CN106636014A - Novel in-vitro and in-vivo infection model based on Ebola virus-like particles - Google Patents

Abstract

The invention provides a novel infection model based on EBOV (Ebola Virus) virus-like particles (VLP) and taking firefly luciferase (Fluc) as a reporter protein. The model enters cells with the help of an EBOV envelope protein (GP); the Fluc can be introduced into the cells after the model enters the cells, so that cell infection can be quantified according to signal intensity of the Fluc in the cells; mouse infection can be quantified through biological imaging according to signal intensity of bioluminescence in a mouse body. Therefore, the inventor can utilize the model to carry out in-vitro and in-vivo pre-screening experiments on a neutralizing antibody and an entered inhibitor of the GP outside a BSL-4 (Biosafety Level-4) laboratory.

Description

A kind of new infection model of in vitro and in vivo based on Ebola virus sample granule

Technical field

The invention belongs to biological technical field, specifically, the present invention relates to a kind of be based on Ebola virus sample The new infection model of in vitro and in vivo of granule.

Background technology

Ebola disease viral disease (Ebola virus disease, EVD) be by Ebola virus (Ebola viruses, EBOV the acute hemorrhage sexually transmitted disease for) causing, is one of most fatefulue infectious disease.EBOV belongs to filamentous virus Section (filoviridae family) Ebola virus belong to (Ebolavirus genus), are currently known and have 5 Kind；Wherein, the fatality rate highest of Zaire Ebola virus (Zaire Ebola virus), and cause 2013-2015 West Africa great outburst, this be 1976 first find EBOV since occur maximum-norm angstrom It is rich to draw epidemic situation.According to estimates, this time the case fatality rate of epidemic situation is up to 70.8%, and counts according to World Health Organization (WHO) (WHO), The infection more than 25000 is had resulted at present, it is dead more than 11000 people, a certain degree of fear of the public is caused, Cause the great attention of national governments.

Although some are carrying out clinical trial for the candidate vaccine and medicine of Ebola, in the market also There is no the product of license listing.Now, globalization process causes flow of personnel increasing, also exacerbates The risk that EBOV is propagated in worldwide, EBOV has become the great prestige of global public health and social stability The side of body.Further, since it has highly infective and high mortality, EBOV is also considered as a kind of preferable biological military Device, to the antibioterrorism cause of countries in the world huge threat is equally constituted.Therefore, epidemic disease of the research and development for EBOV Seedling and Therapeutic Method are extremely urgent.However, as a bio-safety level Four (biosafety level 4, BSL- 4) pathogen, EBOV can only be operated in BSL-4 laboratorys, and this greatly hinders the research and development of vaccine and medicine Process.At present in the world, only less than 30 BSL-4 laboratorys, and only it is distributed in a few Country.Therefore, a safety, quick, easy external In vivo infection system are set up, for EBOV vaccines and The screening and assessment of medicine is significant.

Except natural EBOV, it has been related to set up the report of EBOV Infection in Vitro models before.One kind is to be based on Slow viruss or retroviral pseudoviruss, will EBOV envelope proteins (EBOV GP) be shown to slow viruss or reverse On the surfaces of viral particles of the core granule gag albumen packaging of record virus^[1].In addition, expression EBOV GP and The recombinant vesiculovirus Stomatoviruses of green fluorescent protein (green fluorescent protein, GFP) (recombinant Vesicular Stomatitis Virus,rVSV)^[2]Also it is used as Infection in Vitro model. The advantage of pseudoviruss system is easily to pack, and efficiently reporter gene can be incorporated in infection cell genome simultaneously Expression.The advantage of rVSV be with replication capacity, can by cytopathic effect (cytopathic effects, ) and the expression two indices of GFP judge virus whether infection cell CPE.However, whether pseudoviruss or VSV Granule, is generally all spherical or bullet shaped, and this characteristic with the polymorphic filaments of EBOV is not simultaneously corresponded. Manicassamy etc.^[1]Beta-lactamase and EBOV VP40 amalgamation and expressions are formed containing beta-lactamase VLP, after this VLP infection cells, adds substrate, using the activity of beta-lactamase as index, detection disease Whether poison enters cell.However, beta-lactamase can hinder the formation of virus-like particle^[1].Importantly, The flux of beta-lactam enzyme assay is relatively low, and substrate (the CCF2-AM or CCF4-AM) price for detection is held high It is expensive, therefore the system is not widely used.

Therefore, this area is in the urgent need to exploitation easily operation, and cost is relatively low, it is easy to the Ai Bo of popularization and application Draw infection model.

The content of the invention

It is an object of the invention to provide a kind of new sense of in vitro and in vivo based on Ebola virus sample granule Dye model.

A first aspect of the present invention, there is provided a kind of VLP (virus-like particles, virus-like Grain), the VLP includes Ebola virus VP40 polypeptides or its active fragment, and reporter protein.

In another preference, the reporter protein is wrapped in the inside of the VLP.

In another preference, the reporter protein is luciferase or fluorescin.

In another preference, the reporter protein is that (firefly luciferase, Lampyridea is glimmering for Fluc Light element enzyme) polypeptide or its active fragment or Rluc (Renilla luciferase, Renilla luciferase).

In another preference, the structural protein for constituting the VLP are more comprising the Ebola virus VP40 Peptide or its active fragment, and the reporter protein (Fluc polypeptides or its active fragment) be wrapped in it is described The inside of VLP.Preferably, VLP of the invention, constitutes structural protein hollow so as to constitute by VP40 Granule, and Fluc is wrapped in inside granule, i.e. Fluc is not that same VP40 constitutes together VLP's Structural protein.

In another preference, the VP40 polypeptides are from the following group：

(A) there is SEQ ID NO:The polypeptide of aminoacid sequence shown in 2；

(B) have and SEQ ID NO:Aminoacid sequence >=80% homology shown in 2 is (preferably, >=90% Homology；Deng homology preferably >=95%；Most preferably, >=97% homology) it is many Peptide, and the polypeptide can form in the cell VLP；

(C) by SEQ ID NO:Aminoacid sequence shown in 2 through 1-5 amino acid residue replacement, lack Lose or add and formed, and the derivative polypeptide of VLP can be formed in the cell.

In another preference, the Fluc polypeptides are from the following group：

(A) there is SEQ ID NO:The polypeptide of aminoacid sequence shown in 8；

(B) have and SEQ ID NO:Aminoacid sequence >=80% homology shown in 8 is (preferably, >=90% Homology；Deng homology preferably >=95%；Most preferably, >=97% homology) it is many Peptide, and with the polypeptide of wild type Fluc characteristics；

(C) by SEQ ID NO:Aminoacid sequence shown in 8 through 1-5 amino acid residue replacement, lack Lose or add and formed, and with the derivative polypeptide of wild type Fluc characteristics.

In another preference, the VLP is thread VLP；Preferably described thread VLP length >=1 μm； More preferably diameter is for about 50～150nm.

In another preference, in the VLP mass ratio of reporter protein (such as Fulc) and VP40 be 0.1～ 1：1～0.1, preferably mass ratio is 0.2～1：1～0.2；More preferably mass ratio is 0.25～0.5： 1。

In another preference, in the VLP mol ratio of reporter protein (such as Fulc) and VP40 be 0.1～ 1：1～0.1, preferably mol ratio is 0.15～0.5：1～0.1；More preferably mol ratio be 0.15～ 0.3：1.

In another preference, the VLP also includes Ebola virus GP polypeptides；Preferably, institute is constituted The structural protein for stating VLP include the GP polypeptides.

In another preference, the GP polypeptides include SEQ ID NO.:Aminoacid sequence shown in 4.

In another preference, the VLP also includes Ebola virus NP polypeptides；Preferably, the NP Polypeptide is wrapped in the inside of the VLP.

In another preference, the NP polypeptides include SEQ ID NO.:Aminoacid sequence shown in 6.

In another preference, the VLP has the ability of infection cell (entering cell), and is entering To enter the reporter protein can be imported in (being released to) cell after cell.

In another preference, the cell is the cell that can be infected by Ebola virus, and preferably liver is thin Born of the same parents or nephrocyte.

A kind of a second aspect of the present invention, there is provided host cell, the host cell expression present invention first VLP described in aspect.

In another preference, the host cell is eukaryotic cell or prokaryotic cell.

In another preference, the eukaryotic cell include zooblast (e.g., 293T cells, Chinese hamster ovary celI, Vero cells etc.), plant cell or funguses.

In another preference, the prokaryotic cell includes：Escherichia coli.

In another preference, activity >=10 of Fluc in the host cell culture fluid supernatant⁶, preferably ≥10⁷。

A kind of a third aspect of the present invention, there is provided test kit, the test kit includes first aspect present invention Host cell described in described VLP, and/or second aspect present invention.

In another preference, luciferase substrate is also included in the test kit.

In another preference, the luciferase substrate is fluorescein.

In another preference, the biodiversity resources that the test kit is used in animal body.

A kind of a fourth aspect of the present invention, there is provided test kit of the VLP prepared described in first aspect present invention, The test kit includes：

The plasmid of coding VP40 polypeptides or its active fragment, and

The plasmid of encoding reporter protein or its active fragment.

In another preference, the test kit also includes the plasmid of coding Ebola virus GP polypeptides.

In another preference, the test kit also includes the plasmid of coding Ebola virus NP polypeptides.

A kind of a fifth aspect of the present invention, there is provided method for preparing VLP as described in the first aspect of the invention, Methods described includes step：

Under conditions suitable for the expression, the cell described in second aspect present invention is cultivated, so as to give expression to this VLP described in bright first aspect；With

Separate the VLP.

In another preference, the plasmid of VP40 polypeptides or its active fragment, and encoding reporter protein will be encoded Or the plasmid co-transfection host cell of its active fragment, so as to the cell described in second aspect present invention is obtained.

In another preference, in the step of preparing the cell described in second aspect present invention, VP40 will be encoded The plasmid of polypeptide or its active fragment, and the plasmid of encoding reporter protein or its active fragment, and coding GP The plasmid of polypeptide and/or the plasmid co-transfection host cell of coding NP polypeptides, so as to second party of the present invention is obtained Cell described in face.

In another preference, in transfection process, the plasmid concentration of encoding reporter protein or its active fragment ≥0.1ug/(2×10⁵Individual cell)；Preferably, >=0.5ug/ (2 × 10⁵Individual cell)；It is furthermore preferred that >= 2.5ug/(2×10⁵Individual cell)；Most preferably >=5ug/ (2 × 10⁵Individual cell).

In another preference, in transfection process, the plasmid concentration of encoding reporter protein or its active fragment ≤50ug/(2×10⁵Individual cell).

In another preference, in transfection process, the plasmid for encoding VP40 polypeptides or its active fragment is dense Degree >=0.1ug/ (2 × 10⁵Individual cell)；Preferably, >=0.2ug/ (2 × 10⁵Individual cell)；It is furthermore preferred that ≥0.5ug/(2×10⁵Individual cell)；Most preferably >=1ug/ (2 × 10⁵Individual cell).

In another preference, in transfection process, the plasmid for encoding VP40 polypeptides or its active fragment is dense Degree≤10ug/ (2 × 10⁵Individual cell).

