Effects of menstrual cycle on gene transfection through mouse vagina for DNA vaccine

Depo Medroxyprogesterone (DMPA) Promotes Papillomavirus Infections but Does Not Accelerate Disease Progression in the Anogenital Tract of a Mouse Model

Contraceptives such as Depo-medroxyprogesterone (DMPA) are used by an estimated 34 million women worldwide. DMPA has been associated with increased risk of several viral infections including Herpes simplex virus-2 (HSV-2) and Human immunodeficiency virus (HIV). In the current study, we used the mouse papillomavirus (MmuPV1) anogenital infection model to test two hypotheses: (1) contraceptives such as DMPA increase the susceptibility of the anogenital tract to viral infection and (2) long-term contraceptive administration induces more advanced disease at the anogenital tract. DMPA treatments of both athymic nude mice and heterozygous NU/J (Foxn1nu/+) but ovariectomized mice led to a significantly increased viral load at the anogenital tract, suggesting that endogenous sex hormones were involved in increased viral susceptibility by DMPA treatment. Consistent with previous reports, DMPA treatment suppressed host anti-viral activities at the lower genital tract. To test the impact of long-term contraceptive treatment on the MmuPV1-infected lower genital tract, we included two other treatments in addition to DMPA: 17β-estradiol and a non-hormone based contraceptive Cilostazol (CLZ, Pletal). Viral infections were monitored monthly up to nine months post infection by qPCR. The infected vaginal and anal tissues were harvested and further examined by histological, virological, and immunological analyses. Surprisingly, we did not detect a significantly higher grade of histology in animals in the long-term DMPA and 17β-estradiol treated groups when compared to the control groups in the athymic mice we tested. Therefore, although DMPA promotes initial papillomavirus infections in the lower genital tract, the chronic administration of DMPA does not promote cancer development in the infected tissues in our mouse model.

Development of a Liquid Crystal Formulation that Can Penetrate the Stratum Corneum for Intradermal Delivery of Small Interfering RNA

Topical delivery of small interfering RNA (siRNA) can be an attractive method for the treatment of skin diseases and improving the quality of life of patients. However, it is difficult for siRNA to pass through the two major barriers of the skin: the stratum corneum (SC) and tight junctions. We have previously reported that atopic dermatitis of skin without the SC can be efficiently treated by the intradermal administration of trans-activator of transcription (Tat) peptide and AT1002 (tight junction opening peptide). However, novel drug delivery systems are needed for effective SC penetration. Therefore, in the present study, we aimed to develop a lyotropic liquid crystalline (LC) system containing Tat and AT1002 for effective siRNA penetration through the SC. An LC formulation was prepared using selachyl alcohol and purified water, and its skin penetration ability was evaluated. No fluorescence was observed in mouse skin treated with a siRNA solution, as there was no intradermal localization of siRNA from naked siRNA. However, intradermal delivery of siRNA was remarkable and extensive with the LC formulation containing both Tat and AT1002. Semiquantitative analysis by brightness measurement revealed that the LC formulation containing both Tat and AT1002 had significantly enhanced intact skin permeability than other formulations. These results show that the functional peptides in the LC formulation increased SC penetration and intradermal delivery in the healthy skin. Therefore, this novel LC system may be useful in the treatment of various skin diseases.

Coinjection of IL2 DNA enhances E7-specific antitumor immunity elicited by intravaginal therapeutic HPV DNA vaccination with electroporation

