Biomedical subjects

Zhengrong Cui

Publications and source records attributed to Zhengrong Cui.

At least 19 recordsLinked to original sources

PubMed2006

Nasal immunization with a dual antigen anthrax vaccine induced strong mucosal and systemic immune responses against toxins and bacilli.

Anthrax-vaccine-adsorbed (AVA), the only anthrax vaccine licensed in the U.S., suffers from many major drawbacks. Therefore, there is a need to develop new generation anthrax vaccines that can be easily administered and induce strong immune responses not only against the anthrax toxins, but also against the toxin-producing vegetative anthrax bacilli. In the present study, we evaluated the feasibility of inducing strong mucosal and systemic immune responses against both anthrax toxins and bacilli after nasal immunization using a synthetic double-stranded RNA (dsRNA), polyriboinosinic-polyribocytidylic acid (poly(I:C) or pI:C), as the adjuvant. We have shown that the capsular poly-gamma-D-glutamic acid (PGA) from bacillus was immunogenic when conjugated to a carrier protein and dosed intranasally to mice. We further demonstrated that nasal immunization with the PGA-carrier protein conjugate in combination with the anthrax protective antigen (PA) protein induced both anti-PGA and anti-PA immune responses in mouse sera and lung mucosal secretions. The anti-PA antibody (Ab) response was shown to have anthrax lethal toxin neutralization activity; and the anti-PGA Abs induced were able to activate complement and kill PGA-producing bacteria. These findings demonstrated that it is feasible to develop a novel dual-action nasal anthrax vaccine.

Adjuvants, Immunologic↗

PubMed2006

Nasal immunization with anthrax protective antigen protein adjuvanted with polyriboinosinic-polyribocytidylic acid induced strong mucosal and systemic immunities.

PURPOSE: The current anthrax vaccine adsorbed (AVA) was originally licensed for the prevention of cutaneous anthrax infection. It has many drawbacks, including the requirement for multiple injections and subsequent annual boosters. Thus, an easily administrable and efficacious anthrax vaccine is needed to prevent the most lethal form of anthrax infection, inhalation anthrax. We propose to develop a nasal anthrax vaccine using anthrax protective antigen (PA) protein as the antigen and synthetic double-stranded RNA in the form of polyriboinosinic-polyribocytidylic acid (pI:C) as an adjuvant. METHODS: Mice were nasally immunized with recombinant PA admixed with pI:C. The resulting PA-specific antibody responses and the lethal toxin neutralization activity were measured. Moreover, the effect of pI:C on dendritic cells (DCs) was evaluated both in vivo and in vitro. RESULTS: Mice nasally immunized with rPA adjuvanted with pI:C developed strong systemic and mucosal anti-PA responses with lethal toxin neutralization activity. These immune responses compared favorably to that induced by nasal immunization with rPA adjuvanted with cholera toxin. Poly(I:C) enhanced the proportion of DCs in local draining lymph nodes and stimulated DC maturation. CONCLUSIONS: This pI:C-adjuvanted rPA vaccine has the potential to be developed into an efficacious nasal anthrax vaccine.

Adjuvants, Immunologic↗

PubMed2006

Biodistribution and tumor-accumulation of gadolinium (Gd) encapsulated in long-circulating liposomes in tumor-bearing mice for potential neutron capture therapy.

To deliver and maintain a sufficient amount of Gd into tumors is required for a successful Gd neutron capture therapy (Gd-NCT), but it has been proven to be rather challenging to achieve. Previously, we have reported a Gd-encapsulated liposome formulation that has the potential to overcome this challenge. In the present study, we sought to systemically evaluate the biodistribution and the tumor-accumulation of the Gd in model tumor-bearing mice. The Gd-encapsulated liposomes were injected into mice pre-grafted with two different model tumors. The Gd content in the tumors and other organs were determined at various time after the injection. A sufficient amount of Gd was readily delivered into those two different model tumors. Increasing the dose of Gd by injecting the Gd-encapsulated liposomes multiple times tended to increase the uptake of the Gd by the tumors. Finally, the uptake of Gd by tumors was inversely correlated with the size of the tumors. The Gd-encapsulated liposomes hold great potentials as a Gd delivery system for NCT of small- and medium-size tumors. Alternative strategies may have to be adopted in order to use NCT to treat large, advanced solid tumors, although for which, Gd-NCT might be advantageous over boron-NCT.

