Candidate Vectors Research Articles

Effect of Lactobacillus brevis ATCC 8287 as a feeding supplement on the performance and immune function of piglets

Lactobacillus brevis ATCC 8287, a surface (S-layer) strain, possesses a variety of functional properties that make it both a potential probiotic and a good vaccine vector candidate. With this in mind, our aim was to study the survival of L. brevis in the porcine gut and investigate the effect of this strain on the growth and immune function of recently weaned piglets during a feeding trial. For this, 20 piglets were divided evenly into a treatment and a control group. Piglets in the treatment group were fed L. brevis cells (1×1010) daily for three weeks, whereas those in the control group were provided an equivalent amount of probiotic-free placebo. For assessing the impact of L. brevis supplementation during the feeding trial, health status and weight gain of the piglets were monitored, pre- and post-trial samples of serum and feces were obtained, and specimens of the small and large intestinal mucosa and digesta were collected at slaughter. The results we obtained indicated that L. brevis-supplemented feeding induced a non-significant increase in piglet body weight and caused no change in the morphology of the intestinal mucosa. L. brevis cells were found to localize mainly in the large intestine, but they could not be isolated from feces. To a lesser extent, L. brevis was detected in the small intestine, although there was no specific attachment to the Peyer's patches. Changes in total serum IgG and IgA concentrations were not caused by supplemented L. brevis and no measurable rise in L. brevis-specific IgG was observed. However, analysis of cytokine gene expression in intestinal mucosa revealed downregulation of TGF-β1 in the ileum and upregulation of IL-6 in the cecum in the L. brevis-supplemented group. Based on the results from this study, we conclude that whereas L. brevis appears to have some intestinal immunomodulatory effects, the ability of this strain to survive and colonize within the porcine gut appears to be limited.

Protective efficacy of PLGA microspheres loaded with divalent DNA vaccine encoding the ompA gene of Aeromonas veronii and the hly gene of Aeromonas hydrophila in mice

In the present study, poly (lactic-co-glycolic) acid (PLGA) was used as a carrier for a divalent fusion DNA vaccine encoding the Aeromonas veronii outer membrane protein A (ompA) and Aeromonas hydrophila hemolysins (hly) protein. The recombinant pET-28a-ompA-hly was constructed by inserting the ompA gene and hly gene into a pET-28a expression vector. Loading of ompA-hly antigen module on PLGA microspheres were accomplished by water-in-oil-in-water (W/O/W) encapsulation. The molecular weight and specificity of pET-28a-ompA-hly were detected by dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The microspheres showed an average particle size of 100–150μm and a loading efficiency (LE) of 68.8%. Mice received ompA-hly antigen-loaded PLGA microspheres by intraperitoneal or intragastric administration mounted strong and sustained IgG response, which was significantly higher (p<0.05) than those achieved by pET-28a-ompA-hly antigen alone. OmpA-hly antigen-loaded PLGA microsphere vaccine uniquely conferred a long lasting (30 days) sterile immunity against challenge infection. Results indicated that ompA-hly antigen-loaded PLGA microsphere vaccine is a qualified candidate vector system for sterile protective immunity against A. hydrophila and A. veronii infections.

The Virtues and Vices of Harnessing HSV Vectors for CNS Autoimmunity Modulation

HSV type 1 (HSV‐1) is a common human path‐ ogen, known as the causative agent of recurrent labial herpes (cold sores). HSV is one of the most extensively studied viruses. The broad knowledge on HSV pathogenesis and viral gene functions have enabled the construction of safe HSV vectors for gene therapy purposes. HSV‐1 has natural properties, which are favor‐ able for therapy vectors: the life‐long latent form of infection in the nervous system, which could be exploited for long‐term transgene expression, and the episomal DNA genome, which does not integrate into the host genome. Due to numerous dispensable genes, clon‐ ing of large or multiple transgenes into HSV can be accomplished. The drug susceptibility gene, HSV thymidine kinase, is present in the genome of wild‐type HSV and in most HSV vectors. Moreover, HSV‐1 is a neurotropic virus, naturally seeking its way to the nervous system, making HSV‐1 a promising gene therapy vector candidate for CNS diseases [1,2]. Clinical trials have so far mainly explored HSV‐1 vectors as oncolytic viruses for therapy of brain tumors or other cancers, for example, melanoma [1,3,4]. Similar HSV vectors have potential for gene therapy of neurological disorders, particularly pain [1,2] and CNS autoimmune disease. In this article, we discuss gene therapy of experimen‐ tal autoimmune encephalomyelitis (EAE), the premier animal model for multiple sclerosis (MS). MS and EAE are inflammatory diseases of the CNS, where autoreactive T cells attack the myelin sheath surrounding the nerve axons. Inflammation, axonal loss and demyelination are hallmarks of the diseases. There is still a lack of curative pharmacological therapy for MS, and the current semiselective immuno‐ modulative drugs may predispose some patients

