Sequence and organization of the Neodiprion lecontei nucleopolyhedrovirus genome

All fully sequenced baculovirus genomes, with the exception of the dipteran Culex nigripalpus nucleopolyhedrovirus (CuniNPV), have previously been from Lepidoptera. This study reports the sequencing and characterization of a hymenopteran baculovirus, Neodiprion lecontei nucleopolyhedrovirus (NeleNPV), from the redheaded pine sawfly. NeleNPV has the smallest genome so far published (81,755 bp) and has a GC content of only 33.3%. It contains 89 potential open reading frames, 43 with baculovirus homologues, 6 identified by conserved domains, and 1 with homology to a densovirus structural protein. Average amino acid identity of homologues ranged from 19.7% with CuniNPV to 24.9% with Spodoptera exigua nucleopolyhedrovirus. The conserved set of baculovirus genes has dropped to 29, since NeleNPV lacks an F protein homologue (ac23/ld130). NeleNPV contains 12 conserved lepidopteran baculovirus genes, including that for DNA binding protein, late expression factor 11 (lef-11), polyhedrin, occlusion derived virus envelope protein-18 (odv-e18), p40, and p45, but lacks 21 others, including lef-3, me53, immediate early gene-1, lef-6, pp31, odv-e66, few polyhedra 25k, odv-e25, protein kinase-1, fibroblast growth factor, and ubiquitin. The lack of identified baculovirus homologues may be due to difficulties in identification, differences in host-virus interactions, or other genes performing similar functions. Gene parity plots showed limited colinearity of NeleNPV with other baculoviruses, and phylogenetic analysis indicates that NeleNPV may have existed before the lepidopteran nucleopolyhedrovirus and granulovirus divergence. The creation of two new Baculoviridae genera to fit hymenopteran and dipteran baculoviruses may be necessary.     

Proteins associated with Culex nigripalpus nucleopolyhedrovirus occluded virions

Occlusion-derived virions (ODVs) of the nucleopolyhedrovirus of Culex nigripalpus (CuniNPV) were purified by Ludox density gradient ultracentrifugation, and the proteins were separated by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins were identified by using Edman sequencing, matrix-assisted laser desorption ionization-time of flight mass spectrometry, nanoelectrospray quadrupole time-of-flight mass spectrometry, or a combination of these methods. Half of the 44 polypeptide sequences identified in this analysis were unique open reading frames (ORFs) encoded by the CuniNPV genome and did not show similarity to any other sequences present in protein databases. Of the 22 polypeptides that showed similarities to other baculovirus-encoded proteins, only 17 sequences have previously been identified as structural proteins. The newly identified CuniNPV structural proteins cun058, cun059, cun087, cun106, and cun109 are homologues of Autographa californica nucleopolyhedrovirus (AcMNPV) ORFs 68, 62, 98, 81, and 2, respectively. The products of four genes, namely, lef-1 (cun045), alkaline exonuclease (cun054), helicase (cun089), and DNA polymerase (cun091), were not detected in the CuniNPV ODV preparations. These four genes are conserved among all annotated baculovirus genomes, and their homologues have been detected in the ODV of AcMNPV.     

Pseudotyping Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV): F proteins from group II NPVs are functionally analogous to AcMNPV GP64

GP64, the major envelope glycoprotein of budded virions of the baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV), is involved in viral attachment, mediates membrane fusion during virus entry, and is required for efficient virion budding. Thus, GP64 is essential for viral propagation in cell culture and in animals. Recent genome sequences from a number of baculoviruses show that only a subset of closely related baculoviruses have gp64 genes, while other baculoviruses have a recently discovered unrelated envelope protein named F. F proteins from Lymantria dispar MNPV (LdMNPV) and Spodoptera exigua MNPV (SeMNPV) mediate membrane fusion and are therefore thought to serve roles similar to that of GP64. To determine whether F proteins are functionally analogous to GP64 proteins, we deleted the gp64 gene from an AcMNPV bacmid and inserted F protein genes from three different baculoviruses. In addition, we also inserted envelope protein genes from vesicular stomatitis virus (VSV) and Thogoto virus. Transfection of the gp64-null bacmid DNA into Sf9 cells does not generate infectious particles, but this defect was rescued by introducing either the F protein gene from LdMNPV or SeMNPV or the G protein gene from VSV. These results demonstrate that baculovirus F proteins are functionally analogous to GP64. Because baculovirus F proteins appear to be more widespread within the family and are much more divergent than GP64 proteins, gp64 may represent the acquisition of an envelope protein gene by an ancestral baculovirus. The AcMNPV pseudotyping system provides an efficient and powerful method for examining the functions and compatibilities of analogous or orthologous viral envelope proteins, and it could have important biotechnological applications.     