In another preference, in transfection process, encode VP40 polypeptides or its active fragment plasmid and The concentration ratio of the plasmid of coding GP polypeptides is 1～2：2～1；Preferably 1：1.

In another preference, in transfection process, encode VP40 polypeptides or its active fragment plasmid and The concentration ratio of the plasmid of coding NP polypeptides is 1～2：2～1；Preferably 1：1.

A sixth aspect of the present invention, there is provided VLP as described in the first aspect of the invention, second party of the present invention The purposes of the test kit described in host cell or third aspect present invention described in face, for screening Ebola Viral inhibitors.

In another preference, the purposes is also included for reagent preparation, and the reagent is used to prepare screening The model of Ebola virus inhibitor；Preferably described model includes that cell model or animal are (preferably small-sized Mammal, such as rodent (such as mice) model.

In another preference, the purposes is also included for the biodiversity resources in animal body.

In another preference, the Ebola virus inhibitor includes：Polypeptide (such as antibody) and chemical combination Thing.

A seventh aspect of the present invention, there is provided one kind screening affects (including promoting or suppressing) Ebola virus The inhibitor of infection or the method for accelerator, including step：By the VLP described in first aspect present invention, move Thing cell and material to be tested are contacted, and then detect the activity of the reporter protein of cell interior.

If the activity inhibited of reporter protein, show that material to be tested is Ebola virus inhibitor；Such as The activity of fruit reporter protein is promoted, then show that material to be tested is Ebola virus accelerator.

In another preference, methods described includes step：(1) in experimental group, in thing to be tested and originally In the presence of VLP described in invention first aspect, zooblast is cultivated, then detect the intracellular report The quantity or activity of albumen (preferred luciferase), is designated as Mt；And do not exist and other in thing to be tested Under the conditions of part identical, the zooblast of same type is cultivated, and detect that the intracellular reporter protein is (excellent Select luciferase) quantity or activity, be designated as Mc；

(2) Mt is compared with Mc,

Wherein, if Mt is substantially less than Mc, show that the determinand is to suppress the rich suppression for drawing virus to infect Preparation；If Mt is significantly higher than Mc, show that the determinand is to promote the rich accelerator for drawing virus to infect.

In another preference, described substantially less than refers to Mt/Mc≤1/1.5, preferably≤1/2, more preferably Ground≤1/3.

In another preference, described is significantly higher than finger Mt/Mc >=1.5, preferably >=2, more preferably >=3.

In another preference, the concentration of VLP is in the step (1)：With VP40 in the VLP Concentration is calculated, 0.1～0.5 μ g/ml；Preferably >=0.1 μ g/ml；More preferably >=0.2 μ g/ml.

In another preference, described method also includes step (3)：For the suppression selected in step (2) The rich inhibitor for drawing virus to infect, further tests its suppression to Ebola virus in non-human animal model animal Effect.

If the activity inhibited of reporter protein, show that material to be tested is Ebola virus inhibitor.

In another preference, the zooblast is to be infected by the VLP and/or Ebola virus Cell；Preferably hepatocyte or nephrocyte.

In another preference, the zooblast is selected from：It is thin in the cell and animal body of In vitro culture Born of the same parents.

In another preference, the cell is selected from the group：Hepa1-6 cell strains, NIH3T3 cell strains and L929 cell strains.

In another preference, methods described includes step：In experimental group, by thing to be tested and the present invention VLP described in first aspect is injected in animal body simultaneously or successively, and detects the reporter protein in animal body Activity (preferably, detect animal liverss in reporter protein activity).

In another preference, if the activity inhibited of the reporter protein in the animal body, shows this Material is Ebola virus inhibitor.

In another preference, the injection is intravenous injection.

In another preference, the animal is inhuman small-sized mammalian, is preferably chosen from：It is mice, big Mus.

It should be understood that within the scope of the present invention, above-mentioned each technical characteristic of the present invention and below (such as enforcement Example) in can be combined with each other between each technical characteristic for specifically describing, so as to constitute new or preferred skill Art scheme.As space is limited, here is no longer tired out one by one and is stated.

Description of the drawings

Fig. 1 shows expressions of the EBOVLP/Fluc in 293T cell conditioned mediums, and to its composition and The identification of function.(A) it is used to transfect the plasmid schematic diagram that 293T cells produce EBOVLP/Fluc.(B) with not Same plasmid combinations are transfected after 293T cells jointly, detect each albumen in cell conditioned medium by western blot Expression, and determine the activity of Fluc in cell conditioned medium by adding luciferase substrate.(C) detect After EBOVLP/Fluc or EBOVLP/Fluc/GP- vero cells infections and Huh7.5.1 cells, every 6 hours The activity of Fluc in cell.(D-E) GP will be expressed, the plasmid co-transfection 293T of VP40, NP and Fluc is thin Born of the same parents production EBOVLP/Fluc and during vero cells infection, different Fluc plasmids amount (5 μ g, 2 μ g, 0.5 μ g and 0.05 μ g) for Fluc activity (D) in incasing cellss and the impact for Fluc activity (E) in target cell infection. (F) EBOVLP is for the packaging of reporter gene Renilla luciferase.GP, VP40, NP and Rluc will be expressed Plasmid co-transfection 293T cells, produce EBOVLP/Rluc.Can after EBOVLP/Rluc vero cells infections It is active with the intracellular Rluc for detecting very high.(G-H) EBOVLP is for the packaging of IRF-3 albumen.By table It is thin to illustrate various combination cotransfection 293T up to the plasmid of GP, VP40, NP and the IRF-3 with HA labels Born of the same parents, and the presence (G) of IRF-3 in cell conditioned medium is detected by western blot；Collect what above-mentioned each combination was produced Supernatant is simultaneously used for vero cells infection, detects the presence (H) of IRF-3 in Vero cells after infection.

Fig. 2 shows that EBOVLP/Fluc relies on the GP of perfect in shape and function and enters cell.(A) it is used to pack disease The envelope expression plasmid schematic diagram of malicious sample granule and pseudoviruss.(B) as EBOVLP/Fluc or HIV/EBOVpv loads different GP, when infection Huh7.5.1 cells or Vero cells, Fluc in cell Activity.(C) after loading the EBOVLP infection cells of the wild type GP or GP with F88A point mutation, The activity of Fluc in cell, and expression of two kinds of GP albumen in transfection 293T cells.(D) When EBOVLP/Fluc or EBOVLP/Fluc/GP- infection NPC1 overexpressing cells and GFP overexpressing cells, The activity of Fluc in cell.

Fig. 3 shows that the morphology of the virus-like particle that EBOVLP/Fluc assembles and composition reflect It is fixed.(A) EBOVLP/Fluc expresses sample Jing after sucrose density gradient centrifugation, and western blot detections are each Layer protein component, PCR detects the DNA of Fluc, detects the activity and each layer density of measurement of Fluc.(B) The coomassie brilliant blue staining result and composition analysis of the final purification of samples of EBOVLP/Fluc.Composition VLP's Arrow mark in albumen such as figure.(C) the negative staining Electronic Speculum result of EBOVLP/Fluc and HIV/EBOVpv.

Fig. 4 shows the Western blot quantitative approachs of EBOVLP/Fluc.(A) with escherichia coli The restructuring VP40 of expression be reference standard albumen, western of the anti-VP40 mice serums as detection antibody Blot results.(B) to scheme A in band gray scale as X values, the quality of VP40 is Y value, the mark of generation Directrix curve.According to the standard curve, the amount of VP40 can be calculated by the densitometer of sample.

Fig. 5 shows infection experiments of the EBOVLP/Fluc in mice body.(A) EBOVLP/Fluc and It is Fluc in cell after Hepa1-6, NIH3T3 and L929 that EBOVLP/Fluc/GP- infects three kinds of mouse cells Activity.(B-C) EBOVLP/Fluc and EBOVLP/Fluc/GP- infect BALB/c by tail vein injection Mouse liver cell is separated and detects in cell Fluc activity (B) or put mice by mice, 12h after infection The luminous reading (C) of vivo biodistribution is determined in living imaging instrument.Hydrodynamic injection (hydrodynamic Injection, h.i.) pLenti6-Fluc plasmids mice as positive control.

Fig. 6 show EBOVLP/Fluc can as infection model in vitro (A) and in vivo (B-C) to Ebola Virucidin is evaluated.(A) respectively with the HIV/EBOVpv and EBOVLP/Fluc based on slow viruss Experiment is neutralized to two kinds of Ebola virus neutralizing antibody 13C6 and 6D8.(B) EBOVLP/Fluc with not After with the antibody incubation of dosage, VLP- mixtures of antibodies is infected into BALB/c mouse by tail vein injection, 12h after infection, mice is placed in living imaging instrument and determines the luminous reading of vivo biodistribution.(C) liver area The statistics of bioluminescence reading.Coxsackievirus A16 (Coxsackievirus Group A Type16, CVA16) neutralizing antibody 9B5 test in vitro and in vivo in as negative control.

Specific embodiment

The present inventor obtains and a kind of is based on EBOV virus-like particles by extensive and in-depth study (virus-like particles, VLP), with LUC Photinus pyralis LUC Photinus pyralis FL (firefly luciferase, Fluc it is) the new infection model of reporter protein.The model relies on EBOV envelope protein GP and enters cell, And after into cell can by Fluc import cell in, therefore can according to the signal intensity of Fluc in cell, Cell infection is carried out quantitatively；Also can be strong according to the signal of the bioluminescence in mice body by bio-imaging Degree, is carried out quantitatively to mouse infection.Present invention also offers the purposes of VLP of the invention.The present invention People is it was unexpectedly observed that VLP of the invention has the ability of infection cell, and can lead reporter protein In entering cell, on this basis, the present invention is completed.

Specifically, the inventors discovered that, EBOVLP can by reporter protein parcel wherein and by infect, will report Albumen is delivered in cell.Based on the discovery, in this research, the present inventor establish one it is safe and reliable, With LUC Photinus pyralis LUC Photinus pyralis FL (firefly luciferase, Fluc) for reporter protein, it is easy to external, the body of production Interior infection system.The system has morphologically imitated to greatest extent the filamentous form of true EBOV, while in work( On energy, the process that it enters cell is also similar to EBOV courses of infection, therefore can be used as carrying out in vitro and in vitro The efficient tool of medicine, neutralizing antibody high flux screening.

Before describing the present invention, it should be understood that the invention is not restricted to described concrete grammar and experiment condition, Because this kind of method and condition can change.It should also be understood that term used herein its purpose is only that description Specific embodiment, and it is not intended to be restricted, the scope of the present invention is by only by appended claim Book is limited.

Unless otherwise defined, whole technologies otherwise used herein are respectively provided with such as institute of the present invention with scientific terminology The identical meanings that the those of ordinary skill in category field is generally understood that.As used herein, mentioning what is specifically enumerated When used in numerical value, term " about " means that the value can change from the value enumerated and is not more than 1%.For example, As used herein, state " about 100 " including 99 and 101 and between whole values (for example, 99.1,99.2, 99.3rd, 99.4 etc.).

Although can use in the enforcement or test of the present invention appointing to heretofore described similar or of equal value Where method and material, herein place enumerate preferred method and material.