Characterisation of a spumavirus Gag protein

Background Human prototypic foamy virus (HPFV) belongs to the spumaretrovrinae subfamily and is an attractive vector candidate for gene therapy [1] as it is apathogenic. The Gag protein is not cleaved into matrix (MA), capsid (CA) and nucleocapsid (NC) as occurs in orthoretroviruses; rather, it is able to perform the roles of these proteins as a single polypeptide [2]. Foamy virus Gag proteins are targets for restriction factors such as Trim5a [3] and also interact with the aminoterminal leader peptide of the envelope protein (Env). This Gag-Env interaction is essential for budding of viral particles from the host cell [4,5].

Characterization of three cryptic plasmids from Lactobacillus plantarum G63 that was isolated from Chinese pickle

Three plasmids from Lactobacillus plantarum G63, pG6301, pG6302 and pG6303, were sequenced and have molecular sizes of 3516-bp, 9112-bp and 10047-bp, respectively. We determined the replicons of these plasmids. The pG6301 plasmid carried a replication gene that functioned by the rolling-circle replication mechanism. The Rep protein of pG6302 shared extremely low similarity with a reported plasmid, pLME300, which replicated by a bi-directional mechanism. Both the Rep protein and OriV analyses indicated a similar replication mechanism in pG6302. Conversely, we found neither the Rep protein nor OriV when we analyzed the whole sequence of pG6303. This finding may illustrate a novel replication mechanism. Additionally, the transposon, a mobilization element, was analyzed and compared to a similar insertion sequence (IS) element. A predicted lysozyme gene, pG6303 guhA, was heterologously expressed, but no activity was detected. The pG6302 and pG6303 plasmids contain new replicons and may be useful vector candidates for future molecular manipulation of L. plantarum.

The Attenuated Brucella abortus Strain 19 Invades, Persists in, and Activates Human Dendritic Cells, and Induces the Secretion of IL-12p70 but Not IL-23

BackgroundBacterial vectors have been proposed as novel vaccine strategies to induce strong cellular immunity. Attenuated strains of Brucella abortus comprise promising vector candidates since they have the potential to induce strong CD4+ and CD8+ T-cell mediated immune responses in the absence of excessive inflammation as observed with other Gram-negative bacteria. However, some Brucella strains interfere with the maturation of dendritic cells (DCs), which is essential for antigen-specific T-cell priming. In the present study, we investigated the interaction of human monocyte-derived DCs with the smooth attenuated B. abortus strain (S) 19, which has previously been employed successfully to vaccinate cattle.Methodology/Principal findingsWe first looked into the potential of S19 to hamper the cytokine-induced maturation of DCs; however, infected cells expressed CD25, CD40, CD80, and CD86 to a comparable extent as uninfected, cytokine-matured DCs. Furthermore, S19 activated DCs in the absence of exogeneous stimuli, enhanced the expression of HLA-ABC and HLA-DR, and was able to persist intracellularly without causing cytotoxicity. Thus, DCs provide a cellular niche for persisting brucellae in vivo as a permanent source of antigen. S19-infected DCs produced IL-12/23p40, IL-12p70, and IL-10, but not IL-23. While heat-killed bacteria also activated DCs, soluble mediators were not involved in S19-induced activation of human DCs. HEK 293 transfectants revealed cellular activation by S19 primarily through engagement of Toll-like receptor (TLR)2.Conclusions/SignificanceThus, as an immunological prerequisite for vaccine efficacy, B. abortus S19 potently infects and potently activates (most likely via TLR2) human DCs to produce Th1-promoting cytokines.