The generation and use of therapeutic human papillomavirus (HPV) DNA vaccines represent an appealing treatment method against HPV-associated cervical cancer owing to their safety and durability. Previously, we created a therapeutic HPV DNA vaccine candidate by linking the HPV16-E7 DNA sequence to calreticulin (CRT/E7), which we showed could generate significant E7-specific cytotoxic T lymphocyte (CTL)-mediated antitumor immune responses against HPV16 oncogenes expressing murine tumor model TC-1. Here we assess the therapeutic efficacy of intravaginal immunization with pcDNA3-CRT/E7 followed by electroporation. In addition, we examined whether coadministration of DNA-encoding interleukin 2 (IL2) with the pcDNA3-CRT/E7 could improve the T-cell responses elicited by pcDNA3-CRT/E7. TC-1 tumor-bearing mice vaccinated intravaginally with both pcDNA3-CRT/E7 and IL2 DNA followed by electroporation induced stronger local antitumor CTL response in comparison to mice that received other treatment regimens. Additionally, we found that coadministration of IL2 DNA with pcDNA3-CRT/E7 modified the tumor microenvironment by decreasing the population of regulatory T cells and myeloid-derived suppressor cells relative to that of CTLs. Our data demonstrate the translational potential of local administration of IL2 and pcDNA3-CRT/E7 followed by electroporation in treating cervicovaginal tumors.

Nanoparticles-in-film for the combined vaginal delivery of anti-HIV microbicide drugs

Combining two or more antiretroviral drugs in one medical product is an interesting but challenging strategy for developing topical anti-HIV microbicides. We developed a new vaginal delivery system comprising the incorporation of nanoparticles (NPs) into a polymeric film base - NPs-in-film - and tested its ability to deliver tenofovir (TFV) and efavirenz (EFV). EFV-loaded poly(lactic-co-glycolic acid) NPs were incorporated alongside free TFV into fast dissolving films during film manufacturing. The delivery system was characterized for physicochemical properties, as well as genital distribution, local and systemic 24h pharmacokinetics (PK), and safety upon intravaginal administration to mice. NPs-in-film presented suitable technological, mechanical and cytotoxicity features for vaginal use. Retention of NPs in vivo was enhanced both in vaginal lavages and tissue when associated to film. PK data evidenced that vaginal drug levels rapidly decreased after administration but NPs-in-film were still able to enhance drug concentrations of EFV. Obtained values for area-under-the-curve for EFV were around one log10 higher than those for the free drugs in aqueous vehicle (phosphate buffered saline). Film alone also contributed to higher and more prolonged local drug levels as compared to the administration of TFV and EFV in aqueous vehicle. Systemic exposure to both drugs was low. NPs-in-film was found to be safe upon once daily vaginal administration to mice, with no significant genital histological changes or major alterations in cytokine/chemokine profiles being observed. Overall, the proposed NPs-in-film system seems to be an interesting delivery platform for developing combination vaginal anti-HIV microbicides.

Local HPV Recombinant Vaccinia Boost Following Priming with an HPV DNA Vaccine Enhances Local HPV-Specific CD8+ T-cell-Mediated Tumor Control in the Genital Tract

PURPOSE

Two viral oncoproteins, E6 and E7, are expressed in all human papillomavirus (HPV)-infected cells, from initial infection in the genital tract to metastatic cervical cancer. Intramuscular vaccination of women with high-grade cervical intraepithelial neoplasia (CIN2/3) twice with a naked DNA vaccine, pNGVL4a-sig/E7(detox)/HSP70, and a single boost with HPVE6/E7 recombinant vaccinia vaccine (TA-HPV) elicited systemic HPV-specific CD8 T-cell responses that could traffic to the lesion and was associated with regression in some patients (NCT00788164).

EXPERIMENTAL DESIGN

Here, we examine whether alteration of this vaccination regimen by administration of TA-HPV vaccination in the cervicovaginal tract, rather than intramuscular (IM) delivery, can more effectively recruit antigen-specific T cells in an orthotopic syngeneic mouse model of HPV16(+) cervical cancer (TC-1 luc).