Ebola virus

Ebola virus (Ebola virus disease, EVD) belong to fiber Viraceae journey long filars. The nucleocapsid protein of virion division center by spiral wound genosome RNA and nucleocapsid protein matter and egg White matter virus protein VP35, VP30, L are constituted, and the glycoprotein that virus is included gos deep into virion 10 from surface Nanometer is long, and in addition 10 nanometers then outwardly on mantle surface, and this layer of mantle be from the cell membrane of host, Region between mantle and nucleocapsid protein, referred to as medium space, are made up of virus protein VP40 and VP24.

Each pathogen is made up of the Negative Strand RNA virion of chain.The genome of Ebola virus In there are 18595 bases, 3' ends do not have Polyadenylation, and 5' ends also do not cap (capping). Seven structural protein of genome encoding and a non-structural protein.Gene order is：3' ends Contain important signal to adjust in-NP-VP35-VP40-GP-VP30-VP24-L-5' ends, the noncoding region at two ends The packaging of the transcription, duplication and reovirion of section virus.

Reporter protein

The terms " reporter protein " refer to the albumen encoded by reporter gene (reporter gene).Report Announcement gene is the gene of the protein that a kind of coding can be detected or enzyme, that is to say, that be that its expression is produced Thing is very easy to certified gene.Reporter protein is included but is not limited to：Antibiotic resistance protein, chloromycetin Acetyltransferase (CAT), beta galactosidase, luciferase, fluorescin etc..

Virus-like particle

Virus-like particle (virus-like particles, VLPs) is one or more containing certain virus The hollow bead of structural protein, without viral nucleic acid, it is impossible to autonomous replication, morphologically with real virion Son is same or similar, also referred to as pseudo- virus.

VLP in the present invention is more by Ebola virus VP40 polypeptides or its active fragment and other optional Peptide constitutes structural protein, constitutes the granule of VLP.

VLP of the invention also includes Fluc (firefly luciferase, LUC Photinus pyralis LUC Photinus pyralis FL) Polypeptide or its active fragment, it is preferable that the Fluc is wrapped in the inside of the VLP.

It is preferably carried out in mode in the present invention, can also includes in the structural protein of the VLP：Ebola Viral GP polypeptides and/or Ebola virus NP polypeptides.

It is preferably carried out in mode in the present invention, constitutes and also include in the structural protein of the VLP GP polypeptides.

It is preferably carried out in mode in the present invention, the VLP internal packages there are NP polypeptides.

In being preferably carried out in mode for the present invention, the sequence of Ebola virus VP40 polypeptides is as follows：

MRRVILPTAPPEYMEAIYPARSNSTIARGGNSNTGFLTPESVNGDTPSNPLRPIADDTID HASHTPGSVSSAFILEAMVNVISGPKVLMKQIPIWLPLGVADQKTYSFDSTTAAIMLASY TITHFGKATNPLVRVNRLGPGIPDHPLRLLRIGNQAFLQEFVLPPVQLPQYFTFDLTALK LITQPLPAATWTDDTPTGSNGALRPGISFHPKLRPILLPNKSGKKGNSADLTSPEKIQAI MTSLQDFKIVPIDPTKNIMGIEVPETLVHKLTGKKVTSKNGQPIIPVLLPKYIGLDPVAP GDLTMVITQDCDTCHSPASLPAVVEK(SEQ ID NO.:2)；

Its coding nucleotide sequence is as follows：

ATGCGCCGCGTGATTCTGCCGACAGCCCCACCCGAGTACATGGAGGCCATCTATCCAGCCCGCTCGAACAGTACGATTGCCCGCGGC GGAAACAGCAATACAGGCTTCCTGACCCCGGAGTCGGTGAACGGAGATACCCCCAGTAATCCGCTGCGCCCAATCGCCGATGACACA ATTGATCACGCCTCCCATACCCCGGGCAGCGTGAGCAGCGCCTTTATCCTGGAGGCTATGGTGAATGTGATTTCCGGCCCGAAGGTG CTGATGAAGCAGATCCCCATTTGGCTGCCGCTGGGAGTGGCCGATCAGAAGACCTACAGCTTCGACTCCACCACGGCCGCCATCATG CTGGCCTCGTATACAATTACCCACTTTGGCAAGGCCACCAATCCCCTGGTGCGCGTGAATCGCCTGGGACCGGGAATCCCGGATCAT CCACTGCGCCTGCTGCGCATTGGAAACCAGGCCTTCCTGCAGGAGTTTGTGCTGCCACCCGTGCAGCTGCCCCAGTACTTCACGTTT GACCTGACAGCCCTGAAGCTGATTACCCAGCCCCTGCCAGCCGCCACCTGGACAGATGACACCCCAACCGGCAGCAATGGAGCCCTG CGCCCGGGAATCTCCTTCCACCCAAAGCTGCGCCCCATTCTGCTGCCGAACAAGTCGGGCAAGAAGGGAAATAGCGCCGATCTGACG TCCCCCGAGAAGATCCAGGCCATTATGACAAGTCTGCAGGATTTCAAGATCGTGCCCATTGACCCGACCAAGAACATCATGGGCATT GAGGTGCCAGAGACGCTGGTGCATAAGCTGACCGGCAAGAAGGTGACGTCCAAGAATGGACAGCCAATCATTCCCGTGCTGCTGCCC AAGTATATTGGCCTGGACCCCGTGGCCCCAGGAGACCTGACGATGGTGATCACACAGGATTGCGATACATGCCATTCCCCAGCCAGT CTGCCAGCCGTGGTGGAGAAGTAA(SEQ ID NO.:1)。

In being preferably carried out in mode for the present invention, the sequence of Ebola virus GP polypeptides is as follows：

MGVTGILQLPRDRFKRTSFFLWVIILFQRTFSIPLGVIHNSTLQVSDVDKLVCRDKLSST NQLRSVGLNLEGNGVATDVPSATKRWGFRSGVPPKVVNYEAGEWAENCYNLEIKKPDGSE CLPAAPDGIRGFPRCRYVHKVSGTGPCAGDFAFHKEGAFFLYDRLASTVIYRGTTFAEGV VAFLILPQAKKDFFSSHPLREPVNATEDPSSGYYSTTIRYQATGFGTNETEYLFEVDNLT YVQLESRFTPQFLLQLNETIYASGKRSNTTGKLIWKVNPEIDTTIGEWAFWETKKNLTRK IRSEELSFTAVSNGPKNISGQSPARTSSDPETNTTNEDHKIMASENSSAMVQVHSQGRKA AVSHLTTLATISTSPQSLTTKPGPDNSTHNTPVYKLDISEATQVGQHHRRADNDSTASDT PPATTAAGPLKAENTNTSKSADSLDLATTTSPQNYSETAGNNNTHHQDTGEESASSGKLG LITNTIAGVAGLITGGRRTRREVIVNAQPKCNPNLHYWTTQDEGAAIGLAWIPYFGPAAE GIYTEGLMHNQDGLICGLRQLANETTQALQLFLRATTELRTFSILNRKAIDFLLQRWGGT CHILGPDCCIEPHDWTKNITDKIDQIIHDFVDKTLPDQGDNDNWWTGWRQWIPAGIGVTG VIIAVIALFCICKFVF(SEQ ID NO.:4)；

Its coding nucleotide sequence is as follows：

ATGGGAGTGACCGGCATCCTGCAGCTGCCCCGCGACCGCTTCAAGCGCACGAGTTTCTTTCTGTGGGTGATTATTCTGTTC CAGCGCACGTTCAGCATCCCCCTAGGCGTGATTCACAATAGCACGCTGCAGGTGTCCGATGTGGACAAGCTGGTGTGCCGCGATAAG CTGTCGTCGACCAACCAGCTGCGCTCGGTGGGACTGAATCTGGAGGGAAATGGAGTGGCCACCGATGTGCCCTCCGCCACCAAGCGC TGGGGATTTCGCAGTGGAGTGCCACCGAAGGTGGTGAACTACGAGGCCGGCGAGTGGGCCGAGAATTGCTATAACCTGGAGATCAAG AAGCCGGATGGCAGCGAGTGCCTGCCGGCCGCCCCCGACGGCATTCGCGGATTCCCACGCTGCCGCTACGTGCACAAGGTGTCGGGA ACCGGACCCTGCGCCGGAGATTTCGCCTTTCATAAGGAGGGCGCCTTCTTTCTGTACGACCGCCTGGCCAGCACCGTGATCTATCGC GGAACCACCTTTGCCGAGGGAGTGGTGGCCTTTCTGATTCTGCCCCAGGCCAAGAAGGATTTCTTTTCGAGTCACCCCCTGCGCGAG CCGGTGAATGCCACCGAGGACCCGAGCTCCGGCTACTATTCGACAACCATCCGCTACCAGGCCACCGGCTTCGGAACAAATGAGACC GAGTACCTGTTTGAGGTGGATAACCTGACGTATGTGCAGCTGGAGAGCCGCTTCACCCCGCAGTTTCTGCTGCAGCTGAATGAGACC ATCTATGCCAGCGGAAAGCGCTCCAATACGACAGGCAAGCTGATTTGGAAGGTGAACCCAGAGATCGACACCACGATTGGCGAGTGG GCCTTTTGGGAGACCAAGAAGAACCTGACGCGCAAGATCCGCTCGGAGGAGCTGAGTTTCACCGCCGTGTCCAATGGACCGAAGAAC ATTTCGGGACAGTCCCCCGCCCGCACATCCAGTGATCCAGAGACCAATACAACCAACGAGGACCACAAGATCATGGCCTCGGAGAAC AGCTCCGCTATGGTGCAGGTGCACAGCCAGGGACGCAAGGCCGCCGTGTCCCATCTGACGACACTGGCCACGATCAGCACATCGCCC CAGTCCCTGACCACCAAGCCCGGACCAGATAATAGCACCCATAACACGCCCGTGTACAAGCTGGACATTTCGGAGGCCACCCAAGTG GGACAGCACCATCGCCGCGCCGATAATGACTCGACAGCCAGTGATACCCCCCCGGCCACAACCGCCGCCGGACCACTGAAGGCCGAG AATACGAACACATCGAAGAGTGCCGATAGCCTGGACCTGGCCACCACAACCTCCCCACAGAACTACAGTGAGACCGCCGGCAACAAT AACACACACCATCAGGACACCGGAGAGGAGTCCGCGTCGAGTGGCAAGCTGGGACTGATCACCAATACGATTGCCGGCGTGGCCGGA CTGATTACCGGAGGACGCCGCACACGCCGCGAGGTCATCGTGAATGCCCAGCCCAAGTGCAATCCAAACCTGCACTACTGGACGACA CAGGATGAGGGAGCCGCCATTGGACTGGCCTGGATTCCCTACTTCGGACCCGCCGCCGAGGGAATCTATACCGAGGGCCTGATGCAT AATCAGGACGGCCTGATTTGCGGACTGCGCCAGCTGGCCAATGAGACCACCCAGGCCCTGCAGCTGTTCCTGCGCGCCACAACCGAG CTGCGCACGTTTTCCATCCTGAATCGCAAGGCCATTGATTTCCTGCTGCAGCGCTGGGGAGGAACCTGCCACATCCTGGGACCAGAT TGCTGCATTGAGCCCCATGACTGGACGAAGAACATCACAGATAAGATTGACCAGATCATTCACGATTTCGTGGACAAGACGCTGCCG GACCAGGGAGATAATGACAACTGGTGGACCGGATGGCGCCAGTGGATTCCCGCCGGAATTGGAGTGACCGGAGTGATTATCGCCGTG ATTGCCCTGTTCTGCATCTGCAAGTTTGTGTTTTGA(SEQ ID NO.:3)。