Susceptibility of Anopheles sinensis to Plasmodium vivax in malarial outbreak areas of central China

BackgroundAnopheles sinensis, Anopheles anthropophagus, Anopheles minimus and Anopheles dirus are the major vectors of malaria transmission in China. Anopheles sinensis is considered a secondary vector due to its relatively low malaria-transmission ability. However, in 2005, an outbreak of over 40,000 Plasmodium vivax malaria cases was reported in areas where Anopheles sinensis was the only major vector. Therefore, it is necessary to reassess the malaria transmission ability of this vector species in China.MethodsLaboratory colonies of An. sinensis and An. anthropophagus, and first-generation progeny (F1) of An. sinensis that had been collected in central China, were infected by direct membrane feeding assay with mono-vivax gametocyte-containing blood collected from vivax-infected patients. The mosquitoes were kept for 7 to 14 days post-blood feeding to allow parasites to develop into oocysts and sporozoites. Infectivity was measured by dissecting midguts and salivary glands. The presence of oocysts and sporozoites was determined by microscopy at 7 and 14 days post-blood feeding, and the numbers of gametocytes and asexual parasites, as well as mosquito parasite infections, were determined.ResultsThe positive oocyst and sporozoite feed rates of the 142 pairs of lab-colony An. sinensis and An. anthropophagus were not significantly different, and the same results were found with the 10 pairs of laboratory and F1 An. sinensis. An. sinensis had more oocysts/midgut at 7 days post-feeding than An. anthropophagus, but the gametocytemia, asexual parasitemia, and ratio of macrogametocytes to microgametocytes, did not correlate with either oocyst or sporozoite infection. However, in the oocyst-positive mosquitoes, there was a correlation between gametocytemia and the average oocyst number/midgut.ConclusionsThe susceptibility of An. sinensis (both laboratory and F1) to P. vivax-infected blood is similar to Anopheles anthropophagus, when evaluated by membrane feeding assay under laboratory conditions. In recent years, in central China, the vivax malaria transmission ability of An. sinensis has probably been underestimated. Further studies of this species in other regions are needed. An. sinensis could also be a good candidate vector for evaluating candidate malaria transmission-blocking vaccines (TBV).

Utilizing poxviral vectored vaccines for antibody induction—Progress and prospects

Over the last decade, poxviral vectors emerged as a mainstay approach for the induction of T cell-mediated immunity by vaccination, and their suitability for human use has led to widespread clinical testing of candidate vectors against infectious intracellular pathogens and cancer. In contrast, poxviruses have been widely perceived in the vaccine field as a poor choice of vector for the induction of humoral immunity. However, a growing body of data, from both animal models and recent clinical trials, now suggests that these vectors can be successfully utilized to prime and boost B cells and effective antibody responses. Significant progress has been made in the context of heterologous prime–boost immunization regimes, whereby poxviruses are able to boost responses primed by other vectors, leading to the induction of high-titre antigen-specific antibody responses. In other cases, poxviral vectors have been shown to stimulate humoral immunity against both themselves and encoded transgenes, in particular viral surface proteins such as influenza haemagglutinin. In the veterinary field, recombinant poxviral vectors have made a significant impact with numerous vectors licensed for use against a variety of animal viruses. On-going studies continue to explore the potential of poxviral vectors to modulate qualitative aspects of the humoral response, as well as their amenability to adjuvantation seeking to improve quantitative antibody immunogenicity. Nevertheless, the underlying mechanisms of B cell induction by recombinant poxviruses remain poorly defined, and further work is necessary to help guide the rational optimization of future poxviral vaccine candidates aiming to induce antibodies.

Iterative Reduced-Complexity Graph-Based Detection for LDPC Coded 2D Recording Channels

In this paper, we consider joint detection and decoding for low-density parity-check (LDPC) coded two-dimensional (2D) intersymbol interference (ISI) channels, where message-passing is performed over an overall factor graph representing both the code structure and the channel model. We propose a low-complexity channel detector based on the Chase decoding algorithm to simplify the check node operation by restricting the a posteriori probability (APP) computation to a small subset of candidate vectors. Simulation results show that the proposed receiver provides an adjustable performance/complexity tradeoff and performs close to the full-complexity graph-based receiver.