杆状病毒与昆虫宿主相互作用的研究进展

杆状病毒与昆虫宿主相互作用是一种基本的分子和生态问题, 不仅在农业上, 而且在真核表达系统、 基因治疗、 蛋白表面展示 系统以及基因工程疫苗等方面都有重要的实际应用。杆状病毒还是一种很有潜力的病毒杀虫剂, 而且对环境来说是安全的。研究这些相互 作用也产生了许多重要和有价值的发现。杆状病毒生命循环中存在两种不同形式的病毒, 即包埋型病毒粒子(occlusion derived virus, ODV) 和出芽型病毒粒子(budded virus, BV)。ODV包裹于多角体中, 主要负责宿主的原发感染; 而BV由感染的宿主细胞释放后引发继发 感染。病毒侵染起始于敏感的昆虫宿主食用了污染包涵体病毒的植物。在宿主中肠的碱性环境中, 多角体溶解释放ODV, ODV与宿主肠道 柱状上皮细胞细胞膜融合, 通过内吞体进入细胞。之后核衣壳从内吞体中逃脱并被转运到细胞核。病毒转录和复制在细胞核进行, 新生 的BV粒子从基底膜出芽引起全身感染。杆状病毒与宿主细胞相互作用包括从病毒结合和进入时的相互作用, 到宿主基因表达调节, 以及 修饰与调节细胞和机体所发生的生理和防御的相互作用的复杂和微妙的机制。本文主要以杆状病毒侵染昆虫宿主的过程为线索, 总结和评 述了杆状病毒与昆虫宿主相互作用方面研究的最新进展, 特别是杆状病毒基因在病毒入侵过程中所起的作用。     

Ligand-directed gene targeting to mammalian cells by pseudotype baculoviruses

The baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) can infect a variety of mammalian cells, as well as insect cells, facilitating its use as a viral vector for gene delivery into mammalian cells. Glycoprotein gp64, a major component of the budded AcMNPV envelope, is involved in viral entry into cells by receptor-mediated endocytosis and subsequent membrane fusion. We examined the potential production of pseudotype baculovirus particles transiently carrying ligands of interest in place of gp64 as a method of ligand-directed gene delivery into target cells. During amplification of a gp64-null pseudotype baculovirus carrying a green fluorescent protein gene in gp64-expressing insect cells, however, we observed the high-frequency appearance of a replication-competent virus incorporating the gp64 gene into the viral genome. To avoid generation of replication-competent revertants, we prepared pseudotype baculoviruses by transfection with recombinant bacmids without further amplification in the gp64-expressing cells. We constructed gp64-null recombinant bacmids carrying cDNAs encoding either vesicular stomatitis virus G protein (VSVG) or measles virus receptors (CD46 or SLAM). The VSVG pseudotype baculovirus efficiently transduced a reporter gene into a variety of mammalian cell lines, while CD46 and SLAM pseudotype baculoviruses allowed ligand-receptor-directed reporter gene transduction into target cells expressing measles virus envelope glycoproteins. Gene transduction mediated by the pseudotype baculoviruses could be inhibited by pretreatment with specific antibodies. These results indicate the possible application of pseudotype baculoviruses in ligand-directed gene delivery into target cells.     

Helicoverpa armigera nucleopolyhedrovirus ORF80 encodes a late, nonstructural protein

The Helicoverpa armigera nucleopolyhedrovirus (HearNPV) ORF80 (ha80) has 765 bp encoding a protein with approximately 254 amino acids and a predicted molecular weight of 30.8 kDa. Homologues of ha80 are found in most baculovirus sequences, including those from lepidopteran NPVs, lepidopteran granuloviruses (GVs), hymenopteran baculoviruses, and one dipteran baculovirus, yet their functions remain unclear. In this study we characterized ha80, and showed that it was transcribed late in infected host cells (HzAM1). The product of ha80 was a 31 kDa protein that was not a structural protein of budded virus (BV) or occlusion-derived virus (ODV) particles. Ha80 was first detected in the cytoplasm of infected HzAM1 cells at 12 h p.i., and was observed in the nucleus at later stages of infection, suggesting that it may be involved in transporting viral proteins into the host cell nucleus or play its roles in the nucleus.     

