A New Tandem Gene Construction Method Involving a Cloning System Using <i>Poxvirus DNA polymerase</i>, and Its Application to Gene Expression

A simple method for constructing polymerized genes using only restriction enzymes and commercially available cloning systems was established. In this system, gel isolations or purifications of target genes after restriction enzyme digestions or PCR amplifications, which often cause errors and mutations in the target gene sequence, are not necessary. To verify the usefulness of this method, one, two, four, eight, and sixteen tandem-repeats of the Green Fluorescent Protein (GFP) expression gene in Escherichia coli were sequentially constructed. Efficacies of the GFP gene expression of those plasmids in E. coli showed an increasing trend in accordance with the copy numbers of the gene. On SDS polyacrylamide gel electrophoresis with Coomassie blue staining, no expressed protein could be seen in E. coli cells harboring plasmids that contained one or two copies of the gene. However, expressed protein bands in E. coli cells were clearly detected with 4 copies of the gene. In quantitative analyses involving green fluorescence intensities per culture volume, the expression level in E. coli with 16 copies of the gene was 36.3-fold higher than that in E. coli with one copy at 22 hours after induction.

Subversion of cellular stress responses by poxviruses

Cellular stress responses are powerful mechanisms that prevent and cope with the accumulation of macromolecular damage in the cells and also boost host defenses against pathogens. Cells can initiate either protective or destructive stress responses depending, to a large extent, on the nature and duration of the stressing stimulus as well as the cell type. The productive replication of a virus within a given cell places inordinate stress on the metabolism machinery of the host and, to assure the continuity of its replication, many viruses have developed ways to modulate the cell stress responses. Poxviruses are among the viruses that have evolved a large number of strategies to manipulate host stress responses in order to control cell fate and enhance their replicative success. Remarkably, nearly every step of the stress responses that is mounted during infection can be targeted by virally encoded functions. The fine-tuned interactions between poxviruses and the host stress responses has aided virologists to understand specific aspects of viral replication; has helped cell biologists to evaluate the role of stress signaling in the uninfected cell; and has tipped immunologists on how these signals contribute to alert the cells against pathogen invasionand boost subsequent immune responses. This review discusses the diverse strategies that poxviruses use to subvert host cell stress responses.

Cross-species transmission and host range genes in poxviruses

The persistent epidemic of human mpox, caused by mpox virus (MPXV), raises concerns about the future spread ofMPXV and other poxviruses. MPXV is a typical zoonotic virus which can infect human and cause smallpox-likesymptoms. MPXV belongs to the Poxviridae family, which has a relatively broad host range from arthropods tovertebrates. Cross-species transmission of poxviruses among different hosts has been frequently reported andresulted in numerous epidemics. Poxviruses have a complex linear double-strand DNA genome that encodeshundreds of proteins. Genes related to the host range of poxvirus are called host range genes (HRGs). This reviewbriefly introduces the taxonomy, phylogeny and hosts of poxviruses, and then comprehensively summarizes thecurrent knowledge about the cross-species transmission of poxviruses. In particular, the HRGs of poxvirus aredescribed and their impacts on viral host range are discussed in depth. We hope that this review will provide acomprehensive perspective about the current progress of researches on cross-species transmission and HRGvariation of poxviruses, serving as a valuable reference for academic studies and disease control in the future.

Freeze-Drying Formulations Increased the Adenovirus and Poxvirus Vaccine Storage Times and Antigen Stabilities

Successful vaccines induce specific immune responses and protect against various viral and bacterial infections. Noninactivated vaccines, especially viral vector vaccines such as adenovirus and poxvirus vaccines, dominate the vaccine market because their viral particles are able to replicate and proliferate in vivo and produce lasting immunity in a manner similar to natural infection. One challenge of human and livestock vaccination is vaccine stability related to the antigenicity and infectivity. Freeze-drying is the typical method to maintain virus vaccine stability, while cold chain transportation is required for temperatures about 2 °C–8 °C. The financial and technological resource requirements hinder vaccine distribution in underdeveloped areas. In this study, we developed a freeze-drying formula consisting of bovine serum albumin(BSA), L-glutamic acid(L-Glu), polyethylene glycol(PEG), and dextran(DEX) to improve the thermal stability and activity of viral vaccines, including vaccinia recombinant vaccine(rTTV-OVA) and adenovirus vaccine(Ad5-ENV). We compared a panel of five different formulations(PEG: DEX: BSA: L-GLU = 50:9:0:0(#1), 50:5:4:0(#2), 50:10:9:0(#3),50:0:0:9(#4), and 50:1:0:8(#5), respectively) and optimized the freeze-drying formula for rTTV-OVA and Ad5-ENV. We found that the freeze-drying formulations #2 and #3 could maintain rTTV-OVA infectivity at temperatures of 4 °C and25 °C and that r TTV-OVA immunogenicity was retained during lyophilization. However, formulations #4 and #5 maintained Ad5-ENV infectivity under the same conditions, and Ad5-ENV immunogenicity had maximum retention with freeze-drying formulation #4. In summary, we developed new freeze-drying formulations that increased virus vaccine storage times and retained immunogenicity at an ambient temperature.