Lattice Reduction-Based MIMO Iterative Receiver Using Randomized Sampling

For iterative detection and decoding (IDD) in multiple-input multiple-output (MIMO) systems, although the maximum a posteriori probability (MAP) detector is desirable in terms of performance, it is difficult to be employed due to its prohibitively high complexity as an exhaustive search is used. In this paper, a lattice reduction (LR)-based MIMO detection method is studied to achieve near MAP performance with reasonably low complexity for IDD. The a priori information (API), which is available from a soft-input soft-output (SISO) decoder, is taken into account to generate a list with a randomized successive interference cancellation (SIC) method. More specifically, a joint Gaussian distribution is used to convert the API into the LR domain and a modified sampling distribution, which was originally adopted for near optimal LR-based detection in non-IDD MIMO systems, is derived for random sampling to build a list of candidate vectors of high a posteriori probability (APP) with low complexity. It is shown that the IDD receiver with the proposed method outperforms those with the conventional LR-based methods, where no API is taken into account to build a list. Furthermore, the trade-off between performance and complexity is exploited with varying list length.

Vaccination with recombinant PIV5 expressing influenza neuraminidase provides protection against homologous and heterologous influenza virus infection (P4291)

Abstract Vaccination is considered the most effective measure for controlling influenza virus infection, however current vaccination methods are inadequate. Virus-vectored vaccines offer an appealing alternative. Parainfluenza virus 5 (PIV5), a non-segmented, negative-stranded RNA virus (NNSV) in the family Paramyxoviridae is an appealing vector candidate as it has a stable genome without a DNA phase in its life cycle, is readily grown to high titers in approved vaccine cell lines, and infects many mammals without causing disease. Neuraminidase (NA), a glycoprotein found on the surface of influenza A virus as well as virus-infected cells is more conserved than the hemagglutinin surface glycoprotein, the primary antigen in current influenza vaccines. This increases the likelihood of achieving broad protection if used as a vaccine antigen. We show that vaccination with PIV5 expressing the NA from H5N1 highly pathogenic avian influenza (HPAI; rPIV5-N1 (H5N1)) or pandemic H1N1 (rPIV5-N1 (H1N1)) primes robust NA-specific antibody and T cell responses and confers complete protection against homologous (NA-matched) influenza virus challenge. Moreover, immunization also confers significant cross-protection against challenge with heterologous influenza virus within the same NA type. These results suggest that NA can be an effective vaccine antigen and protect against even a stringent challenge, such as with H5N1 HPAI virus, making it an appealing candidate pandemic influenza vaccine.

Natural Phytoplasma Infection of Four Phloem-Feeding Auchenorrhyncha Across Vineyard Agroecosystems in Central-Eastern Italy

The seasonal variations of grapevine yellow phytoplasma were investigated in four phloem-feeding planthopper and leafhopper species that are vectors of plant disease agents. In total, 1,148 wild specimens were collected from three vineyard agroecosystems in the Marche region (central-eastern Italy), from May to September 2008, and analyzed using polymerase chain reaction-restriction fragment-length polymorphism methods. Of 525 Euscelis lineolatus Brullé, 25.1% were positive for aster yellow phytoplasma (16SrI-C, 16SrI-B subgroups) and stolbur phytoplasma (16SrXII-A subgroup; Vergilbungskrankheit type I [VK-I]). Of 368 Hyalesthes obsoletus Signoret, 19.3% were positive for the 16SrXII-A subgroup (VK-I, VK-II; mainly according to their host plant). Of 146 Neoaliturus fenestratus (Herrich-Schäffer), 15.1% were positive for the 16SrI-C and 16SrI-B subgroups, and 7.3% of 109 Psammotettix alienus (Dahlbom) were positive for the 16SrI-B subgroup. The total inoculation efficiency in the feeding medium assays was 57.1% for P. alienus, 44.7% for E. lineolatus, 44.4% for N. fenestratus and 33.9% for H. obsoletus. All of the phytoplasma subgroups identified in the insect bodies were also detected in their feeding media. Detection of stolbur phytoplasma in E. lineolatus feeding media strengthens the hypothesis that it is a candidate vector of Bois noir disease causal agent. The phytoplasma subgroups detected in the Auchenorrhyncha species showed variations according to season and/or vineyard agroecosystem. This study highlights the different specificities of these phytoplasma-Auchenorrhyncha species relationships, and suggests a primary role of the entire vineyard agroecosystem in the epidemiology of grapevine yellow phytoplasma diseases.