Animals↗

PubMed2006

Topical immunization onto mouse skin using a microemulsion incorporated with an anthrax protective antigen protein-encoding plasmid.

The current anthrax vaccine in the U.S., the anthrax vaccine adsorbed, has several serious drawbacks, most notably the very lengthy and complicated dosing schedule. Thus, there is a critical need to develop an alternative anthrax vaccine with a simplified immunization schedule. To address this need, we evaluated the feasibility of topically priming or boosting onto the skin using an anthrax protective antigen (PA) protein-encoding DNA vaccine. To this end, we have shown that topical immunization of mice onto their skin with a perflubron-based microemulsion incorporated with a PA63-encoding plasmid, pGPA, led to significant PA-specific antibody responses, which have anthrax lethal toxin-neutralization activity. Moreover, topical boosting of mice primed with PA protein with the pGPA-incorporated, perflubron-based microemulsion significantly enhanced the anti-PA antibody responses induced. This topical anthrax DNA vaccine has the potential to be combined with a vaccine, such as the current AVA, to produce a simplified and more convenient dosing schedule.

Administration, Topical↗

PubMed2006

Lecithin-based cationic nanoparticles as a potential DNA delivery system.

Previously, we have reported a novel nanoparticle-based DNA vaccine delivery system, which elicited strong immune responses against antigens of interest encoded by the DNA. The nanoparticles were engineered by cooling pre-formed warm microemulsions comprised of emulsifying wax as the oil phase and hexadecyltrimethyl ammonium bromide (CTAB) as the surfactant. However, the poor aqueous stability of the nanoparticles and the emulsifying wax in the nanoparticles may severely limit the applications of the nanoparticles. In the present study, we used lecithin, a more biocompatible material, instead of emulsifying wax, to prepared lecithin-based cationic nanoparticles. The 50% growth inhibition concentration (IC(50)) of the lecithin-based nanoparticles was found to be more than 1,000-fold higher than that of the emulsifying wax-based nanoparticles. Moreover, the stability of the lecithin nanoparticles was also significantly increased. The size of the nanoparticles did not significantly change during a 6-month storage period at room temperature. Finally, when plasmid DNA was adsorbed on their surface, the lecithin nanoparticles successfully transfected cells in culture. These lecithin-based nanoparticles may hold great potentials as a DNA (vaccine) delivery system.

Animals↗

PubMed2006

Long-circulating gadolinium-encapsulated liposomes for potential application in tumor neutron capture therapy.

Gadolinium neutron capture therapy (Gd-NCT) is a promising cancer therapy modality. One of the key factors for a successful Gd-NCT is to deliver and maintain a sufficient amount of Gd in tumor tissues during neutron irradiation. We proposed to prepare a Gd delivery system by complexing a Gd-containing compound, diethylenetriaminepentaacetic acid (Gd-DTPA), with a polycationic peptide, poly-L-lysine (pLL), and then encapsulate the complexed Gd-DTPA into PEGylated liposomes. Complexation of Gd-DTPA with pLL not only enhanced the encapsulation efficiency of Gd-DTPA in liposomes, but also significantly limited the release of Gd-DTPA from the liposomes. A Gd-DTPA-encapsulated liposome formulation that contained 6.8+/-0.3 mg/mL of pure encapsulated Gd was prepared. The blood half-life of the Gd encapsulated into the liposome formulation was estimated to be about 24 h in healthy tumor-free mice. About 12 h after the Gd-encapsulated liposomes were intravenously injected into mice with pre-established model tumors, the Gd content in the tumors reached an average of 159 microg/g of wet tumor tissue. This Gd-DTPA encapsulated liposome may be used to deliver Gd into solid tumors for NCT and tumor imaging.

Animals↗

PubMed2006

Strong mucosal and systemic immunities induced by nasal immunization with anthrax protective antigen protein incorporated in liposome-protamine-DNA particles.