Identification of Autographa californica nucleopolyhedrovirus ac93 as a core gene and its requirement for intranuclear microvesicle formation and nuclear egress of nucleocapsids

Autographa californica nucleopolyhedrovirus (AcMNPV) orf93 (ac93) is a highly conserved uncharacterized gene that is found in all of the sequenced baculovirus genomes except for Culex nigripalpus NPV. In this report, using bioinformatics analyses, ac93 and odv-e25 (ac94) were identified as baculovirus core genes and thus p33-ac93-odv-e25 represent a cluster of core genes. To investigate the role of ac93 in the baculovirus life cycle, an ac93 knockout AcMNPV bacmid was constructed via homologous recombination in Escherichia coli. Fluorescence and light microscopy showed that the AcMNPV ac93 knockout did not spread by infection, and titration assays confirmed a defect in budded virus (BV) production. However, deletion of ac93 did not affect viral DNA replication. Electron microscopy indicated that ac93 was required for the egress of nucleocapsids from the nucleus and the formation of intranuclear microvesicles, which are precursor structures of occlusion-derived virus (ODV) envelopes. Immunofluorescence analyses showed that Ac93 was concentrated toward the cytoplasmic membrane in the cytoplasm and in the nuclear ring zone in the nucleus. Western blot analyses showed that Ac93 was associated with both nucleocapsid and envelope fractions of BV, but only the nucleocapsid fraction of ODV. Our results suggest that ac93, although not previously recognized as a core gene, is one that plays an essential role in the formation of the ODV envelope and the egress of nucleocapsids from the nucleus.     

Baculovirus VP1054 Is an Acquired Cellular PURα, a Nucleic Acid-Binding Protein Specific for GGN Repeats

Baculovirus VP1054 protein is a structural component of both of the virion types budded virus (BV) and occlusion-derived virus (ODV), but its exact role in virion morphogenesis is poorly defined. In this paper, we reveal sequence and functional similarity between the baculovirus protein VP1054 and the cellular purine-rich element binding protein PUR-alpha (PURα). The data strongly suggest that gene transfer has occurred from a host to an ancestral baculovirus. Deletion of the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) vp1054 gene completely prevented viral cell-to-cell spread. Electron microscopy data showed that assembly of progeny nucleocapsids is dramatically reduced in the absence of VP1054. More precisely, VP1054 is required for proper viral DNA encapsidation, as deduced from the formation of numerous electron-lucent capsid-like tubules. Complementary searching identified the presence of genetic elements composed of repeated GGN trinucleotide motifs in baculovirus genomes, the target sequence for PURα proteins. Interestingly, these GGN-rich sequences are disproportionally distributed in baculoviral genomes and mostly occurred in proximity to the gene for the major occlusion body protein polyhedrin. We further demonstrate that the VP1054 protein specifically recognizes these GGN-rich islands, which at the same time encode crucial proline-rich domains in p78/83, an essential gene adjacent to the polyhedrin gene in the AcMNPV genome. While some viruses, like human immunodeficiency virus type 1 (HIV-1) and human JC virus (JCV), utilize host PURα protein, baculoviruses encode the PURα-like protein VP1054, which is crucial for viral progeny production.     

斜纹夜蛾核多角体病毒（SpltNPV）基因组EcoRI—G片段的序列分析

斜纹夜蛾核多角体病毒 (SpltNPV)基因组EcoRI G片段全长 745 0bp ,包括 7个开放读码框 :vp39、lef 4、cg30、p91、vp33、tlp2 0、AcMNPVORF81同源基因和一个同源区 (hr)。基因组排列比较分析发现 ,这些基因在基因组中的排列 ,在所有已知序列的杆状病毒中都比较保守     

Identification, characterization and phylogenic analysis of conserved genes within the odvp-6e/odv-e56 gene region of Choristoneura fumiferana granulovirus