Enhanced Inter-Prediction Via Shifting Transformation in the H.264/AVC

Inter-prediction based on block-based motion estimation (ME) is used in most video codecs. The closer the prediction to the target block, the lower the residual, and thus more efficient compression can be achieved. In this paper, a new technique called enhanced inter-prediction (EIP) is proposed to improve the prediction candidates using an additional transformation acting while performing ME. A parametric transformation acts within the coding loop of each block to modify the prediction for each motion vector candidate. The EIP is validated in the particular case of a single-parameter shifting transformation. This paper presents an efficient algorithm to compute the best shift for each prediction candidate and a model to select the optimal prediction based on minimum cost integrating the approach with existing rate-distortion optimization techniques in the H.264/AVC video codec. Results show significant improvements with an average of 6% bit-rate reduction compared to the original H.264/AVC.

Vaccination to Conserved Influenza Antigens in Mice Using a Novel Simian Adenovirus Vector, PanAd3, Derived from the Bonobo Pan paniscus

Among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the Pan Adenovirus type 3 (PanAd3, isolated from a bonobo, Pan paniscus) has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. In this study, we inserted into a replication defective PanAd3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (NP) and matrix 1 (M1). We then studied antibody and T cell responses as well as protection from challenge infection in a mouse model. A single intranasal administration of PanAd3-NPM1 vaccine induced strong antibody and T cell responses, and protected against high dose lethal influenza virus challenge. Thus PanAd3 is a promising candidate vector for vaccines, including universal influenza vaccines.

Trichinella spiralis infection reduces tumor growth and metastasis of B16-F10 melanoma cells

Recently, attempts have been made to use parasites as novel candidates for live vaccine vectors against solid tumors. In this study, we examined the effects of Trichinella spiralis (T. spiralis) infection on solid tumor growth and metastasis. After oral infection with T. spiralis larvae, B16-F10 cells were injected subcutaneously and intravenously into C57BL/6 mice to evaluate tumor growth and metastatic potential, respectively. Tumor growth and lung metastases in T. spiralis infected mice were significantly reduced compared with control mice. To elucidate the mechanism of tumor reduction by parasitic infection, we conducted cytokine arrays using mouse serum. CXCL9 and CXCL10 were increased in the infection group and decreased in the infection-tumor group. However, the expression level was not changed in the infection-metastasis group compared to the infection or control-metastasis groups. Although SDF-1 and IL-4 were increased in the infection group, there was no significant change in expression in the infection-tumor group or the infection-metastasis group. Additionally, IL-4 and KC were increased in the infection-tumor group compared to the control-tumor group, but there was no difference in expression between the control-metastasis group and the infection-metastasis group. CXCL13 was significantly increased in the infection-metastasis group only. These results suggest that T. spiralis infection reduced tumor growth and metastasis through a complex transition in cytokine regulation profiles including CXCL9, CXCL10, and CXCL13.

Anopheles moucheti and Anopheles vinckei are candidate vectors of ape Plasmodium parasites, including Plasmodium praefalciparum in Gabon.

During the last four years, knowledge about the diversity of Plasmodium species in African great apes has considerably increased. Several new species were described in chimpanzees and gorillas, and some species that were previously considered as strictly of human interest were found to be infecting African apes. The description in gorillas of P. praefalciparum, the closest relative of P. falciparum which is the main malignant agent of human malaria, definitively changed the way we understand the evolution and origin of P. falciparum. This parasite is now considered to have appeared recently, following a cross-species transfer from gorillas to humans. However, the Plasmodium vector mosquito species that have served as bridge between these two host species remain unknown. In order to identify the vectors that ensure ape Plasmodium transmission and evaluate the risk of transfer of these parasites to humans, we carried out a field study in Gabon to capture Anopheles in areas where wild and semi-wild ape populations live. We collected 1070 Anopheles females belonging to 15 species, among which An. carnevalei, An. moucheti and An. marshallii were the most common species. Using mtDNA-based PCR tools, we discovered that An. moucheti, a major human malaria vector in Central Africa, could also ensure the natural transmission of P. praefalciparum among great apes. We also showed that, together with An. vinckei, An. moucheti was infected with P. vivax-like parasites. An. moucheti constitutes, therefore, a major candidate for the transfer of Plasmodium parasites from apes to humans.