In being preferably carried out in mode for the present invention, the sequence of Ebola virus NP polypeptides is as follows：

MGSATMDSRPQKIWMAPSLTESDMDYHKILTAGLSVQQGIVRQRVIPVYQVNNLEEICQL IIQAFEAGVDFQESADSFLLMLCLHHAYQGDYKLFLESGAVKYLEGHGFRFEVKKRDGVK RLEELLPAVSSGKNIKRTLAAMPEEETTEANAGQFLSFASLFLPKLVVGEKACLEKVQRQ IQVHAEQGLIQYPTAWQSVGHMMVIFRLMRTNFLIKFLLIHQGMHMVAGHDANDAVISNS VAQARFSGLLIVKTVLDHILQKTERGVRLHPLARTAKVKNEVNSFKAALSSLAKHGEYAP FARLLNLSGVNNLEHGLFPQLSAIALGVATAHGSTLAGVNVGEQYQQLREAATEAEKQLQ QYAESRELDHLGLDDQEKKILMNFHQKKNEISFQQTNAMVTLRKERLAKLTEAITAASLP KTSGHYDDDDDIPFPGPINDDDNPGHQDDDPTDSQDTTIPDVVVDPDDGSYGEYQSYSEN GMNAPDDLVLFDLDEDDEDTKPVPNRSTKGGQQKNSQKGQHIEGRQTQSRPIQNVPGPHR TIHHASAPLTDNDRRNEPSGSTSPRMLTPINEEADPLDDADDETSSLPPLESDDEEQDRD GTSNRTPTVAPPAPVYRDHSEKKELPQDEQQDQDHTQEARNQDSDNTQSEHSFEEMYRHI LRSQGPFDAVLYYHMMKDEPVVFSTSDGKEYTYPDSLEEEYPPWLTEKEAMNEENRFVTL DGQQFYWPVMNHKNKFMAILQHHQ(SEQ ID NO.:6)；

Its coding nucleotide sequence is as follows：

ATGGGATCCGCCACCATGGACTCAAGACCTCAGAAGATTTGGATGGCACCCTCCCTCACAGAATCAGACATGGACTATCAT AAGATCCTCACCGCTGGGCTGTCTGTGCAGCAGGGAATCGTCCGGCAGCGCGTCATTCCCGTGTATCAGGTCAACAACCTGGAGGAA ATTTGCCAGCTGATCATTCAGGCCTTCGAGGCTGGCGTGGATTTTCAGGAAAGCGCCGACTCCTTCCTGCTCATGCTGTGCCTCCAC CATGCTTATCAGGGCGATTACAAGCTGTTCCTGGAGAGCGGAGCCGTGAAATACCTGGAGGGGCACGGTTTCCGATTTGAAGTGAAG AAACGGGACGGGGTCAAGCGCCTGGAGGAACTGCTCCCAGCTGTGAGCTCCGGCAAGAACATCAAAAGAACCCTGGCCGCTATGCCC GAGGAAGAGACCACAGAGGCAAATGCCGGCCAGTTCCTGTCTTTTGCAAGTCTGTTCCTCCCCAAGCTCGTGGTCGGAGAGAAGGCT TGCCTGGAAAAAGTGCAGAGACAGATCCAGGTCCACGCTGAGCAGGGCCTGATTCAGTATCCTACTGCATGGCAGAGCGTGGGACAC ATGATGGTCATTTTCCGACTCATGAGGACCAACTTCCTGATCAAGTTTCTGCTCATTCACCAGGGGATGCACATGGTGGCCGGTCAC GATGCAAACGACGCCGTGATCTCCAATTCTGTCGCTCAGGCACGGTTTTCCGGGCTGCTCATCGTGAAGACCGTCCTGGACCACATT CTCCAGAAAACAGAGAGAGGTGTGCGGCTGCATCCTCTCGCTCGCACTGCAAAGGTGAAAAACGAGGTCAATAGTTTCAAGGCAGCC CTGTCTAGTCTCGCCAAACACGGCGAGTACGCCCCTTTTGCTAGGCTGCTCAACCTGAGCGGGGTGAACAATCTGGAGCACGGTCTC TTCCCACAGCTGTCTGCCATCGCTCTCGGAGTGGCAACTGCCCACGGCAGCACCCTGGCTGGAGTCAATGTGGGCGAGCAGTATCAG CAGCTGCGCGAAGCTGCAACAGAGGCAGAAAAGCAGCTCCAGCAGTACGCCGAGTCCCGAGAACTGGACCACCTGGGACTCGACGAT CAGGAGAAGAAAATTCTGATGAACTTCCATCAGAAGAAAAATGAAATCTCTTTTCAGCAGACAAACGCTATGGTGACCCTGCGCAAG GAGCGACTGGCTAAACTCACCGAAGCAATTACAGCCGCTTCCCTGCCTAAGACCTCTGGGCACTATGACGATGACGATGACATCCCC TTCCCTGGGCCAATTAACGATGACGATAATCCAGGTCATCAGGACGATGACCCCACAGATTCACAGGACACTACCATCCCCGATGTG GTCGTGGACCCTGATGACGGCAGCTACGGAGAGTATCAGAGTTACTCAGAAAACGGCATGAATGCCCCAGATGACCTGGTGCTCTTT GATCTGGACGAGGATGACGAAGACACAAAGCCCGTCCCTAACAGAAGTACTAAAGGCGGACAGCAGAAGAACAGCCAGAAAGGCCAG CACATCGAGGGACGACAGACCCAGTCCAGGCCAATTCAGAACGTGCCAGGCCCCCATCGGACTATCCACCATGCTTCTGCACCCCTG ACCGATAACGACAGGAGAAATGAGCCTAGCGGCAGCACCAGCCCTCGCATGCTGACACCAATCAACGAAGAGGCCGACCCCCTGGAT GACGCTGATGACGAGACATCAAGCCTGCCCCCTCTCGAAAGCGATGACGAAGAGCAGGATAGAGACGGAACTTCCAATCGGACACCT ACTGTGGCACCACCCGCCCCAGTCTATAGGGATCACTCCGAGAAGAAAGAACTGCCACAGGACGAGCAGCAGGATCAGGACCATACA CAGGAAGCCAGAAACCAGGATAGTGACAATACTCAGTCAGAGCACAGCTTCGAAGAGATGTACAGGCATATCCTGAGATCACAGGGG CCATTTGATGCTGTGCTGTACTATCACATGATGAAGGACGAGCCCGTCGTGTTCAGTACTTCAGATGGTAAAGAATACACCTATCCT GACTCTCTCGAAGAGGAATACCCTCCCTGGCTGACCGAGAAGGAAGCCATGAACGAGGAAAATCGGTTTGTGACACTGGACGGACAG CAGTTCTATTGGCCCGTGATGAACCACAAAAACAAGTTTATGGCTATTCTCCAGCACCACCAGTGA(SEQ ID NO.:5)。

In being preferably carried out in mode for the present invention, the sequence of the Fluc polypeptides is as follows：

MLYEVMISEDAKNIKKGPAPFYPLEDGTAGEQLHKAMKRYALVPGTIAFTDAHIEVDITYAEYFEMSVRLAEAMKRYGLNT NHRIVVCSENSLQFFMPVLGALFIGVAVAPANDIYNERELLNSMGISQPTVVFVSKKGLQKILNVQKKLPIIQKIIIMDSKTDYQGF QSMYTFVTSHLPPGFNEYDFVPESFDRDKTIALIMNSSGSTGLPKGVALPHRTACVRFSHARDPIFGNQIIPDTAILSVVPFHHGFG MFTTLGYLICGFRVVLMYRFEEELFLRSLQDYKIQKCAAGANPILLLRQKHSD(SEQ ID NO.:8)；

Its coding nucleotide sequence is as follows：

ATGCTATACGAAGTTATGATATCGGAAGACGCCAAAAACATAAAGAAAGGCCCGGCGCCATTCTATCCGCTGGAAGATGGA ACCGCTGGAGAGCAACTGCATAAGGCTATGAAGAGATACGCCCTGGTTCCTGGAACAATTGCTTTTACAGATGCACATATCGAGGTG GACATCACTTACGCTGAGTACTTCGAAATGTCCGTTCGGTTGGCAGAAGCTATGAAACGATATGGGCTGAATACAAATCACAGAATC GTCGTATGCAGTGAAAACTCTCTTCAATTCTTTATGCCGGTGTTGGGCGCGTTATTTATCGGAGTTGCAGTTGCGCCCGCGAACGAC ATTTATAATGAACGTGAATTGCTCAACAGTATGGGCATTTCGCAGCCTACCGTGGTGTTCGTTTCCAAAAAGGGGTTGCAAAAAATT TTGAACGTGCAAAAAAAGCTCCCAATCATCCAAAAAATTATTATCATGGATTCTAAAACGGATTACCAGGGATTTCAGTCGATGTAC ACGTTCGTCACATCTCATCTACCTCCCGGTTTTAATGAATACGATTTTGTGCCAGAGTCCTTCGATAGGGACAAGACAATTGCACTG ATCATGAACTCCTCTGGATCTACTGGTCTGCCTAAAGGTGTCGCTCTGCCTCATAGAACTGCCTGCGTGAGATTCTCGCATGCCAGA GATCCTATTTTTGGCAATCAAATCATTCCGGATACTGCGATTTTAAGTGTTGTTCCATTCCATCACGGTTTTGGAATGTTTACTACA CTCGGATATTTGATATGTGGATTTCGAGTCGTCTTAATGTATAGATTTGAAGAAGAGCTGTTTCTGAGGAGCCTTCAGGATTACAAG ATTCAAAAGTGCGCTGCTGGTGCCAACCCTATTCTCCTTCTTCGCCAAAAGCACTCTGATTGA(SEQ ID NO.:7)。

In the present invention preferably embodiment, the structural protein for constituting the VLP of the present invention include ebola disease Malicious VP40 polypeptides and Ebola virus GP polypeptides, and it is (excellent to include reporter protein inside the VLP Elect Fluc as)；It is preferred that being 0.1～1：1～0.1, preferably mol ratio is 0.15～0.5：1～ 0.1；More preferably mol ratio is 0.15～0.3：1.The inventors discovered that, reporter protein (such as Fulc) With the mol ratio of VP40 only in suitable scope, reporter protein could be detected in infection cell Activity.