RESULTS

We found that pNGVL4a-sig/E7(detox)/HSP70 vaccination followed by cervicovaginal vaccination with TA-HPV increased accumulation of total and E7-specific CD8(+) T cells in the cervicovaginal tract and better controlled E7-expressing cervicovaginal TC-1 luc tumor than IM administration of TA-HPV. Furthermore, the E7-specific CD8(+) T cells in the cervicovaginal tract generated through the cervicovaginal route of vaccination expressed the α4β7 integrin and CCR9, which are necessary for the homing of the E7-specific CD8(+) T cells to the cervicovaginal tract. Finally, we show that cervicovaginal vaccination with TA-HPV can induce potent local HPV-16 E7 antigen-specific CD8(+) T-cell immune responses regardless of whether an HPV DNA vaccine priming vaccination was administered IM or within the cervicovaginal tract.

CONCLUSIONS

Our results support future clinical translation using cervicovaginal TA-HPV vaccination.

Therapeutic and prophylactic DNA vaccines for HIV-1

INTRODUCTION

DNA vaccines have moved into clinical trials in several fields and their success will be important for licensure of this vaccine modality. An effective vaccine for HIV-1 remains elusive and the development of one is troubled by safety and efficacy issues. Additionally, the ability for an HIV-1 vaccine to induce both the cellular and humoral arms of the immune system is needed. DNA vaccines not only offer a safe approach for the development of an HIV-1 vaccine but they have also been shown to elicit both arms of the immune system.

AREAS COVERED

This review explores how DNA vaccine design including the regimen, genetic adjuvants used, targeting, and mode of delivery continues to undergo improvements, thereby providing a potential option for an immunogenic vaccine for HIV-1.

EXPERT OPINION

Continued improvements in delivery technology, in particular electroporation, and the use of prime-boost vaccine strategies will aid in boosting the immunogenicity of DNA vaccines. Basic immunology research will also help discover new potential adjuvant targets that can be combined with DNA vaccination, such as inhibitors of inhibitory receptors.

Nanoparticle-based drug delivery to the vagina: a review

Vaginal drug administration can improve prophylaxis and treatment of many conditions affecting the female reproductive tract, including sexually transmitted diseases, fungal and bacterial infections, and cancer. However, achieving sustained local drug concentrations in the vagina can be challenging, due to the high permeability of the vaginal epithelium and expulsion of conventional soluble drug dosage forms. Nanoparticle-based drug delivery platforms have received considerable attention for vaginal drug delivery, as nanoparticles can provide sustained release, cellular targeting, and even intrinsic antimicrobial or adjuvant properties that can improve the potency and/or efficacy of prophylactic and therapeutic modalities. Here, we review the use of polymeric nanoparticles, liposomes, dendrimers, and inorganic nanoparticles for vaginal drug delivery. Although most of the work toward nanoparticle-based drug delivery in the vagina has been focused on HIV prevention, strategies for treatment and prevention of other sexually transmitted infections, treatment for reproductive tract cancer, and treatment of fungal and bacterial infections are also highlighted.

Biodistribution and pharmacokinetics of dapivirine-loaded nanoparticles after vaginal delivery in mice

PURPOSE

To assess the potential of polymeric nanoparticles (NPs) to affect the genital distribution and local and systemic pharmacokinetics (PK) of the anti-HIV microbicide drug candidate dapivirine after vaginal delivery.

METHODS

Dapivirine-loaded, poly(ethylene oxide)-coated poly(epsilon-caprolactone) (PEO-PCL) NPs were prepared by a nanoprecipitation method. Genital distribution of NPs and their ability to modify the PK of dapivirine up to 24 h was assessed after vaginal instillation in a female mouse model. Also, the safety of NPs upon daily administration for 14 days was assessed by histological analysis and chemokine/cytokine content in vaginal lavages.

RESULTS

PEO-PCL NPs (180-200 nm) were rapidly eliminated after administration but able to distribute throughout the vagina and lower uterus, and capable of tackling mucus and penetrate the epithelial lining. Nanocarriers modified the PK of dapivirine, with higher drug levels being recovered from vaginal lavages and vaginal/lower uterine tissues as compared to a drug suspension. Systemic drug exposure was reduced when NPs were used. Also, NPs were shown safe upon administration for 14 days.