PURPOSE: The very lengthy and complicated dosing schedule of the current anthrax vaccine adsorbed, which was licensed in the USA for the prevention of cutaneous anthrax infection, calls for the development of an efficacious and easily administrable vaccine to prevent against the most lethal form of anthrax infection, the inhalation anthrax. We propose to develop a nasal anthrax vaccine using anthrax protective antigen (PA) protein carried by liposome-protamine-DNA (LPD) particles. METHODS: PA was incorporated in LPD particles and nasally dosed to mice. The resulting PA-specific immune response and lethal toxin neutralization activity were measured. RESULTS: Mice nasally immunized with PA incorporated into LPD particles developed both systemic and mucosal anti-PA responses. The anti-PA immunities induced included the production of anti-PA antibodies (IgG and IgM in the serum and IgA in nasal and lung mucosal secretions) and the proliferation of splenocytes after in vitro stimulation. The anti-PA IgG subtype induced was mainly IgG1. Finally, anthrax lethal toxin neutralization activity was detected both in the serum and in the mucosal secretions. CONCLUSIONS: The anti-PA immune response induced by nasal PA incorporated in LPD was comparable to that induced by nasal PA adjuvanted with cholera toxin or subcutaneously injected PA adjuvanted with aluminum hydroxide.

Administration, Intranasal↗

PubMed2006

Evaluation of the immune response induced by a nasal anthrax vaccine based on the protective antigen protein in anaesthetized and non-anaesthetized mice.

To better protect against inhalational anthrax infection, a nasal anthrax vaccine based on the protective antigen (PA) protein of Bacillus anthracis could be an attractive alternative to the current Anthrax-Vaccine-Adsorbed (AVA), which was licensed for cutaneous anthrax prevention. Previously, we have demonstrated that an anti-PA immune response comparable with that in mice subcutaneously immunized with PA protein adjuvanted with aluminium hydroxide was induced in both the systemic compartment and the mucosal secretions of the nose and lung of anaesthetized mice when they were nasally immunized with PA protein incorporated into previously reported LPD (Liposome-Protamine-DNA) particles. In this study, we evaluated the anti-PA immune response induced by the nasal PA/LPD particles in non-anaesthetized mice and compared it with that in anaesthetized mice. Our data showed that the anti-PA antibody response and the anthrax lethal toxin-neutralization activity induced by the nasal PA/LPD in non-anaesthetized mice was relatively weaker than that in anaesthetized mice. However, the splenocytes isolated from the nasally immunized mice, anaesthetized and non-anaesthetized, proliferated comparably after in-vitro re-stimulation. By evaluating the uptake of fluorescence-labelled LPD particles by phagocytes in the nasal and broncho-alveolar lavages of mice after the nasal administration, we concluded that the relatively weaker anti-PA immune response in the non-anaesthetized mice might be partially attributed to the reduced retention of the PA/LPD particles in the nasal cavity of the non-anaesthetized mice. Data collected in this study are expected to be useful for future anthrax nasal vaccine studies when mice are used as a model.

Administration, Intranasal↗

PubMed2006

Non-invasive immunization on the skin using DNA vaccine.

Skin has evolved to protect not only by acting as a physical barrier, but also by its role in our powerful immune system. As a frontline of the host's defense against pathogens, skin is well equipped for immune surveillance. For example, compared to many other tissues, the epidermis of the skin contains a high population of Langerhans cells, which are very potent immature dendritic cells. Thus, targeting antigens to the skin epidermis should be able to efficiently induce strong immune responses. However, the forbidden barrier posed by the stratum corneum layer of the epidermis prevents effective entrance of antigens into the epidermis. Nevertheless, non-invasive immunization onto the skin has proven in the last several years to be a viable immunization modality. DNA vaccine is a vaccine made of bacterial plasmid DNA encoding an antigen of interest. Upon uptake of the plasmid, host express and process the encoding antigen, and then mount immune responses against it. DNA vaccine is advantageous over many other types of vaccines. The feasibility of non-invasive immunization onto the skin with DNA vaccine has been confirmed. Although the potency of the immune response has proven to be weak, many skin stratum corneum disrupting chemical and physical approaches and DNA vaccine carriers/adjuvants that significantly enhance the resulting immune response have been reported. In addition, research on elucidating the mechanism of immune induction from non-invasively, topically applied DNA vaccine has also been carried out. With further improvement and optimization, non-invasive immunization onto the skin with DNA vaccine should be able to elicit reliable and efficacious immune response to a variety of antigens.

Administration, Cutaneous↗

PubMed2005

Synthetic double-stranded RNA poly(I:C) as a potent peptide vaccine adjuvant: therapeutic activity against human cervical cancer in a rodent model.

