Paradoxical modulation of influenza by intranasal administration of non-replicating adenovirus particles.

Respiratory mucosal infection by airborne microbes is a common event that occurs every day. We report here that intranasal administration of non-replicating adenovirus (Ad) particles to mice could either confer rapid protection against influenza virus (IFV) challenge independent of adaptive immunity, or exacerbate influenza by triggering rapid death. The life-or-death outcome hinges on the time interval between Ad administration and IFV challenge in conjunction with specific mouse/IFV strains. Intranasal instillation of Ad particles 1-47 days prior to IFV challenge conferred rapid protection against influenza in Balb/c mice whereas exposure to Ad 39 days prior to challenge with a specific IFV strain or 1 day post-challenge with that IFV strain induced rapid death in C57BL/6 mice. Notably, consecutive administrations of Ad prior to IFV challenge conferred a synergy in triggering a potent anti-influenza state; even a detrimental Ad exposure 39 days before challenge with the deadly IFV strain was reversed to a beneficial one by subsequent Ad boosts. Results revealed an intricate relationship between infection and innate immunity that is a linchpin around which effects revolve from protective immunity to collateral damage. It is urgent to repeat the experiments with an expanded scope for characterizing the status that defines susceptibility or resistance to IFV infection and subsequently reveal the underlying mechanisms. Whether broad heterologous protective effects induced by AdE and adaptive immunity elicited by vaccination could confer synergy during mitigation of a pandemic remains to be seen.

Noninvasive vaccination as a casus belli to redeem vaccine value in the face of anti-vaccine movements.

Formidable anti-vaccine movements have been growing as a menace to disrupt beneficial vaccine programs. Although the vaccination-associated adverse effects commonly perceived by vaccine resisters usually represent over-reactions to rare manifestations, converging evidence shows that vaccination-associated health threats could be pervasive when systemic inflammation is considered as a side effect that oozes over time. An anti-vaccine movement thus may not be so unfounded even though the myriad cascades triggered by systemic inflammation have not been brought to a clear focus during any anti-vaccine campaign. Since both pro- and anti-vaccine groups are acting on the same primal impulse - "keep people healthy," reconciliation between the two warring factions should be achievable on a palatable trend that fosters the development of noninvasive vaccines which tend to induce local and transient inflammation along the interface with diminished potential to percolate through internal organs.

A Plasmodium vivax Plasmid DNA- and Adenovirus-Vectored Malaria Vaccine Encoding Blood-Stage Antigens AMA1 and MSP142 in a Prime/Boost Heterologous Immunization Regimen Partially Protects Aotus Monkeys against Blood-Stage Challenge.

Malaria is caused by parasites of the genus Plasmodium, which are transmitted to humans by the bites of Anopheles mosquitoes. After the elimination of Plasmodium falciparum, it is predicted that Plasmodium vivax will remain an important cause of morbidity and mortality outside Africa, stressing the importance of developing a vaccine against P. vivax malaria. In this study, we assessed the immunogenicity and protective efficacy of two P. vivax antigens, apical membrane antigen 1 (AMA1) and the 42-kDa C-terminal fragment of merozoite surface protein 1 (MSP142) in a plasmid recombinant DNA prime/adenoviral (Ad) vector boost regimen in Aotus monkeys. Groups of 4 to 5 monkeys were immunized with plasmid DNA alone, Ad alone, prime/boost regimens with each antigen, prime/boost regimens with both antigens, and empty vector controls and then subjected to blood-stage challenge. The heterologous immunization regimen with the antigen pair was more protective than either antigen alone or both antigens delivered with a single vaccine platform, on the basis of their ability to induce the longest prepatent period and the longest time to the peak level of parasitemia, the lowest peak and mean levels of parasitemia, the smallest area under the parasitemia curve, and the highest self-cure rate. Overall, prechallenge MSP142 antibody titers strongly correlated with a decreased parasite burden. Nevertheless, a significant proportion of immunized animals developed anemia. In conclusion, the P. vivax plasmid DNA/Ad serotype 5 vaccine encoding blood-stage parasite antigens AMA1 and MSP142 in a heterologous prime/boost immunization regimen provided significant protection against blood-stage challenge in Aotus monkeys, indicating the suitability of these antigens and this regimen for further development.