CONCLUSIONS

Dapivirine-loaded PEO-PCL NPs were able to provide likely favorable genital drug levels, thus attesting the potential value of using this vaginal drug delivery nanosystem in the context of HIV prophylaxis.

Electroporation mediated DNA vaccination directly to a mucosal surface results in improved immune responses

In vivo electroporation (EP) has been shown to be a highly efficient non-viral method for enhancing DNA vaccine delivery and immunogenicity, when the site of immunization is the skin or muscle of animals and humans. However, the route of entry for many microbial pathogens is via the mucosal surfaces of the human body. We have previously reported on minimally invasive, surface and contactless EP devices for enhanced DNA delivery to dermal tissue. Robust antibody responses were induced following vaccine delivery in several tested animal models using these devices. Here, we investigated extending the modality of the surface device to efficiently deliver DNA vaccines to mucosal tissue. Initially, we demonstrated reporter gene expression in the epithelial layer of buccal mucosa in a guinea pig model. There was minimal tissue damage in guinea pig mucosal tissue resulting from EP. Delivery of a DNA vaccine encoding influenza virus nucleoprotein (NP) of influenza H1N1 elicited robust and sustained systemic IgG antibody responses following EP-enhanced delivery in the mucosa. Upon further analysis, IgA antibody responses were detected in vaginal washes and sustained cellular immune responses were detected in animals immunized at the oral mucosa with the surface EP device. This data confirms that DNA delivery and EP targeting mucosal tissue directly results in both robust and sustainable humoral as well as cellular immune responses without tissue damage. These responses are seen both in the mucosa and systemically in the blood. Direct DNA vaccine delivery enhanced by EP in mucosa may have important clinical applications for delivery of prophylactic and therapeutic DNA vaccines against diseases such as HIV, HPV and pneumonia that enter at mucosal sites and require both cellular and humoral immune responses for protection.

Needle-free intravaginal DNA vaccination using a stearoyl oligopeptide carrier promotes local gene expression and immune responses

The vaginal mucosa is the most common site of infection for viruses that are transmitted through heterosexual intercourse, including human immunodeficiency virus and papillomavirus. Thus, in order to prevent or respond to these infections, strong vaginal immunity is required as the first line of defense. We previously investigated the use of a needle-free injector as a mucosal vaccination tool in rabbits and demonstrated that this is a promising method for stimulating vaginal gene expression and immune responses. In order to improve gene expression, we have examined local vaginal gene transfection efficiency using a non-needle jet injector combined with an effective peptide carrier in rabbits. The carrier used was a stearoyl (STR) peptide with Cys (C), Arg (R) and His (H) residues that form disulfide cross linkages via Cys (STR-CH₂R₄H₂C) which was developed in our previous study. As a result, vaginal gene expression using the needle-free injector combined with STR-CH₂R₄H₂C carrier was significantly improved compared to that without STR-CH₂R₄H₂C carrier. Moreover, intravaginal pDNA vaccination by the needle-free injector combined with STR-CH₂R₄H₂C carrier and CpG-ODN promoted not only local vaginal IgA and IgG, but also serum IgG secretion, to a degree significantly higher than that of naked pDNA.