An unfolding monkeypox outbreak in Europe and beyond

Dear Editor,Monkeypox is a zoonotic disease caused by the monkeypox virus(MPXV),a double-stranded DNA virus in the genus Orthopoxvirus,family Poxviridae.MPXV is known to be transmitted between animals such as rats and squirrels,but animal-to-human and human-to-human transmission has been known in Africa since 1970.Transmission is linked to direct contact with body fluids,skin lesions,and patient items as well as respiratory droplets in case of prolonged face-to-face contact[1].Until recently,only a few cases were associated with travel to endemic countries or contact with infected animals imported from endemic countries.

Migratory Phenomenons, Bioethics and Vaccinations

The evolution of the HIV following migratory phenomenons is reported in an interesting study carried on for 15 years. Polymerase Chain Reaction (PCR) is a technique in molecular biology that amplifies a specific region of deoxyribonucleic acid (DNA), and has been useful in the molecular characterization of viruses as poxviruses. In many countries, such as?Italy,the vaccinations are included in the so-called sanitary obliged not coercive treatments. This means that the obligation is anticipated for all the subjects belonging to one determined range of age to undergo some vaccinations, but these are not subministrated by force in case of refusal. The legitimacy of the obligatory vaccination against the smallpox, with all the risks connected,?stated that such “risks were too much reduced to be seriously taken in consideration for the benefits produced on the collectivity”.?To ratify this obligation brings, however, to the reimbursement of the?incidental?damages produced by the vaccination. Nevertheless, mass vaccination against smallpox continues to be a leading initiative in western countries to guard against bioterrorist attack.

非复制型痘苗病毒的生物学性状研究进展

痘病毒被广泛用于针对多种感染性疾病和癌症的疫苗研究,而非复制型痘苗病毒的发展又进一步提高了其安全性。来源于中国天花疫苗株的复制缺陷型痘苗病毒天坛株(NTV)正是一株非复制型痘苗病毒。为了促进未来NTV作为疫苗候选株在临床中的应用,我们对NTV与另外2株非复制型痘苗病毒,即改良痘苗病毒安卡拉株(MVA)和NYVAC的生物学性状做简要综述,主要讨论了它们的基因组结构、体外生长特性、病毒复制和形态发生、组织中的病毒分布和病毒-宿主细胞间的相互作用。

Vaccinia virus viability under different environmental conditions and different disinfectants treatment

Monkeypox(mpox)outbreak in 2022 has caused more than 91,000 cases,has spread to 115 countries,regions,and territories,and has thus attracted much attention.The stability of poxvirus particles in the environment is recognized as an important factor in determining their transmission.However,few studies have investigated the persistence of poxviruses on material surfaces under various environmental conditions,and their sensitivity to biocides.Here,we systematically measured the stability of vaccinia virus(VACV)under different environmental conditions and sensitivity to inactivation methods via plaque assay,quantitative real‐time polymerase chain reaction(qPCR),and Gaussia luciferase(G‐luciferase)reporter system.The results show that VACV is stable on the surface of stainless steel,glass,clothing,plastic,towel,A4 paper,and tissue and persists much longer at 4℃ and?20℃,but is effectively inactivated by ultraviolet(UV)irradiation,heat treatment,and chemical reagents.Our study raises the awareness of long persistence of poxviruses in the environment and provides a simple solution to inactivate poxviruses using common disinfectants,which is expected to help the control and prevention of mpox virus and future poxvirus outbreaks.

痘病毒非结构蛋白拮抗IFN-I介导免疫逃逸机制研究进展

近些年,猴痘病毒、牛结节性皮肤病病毒等痘病毒给公共卫生和畜牧业健康发展带来了巨大危害,引起全球广泛关注。痘病毒(Poxviridae)是一种大型双链DNA病毒,宿主范围广。在与宿主长期作用过程中,痘病毒通过编码非结构蛋白来逃逸宿主IFN-I介导的免疫反应。本文综述了痘病毒编码的非结构蛋白拮抗IFN-I天然免疫反应的研究进展,为防控痘病毒传播提供理论依据,为痘病毒新型疫苗研发及药物靶点筛选提供参考。

痘病毒病:值得高度重视的一类人兽共患病

痘病毒（poxvirus）是已知的病毒粒子中基因组最大、最复杂的以及宿主范围最广和成员最多的病毒家族,其大部分成员又都能引起动物源性人兽共患病。目前猴痘、羊口疮、禽痘、鼠痘及羊痘在国内外普遍流行、危害严重。本文通过对动物源性人兽共患痘病毒病的介绍,来促进我国加强对痘病毒病的基础理论研究以及防控技术战略储备,以保障人类、动物健康和国家安全。

Unusual global outbreak of monkeypox:what should we do?

Recently,monkeypox has become a global concern amid the ongoing COVID-19 pandemic.Monkeypox is an acute rash zoonosis caused by the monkeypox virus,which was previously concentrated in Africa.The re-emergence of this pathogen seems unusual on account of outbreaks in multiple nonendemic countries and the incline to spread from person to person.We need to revisit this virus to prevent the epidemic from getting worse.In this review,we comprehensively summarize studies on monkeypox,including its epidemiology,biological characteristics,pathogenesis,and clinical characteristics,as well as therapeutics and vaccines,highlighting its unusual outbreak attributed to the transformation of transmission.We also analyze the present situation and put forward countermeasures from both clinical and scientific research to address it.