Due to the inherent lack of immunogenicity of peptides, it is generally recognized that the strong inflammatory signals that are required to elicit specific responses against peptide-based therapeutic tumor vaccines may not be provided by the standard/conventional vaccine adjuvants. In this study, we have demonstrated dsRNA in the form of synthetic pI:C as a potent adjuvant to enhance the specific anti-tumor immune responses against a peptide-based vaccine. When complexed with an MHC I-restricted minimal peptide epitope derived from the HPV 16 E7 protein, the resulting pI:C/E7(49-57) molecular complex induced strong E7(49-57)-specific CTL responses that caused significant regressions of model human cervical cancer tumors pre-established in mice. In addition, although the proportion of DCs in tumor-bearing mice was significantly decreased when compared to that in naïve mice, immunization with pI:C/E7(49-57 )restored the proportion of DCs in tumor-bearing mice. Double-stranded RNA may hold a great potential as an adjuvant to induce cellular immune responses for tumor immunotherapy.

Adjuvants, Immunologic↗

PubMed2005

Gadolinium incorporated reconstituted chylomicron emulsion for potential application in tumor neutron capture therapy.

Gadolinium (Gd) neutron capture therapy (NCT) is currently under development as a potential approach for tumor therapy. Nanoparticles have been suggested as a potential delivery system to carry or target Gd to tumors for thermal or epithermal neutron irradiation. The reconstituted chylomicron emulsion is an artificial chylomicron remnant prepared using commercially available natural and biocompatible lipids. We proposed to use this nanometer-scale emulsion to deliver Gd to solid tumors by modifying the surface of the emulsion. A lipophilic Gd compound, gadolinium acetylacetonate (GdAcAc), was incorporated into the emulsion, resulting in a final pure Gd concentration of more than 1 mg/mL. The apparent solubility of GdAcAc was enhanced by about 6000-fold by this incorporation. The emulsion particles were shown to be stable in a two-week short-term stability study when stored at 4 degrees C. In addition, no extensive particle aggregation was observed when the emulsion particles were incubated in simulated biological media such as serum. Also, GdAcAc does not significantly 'leak' out from the emulsion particles. Only approximately 5% was released in 20 h in a SDS (0.5% w/v) in phosphate buffered saline (pH 7.4, 10 mM) medium. Finally, the emulsion particles were coated with polyethylene glycol (PEG), and injected into Balb/C mice via the tail vein. A significant proportion (71.6 +/- 18.4%) of the PEG-coated, GdAcAc-incorporated emulsion remained circulating in the blood 5 h after the injection, while the PEG-free emulsion was mainly accumulated inside the liver. This chylomicron emulsion may be used to deliver Gd into solid tumors for NCT.

Animals↗

PubMed2005

Targeting primaquine into liver using chylomicron emulsions for potential vivax malaria therapy.

Primaquine (PQ) exerts a broad spectrum of activities against various stages of parasitic malaria. It remains as the only drug that destroys late hepatic stages and latent tissue forms of Plasmodium vivax and Plasmodium ovale. However, systems that can target PQ to liver hepatocytes, where malarial sporozoites reside, are needed to minimize the dose-limiting severe toxicities and side-effects caused by PQ. Recently, a reconstituted artificial chylomicron emulsion was generated using commercially available lipids and was shown to be preferentially taken up by liver hepatocytes following intravenous injection. We proposed to target PQ to hepatocytes by incorporating it into this chylomicron emulsion. We have shown that lipophilized PQ can be readily incorporated into the chylomicron emulsion. The PQ remained inside the emulsion without significant release. Moreover, PQ incorporated inside the emulsion was more stable than free PQ when incubated in serum. Finally, when intravenously injected into mice, the PQ-incorporated chylomicron emulsion led to significantly enhanced accumulation of PQ in liver, when compared to the injection of free PQ. This emulsion could be developed into a promising delivery system to target PQ into hepatocytes for vivax malaria therapy.

Animals↗

PubMed2005

Liposome-polycation-DNA (LPD) particle as a carrier and adjuvant for protein-based vaccines: therapeutic effect against cervical cancer.

