Intranasal Vaccination with Outer-Membrane Protein of Orientia tsutsugamushi induces Protective Immunity Against Scrub Typhus

Scrub typhus develops after the individual is bitten by a trombiculid mite infected with Orientia tsutsugamushi. Since it has been reported that pneumonia is frequently observed in patients with scrub typhus, we investigated whether intranasal (i.n.) vaccination with the outer membrane protein of O. tsutsugamushi (OMPOT) would induce a protective immunity against O. tsutsugamushi infection. It was particular interest that when mice were infected with O. tsutsugamushi, the bacteria disseminated into the lungs, causing pneumonia. The i.n. vaccination with OMPOT induced IgG responses in serum and bronchoalveolar lavage (BAL) fluid. The anti-O. tsutsugamushi IgA Abs in BAL fluid after the vaccination showed a high correlation of the protection against O. tsutsugamushi. The vaccination induced strong Ag-specific Th1 and Th17 responses in the both spleen and lungs. In conclusion, the current study demonstrated that i.n. vaccination with OMPOT elicited protective immunity against scrub typhus in mouse with O. tsutsugamushi infection causing subsequent pneumonia.

Bacillus subtilis spores as adjuvants against avian influenza H9N2 induce antigen-specific antibody and T cell responses in White Leghorn chickens

Low-pathogenicity avian influenza H9N2 remains an endemic disease worldwide despite continuous vaccination, indicating the need for an improved vaccine strategy. Bacillus subtilis (B. subtilis), a gram-positive and endospore-forming bacterium, is a non-pathogenic species that has been used in probiotic formulations for both animals and humans. The objective of the present study was to elucidate the effect of B. subtilis spores as adjuvants in chickens administered inactivated avian influenza virus H9N2. Herein, the adjuvanticity of B. subtilis spores in chickens was demonstrated by enhancement of H9N2 virus-specific IgG responses. B. subtilis spores enhanced the proportion of B cells and the innate cell population in splenocytes from chickens administered both inactivated H9N2 and B. subtilis spores (Spore + H9N2). Furthermore, the H9N2 and spore administration induced significantly increased expression of the pro-inflammatory cytokines IL-1β and IL-6 compared to that in the H9N2 only group. Additionally, total splenocytes from chickens immunized with inactivated H9N2 in the presence or absence of B. subtilis spores were re-stimulated with inactivated H9N2. The subsequent results showed that the extent of antigen-specific CD4⁺ and CD8⁺ T cell proliferation was higher in the Spore + H9N2 group than in the group administered only H9N2. Taken together, these data demonstrate that B. subtilis spores, as adjuvants, enhance not only H9N2 virus-specific IgG but also CD4⁺ and CD8⁺ T cell responses, with an increase in pro-inflammatory cytokine production. This approach to vaccination with inactivated H9N2 together with a B. subtilis spore adjuvant in chickens produces a significant effect on antigen-specific antibody and T cell responses against avian influenza virus.

Plant factory: new resource for the productivity and diversity of human and veterinary vaccines

Vaccination is one of the most successful strategies to prevent diseases caused by pathogens. Although various expression systems including Escherichia coli, yeast, insect, and mammalian cells are currently used for producing many of vaccines, these conventional platforms have the limitation of post-translational modification, high cost, and expensive scalability. In this respect, the plant-based expression system has been considered as an attractive platform to produce recombinant vaccines due to fast, cost-effective and scalable production as well as safety. This review discusses the development of plant-derived vaccines and the current stage of plant-based expression system.

Zika Virus-Immune Plasmas from Symptomatic and Asymptomatic Individuals Enhance Zika Pathogenesis in Adult and Pregnant Mice

Preexisting immunity against dengue virus or West Nile virus was previously reported to mediate antibody-dependent enhancement (ADE) of Zika virus (ZIKV) infection in a mouse model. We show here that ZIKV-immune plasma samples from both symptomatic and asymptomatic individuals mediated ZIKV ADE of infection in vitro and in mice. In a lethal infection model with a viral inoculum 10 times higher, both ADE and protection were observed, depending on the amount of infused immune plasma. In a vertical-transmission model, ZIKV-immune plasma infused to timed pregnant mice increased fetal demise and decreased the body weight of surviving fetuses. Depletion of IgG from an immune plasma abolished ADE of infection, and the presence of purified IgG alone mediated ADE of infection. Higher viral loads and proinflammatory cytokines were detected in mice treated with ZIKV-immune plasma samples compared to those receiving control plasma. Together, these data show that passive immunization with homotypic ZIKV antibodies, depending on the concentration, could either worsen or limit a subsequent ZIKV infection.IMPORTANCE Antibody-dependent enhancement (ADE) of virus infection is common to many viruses and is problematic when plasma antibody levels decline to subneutralizing concentrations. ADE of infection is especially important among flaviviruses, many of which are the cause of global health problems. Recently, human plasma samples immune to heterologous flaviviruses were shown to promote Zika virus (ZIKV) infection. Here we showed in immunocompromised mouse models that homologous immune plasma samples protect mice from subsequent infection at high antibody concentrations but that they mediate ADE of infection and increase ZIKV pathogenesis in adult mice and fetal demise during pregnancy at low concentrations.