Amino-functionalized mesoporous silica nanoparticles: adsorption and protection for pcDNA3.1(+)-PKB-HA

This work evaluated the adsorption and protection capacities of amino-functionalized mesoporous silica nanoparticles (Am-MSNs) for the recombinant DNA (rDNA), pcDNA3.1(+)-PKB-HA. The in vitro biocompatibility of Am-MSNs was also tested on HeLa and A549 cells, respectively. The results reveal that the MSNs modified with 3-aminopropyltriethoxysilane exhibit good adsorption capacity for pcDNA3.1(+)-PKB-HA at physiological conditions and the adsorption amount is higher than that of other silica nanoparticles. Moreover, the material can also protect pcDNA3.1(+)-PKB-HA from enzymatic degradation completely and presents high in vitro biocompatibility. This demonstrates that Am-MSNs may be potential nonviral vector candidates for pcDNA3.1(+)-PKB-HA.

A fast VLSI architecture of a hierarchical block matching algorithm for motion estimation

In this paper, an efficient VLSI architecture of a hierarchical block matching algorithm has been proposed for motion estimation. At the lowest resolution level, two motion vector (MV) candidates are selected to get better performance. In the next search level, these two candidates provide the center points for local searches to get one MV candidate. Then, at next level and the finest level, one MV candidate is chosen from one local search area (LSA), defined by the MV candidate, obtained from lower resolution level. This architecture requires nine processing elements and data are processed in such a way that calculation to obtain frames of different resolution is overlapped with the MV calculation. Simulation results indicate that this architecture is more area-efficient and faster than many full-search, three-step-search and multiresolution architectures which makes it suitable for SD and HD video. To avoid the delay due to pipelining, the MVs of all the macro-blocks are calculated for one resolution level and stored in RAM to get LSA for next resolution level. This architecture with about 16 K gates is implemented for a search range of [?15, +15]. As this architecture requires only two-port memory, which is very common in most consumer electronics systems, it can be integrated easily in any existing system at the expense of a very small area.

GA Based PHOG-PCA Feature Weighting for On-RoadVehicle Detection

Vehicle detection is an important issue in driver assistance systems and self-guided vehicles that includes two stages of hypothesis generation and verification. In the first stage, potential vehicles are hypothesized and in the second stage, all hypothesis are verified. The focus of this work is to classify vehicle candidate images into vehicle and non-vehicle classes. We extract Pyramid Histograms of Oriented Gradients (PHOG) features from a traffic image as candidates of feature vectors to detect vehicles. Principle Component Analysis (PCA) is applied to these PHOG feature vectors as a dimension reduction tool to obtain the PHOG- PCA vectors. Then we employ real coded chromosome Genetic Algorithm (GA) and linear Support Vector Machine (SVM) to classify the PHOG-PCA features as well as to improve their performance and generalization. Our tests show good classification accuracy of more than 96% correct classification on realistic on-road vehicle images.

Delivery system for DNAzymes using arginine-modified hydroxyapatite nanoparticles for therapeutic application in a nasopharyngeal carcinoma model

DNAzymes are synthetic, single-stranded, catalytic nucleic acids that bind and cleave target mRNA in a sequence-specific manner, and have been explored for genotherapeutics. One bottleneck restricting their application is the lack of an efficient delivery system. As an inorganic nanomaterial with potentially wide application, nano-hydroxyapatite particles (nHAP) have attracted increasing attention as new candidates for nonviral vectors. In this study, we developed an nHAP-based delivery system and explored its cellular uptake mechanisms, intracellular localization, and biological effects. Absorption of arginine-modified nanohydroxyapatite particles (Arg-nHAP) and DZ1 (latent membrane protein 1 [LMP1]-targeted) reached nearly 100% efficiency under in vitro conditions. Using specific inhibitors, cellular uptake of the Arg-nHAP/DZ1 complex was shown to be mediated by the energy-dependent endocytosis pathway. Further, effective intracellular delivery and nuclear localization of the complex was confirmed by confocal microscopy. Biologically, the complex successfully downregulated the expression of LMP1 in nasopharyngeal carcinoma cells. In a mouse tumor xenograft model, the complex was shown to be delivered efficiently to tumor tissue, downregulating expression of LMP1 and suppressing tumor growth. These results suggest that Arg-nHAP may be an efficient vector for nucleic acid-based drugs with potential clinical application.