With the successful identification of many tumor-specific antigens, tumor-associated antigens, and the potential of using unfractioned tumor cell derivatives as tumor antigens, a system and/or adjuvant that can deliver these antigens and help them to induce strong and effective anti-tumor immune responses is greatly needed. Previously, we reported that a MHC class I-restricted peptide epitope derived from human papillomavirus (HPV) 16 E7 protein, when incorporated into a clinically proven safe LPD (liposome-polycation-DNA) particle, was able to effectively eradicate tumors established in mice. Cervical cancer is the second most common cancer among women worldwide. HPV infection is clearly linked to this cancer. Vaccines based on the early (E) gene products of HPV could be effective in controlling it. However, besides the fact that epitope vaccines have many limitations particularly, concerning the diverse HLAs in humans, the use of the epitope as an antigen prevented us from fully characterizing the immune responses induced by the LPD as a vaccine carrier and/or adjuvant in previous studies. In the present study, by using the HPV 16 E7 protein as an antigen, we first showed that LPD, as a vaccine carrier and adjuvant induced strong and robust immune responses, both cellular and antibody. We then showed that immunization with LPD particles incorporated with either the wild type HPV 16 E7 protein or a potentially safer mutant induced strong immune responses that caused complete regressions of a model cervical cancer tumor established in murines. LPD could be a potent vaccine carrier and/or adjuvant for many antigens.

Adjuvants, Immunologic↗

PubMed2005

Novel D-penicillamine carrying nanoparticles for metal chelation therapy in Alzheimer's and other CNS diseases.

Metal ions accumulate in the brain with aging and in several neurodegenerative diseases. Aside from the copper storage disease, Wilson's disease, recent attention has focused on the accumulation of zinc, copper and iron in the Alzheimer's disease (AD) brain and the accumulation of iron in Parkinson's disease. In particular, the parenchymal deposition of beta-amyloid (Abeta) and its interaction with metal ions has been postulated to play a role in the progression of AD. Thus, the strategy of lowering brain metal ions and targeting the interaction of Abeta peptide and metal ions through the administration of chelators has merit. Our recent finding that nanoparticle delivery systems can cross the blood-brain barrier has led us to investigate whether chelators delivered conjugated to nanoparticles could act to reverse metal ion induced protein precipitation. In the present studies, the Cu (I) chelator D-penicillamine was covalently conjugated to nanoparticles via a disulfide bond or a thioether bond. Nanoparticle-chelator conjugates were stable between pH 6-8 in aqueous suspension if stored at 4 degrees C, and did not aggregate when challenged with salts and serum. Release of D-penicillamine from the nanoparticles was achieved using reducing agents such as dithiothreitol (as a model for glutathione). Nanoparticles treated only under reducing conditions that released the conjugated D-penicillamine were able to effectively resolubilize copper-Abeta (1-42) aggregates. These results indicate that nanoparticles have potential to deliver D-penicillamine to the brain for the prevention of Abeta (1-42) accumulation, as well as to reduce metal ion accumulation in other CNS diseases.

Alzheimer Disease↗

PubMed2005

DNA vaccine.

The DNA vaccine has proven to be one of the most promising applications in the field of gene therapy. Due to its unique ability to readily induce humoral as well as cellular immune responses, it attracted great interest when the concept was first confirmed in the early 1990s. After thousands of articles related to the DNA vaccine were published, scientists began to realize that although the DNA vaccine is very effective in small animal models, its effectiveness in recent clinical trails is rather disappointing. Therefore, current effort has been shifted to understanding the different performance of the DNA vaccine in mouse and large animal models and on how to transfer the success of the DNA vaccine in small animals to large animals and humans.

AIDS Vaccines↗

PubMed2004

Strong T cell type-1 immune responses to HIV-1 Tat (1-72) protein-coated nanoparticles.

A significant emphasis has been placed on the development of adjuvants and/or delivery systems to improve both antibody production and cell-mediated immune responses. We previously reported on a novel anionic nanoparticle, which led to enhanced humoral and T helper type-1 (Th1) biased immune responses in mice when coated with cationized model antigen. Tat (1-72) is a conserved regulatory HIV-1 protein. It was hypothesized that HIV vaccine strategies employing Tat (1-72) may be a promising approach. Although previous reports have suggested that Tat (1-86) may be immunosuppressive, it was demonstrated in this present study that Tat (1-72) was not immunosuppressive when co-administered to mice with ovalbumin (OVA). Tat (1-72) was coated on novel anionic nanoparticles. BALB/c mice were immunized with Tat (5 microg)-coated nanoparticles (15 microg) by subcutaneous injection on days 0 and 14. Antibody and cytokine release were determined on day 28 and compared to Tat (5 microg) adjuvanted with Alum (15 microg) as a Th2 control, Tat (5 microg) adjuvanted with Lipid A (50 microg) as a Th1 control. Immunization of BALB/c mice with Tat-coated nanoparticles resulted in antibody levels (IgG and IgM) comparable to those elicited from Tat and Alum. However, Tat-coated nanoparticles led to a Th1 biased immune response. The IFN-gamma release from splenocytes with Tat-coated nanoparticles was comparable to that from mice immunized with Tat and Lipid A, and 3.3-fold greater than that from mice immunized with Tat and Alum. These studies warrant further investigation of these nanoparticles to enhance both antibody and cellular-based immune responses.