The genes that are located within the odvp-6e/odv-e56 region of the Choristoneura fumiferana granulovirus (ChfuGV) were identified by sequencing the 11 kb BamHI restriction fragment on the ChfuGV genome. The global GC content that was calculated from the data obtained from this genomic region was 34.96%. The open-reading frames (ORFs), located within the odvp-6e/odv-e56 region, are presented and compared to the equivalent ORFs that are located at the same region in other GVs. This region is composed of 14 ORFs, including three ORFs that are unique to ChfuGV with no obvious homologues in other baculoviruses as well as eleven ORFs with homologues to granuloviral ORFs, such as granulin, CfORF2, pk-1, ie-1, odv-e18, p49, and odvp-6e/odv-e56. In this study, the conceptual products of seven major conserved ORFs (granulin, CfORF2, IE-1, ODV-E18, p49 and ODVP-6E/ODV-E56) were used in order to construct phylogenetic trees. Our results show that granuloviruses can be grouped in 2 distinct groups as follows: Group I; Choristoneura fumiferana granulovirus (ChfuGV), Cydia pomonella granulovirus (CpGV), Phthorimaea operculella granulovirus (PhopGV), and Adoxophyes orana granulovirus (AoGV). Group II; Xestia c-nigrum granulovirus (XcGV), Plutella xylostella granulovirus (PxGV), and Trichoplusia ni granulovirus (TnGV). The ChfuGV conserved proteins are most closely related to those of CpGV, PhopGV, and AoGV. Comparative studies, performed on gene arrangements within this region of genomes, demonstrated that three GVs from group I maintain similar gene arrangements.     

中国棉铃虫单粒包埋核多角体病毒（HaSNPV）HindⅢ-Ⅰ片段的序列分析与基因排列研究

对中国棉铃虫单粒包埋核多角体病毒（HaSNPV)基因组中的HindⅢ-Ⅰ片段的序列进行分析,该片段全长7501nt,包括10个开放阅读框：AcMNPV ORF111的同源基因（Ac 111),晚期表达因子2（lef-2）基因,病毒核壳结构蛋白p24基因、gp16基因、多角体包膜蛋白（polyhedron envelope protein,pep)基因、AcMNPV ORF63的同源基因（Ac63),38.7kD基因,晚期表达因子1（lef-1) 基因,及两个特有基因HaSNPV orf591和HasSNPV orf435。基因组的排列比较分析发现与AcMNPV有较大区别。     

Sequence analysis and organization of the Neodiprion abietis nucleopolyhedrovirus genome

Of 30 baculovirus genomes that have been sequenced to date, the only nonlepidopteran baculoviruses include the dipteran Culex nigripalpus nucleopolyhedrovirus and two hymenopteran nucleopolyhedroviruses that infect the sawflies Neodiprion lecontei (NeleNPV) and Neodiprion sertifer (NeseNPV). This study provides a complete sequence and genome analysis of the nucleopolyhedrovirus that infects the balsam fir sawfly Neodiprion abietis (Hymenoptera, Symphyta, Diprionidae). The N. abietis nucleopolyhedrovirus (NeabNPV) is 84,264 bp in size, with a G+C content of 33.5%, and contains 93 predicted open reading frames (ORFs). Eleven predicted ORFs are unique to this baculovirus, 10 ORFs have a putative sequence homologue in the NeleNPV genome but not the NeseNPV genome, and 1 ORF (neab53) has a putative sequence homologue in the NeseNPV genome but not the NeleNPV genome. Specific repeat sequences are coincident with major genome rearrangements that distinguish NeabNPV and NeleNPV. Genes associated with these repeat regions encode a common amino acid motif, suggesting that they are a family of repeated contiguous gene clusters. Lepidopteran baculoviruses, similarly, have a family of repeated genes called the bro gene family. However, there is no significant sequence similarity between the NeabNPV and bro genes. Homologues of early-expressed genes such as ie-1 and lef-3 were absent in NeabNPV, as they are in the previously sequenced hymenopteran baculoviruses. Analyses of ORF upstream sequences identified potential temporally distinct genes on the basis of putative promoter elements.     