Advancements in the field of intravaginal siRNA delivery

The vaginal tract is a suitable site for the administration of both local and systemic acting drugs. There are numerous vaginal products on the market such as those approved for contraception, treatment of yeast infection, hormonal replacement therapy, and feminine hygiene. Despite the potential in drug delivery, the vagina is a complex and dynamic organ that requires greater understanding. The recent discovery that injections of double stranded RNA (dsRNA) in Caenorhabditis elegans (C. elegans) results in potent gene specific silencing, was a major scientific revolution. This phenomenon known as RNA interference (RNAi), is believed to protect host genome against invasion by mobile genetic elements such as transposons and viruses. Gene silencing or RNAi has opened new potential opportunities to study the function of a gene in an organism. Furthermore, its therapeutic potential is being investigated in the field of sexually transmitted infections such as human immunodeficiency virus (HIV) and other diseases such as age-related macular degeneration (AMD), diabetes, hypercholesterolemia, respiratory disease, and cancer. This review will focus on the therapeutic potential of siRNA for the treatment and/or prevention of infectious diseases such as HIV, HPV, and HSV within the vaginal tract. Specifically, formulation design parameters to improve siRNA stability and therapeutic efficacy in the vaginal tract will be discussed along with challenges, advancements, and future directions of the field.

RNA interference for the treatment of papillomavirus disease

Human Papillomavirus (HPV)-induced diseases are a significant burden on our healthcare system and current therapies are not curative. Vaccination provides significant prophylactic protection but effective therapeutic treatments will still be required. RNA interference (RNAi) has great promise in providing highly specific therapies for all HPV diseases yet this promise has not been realised. Here we review the research into RNAi therapy for HPV in vitro and in vivo and examine the various targets and outcomes. We discuss the idea of using RNAi with current treatments and address delivery of RNAi, the major issue holding back clinical adoption. Finally, we present our view of a potential path to the clinic.

Drug discovery by formulation design and innovative drug delivery systems (DDS)

This review describes studies on drug discovery using a rational formulation design and innovative, drug delivery systems (DDS) for biomaterials such as therapeutic peptides and nucleotides. The microcapsules of the LH-RH superagonist leuprorelin acetate prepared using the new in-water drying method and biodegradable polymers, such as PLGA and PLA, could achieve a long-term sustained release for 1-6 months thereby facilitating easily treatment of hormone-dependent diseases, prostate cancer, endometriosis, and precocious puberty. This DDS technology showed an improvement in patient QOL and highly promoted the clinical value of the agonist. Moreover, PLGA microcapsules of siRNAs against VEGF, cFLIP, Raf-1, and Int6 have also been developed to treat various cancers and arteriosclerosis obliterans. To develop therapeutic nucleotides, a particle design is created using functional peptides, such as cell penetrating peptides (CPP), nuclear localizing signals (NLS), tight junction reversible openers (AT1002), bombesin, and dynein light chain-associated sequences. siRNA use should lead to a paradigm shift in drug discovery against various diseases. Tat analog with NLS could enhance the potency of a vaginal DNA vaccine. The artificial Tat CPP of STR-CH(2)R(4)H(2)C synthesized in our laboratory could efficiently deliver siRNAs into many types of cells and enhance the therapeutic effects for treating sarcoma, atopic dermatitis, allergic rhinitis, and asthma by intratumor injection and inhalation of the nanoparticles. Tat and AT1002 analogs used to treat atopic dermatitis in mice increased cell membrane permeability to siRelA, a siRNA against a subclass of NF-κB, and exhibited striking therapeutic and preventive effects.

In vivo distribution of surface-modified PLGA nanoparticles following intravaginal delivery

Intravaginal (ivag) delivery, which is a proven way to confer local protection against STDs contracted via the reproductive tract, is complicated by the mucus gel barrier, the hormone cycle, and the harsh mucosal environment that leads to low residence-time for administered agents. Polymer delivery vehicles may be useful in overcoming these barriers. In this study, we explored the fate of nanoparticles (NP) made from poly(lactide-co-glycolide) (PLGA) in the mouse reproductive tract after ivag delivery. The nanoparticles were modified to display avidin (Avid-NP) or 2 kDa PEG (PEG-NP) on their surface. Vaginal retention fractions for both muco-adhesive Avid-NP and stealthy PEG-NP were 5× higher than unmodified PLGA particles (NP). The amount of particles associated with mucus differed across formulations (Avid-NP>NP>PEG-NP). PEG-NP was found at higher concentration in the tissue than Avid-NP and NP up to 6h after delivery, and particles were found within epithelial cells, the underlying submucosal stromal and fibroblast cells of the vaginal tissue. Our results demonstrate that surface properties of nanoparticles can impact their fates following ivag delivery. Moreover, we show that the muco-evasive PEG-modified nanoparticles are the most effective among the delivery vehicles tested for this application.