Intranasal immunization with pneumococcal surface protein A in the presence of nanoparticle forming polysorbitol transporter adjuvant induces protective immunity against the Streptococcus pneumoniae infection

Developing effective mucosal subunit vaccine for the Streptococcus pneumoniae has been unsuccessful mainly because of their poor immunogenicity with insufficient memory T and B cell responses. We thus address whether such limitation can be overcome by introducing effective adjuvants that can enhance immunity and show here that polysorbitol transporter (PST) serves as a mucosal adjuvant for a subunit vaccine against the Streptococcus pneumoniae. Pneumococcal surface protein A (PspA) with PST adjuvant induced protective immunity against S. pneumoniae challenge, especially long-term T and B cell immune responses. Moreover, we found that the PST preferentially induced T helper (Th) responses toward Th2 or T follicular helper (Tfh) cells and, importantly, that the responses were mediated through antigen-presenting cells via activating a peroxisome proliferator-activated receptor gamma (PPAR-γ) pathway. Thus, these data indicate that PST can be used as an effective and safe mucosal vaccine adjuvant against S. pneumoniae infection. STATE OF SIGNIFICANCE: In this study, we suggested the nanoparticle forming adjuvant, PST works as an effective adjuvant for the pneumococcal vaccine, PspA. The PspA subunit vaccine together with PST adjuvant efficiently induced protective immunity, even in the long-term memory responses, against Streptococcus pneumoniae lethal challenge. We found that PspA with PST adjuvant induced dendritic cell activation followed by follicular helper T cell responses through PPAR-γ pathway resulting long-term memory antibody-producing cells. Consequently, in this paper, we suggest the mechanism for safe nanoparticle forming subunit vaccine adjuvant against pneumococcal infection.

Sublingual Immunization With an RSV G Glycoprotein Fragment Primes IL-17-Mediated Immunopathology Upon Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is the leading cause of serious respiratory tract disease but there is no licensed RSV vaccine. Immunopathological mechanisms have long been suspected as operating in the development of severe RSV disease and have hampered the development of safe and effective vaccines. Here, we show that unlike intranasal immunization, sublingual immunization with RSV glycoprotein fragment containing the central conserved region (Gcf) primes the host for severe disease upon RSV challenge. This increased pathology does not require replication by the challenge virus and is associated with massive infiltration of inflammatory cells, extensive cell death, and excessive mucus production in the airway and lungs. This exacerbated RSV disease primed by sublingual Gcf immunization is distinct from the immunopathology by G-expressing vaccinia virus or formalin-inactivated RSV, and preceded by prominent IL-17 production. IL-17 deficiency abolished the enhanced disease. Our results suggest a novel mechanism of RSV vaccine-induced immunopathology by IL-17, and highlights the importance of vaccination site.

Label-Free Pathogen Detection by a Deoxyribozyme Cascade with Visual Signal Readout

A colorimetric nucleic acid based test for label-free pathogen detection has been developed and used for the detection of the Zika virus. The test relies on nucleic acid sequence-based amplification (NASBA) of a viral RNA followed by interrogation of the amplicon by a cascade of deoxyribozymes constituting a visual split deoxyribozyme (vsDz) probe. The probe consists of a split phosphodiesterase deoxyribozyme, which forms its catalytic core upon binding to a specific amplicon fragment. The catalytically active complex recognizes and cleaves an inhibited peroxidase-like deoxyribozyme (PDz), thereby activating it. Active PDz catalyzes hydrogen peroxide-mediated oxidation of a colorless substrate into a colored product, thereby generating a visible signal. Viral RNA (106 copies/mL or higher) triggers intense color within 2 hr. The test selectively differentiates between Zika and closely related dengue and West Nile viruses. The reported technology combines isothermal amplification and visual detection and therefore represents a basis for the future development of a cost-efficient and instrument-free method for point-of-care nucleic acid analysis.

MicroRNA screening identifies miR-134 as a regulator of poliovirus and enterovirus 71 infection

MicroRNAs (miRNAs) regulate virus replication through multiple mechanisms. Poliovirus causes a highly debilitating disease and though global efforts to eradicate polio have sharply decreased polio incidence, unfortunately three countries (Afghanistan, Nigeria and Pakistan) remain polio-endemic. We hypothesize that understanding the host factors involved in polio replication will identify novel prophylactic and therapeutic targets against polio and related viruses. In this data set, employing genome wide screens of miRNA mimics and inhibitors, we identified miRNAs which significantly suppressed polio replication. Specifically, miR-134 regulates poliovirus replication via modulation of ras-related nuclear protein (RAN), an important component of the nuclear transport system. MiR-134 also inhibited other Picornaviridae viruses including EV71, a growing concern and a high priority for vaccination in Asian countries like China. These findings demonstrate a novel mechanism for miRNA regulation of poliovirus and other Picornaviridae viruses in host cells, and thereby may provide a novel approach in combating infection and a potential approach for the development of anti-Picornaviridae strategies.

Zika virus infection during the period of maximal brain growth causes microcephaly and corticospinal neuron apoptosis in wild type mice

Zika virus (ZIKV) infection in pregnant women has been established as a cause of microcephaly in newborns. Here we test the hypothesis that neurodevelopmental stages when the brain is undergoing rapid growth are particularly vulnerable to the effects of ZIKV infection. We injected ZIKV intracranially into wild type C57BL/6 mice at two different time points: early postnatal development, when the brain is growing at its maximal rate, and at weaning, when the brain has largely reached adult size. Both time points showed widespread immunoreactivity for ZIKV and cleaved caspase 3 (CC3, a marker of apoptosis) throughout the brain. However, in early postnatal ZIKV injected mice, some brain areas and cell types display particularly large increases in apoptosis that we did not observe in older animals. Corticospinal pyramidal neurons, a cell type implicated in human microcephaly associated with ZIKV infection, are an example of one such cell type. Proliferating cells in the ventricular zone stem cell compartment are also depleted. These findings are consistent with the hypothesis that periods of rapid brain growth are especially susceptible to neurodevelopmental effects of ZIKV infection, and establish a valuable model to investigate mechanisms underlying neurodevelopmental effects of ZIKV infection and explore candidate therapeutics.