Sequence analysis of the genome of the Neodiprion sertifer nucleopolyhedrovirus

The genome of the Neodiprion sertifer nucleopolyhedrovirus (NeseNPV), which infects the European pine sawfly, N. sertifer (Hymenoptera: Diprionidae), was sequenced and analyzed. The genome was 86,462 bp in size. The C+G content of 34% was lower than that of the majority of baculoviruses. A total of 90 methionine-initiated open reading frames (ORFs) with more than 50 amino acids and minimal overlapping were found. From those, 43 ORFs were homologous to other baculovirus ORFs, and 29 of these were from the 30 conserved core genes among all baculoviruses. A NeseNPV homolog to the ld130 gene, which is present in all other baculovirus genomes sequenced to date, could not be identified. Six NeseNPV ORFs were similar to non-baculovirus-related genes, one of which was a trypsin-like gene. Only one iap gene, containing a single BIR motif and a RING finger, was found in NeseNPV. Two NeseNPV ORFs (nese18 and nese19) were duplicates transcribed in opposite orientations from each other. NeseNPV did not have an AcMNPV ORF 2 homolog characterized as the baculovirus repeat ORF (bro). Six homologous regions (hrs) were located within the NeseNPV genome, each containing small palindromes embedded within direct repeats. A phylogenetic analysis was done to root the tree based upon the sequences of DNA polymerase genes of NeseNPV, 23 other baculoviruses, and other phyla. Baculovirus phylogeny was then constructed with 29 conserved genes from 24 baculovirus genomes. Culex nigripalpus nucleopolyhedrovirus (CuniNPV) was the most distantly related baculovirus, branching to the hymenopteran NeseNPV and the lepidopteran nucleopolyhedroviruses and granuloviruses.     

Genetic variation and virulence of Autographa californica multiple nucleopolyhedrovirus and Trichoplusia ni single nucleopolyhedrovirus isolates

To determine the genetic diversity within the baculovirus species Autographa calfornica multiple nucleopolyhedrovirus (AcMNPV; Baculoviridae: Alphabaculovirus), a PCR-based method was used to identify and classify baculoviruses found in virus samples from the lepidopteran host species A. californica, Autographa gamma, Trichoplusia ni, Rachiplusia ou, Anagrapha falcifera, Galleria mellonella, and Heliothis virescens. Alignment and phylogenetic inference from partial nucleotide sequences of three highly conserved genes (lef-8, lef-9, and polh) indicated that 45 of 74 samples contained isolates of AcMNPV, while six samples contained isolates of Rachiplusia ou multiple nucleopolyhedrovirus strain R1 (RoMNPV-R1) and 25 samples contained isolates of the species Trichoplusia ni single nucleopolyhedrovirus (TnSNPV; Alphabaculovirus). One sample from A. californica contained a previously undescribed NPV related to alphabaculoviruses of the armyworm genus Spodoptera. Data from PCR and sequence analysis of the ie-2 gene and a region containing ORF ac86 in samples from the AcMNPV and RoMNPV clades indicated a distinct group of viruses, mostly from G. mellonella, that are characterized by an unusual ie-2 gene previously found in the strain Plutella xylostella multiple nucleopolyhedrovirus CL3 (PlxyMNPV-CL3) and a large deletion within ac86 previously described in the AcMNPV isolate 1.2 and PlxyMNPV-CL3. PCR and sequence analysis of baculovirus repeated ORF (bro) genes revealed that the bro gene ac2 was split into two separate bro genes in some samples from the AcMNPV clade. Comparison of sequences in this region suggests that ac2 was formed by a deletion that fused the two novel bro genes together. In bioassays of a selection of isolates against T. ni, significant differences were observed in the insecticidal properties of individual isolates, but no trends were observed among the AcMNPV, TnSNPV, or RoMNPV groups of isolates. This study expands on what we know about the variation of AcMNPV, AcMNPV-like and TnSNPV viruses, provides novel information on the distinct groups in which AcMNPV isolates occur, and contributes to data useful for the registration, evaluation, and improvement of AcMNPV, AcMNPV-like, and TnSNPV isolates as biological control agents.     