Cell-penetrating peptide-modified block copolymer micelles promote direct brain delivery via intranasal administration

PURPOSE

In order to develop non-invasive and effective nose-to-brain delivery of drugs, we synthesized Tat analog-modified methoxy poly(ethylene glycol) (MPEG)/poly(ε-caprolactone) (PCL) amphiphilic block copolymers through the ester bond.

METHODS

We evaluated the brain distribution of coumarin, acting as a model chemical, after intravenous or intranasal administration of MPEG-PCL. In addition, cellular uptake of coumarin by rat glioma cells transfected with coumarin-loaded MPEG-PCL or MPEG-PCL-Tat was determined. Finally, we determined the brain distribution and biodistribution after intranasal administration of coumarin-loaded MPEG-PCL-Tat.

RESULTS

The amount of coumarin in the brain after intranasal administration was significantly higher than that after intravenous administration. In addition, cellular uptake of coumarin using MPEG-PCL was the lowest, while cellular uptake of coumarin using Tat-modified MPEG-PCL (MPEG-PCL-Tat) was higher than that of MPEG-PCL. Therefore, the brain distribution of coumarin administered using MPEG-PCL-Tat was significantly greater than that using MPEG-PCL. Then, the coumarin distribution after MPEG-PCL-Tat administration in non-targeted tissues (lung, liver, heart, kidney and spleen) was lower than that after coumarin administration without nanomicelles.

CONCLUSION

We have demonstrated that utilization of nano-sized micelles modified with Tat can facilitate direct intranasal brain delivery.

Vaginal delivery of siRNA using a novel PEGylated lipoplex-entrapped alginate scaffold system

Sustained vaginal delivery of siRNA has been precluded by the mucosal barrier lining the vaginal tract. In contrast to prior reports, we showed that conventional lipoplexes administered intravaginally are unable to reach the vaginal epithelium under normal physiological conditions. Here we have developed a novel alginate scaffold system containing muco-inert PEGylated lipoplexes to provide a sustained vaginal presence of lipoplexes in vivo and to facilitate the delivery of siRNA/oligonucleotides into the vaginal epithelium. These PEGylated lipoplex-entrapped alginate scaffolds (PLAS) were fabricated using a freeze-drying method and the entrapment efficiency, release rate, and efficacy were characterized. We demonstrated that the PLAS system had an entrapment efficiency of ~50%, which released PEGylated lipoplexes gradually both in vitro and in vivo. While the presence of alginate diminished the cell uptake efficiency of PEGylated lipoplexes in vitro, as expected, we showed a six-fold increase their uptake into the vaginal epithelium compared to existing transfection systems following intravaginal administration in mice. A significant knockdown of Lamin A/C level was also observed in vaginal tissues using siLamin A/C-containing PLAS system in vivo. Overall, our results indicated the potential of the biodegradable PLAS system for the sustained delivery of siRNA/oligonucleotides to vaginal epithelium.

DNA vaccines for targeting bacterial infections

DNA vaccination has been of great interest since its discovery in the 1990s due to its ability to elicit both humoral and cellular immune responses. DNA vaccines consist of a DNA plasmid containing a transgene that encodes the sequence of a target protein from a pathogen under the control of a eukaryotic promoter. This revolutionary technology has proven to be effective in animal models and four DNA vaccine products have recently been approved for veterinary use. Although few DNA vaccines against bacterial infections have been tested, the results are encouraging. Because of their versatility, safety and simplicity a wider range of organisms can be targeted by these vaccines, which shows their potential advantages to public health. This article describes the mechanism of action of DNA vaccines and their potential use for targeting bacterial infections. In addition, it provides an updated summary of the methods used to enhance immunogenicity from codon optimization and adjuvants to delivery techniques including electroporation and use of nanoparticles.