MicroRNA-555 has potent antiviral properties against poliovirus

Vaccination with live-attenuated polio vaccine has been the primary reason for the drastic reduction of poliomyelitis worldwide. However, reversion of this attenuated poliovirus vaccine occasionally results in the emergence of vaccine-derived polioviruses that may cause poliomyelitis. Thus, the development of anti-poliovirus agents remains a priority for control and eradication of the disease. MicroRNAs (miRNAs) have been shown to regulate viral infection through targeting the viral genome or reducing host factors required for virus replication. However, the roles of miRNAs in poliovirus (PV) replication have not been fully elucidated. In this study, a library of 1200 miRNA mimics was used to identify miRNAs that govern PV replication. High-throughput screening revealed 29 miRNAs with antiviral properties against Sabin-2, which is one of the oral polio vaccine strains. In particular, miR-555 was found to have the most potent antiviral activity against three different oral polio attenuated vaccine strains tested. The results show that miR-555 reduced the level of heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNP C) required for PV replication in the infected cells, which in turn resulted in reduction of PV positive-strand RNA synthesis and production of infectious progeny. These findings provide the first evidence for the role of miR-555 in PV replication and reveal that miR-555 could contribute to the development of antiviral therapeutic strategies against PV.

Development of safe and effective RSV vaccine by modified CD4 epitope in G protein core fragment (Gcf)

Respiratory syncytial virus (RSV) is a major cause of respiratory tract infection in infants and young children worldwide, but currently no safe and effective vaccine is available. The RSV G glycoprotein (RSVG), a major attachment protein, is an important target for the induction of protective immune responses during RSV infection. However, it has been thought that a CD4⁺ T cell epitope (a.a. 183–195) within RSVG is associated with pathogenic pulmonary eosinophilia. To develop safe and effective RSV vaccine using RSV G protein core fragment (Gcf), several Gcf variants resulting from modification to CD4⁺ T cell epitope were constructed. Mice were immunized with each variant Gcf, and the levels of RSV-specific serum IgG were measured. At day 4 post-challenge with RSV subtype A or B, lung viral titers and pulmonary eosinophilia were determined and changes in body weight were monitored. With wild type Gcf derived from RSV A2 (wtAGcf), although RSV A subtype-specific immune responses were induced, vaccine-enhanced disease characterized by excessive pulmonary eosinophil recruitment and body weight loss were evident, whereas wtGcf from RSV B1 (wtBGcf) induced RSV B subtype-specific immune responses without the signs of vaccine-enhanced disease. Mice immunized with Th-mGcf, a fusion protein consisting CD4⁺ T cell epitope from RSV F (F_51–66) conjugated to mGcf that contains alanine substitutions at a.a. position 185 and 188, showed higher levels of RSV-specific IgG response than mice immunized with mGcf. Both wtAGcf and Th-mGcf provided complete protection against RSV A2 and partial protection against RSV B. Importantly, mice immunized with Th-mGcf did not develop vaccine-enhanced disease following RSV challenge. Immunization of Th-mGcf provided protection against RSV infection without the symptom of vaccine-enhanced disease. Our study provides a novel strategy to develop a safe and effective mucosal RSV vaccine by manipulating the CD4⁺ T cell epitope within RSV G protein.

Orientia tsutsugamushi infection induces CD4+ T cell activation via human dendritic cell activity

Orientia tsutsugamushi, a gram-negative bacterium, causes severe acute febrile illness in humans. Despite this danger, the route of infection, infectivity, and protective mechanisms of the host's immune response to O. tsutsugamushi are unclear. Dendritic cells (DCs) are one of the most important cell types in bridging the innate and adaptive immune responses. In this study, we observed that O. tsutsugamushi infects and replicates in monocyte-derived DCs (MODCs). During infection and replication, the expressions of the cytokines IL-12 and TNF-α, as well as the co-stimulatory molecules CD80, CD83, CD86, and CD40, were increased in MODCs. When O. tsutsugamushi-treated MODCs were co-cultured with autologous CD4(+) T cells, they enhanced production of IFN-γ, a major Th1 cytokine. Collectively, our results show that O. tsutsugamushi can replicate in MODCs and can simultaneously induce MODC maturation and increase proinflammatory cytokine levels in MODCs that subsequently activate CD4(+) T cells.

Supplementation of oil-based inactivated H9N2 vaccine with M2e antigen enhances resistance against heterologous H9N2 avian influenza virus infection

Avian influenza virus (AIV) subtype H9N2 has been evolving rapidly and vaccine escape variants have been reported to cause circulation of infections and economic losses. In the present study, we developed and evaluated ectodomain of the AIV matrix 2 (M2e) protein as a supplementing antigen for oil-based inactivated H9N2 vaccine to increase resistance against vaccine escape variants. AIV H9N2 M2e antigen was expressed in Escherichia coli and supplemented to inactivated H9N2 oil emulsion vaccine. Specific pathogen-free chickens received a single injection of inactivated H9N2 oil emulsion vaccines with or without M2e supplementation. At three weeks post vaccination, hemagglutination inhibition tests and enzyme-linked immunosorbent assays were performed to determine serological immune responses. Challenge study using a vaccine escape H9N2 variant was performed to evaluate the efficacy of M2e supplementation. M2e antigen supplemented in oil emulsion vaccine was highly immunogenic, and a single M2e-supplemented vaccination reduced challenge virus replication and shedding more effectively than non-supplemented vaccination.