杨扇舟蛾颗粒体病毒晚期表达因子的分析

【目的】本研究对杨扇舟蛾颗粒体病毒(Clostera anachoreta granulovirus,Clan GV)的晚期表达因子(Late expression factors,LEFs)进行生物信息学分析,并对Clan GV的lefs与其它杆状病毒的lefs进行对比,对鉴定lef基因和研究Clan GV的感染机制具有重要意义。【方法】使用ORF finder在线程序进行开放阅读框(ORFs)分析,BLASTP程序用于蛋白序列的同源分析,DNAStar和DNAClub生物学软件用于对序列进行处理和分析,采用BLAST在公共数据库中对序列进行比对,Clustal W Version 1.8和Gene Doc 2.7用于多序列的比对和分析,用MEGA 6.06的NJ法进行系统发育分析。【结果】Clan GV基因组包括15个lef基因,分别为ie-1、lef-2、39k、lef-11、p35、p47、lef-1、lef-6、lef-5、lef-4、dnapol、lef-3、lef-9、lef-8和lef-10。Clan GV与云杉枞色卷蛾颗粒体病毒(Choristoneura occidentalis granulovirus,Co GV)、黄地老虎颗粒体病毒(Agrotis segetum granulovirus,As GV)、苹果异形小卷蛾颗粒体病毒(Cryptophlebia leucotreta granulovirus,Cl GV)、马铃薯块茎蛾颗粒体病毒(Phthorimaea operculella granulovirus,Po GV)和苹果蠹蛾颗粒体病毒(Cydia pomonella granulovirus,Cp GV)有着较近的亲缘关系。颗粒体病毒中只有Clan GV和分月扇舟蛾颗粒体病毒含有p35。Clan GV的lef-2的转录方向不同于其它12个颗粒体病毒。γ和δ杆状病毒分别只含有7个和3个Clan GV的lef同源基因。Clan GV的lefs跟其它杆状病毒lefs的相似性较低,其中Clan GV与其它颗粒体病毒间的相似性高于Clan GV与核型多角体病毒间的相似性。Clan GV的lef-2、39k、p35、lef-5、dnapol和lef-9在启动子上游拥有TATA box;p47和lef-1在TATA下游20~40 bp处还有一个CACT基序;lef-11、p35、lef-6、lef-5、lef-3、lef-9、lef-8和lef-10这8个基因有晚期启动子基序TAAG;而p35、lef-5、lef-9和lef-10上游既有TATA又有TAAG基序。【结论】结果为研究杆状病毒的基因功能和感染机制提供了数据基础。     

In vitro and in vivo gene delivery by recombinant baculoviruses

Although recombinant baculovirus vectors can be an efficient tool for gene transfer into mammalian cells in vitro, gene transduction in vivo has been hampered by the inactivation of baculoviruses by serum complement. Recombinant baculoviruses possessing excess envelope protein gp64 or other viral envelope proteins on the virion surface deliver foreign genes into a variety of mammalian cell lines more efficiently than the unmodified baculovirus. In this study, we examined the efficiency of gene transfer both in vitro and in vivo by recombinant baculoviruses possessing envelope proteins derived from either vesicular stomatitis virus (VSVG) or rabies virus. These recombinant viruses efficiently transferred reporter genes into neural cell lines, primary rat neural cells, and primary mouse osteal cells in vitro. The VSVG-modified baculovirus exhibited greater resistance to inactivation by animal sera than the unmodified baculovirus. A synthetic inhibitor of the complement activation pathway circumvented the serum inactivation of the unmodified baculovirus. Furthermore, the VSVG-modified baculovirus could transduce a reporter gene into the cerebral cortex and testis of mice by direct inoculation in vivo. These results suggest the possible use of the recombinant baculovirus vectors in combination with the administration of complement inhibitors for in vivo gene therapy.     

核衣壳蛋白VP39融合TAT转导肽对杆状病毒转导哺乳动物细胞的影响

为了提高昆虫杆状病毒在哺乳动物细胞中转导基因的效率,构建了重组杆状病毒AcRed-tat和AcRed。两者都能在哺乳动物细胞内表达红色荧光蛋白作为报告基因。同时,AcRed-tat带有HIV-1Tat转导肽、病毒主要衣壳蛋白基因vp39及增强型绿色荧光蛋白(egfp)三者的融合基因,并由杆状病毒多角体启动子表达,能够在昆虫细胞中表达该Tat融合蛋白,并掺入子代病毒粒子。而AcRed作为相应的对照病毒,带有多角体启动子表达vp39和egfp的融合基因。2株病毒分别转导哺乳动物细胞后,利用流式细胞仪检测报告基因的表达水平,发现在CHO和Vero细胞中AcRed-Tat介导的报告基因表达水平明显高于AcRed,而在HEK293细胞中2株病毒介导的报告基因表达水平差异不显著。结果表明Tat转导肽可以提高杆状病毒对一部分哺乳动物细胞的转导效率,为改进杆状病毒-哺乳动物细胞转导载体提供了新的思路。