Vaccine delivery by polymeric vehicles in the mouse reproductive tract induces sustained local and systemic immunity

Design of easily administered vaccines to protect the female reproductive tract against STIs such as HIV, HPV and HSV is a major step in improving world health standards. However, the effect of immunization routes and regimens (prime/boost) on immune response is not well-understood. Here, we present a systematic study of vaccine delivery by different routes and prime/boosting regimens to produce a robust humoral immune response in the reproductive tract. A model antigen, ovalbumin (OVA), was delivered orally or intranasally via polymer particles, and intravaginally via polymer disks to female mice. Repeated prime/boost at a single site result in high OVA-specific antibody levels in the serum for mice immunized orally (IgA) and invaginally (IgA and IgG) after 3 months. Vaginal antibody titers were the highest for mice immunized by intravaginal routes. Vaginal boosting following intranasal or oral priming did not appear to offer similar advantages to those primed intravaginally. Systemic immunization with OVA in Freund's adjuvant produced robust serum IgG levels, but little serum IgA or antibodies in the vaginal washings. All immunization schemes produced a significant level of IgG in the intestinal mucosa, with the exception of nasal priming followed by intravaginal boost with slow-releasing disks. In contrast, only immunization by nasal priming and intravaginal boost with fast-releasing disks was able to achieve significantly high intestinal IgA titers.

Effective vaginal DNA delivery with high transfection efficiency is a good system for induction of higher local vaginal immune responses

Objectives

To investigate the local vaginal and systemic immune responses of effective vaginal DNA delivery with high transfection efficiency, we determined the effects on Th1-dependent cytokine (interferon-γ) production in spleen and inguinal lymph node cells and antibody responses of vaginal pDNA immunization with a cell-penetrating peptide, and compared our vaginal immunization with intradermal and intranasal immunizations.

Methods

Mice were immunized by vaginal, nasal or dermal administration of pCMV-OVA with or without peptide carriers, and serum, vaginal fluids, spleen and inguinal cells were harvested. The serum immunoglobulin (Ig)G2a and vaginal IgA antibody responses were determined by sandwich enzyme-linked immunosorbent assay (ELISA). The interferon-γ production from spleen cells or inguinal lymph node cells was determined by an ELISA kit.

Key findings

The direct vaginal immunization strongly induced IgA in the vaginal fluids and interferon-γ production in the local lymph node draining from the vagina. In addition, co-vaccination with the peptide carriers elevated these immune responses compared with vaccination with pCMV-OVA alone. Vaginal immunization with high transfection efficiency promoted vaginal IgA production to a significantly greater extent than intradermal or nasal immunization.

Conclusions

These results suggested that direct vaginal DNA vaccines under high transfection conditions induced higher local vaginal antibody than that by intranasal or intradermal administration, and peptide carriers effectively elevated mucosal immune responses. Therefore, this vaginal DNA vaccination method may be expected to be useful in the prevention and treatment methods for vaginal infectious diseases such as HIV infection.

Mucosal immunity and protection against HIV/SIV infection: strategies and challenges for vaccine design

To date, most HIV vaccine strategies have focused on parenteral immunization and systemic immunity. These approaches have not yielded the efficacious HIV vaccine urgently needed to control the AIDS pandemic. As HIV is primarily mucosally transmitted, efforts are being re-focused on mucosal vaccine strategies, in spite of complexities of immune response induction and evaluation. Here, we outline issues in mucosal vaccine design and illustrate strategies with examples from the recent literature. Development of a successful HIV vaccine will require in-depth understanding of the mucosal immune system, knowledge that ultimately will benefit vaccine design for all mucosally transmitted infectious agents.