Functional characteristics of porcine peripheral T cells stimulated with IL-2 or IL-2 and PMA

In human or mouse, mature T cells express either CD4 or CD8, resulting in different functions in the periphery. Interestingly, porcine CD4 and CD8 double positive (DP) T cells are present in the blood, and their proportions change from youth to adulthood. However, the features of these cells in swine are poorly understood. We investigated the fate of porcine peripheral T cells based on their functional characteristics, including proliferation and the expression of CD4 and CD8 co-receptors. The results showed that all the populations changed their CD8 expression in a time-dependent manner and porcine T cells had different proliferative pattern from human T cells. The results further revealed that Th2 cytokines were increased later in porcine T cells compared to human T cells upon stimulation with IL-2+PMA. Collectively, we found that the fate of porcine peripheral T cells is different from that of human T cells, and the changes occur in a time- and stimulation-dependent manner.

Neonatal immunization with respiratory syncytial virus glycoprotein fragment induces protective immunity in the presence of maternal antibodies in mice

Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for development of RSV vaccine. In this study, we first show that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice can induce systemic humoral immune responses and protective immunity against RSV without causing lung eosinophilia, although antibody response was shifted to a Th2 response. Next, we examined whether the presence of maternal anti-RSV antibodies would affect the responsiveness and protection efficacy of Gcf in newborn mice, since infants can possess RSV-specific maternal antibodies due to frequent RSV re-infections to adults. Intranasal administration of Gcf induced antibody response and increased IFNγ secretion and protected mice against RSV challenge without severe lung eosinophilia, even in the presence of high levels of RSV-specific maternal antibodies. Thus, our findings suggest that Gcf may be an effective and safe RSV vaccine during the neonatal period.

Sublingual delivery of vaccines for the induction of mucosal immunity

The mucosal surfaces are constantly exposed to incoming pathogens which can cause infections that result in severe morbidity and/or mortality. Studies have reported that mucosal immunity is important for providing protection against these pathogens and that mucosal vaccination is effective in preventing local infections. For many years, the sublingual mucosa has been targeted to deliver immunotherapy to treat allergic hypersensitivities. However, the potential of vaccine delivery via sublingual mucosal has received little attention until recently. Recent studies exploring such potential have documented the safety and effectiveness of sublingual immunization, demonstrating the ability of sublingual immunization to induce both systemic and mucosal immune responses against a variety of antigens, including soluble proteins, inter particulate antigens, and live-attenuated viruses. This review will summarize the recent findings that address the promising potential of sublingual immunization in proving protection against various mucosal pathogens.

Neonatal immunization with respiratory syncytial virus glycoprotein fragment induces protective immunity in the presence of maternal antibodies in mice (P4277)

Respiratory syncytial virus (RSV) is the major cause of severe lower respiratory tract infections in infants and the elderly worldwide. The significant morbidity and mortality associated with this infection underscores the urgent need for development of an RSV vaccine. In this study, we first show that intranasal administration of RSV glycoprotein core fragment (Gcf) to neonatal mice can induce systemic humoral immune responses and protective immunity against RSV without causing lung eosinophilia, although antibody response was shifted to a Th2 response. Next, we examined whether the presence of maternal anti-RSV antibodies affects the responsiveness and protection efficacy of Gcf in newborn mice, since infants can have RSV-specific maternal antibodies since adults are frequently reinfected with RSV. Intranasal administration of Gcf induced antibody response and IFNγ secretion and protected mice against RSV challenge without lung eosinophilia even in the presence of high levels of RSV-specific maternal antibodies. Thus, our findings suggest that Gcf may be an effective and safe RSV vaccine during the neonatal period.

Sublingual immunization with M2-based vaccine induces broad protective immunity (P4301)

Background: M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored. Methods and Results: A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs. Conclusions: The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections.

Sublingual administration of bacteria-expressed influenza virus hemagglutinin 1 (HA1) induces protection against infection with 2009 pandemic H1N1 influenza virus

Influenza viruses are respiratory pathogens that continue to pose a significantly high risk of morbidity and mortality of humans worldwide. Vaccination is one of the most effective strategies for minimizing damages by influenza outbreaks. In addition, rapid development and production of efficient vaccine with convenient administration is required in case of influenza pandemic. In this study, we generated recombinant influenza virus hemagglutinin protein 1 (sHA1) of 2009 pandemic influenza virus as a vaccine candidate using a well-established bacterial expression system and administered it into mice via sublingual (s.l.) route. We found that s.l. immunization with the recombinant sHA1 plus cholera toxin (CT) induced mucosal antibodies as well as systemic antibodies including neutralizing Abs and provided complete protection against infection with pandemic influenza virus A/CA/04/09 (H1N1) in mice. Indeed, the protection efficacy was comparable with that induced by intramuscular (i.m.) immunization route utilized as general administration route of influenza vaccine. These results suggest that s.l. vaccination with the recombinant non-glycosylated HA1 protein offers an alternative strategy to control influenza outbreaks including pandemics.