Present invention additionally comprises according to the derivant and analog of VLP of the present invention.As used herein, term " spreads out Biology " and " analog " refer to the virus-like particle for being kept substantially the VLP functions or activity of the present invention. It can on the basis of the polypeptide of VLP of the present invention is constituted, (i) there is one or several conservative or non-conservative Acidic amino acid residue (preferred conservative amino acid) is substituted, or (ii) residual in one or more aminoacid There is substituted radical, or (iii) and another compound fusion, or the aminoacid sequence that (iv) is additional in base Fusion (with the fusion of the sequence label such as targeting sequencing, secretion sequence or 6His).According to teaching herein, this A little derivants and analog belong to scope known to those skilled in the art.

The preferred reactive derivative of one class refer to constitute VLP each polypeptide aminoacid sequence compared with, have to Many 3, preferably at most 2, more preferably at most 1 aminoacid is by the similar or close aminoacid of property Replace and form polypeptide.These conservative variation's polypeptides carry out amino acid substitution and produce preferably based on Table A.

Table A

The present invention also provides the analog of VLP of the present invention.These analog can with the difference of the VLP of the present invention To be difference on aminoacid sequence, or not affect the difference on the modified forms of sequence, Huo Zhejian And have it.

The polynucleotide of the present invention can be DNA form or rna form.DNA form includes cDNA, gene The DNA of group DNA or synthetic.DNA can be single-stranded or double-strand.DNA can be coding strand or Noncoding strand.

The invention further relates to the variant of above-mentioned polynucleotide, its coding has identical with polypeptide according to the present invention Aminoacid sequence protein fragments, analogs and derivatives.The variant of this polynucleotide can be day The variant that the allelic variant for so occurring or non-natural occur.These nucleotide variants include replacing variation Body, Deletion variants and insert variation.As known in the art, allelic variant is a polynucleotide Alternative forms, it is probably the replacement of one or more nucleotide, disappearance or inserts, but will not be from essence The upper function of changing its coded polypeptide.

As used herein, term " primer " refers to matched with template, in the presence of archaeal dna polymerase Can be that starting point carries out synthesizing the general name with the oligonucleotide acid of the DNA of template complementation with it.Primer can be Natural RNA, DNA, or any type of natural nucleotide.Primer can even is that non-natural Nucleotide such as LNA or ZNA etc..On primer " generally " (or " substantially ") and template on a chain One special sequence is complementary.Primer must could start to extend with template an abundant complementation of chain, but The sequence of primer need not be with the sequence complete complementary of template.Such as, in the primer that a 3' end and template are complementary 5' ends add the preceding paragraph and the not complementary sequence of template, such primer is still generally complementary with template.As long as There is sufficiently long primer sufficiently to be combined with template, non-fully complementary primer can also be formed with template and drawn Thing-template composite, so as to be expanded.

Constitute the nucleotide full length sequence or its fragment of each polypeptide of VLP of the present invention generally can be expanded with PCR The method of increasing method, recombination method or synthetic is obtained.For PCR TRAP, can be according to published relevant Nucleotide sequence, especially open reading frame sequence designing primer, and with commercially available cDNA storehouses or by this CDNA storehouses known to art personnel prepared by conventional method expand and obtain relevant sequence as template. When sequence is longer, it is often necessary to carry out twice or multiple PCR is expanded, the piece for then again amplifying each time Section is stitched together by proper order.

Once obtain relevant sequence, it is possible to obtain relevant sequence in large quantity with recombination method.This leads to It is often to be cloned into carrier, then proceeds to cell, then in the host cell by conventional method from after propagation Isolated relevant sequence.

Additionally, relevant sequence can also be synthesized with the method for synthetic, when especially fragment length is shorter. Generally, by first synthesizing multiple small fragments, being then attached again can obtain the very long fragment of sequence.

It is optimized for obtaining the gene of the present invention using the method for round pcr DNA amplification/RNA.For PCR Primer can be properly selected according to the sequence information of invention disclosed herein, and available conventional method is closed Into.Can be with conventional method as separated the DNA/RNA fragments with purification amplification by gel electrophoresiss.

The present invention also relates to the carrier of polynucleotide, the carrier of these polynucleotide is comprising composition VLP of the present invention Polypeptide polynucleotide, and with the present invention carrier Jing genetic engineerings produce host cell, Yi Jijing The method that recombinant technique produces VLP of the present invention.

By conventional recombinant DNA technology, can be used to express or produce the present invention using the carrier of the present invention VLP.In general there are following steps：

(1). constitute the polynucleotide (or variant) of each albumen of VLP of the present invention with coding, or with containing The suitable host cell of recombinant expression carrier cotransfection (preferably 293T cells) of the polynucleotide；

(2). the host cell cultivated in suitable culture medium；

(3). separation, purification VLP of the invention from culture medium or cell.

In mode is preferably carried out, in transfection process, the plasmid of encoding reporter protein or its active fragment Concentration >=0.1ug/ (2 × 10⁵Individual cell)；Preferably, >=0.5ug/ (2 × 10⁵Individual cell)；It is furthermore preferred that ≥2.5ug/(2×10⁵Individual cell)；Most preferably >=5ug/ (2 × 10⁵Individual cell).

In another preference, in transfection process, the plasmid concentration of encoding reporter protein or its active fragment ≤50ug/(2×10⁵Individual cell).

In another preference, in transfection process, the plasmid for encoding VP40 polypeptides or its active fragment is dense Degree >=0.1ug/ (2 × 10⁵Individual cell)；Preferably, >=0.2ug/ (2 × 10⁵Individual cell)；It is furthermore preferred that ≥0.5ug/(2×10⁵Individual cell)；Most preferably >=1ug/ (2 × 10⁵Individual cell).

In another preference, in transfection process, the plasmid for encoding VP40 polypeptides or its active fragment is dense Degree≤10ug/ (2 × 10⁵Individual cell).

Through research, the inventors discovered that, the plasmid concentration of encoding reporter protein is too low in transfection process, Can cause that the activity of reporter protein cannot be detected after VLP infection cells.And excessive concentration, infection can be reduced Efficiency, and the VLP yield of appreciable impact host cell.And encode VP40 polypeptides plasmid concentration it is too low or The too high VLP yield that can affect host cell, is preferably carried out in mode at one, in transfection process, The plasmid concentration of encoding reporter protein or its active fragment is for about 5ug/ (2 × 10⁵Individual cell), coding VP40 The plasmid concentration of polypeptide is for about 1ug/ (2 × 10⁵Individual cell), coding GP polypeptides plasmid concentration be for about 1ug/ (2 ×10⁵Individual cell), coding NP polypeptides plasmid concentration be for about 1ug/ (2 × 10⁵Individual cell).

Method well-known to those having ordinary skill in the art can be used to build containing albumen of the present invention (composition VLP of the present invention Each polypeptide or its active fragment) DNA sequences encoding and suitable transcription/translation control signal table Up to carrier.These methods include recombinant DNA technology in vi, DNA synthetic technologys, In vivo recombination technology etc.. Described DNA sequence can be effectively connected in the appropriate promoter in expression vector, to instruct mRNA to synthesize. Expression vector is also including the ribosome binding site and transcription terminator of translation initiation.

Additionally, expression vector preferably includes one or more selected markers, to provide for selecting The dihydrofolate reductase of the phenotypic character of the host cell of conversion, such as eukaryotic culture, neomycin resist Property and green fluorescent protein (GFP), or for colibacillary tetracycline or amicillin resistance.

Carrier comprising above-mentioned appropriate DNA sequence and appropriate promoter or control sequence, can be used for The appropriate host cell of conversion, allows it to marking protein.

Host cell can be prokaryotic cell, such as bacterial cell；Or low eukaryotic cell, such as yeast cells； Or higher eucaryotic cells, such as mammalian cell.Representative example has：Escherichia coli, streptomyces Bacterial cell；Fungal cell's such as yeast；Plant cell；The insect cell of fruit bat S2 or Sf9；CHO、NS0、 Zooblast of COS7 or 293 cells etc..

Can be carried out with routine techniquess well known to those skilled in the art with recombinant DNA transformed host cell.Work as place When master is prokaryote such as escherichia coli, can absorb the competent cell of DNA can harvest after exponential phase of growth, Processed with CaCl2 methods, step used is generally well-known in the art.Another kind of method is to use MgCl2. If desired, conversion also can be carried out with the method for electroporation.When host is eukaryote, can select following DNA transfection methods：Calcium phosphate precipitation, conventional mechanical methods such as microinjection, electroporation, liposome Packaging etc..

The transformant of acquisition can use conventional method culture, express the polypeptide of the coded by said gene of the present invention.Root According to host cell used, culture medium used may be selected from various conventional mediums in culture.It is being suitable to host Cultivated under conditions of cell growth.After host cell growth is to appropriate cell density, with suitably Method (such as temperature transition or chemical induction) induces the promoter of selection, and cell is further cultured for into a period of time.

Acquisition VLP in the above methods in the cell or can be secreted into extracellular.If desired, can profit Separated by various separation methods and purification VLP with its physics, chemistry and other characteristics.These methods It is well-known to those skilled in the art.The example of these methods is included but is not limited to：At conventional renaturation Manage, (salting-out method) is processed with protein precipitant, is centrifuged, is permeated broken bacterium, surpasses process, ultracentrifugation, molecule Sieve chromatography (gel filtration), adsorption chromatography, ion-exchange chromatography, high performance liquid chroma- tography (HPLC) and other are each Plant liquid chromatography (LC) technology and the combination of these methods.

Main advantages of the present invention are：

(1) construct first it is a kind of be capable of infection cell based on EBOV with LUC Photinus pyralis LUC Photinus pyralis FL as report base The VLP of cause, can serve as Ebola virus infection model；

(2) VLP of the invention can enter cell by infection, and can be by reporter protein (such as Fluc) In importing cell, therefore cell infection can be carried out quantitatively according to the signal intensity of Fluc in cell.

(3) VLP of the invention has a form similar with natural Ebola virus, preferably as angstrom winning Draw the inner or in vitro research of virus.

(4) using the Ebola virus infection model of VLP of the invention, while being applied in vitro and in vivo sense Dye experiment, easily operation, and cost is relatively low, it is easy to popularization and application.

(5) EBOV vaccines can be carried out in BSL-4 experiments outdoor by the model of the present invention and the pre- of medicine is commented Estimate, therefore the saving for R＆D costs and Efficiency are improved and are significant.

With reference to specific embodiment, the further old present invention in detail.It should be understood that these embodiments are only used for The bright present invention rather than restriction the scope of the present invention.The experiment side of unreceipted detailed conditions in the following example Method, generally writes according to normal condition such as U.S. Sambrook.J etc.《Molecular Cloning: A Laboratory room guide》It is (yellow Training hall etc. is translated, Beijing：Science Press, 2002) described in condition, or built according to manufacturer The condition of view.Unless otherwise indicated, otherwise percentage ratio and number are calculated by weight.It is used in following examples Experiment material and reagent can obtain from commercially available channel if no special instructions.