The Yin-Yang arms of vaccines: disease-fighting power versus tissue-destructive inflammation.

The disease-fighting power of vaccines has defeated many pathogens and has been credited with global reduction of mortality and morbidity. However, most vaccine developments focus on the enhancement of effector responses with systemic inflammation and the consequences overlooked. Recent evidence shows that systemic inflammatory phenotypes, acute or chronic, are both detrimental and should be avoided if possible. Since noninvasive vaccination by painless delivery of nasal vaccines and skin patch vaccines could elicit potent protective immunity without inducing systemic inflammation, it can be predicted that vaccinology will increasingly see the abandonment of the 'needle-injection' paradigm for vaccine development. The findings that specific viral particles could rapidly remodel the tissue environment postinfection in favor of some pathogens with the capacity to suppress others illustrate the pressing need for a deeper understanding of the underlying mechanisms in order to unlock the full potential of immunological intervention.

An adenovirus-vectored nasal vaccine confers rapid and sustained protection against anthrax in a single-dose regimen.

Bacillus anthracis is the causative agent of anthrax, and its spores have been developed into lethal bioweapons. To mitigate an onslaught from airborne anthrax spores that are maliciously disseminated, it is of paramount importance to develop a rapid-response anthrax vaccine that can be mass administered by nonmedical personnel during a crisis. We report here that intranasal instillation of a nonreplicating adenovirus vector encoding B. anthracis protective antigen could confer rapid and sustained protection against inhalation anthrax in mice in a single-dose regimen in the presence of preexisting adenovirus immunity. The potency of the vaccine was greatly enhanced when codons of the antigen gene were optimized to match the tRNA pool found in human cells. In addition, an adenovirus vector encoding lethal factor can confer partial protection against inhalation anthrax and might be coadministered with a protective antigen-based vaccine.

Perspectives on replication-incompetent nasal influenza virus vaccines.

Influenza is an emerging as well as resurging contagious disease with a worldwide impact on public health. Although broad administration of the licensed influenza virus (IFV) vaccines has mitigated the disease in many countries over the years, there are intrinsic problems associated with them. The study under evaluation reports that a novel PB2-knockout nonreplicating nasal IFV vaccine has been generated with the capacity to confer protection of mice against live IFV challenges. Moreover, an exogenous gene expressed from the bioengineered PB2-knockout IFV could elicit an immune response against the exogenous protein, showing its potential to deliver transgenes as a vector. The risk-benefit ratio of this new influenza vaccine vector is discussed.

Adenovirus-vectored drug-vaccine duo as a potential driver for conferring mass protection against infectious diseases.

The disease-fighting power of vaccines has been a public health bonanza credited with the worldwide reduction of mortality and morbidity. The goal to further amplify its power by boosting vaccine coverage requires the development of a new generation of rapid-response vaccines that can be mass produced at low costs and mass administered by nonmedical personnel. The new vaccines also have to be endowed with a higher safety margin than that of conventional vaccines. The nonreplicating adenovirus-vectored vaccine holds promise in boosting vaccine coverage because the vector can be rapidly manufactured in serum-free suspension cells in response to a surge in demand, and noninvasively administered by nasal spray into human subjects in compliance with evolutionary medicine. In contrast to parenteral injection, noninvasive mucosal vaccination minimizes systemic inflammation. Moreover, pre-existing adenovirus immunity does not interfere appreciably with the potency of an adenovirus-vectored nasal vaccine. Nasal administration of adenovirus vectors encoding pathogen antigens is not only fear-free and painless, but also confers rapid and sustained protection against mucosal pathogens as a drug-vaccine duo since adenovirus particles alone without transgene expression can induce an anti-influenza state in the airway. In addition to human vaccination, animals can also be mass immunized by this class of vectored vaccines.