Sublingual immunization with recombinant adenovirus encoding SARS-CoV spike protein induces systemic and mucosal immunity without redirection of the virus to the brain

Background

Sublingual (s.l.) administration of soluble protein antigens, inactivated viruses, or virus-like particles has been shown to induce broad immune responses in mucosal and extra-mucosal tissues. Recombinant replication-defective adenovirus vectors (rADVs) infect mucosa surface and therefore can serve as a mucosal antigen delivery vehicle. In this study we examined whether s.l. immunization with rADV encoding spike protein (S) (rADV-S) of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) induces protective immunity against SARS-CoV and could serve as a safe mucosal route for delivery of rADV.

Results

Here, we show that s.l. administration of rADV-S induced serum SARS-CoV neutralizing and airway IgA antibodies in mice. These antibody responses are comparable to those induced by intranasal (i.n.) administration. In addition, s.l. immunization induced antigen-specific CD8⁺ T cell responses in the lungs that are superior to those induced by intramuscular immunization. Importantly, unlike i.n. administration, s.l. immunization with rADV did not redirect the rADV vector to the olfactory bulb.

Conclusion

Our study indicates that s.l. immunization with rADV-S is safe and effective in induction of a broad spectrum of immune responses and presumably protection against infection with SARS-CoV.

Dual role of respiratory syncytial virus glycoprotein fragment as a mucosal immunogen and chemotactic adjuvant

Respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract disease in infancy and early childhood. Despite its importance as a pathogen, there is no licensed vaccine to prevent RSV infection. The G glycoprotein of RSV, a major attachment protein, is a potentially important target for protective antiviral immune responses and has been shown to exhibit chemotactic activity through CX3C mimicry. Here, we show that sublingual or intranasal immunization of a purified G protein fragment of amino acids from 131 to 230, designated Gcf, induces strong serum IgG and mucosal IgA responses. Interestingly, these antibody responses could be elicited by Gcf even in the absence of any adjuvant, indicating a novel self-adjuvanting property of our vaccine candidate. Gcf exhibited potent chemotactic activity in in vitro cell migration assay and cysteine residues are necessary for chemotactic activity and self-adjuvanticity of Gcf in vivo. Mucosal immunization with Gcf also provides protection against RSV challenge without any significant lung eosinophilia or vaccine-induced weight loss. Together, our data demonstrate that mucosal administration of Gcf vaccine elicits beneficial protective immunity and represents a promising vaccine regimen preventing RSV infection.

Evaluation of protective efficacy of respiratory syncytial virus vaccine against A and B subgroup human isolates in Korea

Human respiratory syncytial virus (HRSV) is a significant cause of upper and lower respiratory tract illness mainly in infants and young children worldwide. HRSV is divided into two subgroups, HRSV-A and HRSV-B, based on sequence variation within the G gene. Despite its importance as a respiratory pathogen, there is currently no safe and effective vaccine for HRSV. In this study, we have detected and identified the HRSV by RT-PCR from nasopharyngeal aspirates of Korean pediatric patients. Interestingly, all HRSV-B isolates exhibited unique deletion of 6 nucleotides and duplication of 60 nucleotides in the G gene. We successfully amplified two isolates ('KR/A/09-8' belonging to HRSV-A and 'KR/B/10-12' to HRSV-B) on large-scale, and evaluated the cross-protective efficacy of our recombinant adenovirus-based HRSV vaccine candidate, rAd/3xG, by challenging the immunized mice with these isolates. The single intranasal immunization with rAd/3xG protected the mice completely from KR/A/09-8 infection and partially from KR/B/10-12 infection. Our study contributes to the understanding of the genetic characteristics and distribution of subgroups in the seasonal HRSV epidemics in Korea and, for the first time, to the evaluation of the cross-protective efficacy of RSV vaccine against HRSV-A and -B field-isolates.

Intranasal immunization with plasmid DNA encoding spike protein of SARS-coronavirus/polyethylenimine nanoparticles elicits antigen-specific humoral and cellular immune responses

Background

Immunization with the spike protein (S) of severe acute respiratory syndrome (SARS)-coronavirus (CoV) in mice is known to produce neutralizing antibodies and to prevent the infection caused by SARS-CoV. Polyethylenimine 25K (PEI) is a cationic polymer which effectively delivers the plasmid DNA.

Results

In the present study, the immune responses of BALB/c mice immunized via intranasal (i.n.) route with SARS DNA vaccine (pci-S) in a PEI/pci-S complex form have been examined. The size of the PEI/pci-S nanoparticles appeared to be around 194.7 ± 99.3 nm, and the expression of the S mRNA and protein was confirmed in vitro. The mice immunized with i.n. PEI/pci-S nanoparticles produced significantly (P < 0.05) higher S-specific IgG1 in the sera and mucosal secretory IgA in the lung wash than those in mice treated with pci-S alone. Compared to those in mice challenged with pci-S alone, the number of B220⁺ cells found in PEI/pci-S vaccinated mice was elevated. Co-stimulatory molecules (CD80 and CD86) and class II major histocompatibility complex molecules (I-A^d) were increased on CD11c⁺ dendritic cells in cervical lymph node from the mice after PEI/pci-S vaccination. The percentage of IFN-γ-, TNF-α- and IL-2-producing cells were higher in PEI/pci-S vaccinated mice than in control mice.

Conclusion

These results showed that intranasal immunization with PEI/pci-S nanoparticles induce antigen specific humoral and cellular immune responses.

Conduction Properties Of Decellularized Nerve Biomaterials

The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15-20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ≤ 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the "gold standard", autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising electroconductivity.