Materials and methods

The structure of recombiant plasmid

According to the strain Zaire that 2014 for announcing before are separated in patient body from West Africa ebolavirus isolate H.sapiens-wt/GIN/2014/Gueckedou-C07(GenBank ID: KJ660347.2) sequence, the gene end count numeral for encoding EBOV VP40 and GP albumen optimizes and synthesizes (south Jing Jinsirui companies), the gene order such as SEQ ID NO. of VP40:Shown in 1, the gene sequence of GP albumen Row such as SEQ ID NO.:Shown in 3；According to strain Zaire ebolavirus isolate H.sapiens-tc/COD/1976/Yambuku-Mayinga(GenBank ID:NC_002549.1 sequence) Row, the gene (Nanjing Jin Sirui companies) of composite coding NP, sequence such as SEQ ID NO.:Shown in 5.On State gene to insert respectively on mammalian expression vector pcDNA3.1 (purchased from Thermo Fisher companies), Build plasmid pcDNA-EBOV GP, pcDNA-EBOV VP40 and pcDNA-EBOV NP.

Using PCR with pVSVG^[5]For masterplate expand VSVG transmembrane region (trans-membrane domain, TMD) and cytoplasmic tail genetic fragment (cytoplasmic tail, CT), the primer is as follows:Positive 5 ' CGGATATCAAAAGCTCTATT 3’(SEQ ID NO.:9)；Reverse 5 ' GCCTCGAGTCACTTTCCAAG 3’(SEQ ID NO.:10), double digestion is carried out to PCR fragment using EcoRV and XhoI, is inserted In entering carrier pcDNA3.1-, plasmid pcDNA-VSVGTMD is built.EBOV GP fragments are expanded using PCR, The primer is as follows：5 ' GTGGAATTCGCCACCATGGGAGTGACCGGCATCCT GCAGCTG 3 ' of forward direction (SEQ ID NO.:11)；Reverse 5 ' GAGGATATCCTGGCGCCATCCGGTCCACCAGTTGTC 3 ' (SEQ ID NO.:12), PCR fragment and pcDNA-VSVGTMD are distinguished using EcoRI and EcoRV Double digestion, connects after recovery, builds plasmid pcDNA-EBOV GP/VSVGTMD.

Using over-lap PCR (overlap PCR), GP point mutation plasmid pcDNA3.1-GP F88A, institute are built It is as follows with primer：Fragment 1:5 ' CTGGCTAGCATGGGAGTGACCGGCATCCTGCAGC 3 ' of forward direction (SEQ ID NO.:13), reverse 5 ' GCACTCCACTGCGAGCTCCCCAGCGCTTGGTGGCGG 3 ' (SEQ ID NO.:14)；Fragment 2:5 ' CCAAGCGCTGGGGAGCTCGCAGTGGAGTGCCACCG of forward direction 3’(SEQ ID NO.:15)；Reverse 5 ' GGGGGATCCT CAAAACACAAACTTG CAGATGC 3 ' (SEQ ID NO.:16).NheI and BamHI double digestions are carried out to PCR fragment, loads carrier pcDNA3.1 In, build plasmid pcDNA-GP F88A.

People is expanded as masterplate with Huh7.5.1 cells (being purchased from Chinese Academy of Sciences's cell bank) cDNA using primer NPC1 genetic fragment (forward primers：5’cccgctagcATGACCGCTCGCGGCCTGGCCCTTGGC 3’ (SEQ ID NO.:17)；Reverse primer：5’ggcggatccCTAGAAATTTAGAAGCCGTTCGCGCTCTG 3’(SEQ ID NO.:18) in), being inserted into expression plasmid carrier pcDNA3.1, plasmid is built pcDNA3.1-NPC1。

Cell line and antibody

The cell lines such as 293T, Huh-7.5.1, Vero, Hepa1-6, NIH3T3 and L929 are purchased from China Academy of science's cell bank or Thermo Fisher companies, be incubated at completely containing 10% inactivated fetal bovine serum (FBS, Gibco) and 1% penicillin/streptomycin (Gibco) Dulbecco ' s Modified Eagle ' s culture In base (DMEM, Gibco).

For EBOV NP and it is coupled the list of horseradish peroxidase (Horseradish peroxidase, HRP) (antibody prepares list of references to clonal antibody：Wang Xiao shuts out, Liu Yang, Wang Haoting, etc. Ebola virus NP eggs White monoclonal antibody prepare and antigenic peptides positioning. biological engineering journal, 2012,28 (11):1317-1327.)

It is as follows by Summarization for Preparation Methods for the polyclonal serum of EBOV VP40：EBOV is expanded with PCR method VP40 genes, build prokaryotic expression plasmid and simultaneously convert escherichia coli, abduction delivering and purification VP40 restructuring eggs In vain, immune BALB/c mouse, obtains polyclonal antibody.

Monoclonal antibody 13C6 and 6D8 for EBOV GP utilizes the sequence of the corresponding antibodies announced^[6] Optimize and synthesize (Nanjing Jin Sirui) 13C6 and 6D8 variable region genes, construction expression plasmid, using branched poly- Aziridine (branched Polyethylenimine, PEI；408727, Sigma-Aldrich), will The plasmid corotation 293T cells of encoding heavy chain and light chain, after 37 DEG C are cultivated 4 hours, culture medium are changed to and are contained There is the DMEM of 10 μM of sodium butyrates (Sodium butyrate), after continuing to cultivate 8 hours, culture medium is changed For FreeStyle 293 (FS293, Gibco), supernatant is harvested after 72 hours, using HiTrap rProtein A FF column (GE Healthcare) purification, obtains antibody.

The preparation of EBOVLP and infection experiment

To prepare EBOVLP/Fluc, using PEI by pcDNA-EBOV GP, pcDNA-EBOV VP40 and PcDNA-EBOV NP and pcDNA-Fluc corotation 293T cells (are purchased from Chinese Academy of Sciences's cell bank), After 37 DEG C of culture 4h, culture medium is changed to into the complete DMEM containing 10 μM of sodium butyrates, continues to cultivate after 8h, Culture medium is changed to into FS293, supernatant is harvested after 48 hours and high speed centrifugation is removed cell debriss.Using same Method prepare EBOVLP/Fluc/GP-, i.e., the VLP without GP albumen is used as negative control.

Before EBOVLP infection experiment 24h, in 96 orifice plates, 1 × 10 is added per hole⁴Individual Vero or Huh7.5.1 Cell.Using Western blot it is quantitative to contained VP40 in supernatant VLP after, per hole add contain VP40150ng VLP, after incubation certain hour, abandon supernatant, the cell in hole is washed into three times with aseptic PBS, then 50 μ l lysates Cell culture lysis reagent (Promega, Madison, WI) are added per hole Cell lysis, add afterwards 30 μ l substrates Luciferase substrate (Promega) per hole, and Using Varioskan^TMFlash multimode reader determine the activity of Fluc.

The preparation of HIV/EBOVpv and infection experiment

The method of HIV/EBOVpv is prepared before as described in report^[1].In short, will using PEI pNL4-3.Luc.R-.E-^[7]With pcDNA-EBOV GP corotation 293T cells, 37 DEG C culture 4 hours after, Culture medium is changed to into the DMEM containing sodium butyrate, after continuing to cultivate 8 hours, culture medium FS293 is changed to into, Supernatant is harvested after 48h and removal cell debriss are centrifuged.In the infection experiment of HIV/EBOVpv, first, profit The HIV p24 levels of supernatant are determined with ELISA, HIV/EBOVpv is carried out quantitatively, it is advance with postoperative infection The cell being layered in 96 orifice plates.72h determines the activity of Fluc using said method after infection.

Neutralization experiment

A certain amount of HIV/EBOVpv or EBOVLP/Fluc is mixed with neutralizing antibody after purification, 37 DEG C Incubation 1h, subsequently adds antigen-antibody mixture on the Vero cells being layered in advance in 96 orifice plates, in sense 48-72h determines the activity of Fluc after dye.

Sucrose density gradient purification

By EBOVLP expression plasmid corotation 293T cells, 24h's, 48h and 72h is upper after collection transfection Clearly, supernatant is placed on 25% sucrose cushions, 27,000rpm ultracentrifugation 3h.Use after the resuspended precipitations of PBS 20%, 30%, 40%, 50%, 60% sucrose is cooked discontinuous density gradient centrifugation, and 39,000rpm are centrifuged 2h, Sample is harvested, and using ELISA and Western blot detection samples.Finally collect EBOVLP enrichments The number of plies, is placed on 25% sucrose cushions, 27,000rpm centrifugations 3 hours, the resuspended precipitations of PBS.

SDS-PAGE and Western blot

Protein sample containing EBOVLP is mixed with SDS-PAGE sample-loading buffers, is boiled and added after cooling On 10% polyacrylamide gel being configured, electrophoresis is carried out.After electrophoresis terminates, gel is put into and examines horse Dyeing in this light blue dye liquor (R-250), dyeing is put into gel in destaining solution after terminating, decolouring post analysis knot Really.Or after electrophoresis terminates, the albumen on gel is transferred on pvdf membrane, after the completion of transfer, use State that corresponding VP40, NP and GP mono- are anti-to carry out incubation 2h, subsequently with 1:The HRP labellings of 5000 dilutions Anti- (goat anti-human IgG-HRP, Sigma) room temperature effect 1h of Goat anti human IgG bis-.It is eventually adding Appropriate ECL chemical illuminating reagents are substrate, and LAS4000 scanning analysis instrument (Fujifilm) obtains Western Blot results.

ELISA

Protein sample containing EBOVLP is diluted with PBS, in adding elisa plate, 4 DEG C of coatings are overnight. PBST (PBS containing 0.05%Tween-2) board-washing three times, subsequently adds the defat cattle of 100 μ l 5% per hole 37 DEG C of milk is closed 1 hour, PBST board-washings three times；The μ l of 13C6 antibody 50 per hole after addition dilution, 37 DEG C Incubation 2 hours, PBST board-washings three times；1 is added per hole:The Goat anti human IgG of the HRP labellings of 5000 dilutions Two anti-(goat anti-human IgG-HRP, Sigma) 50 μ l, 37 DEG C are incubated 2 hours, PBST board-washings Three times.The TMB nitrite ions of 50 μ l, room temperature is added to place per hole afterwards 5 to 10 minutes, it is last per hole Add terminate liquid (the 1M H of 50 μ l₃PO₄), color development stopping reaction is placed in 96 orifice plates in microplate reader, reads Take the OD values of 450nm.

Electronic Speculum is detected

Purified EBOVLP and HIV/EBOVpv protein samples are placed on carbon coating copper mesh, 0.2% is used After phosphotungstic acid negative staining, observation detection under Tecnai G2Spirit 120kV transmission electron microscopes is placed in.

Mouse infection and vivo biodistribution luminescence imaging are tested

Female 6 week old BALB/c mouse are purchased from Shanghai Ling Chang bio tech ltd.Noted by tail vein Penetrate, entered with the dosage of VLP (EBOVLP/Fluc or EBOVLP/Fluc/GP-) every mice of 2 μ g VP40 Row infection.After 12 hours, isoflurane inhalation anesthesia is carried out to mice, and to every mouse peritoneal injection 1.5mg Fluorescein (Caliper Life Sciences), the mice after process is placed in into IVIS Lumina II On platform (Caliper Life Sciences), vivo biodistribution luminous intensity is determined.

