离子消毒剂和0.2%的洗必泰毒性等级为中度毒性（2级）,5.25%次氯酸钠和3%过氧化氢毒性等级为重度毒性（4级）。结论 不同消毒剂在体外的细胞毒性不同,过氧化氢纳米银离子和洗必泰在牙科综合治疗台水路污染控制的常用浓度上对细胞的毒性低于次氯酸钠和过氧化氢,相对安全。     

RNA replicons - a new approach for influenza virus immunoprophylaxis

RNA replicons are derived from either positive- or negative-strand RNA viruses. They represent disabled virus vectors that are not only avirulent, but also unable to revert to virulence. Due to autonomous RNA replication, RNA replicons are able to drive high level, cytosolic expression of recombinant antigens stimulating both the humoral and the cellular branch of the immune system. This review provides an update on the available literature covering influenza virus vaccines based on RNA replicons. The pros and cons of these vaccine strategies will be discussed and future perspectives disclosed.     

Hematotoxicity and genotoxicity evaluations in Swiss mice intraperitoneally exposed to Bacillus thuringiensis (var kurstaki) spore crystals genetically modified to express individually Cry1Aa,Cry1Ab,Cry1Ac,or Cry2Aa

Bacillus thuringiensis (Bt) has been widely used in foliar sprays as part of integrated pest management strategies against insect pests of agricultural crops. Since the advent of genetically modified plants expressing Bt δ‐endotoxins, the bioavailability of Cry proteins has increased, and therefore for biosafety reasons their adverse effects should be studied, mainly for nontarget organisms. We evaluated, in Swiss mice, the hematotoxicity and genotoxicity of the genetically modified strains of Bt spore crystals Cry1Aa, 1Ab, 1Ac, or 2Aa at 27 mg/kg, and Cry1Aa, 1Ab and 2Aa also at 136 and 270 mg/kg, administered with a single intraperitoneal injection 24 h before euthanasia. Controls received filtered water or cyclophosphamide. Blood samples collected by cardiac puncture were used to perform hemogram, and bone marrow was extracted for the micronucleus test. Bt spore crystals presented toxicity for lymphocytes when in higher doses, which varied according to the type of spore crystal studied, besides promoting cytotoxic and genotoxic effects for the erythroid lineage of bone marrow, mainly at highest doses. Although the profile of such adverse side effects can be related to their high level of exposure, which is not commonly found in the environment, results indicated that these Bt spore crystals were not harmless to mice. This suggests that a more specific approach should be taken to increase knowledge about their toxicological properties and to establish the toxicological risks to nontarget organisms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 970–978, 2016.     

生物安全实验室中生物安全柜使用现状调查

目的了解浙江省生物安全实验室内生物安全柜的使用现状,确保实验室生物安全。方法采用资料调查和现场检测的方法对医疗疾控机构实验室使用中生物安全柜现状进行了调查。结果共调查42家实验室120台生物安全柜,其中A2型生物安全柜占70%,B2型生物安全柜占30%。这些生物安全柜摆放位置符合生物安全要求的占67.5%,洁净度合格率为75.8%。生物安全柜内微小气候检测指标多数合格率较低。结论医疗机构实验室生物安全柜性能检测合格率较低,存在生物安全隐患。     

医院检验科工作人员的生物安全防护

探讨医院检验科工作人员的生物安全预防教育,生物安全防护意识,生物安全防护措施,使实验室每个工作人员不仅成为生物安全的受益者,又是合格的管理者。