DNA vaccine encoding spike protein of SARS-coronavirus loaded polyethylenimine elicits antigen-specific immune responses in mice immunized through intranasal route (42.8)

The spike protein (S) of severe acute respiratory syndrome (SARS) coronavirus-(CoV) is a ~180-kDa glycoprotein, which is essentially required its recognition of and binding to host receptors. It has been known that the receptor-binding motif of spike protein can produce neutralizing antibodies and therefore prevent the infection caused by SARS-CoV. Polyethylenimine (PEI) is one of the most widely used and effective nanoparticles, which have been tested for its use in the drug delivery system including DNA vaccine. In the present study, we examined the immune responses in BALB/c mice after immunized with SARS DNA vaccine in a pci-S/PEI complex form via intranasal (i.n.) route. PEI/pci-S nanoparticles showed a spherical shape with size around 194+/-99nm. The mice intranasally immunized with pci-S/PEI nanoparticles produced significantly (P&lt;0.05) higher S-specific IgA as well as B220+ cells in the lung wash than those in mice treated with pci-S alone. CD80, CD86 and Class II MHC molecules (I-Ad) were increased on pulmonary dendritic (CD11c+) cells after vaccination. The percentage of IFN-gamma, TNF-alpha, and IL-2 producing cells were also higher in PEI/pci-S vaccinated mice than in either pci-S or pci-mock treated mice. Taken together, our results showed that immunization with pci-S/PEI nanoparticles induce antigen specific humoral and cellular immune responses.

Tumor angiogenesis promoted by ex vivo differentiated endothelial progenitor cells is effectively inhibited by an angiogenesis inhibitor, TK1-2

Neovascularization plays a critical role in the growth and metastatic spread of tumors and involves recruitment of circulating endothelial progenitor cells (EPC) from bone marrow as well as sprouting of preexisting endothelial cells. In this study, we examined if EPCs could promote tumor angiogenesis and would be an effective cellular target for an angiogenesis inhibitor, the recombinant kringle domain of tissue-type plasminogen activator (TK1-2). When TK1-2 was applied in the ex vivo culture of EPCs isolated from human cord blood, TK1-2 inhibited adhesive differentiation of mononuclear EPCs into endothelial-like cells. In addition, it inhibited the migration of ex vivo cultivated EPCs and also inhibited their adhesion to fibronectin matrix or endothelial cell monolayer. When A549 cancer cells were coimplanted along with ex vivo cultivated EPCs s.c. in nude mice, the tumor growth was increased. However, the tumor growth and the vascular density of tumor tissues increased by coimplanted EPCs were decreased upon TK1-2 treatment. Accordingly, TK1-2 treatment reduced the remaining number of EPCs in tumor tissues and their incorporation into the host vascular channels. In addition, overall expression levels of vascular endothelial growth factor (VEGF) and von Willebrand factor in tumor tissues were decreased upon TK1-2 treatment. Interestingly, strong VEGF expression by implanted EPCs was decreased by TK1-2. Finally, we confirmed in vitro that TK1-2 inhibited VEGF secretion of EPCs. TK1-2 also inhibited endothelial cell proliferation and migration induced by the conditioned medium of EPCs. Therefore, we concluded that EPCs, as well as mature endothelial cells, could be an important target of TK1-2.

The recombinant kringle domain of urokinase plasminogen activator inhibits in vivo malignant glioma growth

In a previous report, the recombinant kringle domain (UK1) of the urokinase type plasminogen activator (uPA) showed antiangiogenic activity. Here, we investigated in vivo antitumor effects of the UK1 of human uPA employing a brain tumor model. The systemic administration of UK1 purified from pichia expression (10 and 50 mg/kg/day intraperitoneally for 25 days) led to suppress the growth of a U87 human glioma xenograft, implanted into the brains of male BALB/cSlc nude mice, by 35% and 80%, respectively. In the immunohistochemical analysis, the tumors treated with UK1 showed decreased vascularity and expression of angiogenesis-related factors including vascular endothelial growth factor (VEGF), angiogenin, alpha-smooth muscle actin, von Willebrand's factor, and CD31 (PECAM-1 [Platelet endothelial cell adhesion molecule-1]), and increased apoptosis. UKl inhibited the in vitro proliferation and tube formation of VEGF-stimulated endothelial cells but not the proliferation of glioma cells. These results suggest that UK1 inhibits the malignant glioma growth by suppression of angiogenesis.

Botulinum toxin A for the management of vulvodynia

Clinically, botulinum toxin A blocks the cholinergic innervation of the target tissue. Recently, it has been proved effective not only at a neuromuscular junction but also within parasympathetic or sympathetic neural synapses. Seven women with pain on genitalia that could not be controlled with conventional pain managements were enrolled in this study. Twenty to 40 U of botulinum toxin A were used in each injection. Injection sites were the vestibule, levator ani muscle or the perineal body. Repeat injections were administered every 2 weeks if the patient's symptoms had not fully subsided. In all patients, pain had disappeared with botulinum toxin A injections. Five patients needed to be injected twice; the other two patients needed only one injection. We did not observe complications related to botulinum toxin A injections, such as pain, hemorrhage, infection, muscle paralysis or other complications. The subjective pain score improved from 8.3 to 1.4, and no one has experienced a recurrence (the follow-up period was four to 24 months, with a mean follow-up of 11.6 months). Botulinum toxin A is effective in blocking nociception. Even though further investigation and well-controlled study will be necessary, we suggest that the botulinum toxin therapy would be useful and safe in managing vulvodynia of muscular or neuroinflammatory origins.