AIDS Vaccines↗

PubMed2004

Coating of mannan on LPD particles containing HPV E7 peptide significantly enhances immunity against HPV-positive tumor.

PURPOSE: Previously, our laboratory has reported that liposome-protamine-DNA (LPD) nanoparticle is an effective delivery system for tumor-associated antigens. Mannan, which potentially targets antigen-presenting cells, was coated on LPD to further enhance its antitumor activity. METHODS: Cholesterol-conjugated mannan was coated on LPD. The abilities of mannan-coated LPD to target antigen-presenting cells, to activate dendritic cells, and to induce antitumor immunity were investigated and compared to those of LPD alone. RESULTS: Both in vitro and in vivo uptake of LPD showed that mannan-coated LPD particles were preferably taken up by dendritic cells and macrophages. In addition, the expression of co-stimulatory molecules CD80/CD86 on DC2.4 cells after co-incubation with mannan-coated LPD was significantly higher than that after co-incubation with LPD. A model major histocompatibility complex class I-restricted peptide antigen from HPV 16 E7 protein was incorporated into LPD to immunize mice against the growth of TC-1 tumor cells expressing E7 protein. Coating with mannan significantly enhanced both preventive and therapeutic activities of LPD/E7. Finally, the release of IFN-gamma from isolated splenocytes was significantly enhanced when mice were immunized with mannan-coated LPD/E7 than with LPD/E7 alone. CONCLUSION: Targeting of the LPD/E7 to local draining lymph nodes by mannan is partially responsible for the enhanced anti-tumor activity.

Animals↗

PubMed2003

Intradermal immunization with novel plasmid DNA-coated nanoparticles via a needle-free injection device.

A high population of dendritic cells in the skin makes intradermal (ID) immunization an attractive route. We sought to further enhance immune responses from a previously reported novel nanoparticle-based DNA vaccine delivery system by administering the system intradermally into mouse skin using Biojector 2000, a needle-free jet injection device. Two mouse studies were carried out. Balb/C mice (n=5-6) were immunized on day 0, 7, and 14 by subcutaneous injection or via the Biojector 2000 with pDNA alone (CMV-beta-galactosidase, 5 micro g), pDNA-coated nanoparticles, or beta-galactosidase protein (10 micro g) adjuvanted with 'Alum' (15 micro g). On day 28, mice were sacrificed and specific serum IgG and IgA titer, in vitro cytokine release, and cell proliferation of isolated splenocytes were determined. Similar to previous reports, in both mouse studies, SC immunization with pDNA-coated nanoparticles led to over a log increase in specific serum IgG titer as compared to immunization with pDNA alone. For pDNA alone, jet and SC injection did not result in significant differences in IgG titer. In contrast, for pDNA-coated nanoparticles, jet injection led to as high as a 20-fold enhancement in IgG titer over SC injection. In addition, jet injection of pDNA-coated nanoparticles enhanced the IgG titer by more than 200-fold over jet injection of pDNA alone. Also, jet injection of pDNA-coated nanoparticles resulted in significantly enhanced specific serum IgA titer. For in vitro cytokine release, immunization with pDNA-coated nanoparticles by jet injection enhanced IFN-gamma and IL-4 release over pDNA alone by 6- and 5-fold, respectively. SC injection of pDNA-coated nanoparticles also resulted in enhanced IFN-gamma and IL-4 release over pDNA alone although with less magnitude. Finally, immunization with pDNA-coated nanoparticles, by both jet injection and SC injection, led to improved splenocyte proliferation over pDNA alone. In conclusion, a combination of a novel cationic nanoparticle-based DNA delivery system with ID jet injection led to enhanced antibody production, Th-1/Th-2 balanced cytokine release, and enhanced splenocyte proliferation.

Animals↗