Adenovirus-vectored drug-vaccine duo as a rapid-response tool for conferring seamless protection against influenza.

Few other diseases exert such a huge toll of suffering as influenza. We report here that intranasal (i.n.) administration of E1/E3-defective (ΔE1E3) adenovirus serotype 5 (Ad5) particles rapidly induced an anti-influenza state as a means of prophylactic therapy which persisted for several weeks in mice. By encoding an influenza virus (IFV) hemagglutinin (HA) HA1 domain, an Ad5-HA1 vector conferred rapid protection as a prophylactic drug followed by elicitation of sustained protective immunity as a vaccine for inducing seamless protection against influenza as a drug-vaccine duo (DVD) in a single package. Since Ad5 particles induce a complex web of host responses, which could arrest influenza by activating a specific arm of innate immunity to impede IFV growth in the airway, it is conceivable that this multi-pronged influenza DVD may escape the fate of drug resistance that impairs the current influenza drugs.

Avian influenza in ovo vaccination with replication defective recombinant adenovirus in chickens: vaccine potency, antibody persistence, and maternal antibody transfer.

Protective immunity against avian influenza (AI) can be elicited in chickens in a single-dose regimen by in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad)-vector encoding the AI virus (AIV) hemagglutinin (HA). We evaluated vaccine potency, antibody persistence, transfer of maternal antibodies (MtAb), and interference between MtAb and active in ovo or mucosal immunization with RCA-free recombinant Ad expressing a codon-optimized AIV H5 HA gene from A/turkey/WI/68 (AdTW68.H5(ck)). Vaccine coverage and intrapotency test repeatability were based on anti-H5 hemagglutination inhibition (HI) antibody levels detected in in ovo vaccinated chickens. Even though egg inoculation of each replicate was performed by individuals with varying expertise and with different vaccine batches, the average vaccine coverage of three replicates was 85%. The intrapotency test repeatability, which considers both positive as well as negative values, varied between 0.69 and 0.71, indicating effective vaccination. Highly pathogenic (HP) AIV challenge of chicken groups vaccinated with increasing vaccine doses showed 90% protection in chickens receiving > or = 10(8) ifu (infectious units)/bird. The protective dose 50% (PD50) was determined to be 10(6.5) ifu. Even vaccinated chickens that did not develop detectable antibody levels were effectively protected against HP AIV challenge. This result is consistent with previous findings ofAd-vector eliciting T lymphocyte responses. Higher vaccine doses significantly reduced viral shedding as determined by AIV RNA concentration in oropharyngeal swabs. Assessment of antibody persistence showed that antibody levels of in ovo immunized chickens continued to increase until 12 wk and started to decline after 18 wk of age. Intramuscular (IM) booster vaccination with the same vaccine at 16 wk of age significantly increased the antibody responses in breeder hens, and these responses were maintained at high levels throughout the experimental period (34 wk of age). AdTW68.H5(ch)-immunized breeder hens effectively transferred MtAb to progeny chickens. The level of MtAb in the progenies was consistent with the levels detected in the breeders, i.e., intramuscularly boosted breeders transferred higher concentrations of antibodies to the offspring. Maternal antibodies declined with time in the progenies and achieved marginal levels by 34 days of age. Chickens with high maternal antibody levels that were vaccinated either in ovo or via mucosal routes (ocular or spray) did not seroconvert. In contrast, chickens without MtAb successfully developed specific antibody levels after either in ovo or mucosal vaccination. These results indicate that high levels of MtAb interfered with active Ad-vectored vaccination.

Propionibacterium acnes CAMP factor and host acid sphingomyelinase contribute to bacterial virulence: potential targets for inflammatory acne treatment.