Potent anti-tumor and prolonged survival effects of E. coli-derived non-glycosylated kringle domain of tissue-type plasminogen activator

The two-kringle domain of tissue-type plasminogen activator (TK1-2) has been identified as a novel angiogenesis inhibitor. In the previous study, purified Pichia-derived TK1-2 has been shown to suppress in vivo growth of human lung and colon cancer cells. Here, we demonstrate that E. coli-derived non-glycosylated TK1-2 suppresses tumor growth more potently than Pichia-derived TK1-2 and prolongs the survival of tumor bearing mice. The recombinant TK1-2 prepared through E. coli expression, His-tag affinity chromatography and in vitro refolding was injected intraperitoneally once daily into nude mice 7 days after subcutaneous implantation with PC14 lung cancer cells (n=10). Measurement of tumor volumes indicated that low-dose TK1-2 treatment (10 mg/kg) suppressed tumor growth by approximately 85.2% (p<0.01), while high-dose TK1-2 treatment (50 mg/kg) even more potently inhibited tumor growth (>93.8%) (p<0.005). Treatment of TK1-2 also prolonged the survival of tumor-bearing mice in a dose-dependent fashion. In an independent HCT116 xenograft model, E. coli-derived TK1-2 was more effective in suppressing tumor growth than Pichia-derived TK1-2. Immunohistochemical analysis of tumor tissue also revealed that the expression of VEGF, SMA-alpha, TNF-alpha and angiogenin was less positive in the E. coli-derived TK1-2-treated group than in the Pichia-derived TK1-2-treated group. These results suggest that E. coli-derived refolded, non-glycosylated TK1-2 can be used more effectively as an anti-cancer agent.

The kringle domain of tissue-type plasminogen activator inhibits in vivo tumor growth

The two-kringle domain of tissue-type plasminogen activator (t-PA) has previously been shown to contain anti-angiogenesis activity. In this study, we explored the potential in vivo anti-tumor effects of the recombinant kringle domain (TK1-2) of human t-PA. Anti-tumor effects of purified Pichia-driven TK1-2 were examined in nude mice models by subcutaneous implantation of human lung (A-549) and colon (DLD-1, HCT-116) cancer cell lines. Mice bearing the tumors were injected with PBS or purified TK1-2 (30 mg/kg) i.p. every day for 22 days. TK1-2 treatment suppressed the A-549, DLD-1, and HCT-116 tumor growth by 85.3%, 52.4%, and 62.5%, respectively. Immunohistological examination of the tumor tissues showed that TK1-2 treatment decreased the vessel density and also the expression of angiogenesis-related factors including angiogenin, VEGF, alpha-SMA, vWF, and TNF-alpha, and increased the apoptotic fraction of cells. TK1-2 neither inhibited in vitro growth of these cancer cells nor affected t-PA-mediated fibrin clot lysis. These results suggest that TK1-2 inhibits the tumor growth by suppression of angiogenesis without interfering with fibrinolysis.

Effects of estrogen on nitric oxide synthase and histological composition in the rabbit clitoris and vagina

We investigated the functional and histological changes after oophorectomy in the rabbit clitoris and vagina to determine the mechanism responsible for the development of arousal disorder in postmenopausal women. Twenty mature female New Zealand white rabbits were randomly divided into three groups: control; oophorectomy; and estrogen replacement after oophorectomy. We compared the nitric oxide synthase (NOS) activity and the degree of expression of neuronal (nNOS) and endothelial NOS (eNOS) using biochemical and Western blot analysis in clitoral and vaginal tissues. Histological change of smooth muscle and collagen contents in those tissues were also compared using Masson's trichrome staining. NOS activity and the expression of nNOS and eNOS were significantly increased in the oophorectomized group while there was a decrease to the level of the control group in the estrogen replacement group. Histological examination showed that oophorectomy induced a significant increase in collagen and decrease in muscle content in both clitoris and vagina, while the ratio of smooth muscle content was increased significantly after the estrogen replacement. Our results clearly demonstrate that estrogen deficiency induces compensatory NOS production which may be related to decreases in muscle to collagen ratio in female rabbit genital organs.

Hemodynamic insult by vascular risk factors and pharmacologic erection in men with erectile dysfunction: Doppler sonography study

To evaluate the penodynamic impact of known vascular risk factors in men with erectile dysfunction, we obtained thorough medical histories covering diabetes, hypertension, heart disease and hypercholesterolemia, alcohol ingestion, and smoking in 265 consecutive patients. We also measured their penile hemodynamic parameters by color duplex ultrasonography after intracavernous prostaglandin E1 injection. In patients with vascular risk factors there was a statistically significant decrease in the peak systolic velocity and increase in the end-diastolic velocity of the cavernosal artery (P < 0.01). Those men who had diabetes had higher average end-diastolic velocities and lower resistance indices (P < 0.01). Smoking and alcohol use also affected penile hemodynamics (P < 0.05). These data confirm that vascular risk factors do increase the likelihood of vasculogenic impotence and that diabetes plays a major role in veno-occlusive dysfunction in the penis.

A novel function of haptoglobin: haptoglobin-haemoglobin complex induces apoptosis of hepatocarcinomatous Hep 3B cells

Haptoglobin-haemoglobin complex (Cx) showed a cytotoxic effect on the growth of Hep 3B (human hepatocellular carcinoma) cells, dose dependently. The antiproliferative effect of Cx on the multiplication of Hep 3B cells was augmented by the presence of prostaglandin (PG) D2. Antihuman Hb IgG abolished the effect of Cx, dose-dependently, which indicates that the antiproliferative effect of Cx really is exerted by Cx. Hep 3B cells treated with Cx showed the characteristic biochemical changes of apoptosis, such as DNA fragmentation which was blocked by pretreatment with cycloheximide, and the increase of transglutaminase expression. Thus, the antiproliferative effect of Cx against Hep 3B cells occurs via the typical apoptotic pathway.