Mice neutralizing antibody protection test in vivo

Neutralizing antibody after purification is mixed with the EBOVLP/Fluc of 2 μ g VP40,1h is incubated at room temperature, with Afterwards antigen-antibody mixture is passed through into tail vein injection infecting mouse.12h utilizes said method after infection Bioluminescence in mice body is detected.

Statistical analysis

All data separate GraphPad Prism 5.0c (GraphPad Software, CA) in this research Student t test or one-way ANOVA carry out significant difference analysis in software.Significance analysis Method for expressing is as follows：ns P≥0.05,*P<0.05,**P<0.01,***P<0.001.

Packagings of the EBOVLP of embodiment 1 to reporter gene protein

In order to express the EBOVLP comprising Fluc (EBOVLP/Fluc), the present inventor constructs coding The plasmid (Figure 1A) of Fluc, VP40, NP and GP, and in different combinations by these plasmid co-transfections 293T cells, by Western blot the expression of VLP in supernatant is detected.As shown in Figure 1B, will encode The common transfectional cell (lane 1) of VP40, NP, GP and Fluc plasmid, three kinds of virus proteins are all in cell It is middle to express and be discharged in cell conditioned medium, and the activity of Fluc is detected in supernatant；And it is independent During expression Fluc, Fluc cannot be secreted into (lane 8) in supernatant, and this shows that Fluc albumen is successfully wrapped In being attached to VLP, and with VLP be discharged into it is extracellular.Because VP40 can individually be assembled into virus-like Grain, as long as therefore while express VP40 and Fluc (lane 5), regardless of whether with NP (lane 2) or GP (lane 3) coexpression, Fluc can be wrapping in the VLP of NP40 so that very high Fluc letters are presented in supernatant Number.By contrast, NP cannot individually be assembled into VLP, therefore as NP and Fluc coexpressions, supernatant It is middle without Fluc signals (lane 6).Although in expression NP+GP (lane 4) and the supernatant of GP (lane 7) In also detected that Fluc signals, but GP can not form independent VLP, therefore this is likely due to GP tools There is cytotoxicity, increased permeability of cell membrane and the reason being discharged into part Fluc in supernatant.

Reporter gene protein in being wrapped in is imported cell by the EBOVLP of embodiment 2 by infection

Although individually VP40 can also be wrapped in Flu in VLP, contain when the present inventor uses Whole granule EBOVLP/Fluc (lane 1) and lack the granule EBOVLP/Fluc/GP- (lane of GP albumen 2) during Supernatant infection cell, EBOVLP/Fluc infection cell and can discharge Fluc and enter cell, cause Intracellular Fluc signals peak after infection 6h, and EBOVLP/Fluc/GP- is due to lacking GP albumen And do not possess infectious (Fig. 1 C).Although the Fluc being discharged in cell is degraded quickly after 6h, After infection 48h and 72h, the intracellular of EBOVLP/Fluc infection still can detect that obvious Fluc signals, Significant difference is presented with the cell of EBOVLP/Fluc/GP- infection.

Subsequently the present inventor have detected the activity of the intracellular Fluc of 293T after transfection, it is desirable to judge packaging with this The relation of the Fluc signals produced after amount and target cell infection that Fluc is expressed in cell.Fig. 1 D-E are tested As a result show, the reduction of the Fluc plasmids transfected during with packaging EBOVLP/Fluc, Fluc in incasing cellss Yield also reduce therewith, so as to cause signal during target cell infection also to reduce；As Fluc in incasing cellss Activity be less than 10⁶When (0.05 μ g Fluc plasmids/(2 × 10⁵Individual cell)) (Fig. 1 D), now produce EBOVLP/Fluc just cannot produce visible signal (Fig. 1 E) for target cell infection.The result shows Can be used for the EBOVLP/Fluc of target cell infection needs have a large amount of reporter gene protein Fluc in packaging process Expression.

The present inventor is also by other intracellular proteins, such as reporter gene Renilla luciferase (Rluc) (figures 1F) or human interferon regulatory factor -3 (Interferon regulatory Factor 3, IRF-3) (figure 1G-H) with VP40, GP and NP co expression, these albumen can together be assembled into granule with VP40, And with further infecting the ability of other cells.EBOVLP/Rluc to the infection of daughter cell with EBOVLP/Fluc basically identical (Fig. 1 F)；Although in the presence of GP, IRF-3 may be used It is only complete in be discharged into supernatant (Fig. 1 G), but after the Supernatant infection Vero cells with collection Containing all GP, the granule EBOVLP/IRF3 of VP40, NP and IRF-3 albumen just can will be contained in therein IRF-3 is delivered in target cell (Fig. 1 H).The present inventor speculate this be because EBOVLP granules itself are larger, The reason for more other intracellular proteins can be wrapped up.The characteristic of this high carrying capacity so that EBOVLP in the future can Can be used as a kind of carrier, transferrin on a cellular level.

The active detection method of Fluc is as follows：Cell abandons supernatant, with nothing after the infected corresponding time Bacterium PBS washes the cell in hole three times, and 50 μ l lysate Cell culture lysis are then added per hole Reagent (Promega, Madison, WI) cell lysis, add afterwards 30 μ l substrates per hole Luciferase substrate (Promega), and utilize Varioskan^TMflash multimode Reader determines the active readings of Fluc.

The EBOVLP of embodiment 3 relies on the GP with complete function and enters cell

In order to determine whether EBOVLP depends on GP, the present inventor to construct the different peplos of coding into cell The plasmid (Fig. 2A) of glycoprotein：One is wild type EBOV GP genes, and one is that the entrance reported before is thin The GP F88A mutant genes of born of the same parents' reduced capability^[3], one is vesicle Stomatoviruses G eggs as positive control (vesicular stomatitis virus glycoprotein G, VSVG) gene, and EBOV GP in vain With the mosaic gene of VSVG, the wherein membrane spaning domain of GP (transmembrane domain, TMD) quilt The TMD of VSVG replaces, and GP is positioned on cell membrane, and the present inventor is GP/VSVGTMD to the unnamed gene. Meanwhile, the present inventor constructs the EBOV slow viruss (HIV/EBOVpv) that HIV is skeleton according to previous report As reference, i.e., by by the plasmid corotation of slow virus carrier pNL4-3.Luc.E-R- and coding EBOV GP Cell, expression obtains the recombinant slow virus with EBOV GP.

Firstly, since EBOVGP is positioned at endocytoplasmic reticulum (ER), the present inventor speculates, is positioned at cell The GP of film will may be combined more with VP40/NP granules, so as to have more infectiousness.In order to verify this It is individual it is assumed that the present inventor express the EBOVLP/Fluc that carries four kinds of different glycoproteins of the above or HIV/EBOVpv, and infect n cell with it.As shown in Figure 2 B, wild type GP can make EBOVLP/Fluc With the ability that HIV/EBOVpv obtains infection cell, so as to pass through albumen transmission and genome conformity respectively Form so that it is active to detect Fluc in infected cell, and without the matched group of GP Then no signal or pickup electrode are weak in the cell of EBOVLP/Fluc/GP- infection.The result shows EBOVLP/Fluc All it is that GP is relied on the infectivity of HIV/EBOVpv EBOV.Make the present inventor surprisingly, although with VSVG is more infectious for the VLP and pseudoviruss of envelope protein, but is with chimeric protein GP/VSVGTMD During envelope protein, VLP or pseudoviruss all cannot infection cell (Fig. 2 B), this prompting the present inventor, The TMD of EBOV GP is particularly significant for the cell entered function that GP is mediated, and works as the present inventor by GP's TMD is replaced with after the TMD of VSVG, is destroyed its original function or has been had influence on GP albuminous coat outskirts Conformation.

Secondly, whether it is by GP and receptor binding to further inquire into EBOVLP/Fluc into cell Mediation, the present inventor introduce on GP one reported in the past cause enter cell function weaken Mutation F88A, this mutation can destroy the combination of GP and receptor people Niemann-Pick C1 (NPC1), and Virus mainly enters cell by the combination of GP and NCP1.Although wild type GP and GP F88A Express all in 293T cells, but after the VLP infection cells with GP F88A, be nearly no detectable Fluc The combination energy of activity, the VLP (Fig. 2 C) substantially less than with wild type GP, this explanation destruction GP and receptor Power can destroy VLP and enter cell.Additionally, on the 293T cells of people's NPC1 overexpression, EBOVLP/Fluc Infectivity significantly increase, and without GP matched group EBOVLP/Fluc/GP- whether in NPC1 or On the cell of GFP overexpressions, all without infectivity (Fig. 2 D).These results indicate that EBOVLP enters thin Born of the same parents depend on the combination between GP-NCP1, and the process that this enters cell with EBOV in natural surroundingses is consistent.

The identification of the EBOVLP/Fluc of embodiment 4 with it is quantitative

In order to verify whether EBOVLP/Fluc forms correct form, the present inventor passes through 25% sucrose cushions Concentration supernatant, and identification is analyzed by the sucrose density gradient centrifugation of 20%-60%.After purification EBOVLP/Fluc, its GP, NP and VP40 all concentrate on it is specific which floor, mainly 4-9 layers (Fig. 3 A), Show that EBOVLP/Fluc has been assembled into virus-like particle.Surprisingly, it was found that not only luciferase Fluc, has the plasmid of a small amount of coding Fluc equally and GP, NP and VP40 are fallen below in identical layer, says In bright EBOVLP/Fluc assembling process, not only by Fluc albumen, and the plasmid of Fluc is also packaged in In granule.Next, the component in order to detect EBOVLP/Fluc, the present inventor harvested GP, NP, VP40 is more, and the number of plies (4-9 layers) at Fluc enzymatic activity peak values carries out SDS-PAGE analyses；Pass through Coomassie brilliant blue staining can be clearly seen that the band (Fig. 3 B) of GP, NP, VP40 and Fluc, and pass through ImageJ softwares are quantitative, and the mass ratio for drawing Fluc and VP40 is 0.257, and molal quantity ratio is 0.171. Finally, in order to determine the morphological characteristic of EBOVLP/Fluc, the present inventor carries out in EBOVLP/Fluc samples Negative staining, by electron microscope observation, and is compared with HIVpv/GP.As shown in Figure 3 C, EBOVLP/Fluc is presented diameter 100nm or so, length more than 1 μm of typical filamentous particle, and HIVpv/GP is much smaller, is the spheroidal particle of diameter～100nm.These results confirm EBOVLP/Fluc With the plesiomorphism of natural EBOV.