Expression and amplification of cellular oncogenes in human developing placenta and neoplastic trophoblastic tissue

To confirm the expression of cellular oncogenes during normal development, their differential RNA levels in developing human placenta have been studied using radioactive probes such as v-abl, v-erbA, v-fms, v-mos, v-myc, N-ras and v-src. The c-mos and N-ras genes are expressed and amplified at high levels especially in term placenta, while c-abl, and c-erbA are expressed constantly during development. These findings indicate that c-mos and N-ras genes may be closely linked to normal differentiation, although c-abl and c-erbA may participate in overall developmental processes. In contrast, transcripts of c-myc and c-src are enhanced at first trimester and decreased sequentially thereafter, showing that these genes may play a role in early proliferation. Expression patterns of c-fms gene are same as that of c-myc and c-src except reelevation at term. In addition, to characterize the effect of cellular oncogene expression has been also examined in hydatidiform mole and tumor cells such as BeWo and choriocarcinoma. All cellular oncogenes examined in this study were significantly overexpressed. Thus, our results suggest that cellular oncogene activation may be strongly associated with neoplastic change of trophoblast.

Simple spectrophotometric determination of haptoglobin-haemoglobin complex in haemolysed samples

The concentration of haptoglobin-haemoglobin complex in haemolysed serum was measured by reducing the sample with sodium hydrosulphite. The absorption spectra of serum before and after sodium hydrosulphite treatment were compared, and the absorbance change was used to determine the amount of haemoglobin in the sample. By analysing the difference absorption spectra of various types of haemoglobin-containing samples, it was also possible to determine the haptoglobin level in samples haemolysed severely beyond their haemoglobin-binding capacities. When the present methods are used, along with the spectrophotometric method for free haptoglobin, one can measure separately the amounts of free haptoglobin, haptoglobin-haemoglobin complex, and free haemoglobin in samples with varying degrees of haemolysis.

Simple spectrophotometric determination of haptoglobin level in serum

Haptoglobin concentration was determined from the change caused in the absorption spectrum of hemoglobin due to binding with haptoglobin. Absorbance changed markedly near the Soret band, and a linear correlation could be observed between the extent of the absorbance change and the amount of free haptoglobin. The levels of serum haptoglobin measured by the present method correlated well with those determined by an electrophoretic or a peroxidase method. High concentrations (more than 10 mg/100 ml) of hematin gave positive interference in the measured haptoglobin level, whereas bilirubin and chylomicron showed low levels of interference. The proposed method could be used as a simple and reliable method for the determination of haptoglobin level in various types of sample.

Inhibition of prostaglandin synthase activity of sheep seminal vesicular gland by human serum haptoglobin

Serum haptoglobin was added to the reaction mixture of prostaglandin synthase (EC 1.14.99.1) and its inhibitory effect was studied [1-14C]Arachidonic acid was used as substrate and the enzyme activity was estimated by monitoring the radioactivity of the products after thin layer chromatography. With or without addition of hemoglobin to the reaction mixture, both the purified haptoglobin 1-1 and 2-2 showed inhibitory activity. In the presence of 5 microM hematin, however, inhibitory activity haptoglobin was not observed. Inhibition of prostaglandin synthesis in the system depended on the molar ratio of haptoglobin to hemoglobin in the reaction mixture. These results demonstrate that haptoglobin inhibits prostaglandin synthase by restricting available heme group for the enzyme activity through complexing with hemoglobin. However, haptoglobin did not inhibit completely the stimulatory effect of free hemoglobin. Relevant significant of this effect was discussed.

Local Shwartzman-like phenomenon prepared with haptoglobin-hemoglobin complex and provoked with prostaglandin

Intradermal injection of haptoglobin-hemoglobin (Hp-Hb) complex followed by intravenous injection of prostaglandin (PG) F2a or E2 produced a local Shwartzman-like phenomenon (LSLP) in rabbits, whereas PGE1 has no provoking action. Intradermal injection of hemoglobin or erythrocytes also produced LSLP when provoked with endotoxin or PGF2alpha. The provoking action of endotoxin in the local shwartzman reaction may not be entirely mediated through PGs.

Inhibition of the local Shwartzman reaction by turpentine, prostaglandin E2 and carbon tetrachloride

The conventional local Shwartzman reaction (LSR) did not occur in rabbits whose plasma haptoglobin (Hp) was lowered by treatment with carbon tetrachloride, nor in animals in whom Hp was elevated after treatment with turpentine, or PGE2 or endotoxin. The possible mechanisms of such inhibition of the LSR are discussed.

An abnormal human IgA1 half-molecule

An IgA1 half-molecule, which is composed of a deleted alpha1 chain linked with a disulfide bond to an intact kappa chain, was detected in a patient (Cha). The molecular weights of the paraprotein and the isolated alpha1 chain were estimated to be 75 000 and 53 000, respectively. Identification of tyrosine as the C-terminal amino acid and the presence of idiotypic determinants in the abnormal alpha1 chain indicated that the molecule would have an intact N-terminal variable region and a C-terminal region. Furthermore, no cleavage of the abnormal protein into Fab and Fc by proteolytic enzyme isolated from Neisseria gonorrhoeae suggested the absence of a "hinge" region in the abnormal alpha1 chain.