In order to set up the infection system of in vitro and in vivo, inventor developed for EBOVLP/Fluc's Western blot quantitative approachs, it is reference that this method is utilized in the restructuring VP40 of expression in escherichia coli Standard, anti-VP40 mice serums are used as detection antibody.As shown in figure 4, this method, VP40's is minimum Detection is limited to 2ng；Correlation coefficient (R of the range of linearity of standard curve in 2-8ng VP40²) be 0.993.Using this method, the present inventor detects that EBOVLP/Fluc expression plasmids transfect 293T cells After 48 hours, the expression of VP40 is 0.13ng/ μ l in supernatant.And repeat experiment three times, gained The result for arriving is similar.By this quantitative criteria, it may be determined that the amount of EBOVLP in infection experiment.This is determined Amount method similar to the Clinical detection of HIV or experiment in, by measure p24^GagAmount come quantitative HIV or The classical way of HIVpv^[4]。

The mouse infection experiment of the EBOVLP/Fluc of embodiment 5

The experiment of EBOV zoogenetic infections is strictly limited and is desirable with BSL-4 laboratorys, therefore the present inventor EBOVLP/Fluc infecting mouses, so as to Fluc is transported in mouse cell, by the method for living imaging Infection is carried out quantitatively, in this, as a non-replicating, the EBOV infection models of single-wheel infection.Due to Experiment before is always carried out on monkey or people's cell, therefore the present inventor probes into first EBOVLP/Fluc is in vitro to the infection ability of mouse cell.As shown in Figure 5A, EBOVLP/Fluc shows Go out extensive cell tropism, three kinds of mouse cell lines Hepa1-6, (cell is purchased from NIH3T3 and L929 Purchased from Chinese Academy of Sciences's cell bank) can be infected by it.Next, the present inventor is by tail vein injection, With the infection BALB/c mouse of the EBOVLP/Fluc (or EBOVLP/Fluc/GP-) containing 2 μ g VP40. After infection 12h, mouse liver cell is separated and detects that Fluc is active in cell by the present inventor.With external sense Dye is consistent, and Fluc is successfully imported hepatocyte by EBOVLP/Fluc, and EBOVLP/Fluc/GP- is then because lacking Weary envelope protein fails infecting mouse hepatocyte (Fig. 5 B).Importantly, EBOVLP/Fluc infection is little Mus produce very strong bioluminescence signal, 2-log higher than the mice of EBOVLP/Fluc/GP- infection, this table The infection of the bright EBOVLP/Fluc in mice body is also to rely on GP's.Data above shows this non-multiple The EBOV infected animal models of type processed are successfully established.

The EBOVLP/Fluc of embodiment 6 is evaluated neutralizing antibody as in vitro and in vivo infection model

In order to verify that EBOVLP/Fluc can be as infection model in vitro and in vivo in Ebola virus and anti- Body is evaluated, the EBOV neutralizations that the present inventor's expression and purification two kinds of 13C6 and 6D8 were reported before Antibody, is verified by external neutralization experiment and internal fluorescence imaging experiments to the model.From Fig. 6 A As can be seen that as pseudoviruss system HIV/EBOVpv, EBOVLP/Fluc also can in vitro by 13C6 Neutralize with two kinds of antibody of 6D8, and antibody dosage dependency is presented, and cannot be by control antibodies Coxsackie viruss The type of A groups 16 (Coxsackievirus Group A Type16, CVA16) neutralizing antibody 9B5 is neutralized.This Inventor further verified in mouse model, by EBOVLP/Fluc and various dose (200 μ g, 20 μ g) 13C6 antibody incubations after, by VLP- mixtures of antibodies by tail vein injection infect BALB/c it is little Mice is placed in living imaging instrument and determines the luminous reading of vivo biodistribution by Mus, 12h after infection.Such as Fig. 6 B institutes Show, compared with control antibodies 9B5, antibody 13C6 has neutralized in vivo EBOVLP/Fluc to liver cell Intrusion, show the liver area fluorescence intensity (Fig. 6 C) for substantially reducing (p=0.0155).

Discuss

Although the great outburst to West Africa ebola hemorrhagic fever in 2015 in 2013 has been obtained for control, this Secondary epidemic situation causes attention and vigilance of the whole world to EBOV height so that the exploitation of EBOV vaccines/medicine It is very urgent.But the EBOV infection models of the shortage of necessary assessment tool, i.e. in vitro and in vivo, Jing hinders the progress of vaccine and medicine significantly.On the one hand, EBOV infection experiments, either cell training Support or zoopery is required for being carried out in BSL-4 facilities, and the scientific research institution of the overwhelming majority all cannot expire Sufficient this hardware requirement.On the other hand, the succedaneum of Infection in Vitro model, the vacation such as based on slow viruss Virus, rVSV, or the VLP of beta lactamase fusion, or form differs greatly with authentic particles, or It is prohibitively expensive to be difficult to by wide popularization and application.And according to known to the present inventor, still not having at present can be in BSL-4 Outside operate EBOV animal infection modals.Therefore in our current research, inventor developed one kind is based on VLP, new E BOV infection model suitable in vitro and in vivo.

The present inventor is also once by Fluc and VP40 amalgamation and expressions, it is desired to be able to produce capsid surface with report The VLP of gene, result of the test shows, although Fluc-VP40 defines VLP, but Fluc does not but live Property.Therefore the present inventor's remedies, by Fluc and VP40 coexpressions, Fluc can be with VP40 in cell In be assembled into granule (being wrapped in inside VLP) and be discharged into extracellular (Figure 1B), and by Fluc and GP Coexpression, also results in Fluc and is discharged into extracellular, and this is that the toxicity having due to GP can cause cell-permeant Sexually revise and discharge Fluc.But, the VLP for only carrying GP can be by way of infection by Fluc Present (Fig. 1 C) in Vero cells, this shows that the infection of the EBOVLP has GP dependencies.Fig. 2 energy Enough further to prove this viewpoint, mutant F88A GP enter the decrease of cell function, to a great extent On reduce the infectivity of VLP, and the cell of EBOV receptor NPC1 overexpression is easier to be felt by EBOVLP Dye (Fig. 2 C and 2D).The characteristics of EBOVLP/Fluc relies on GP into cell so as to be very suitable for as sieve Needle selection is to the neutralizing antibody of GP and the instrument of entry inhibitor.

At present, have been set up based on the HIV of biodiversity resources, dengue virus and hepatitis C viruss Animal infection modal.In our current research, inventors demonstrated that EBOVLP can be used as one kind safely, effectively With the instrument of economic imitation EBOV infection animals.As the present inventor with EBOVLP/Fluc from tail vein sense Dye mice when, it by tail vein Jing posterior vena cava reach liver, so as to cause liver in bioluminescence (Fig. 5 C), this is likely due to EBOVLP and enters liver endothelial cell, because EBOV main infection endotheliums are thin Born of the same parents.Through the checking of external neutralization experiment (Fig. 6 A) and protection test in vivo (Fig. 6 B-C), the model energy It is enough that effectively Ebola virus neutralizing antibody is evaluated.This is to test outdoor foundation in BSL-4 first EBOV animal infection modals.

In sum, two characteristics of the new E BOV infection model that the present inventor develops based on EBOVLP： First, the process into cell relies on protein mediated with GP, and second, can be by Fluc after into cell In importing cell.The model is applied in vitro and in vivo infection experiment simultaneously, easily operation, and cost is relatively low, Application easy to spread.Can test outdoor in BSL-4 by the system carries out the pre- of EBOV vaccines and medicine Assess, therefore the saving for R＆D costs and Efficiency are improved and are significant.And EBOV institutes Only have two members, i.e. Ebola virus category and Marburg virus category, these viruses in the filamentous virus section of category Structure it is similar.Therefore, the research of the present inventor can be building for other viral infection models of filamentous virus section It is vertical that certain guidance is provided.

The all documents referred in the present invention are all incorporated as in this application reference, just as each document It is individually recited as with reference to such.In addition, it is to be understood that after the above-mentioned teachings for having read the present invention, Those skilled in the art can make various changes or modifications to the present invention, and these equivalent form of values equally fall within this Shen Please appended claims limited range.

List of references

1.Manicassamy,B.and L.Rong,Expression of Ebolavirus glycoprotein on the target cells enhances viral entry.Virol J,2009.6:p.75.

2.Martinez,O.,et al.,Impact of Ebola mucin-like domain on antiglycoprotein antibody responses induced by Ebola virus-like particles.J Infect Dis,2011.204Suppl 3:p. S825‐32.

3.Martinez,O.,et al.,A mutation in the Ebola virus envelope glycoprotein restricts viral entry in a host species-and cell-type-specific manner.J Virol,2013.87(6):p.3324‐34.

4.Chen,B.K.,et al.,Distinct modes of human immunodeficiency virus type 1proviral latency revealed by superinfection of nonproductively infected cell lines with recombinant luciferase-encoding viruses.J Virol,1994.68(2):p.654‐60.

5.Tong,Y.,et al.,Tupaia CD81,SR-BI,claudin-1,and occludin support hepatitis C virus infection.J Virol,2011.85(6):p.2793‐802.

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Claims (10)

1. a kind of VLP (virus-like particles, virus-like particle), it is characterised in that described VLP includes Ebola virus VP40 polypeptides or its active fragment, and reporter protein, and the reporter protein It is wrapped in the inside of the VLP.

2. VLP as claimed in claim 1, it is characterised in that reporter protein and VP40 in the VLP Mol ratio is 0.1～1：1～0.1, preferably mol ratio is 0.15～0.5：1～0.1；More preferably rub You are than being 0.15～0.3：1.

3. VLP as claimed in claim 1, it is characterised in that the VLP has the ability of infection cell, And the reporter protein can be imported in cell after into cell.

4. VLP as claimed in claim 1, it is characterised in that the VLP also includes Ebola virus GP polypeptides.

5. a kind of host cell, it is characterised in that the VLP described in the host cell expression claim 1.

6. a kind of test kit, it is characterised in that the test kit include the VLP described in claim 1 and / or claim 5 described in host cell.

7. a kind of test kit of the VLP prepared described in claim 1, it is characterised in that the test kit Including：

The plasmid of coding VP40 polypeptides or its active fragment, and

The plasmid of encoding reporter protein or its active fragment；

Preferably, the test kit also includes the plasmid of coding Ebola virus GP polypeptides；And/or

The test kit also includes the plasmid of coding Ebola virus NP polypeptides.

8. a kind of method for preparing VLP as claimed in claim 1, it is characterised in that methods described includes Step：

Under conditions suitable for the expression, the cell described in claim 5 is cultivated, so as to give expression to claim VLP described in 1；With

Separate the VLP.

9. the host cell or claim 6 described in VLP as claimed in claim 1, claim 5 The purposes of described test kit, it is characterised in that for screening screening Ebola virus inhibitor；It is preferred that The purposes also includes that for reagent preparation the reagent is used to make the mould of screening Ebola virus inhibitor Type；Preferably described model includes that cell model or animal are (preferably small-sized mammalian, such as mice, big Mus etc.) model.

10. it is a kind of screening Ebola virus inhibitor method, it is characterised in that including step：By right It is required that the VLP described in 1, zooblast and test substance are contacted, then the activity of examining report albumen；It is excellent Selection of land, methods described includes step：(1) in experimental group, in thing to be tested and first aspect present invention institute In the presence of the VLP for stating, zooblast is cultivated, then detect intracellular reporter protein (the preferred fluorescence Plain enzyme) quantity or activity, be designated as Mt；And do not exist and other conditions identical condition in thing to be tested Under, the zooblast of same type is cultivated, and detect the intracellular reporter protein (preferred luciferase) Quantity or activity, be designated as Mc；

(2) Mt is compared with Mc,

Wherein, if Mt is substantially less than Mc, show that the determinand is to suppress the rich suppression for drawing virus to infect Preparation；If Mt is significantly higher than Mc, show that the determinand is to promote the rich accelerator for drawing virus to infect.