BACKGROUND: In the progression of acne vulgaris, the disruption of follicular epithelia by an over-growth of Propionibacterium acnes (P. acnes) permits the bacteria to spread and become in contact with various skin and immune cells. METHODOLOGY/PRINCIPAL FINDINGS: We have demonstrated in the present study that the Christie, Atkins, Munch-Peterson (CAMP) factor of P. acnes is a secretory protein with co-hemolytic activity with sphingomyelinase that can confer cytotoxicity to HaCaT keratinocytes and RAW264.7 macrophages. The CAMP factor from bacteria and acid sphingomyelinase (ASMase) from the host cells were simultaneously present in the culture supernatant only when the cells were co-cultured with P. acnes. Either anti-CAMP factor serum or desipramine, a selective ASMase inhibitor, significantly abrogated the P. acnes-induced cell death of HaCaT and RAW264.7 cells. Intradermal injection of ICR mouse ears with live P. acnes induced considerable ear inflammation, macrophage infiltration, and an increase in cellular soluble ASMase. Suppression of ASMase by systemic treatment with desipramine significantly reduced inflammatory reaction induced by intradermal injection with P. acnes, suggesting the contribution of host ASMase in P. acnes-induced inflammatory reaction in vivo. Vaccination of mice with CAMP factor elicited a protective immunity against P. acnes-induced ear inflammation, indicating the involvement of CAMP factor in P. acnes-induced inflammation. Most notably, suppression of both bacterial CAMP factor and host ASMase using vaccination and specific antibody injection, respectively, cooperatively alleviated P. acnes-induced inflammation. CONCLUSIONS/SIGNIFICANCE: These findings envision a novel infectious mechanism by which P. acnes CAMP factor may hijack host ASMase to amplify bacterial virulence to degrade and invade host cells. This work has identified both CAMP factor and ASMase as potential molecular targets for the development of drugs and vaccines against acne vulgaris.

Avian influenza mucosal vaccination in chickens with replication-defective recombinant adenovirus vaccine.

We evaluated protection conferred by mucosal vaccination with replication-competent adenovirus-free recombinant adenovirus expressing a codon-optimized avian influenza (AI) H5 gene from A/turkey/WI/68 (AdTW68.H5ck). Commercial, layer-type chicken groups were either singly vaccinated ocularly at 5 days of age, singly vaccinated via spray at 5 days of age, or ocularly primed at 5 days and ocularly boosted at 15 days of age. Only chickens primed and boosted via the ocular route developed AI systemic antibodies with maximum hemagglutination inhibition mean titers of 3.9 log2 at 32 days of age. In contrast, single vaccination via the ocular or spray routes maintained an antibody status similar to unvaccinated controls. All chickens (16/16) subjected to ocular priming and boosting with AdTW68.H5ck survived challenge with highly pathogenic AI virus A/chicken/Queretaro/14588-19/95 (H5N2). Single ocular vaccination resulted in 63% (10/16) of birds surviving the challenge followed by a 44% (7/16) survival of single-sprayed vaccinated birds. Birds vaccinated twice via the ocular route also showed significantly lower (P < 0.05) AI virus RNA concentrations in oropharyngeal swabs compared to unvaccinated-challenged controls.

Avian influenza vaccination in chickens and pigs with replication-competent adenovirus-free human recombinant adenovirus 5.

Protective immunity to avian influenza (AI) virus can be elicited in chickens by in ovo or intramuscular vaccination with replication-competent adenovirus (RCA)-free human recombinant adenovirus serotype 5 (Ad5) encoding AI virus H5 (AdTW68.H5) or H7 (AdCN94.H7) hemagglutinins. We evaluated bivalent in ovo vaccination with AdTW68.H5 and AdCN94.H7 and determined that vaccinated chickens developed robust hemagglutination inhibition (HI) antibody levels to both H5 and H7 AI strains. Additionally, we evaluated immune responses of 1-day-old chickens vaccinated via spray with AdCN94.H7. These birds showed increased immunoglobulin A responses in lachrymal fluids and increased interleukin-6 expression in Harderian gland-derived lymphocytes. However, specific HI antibodies were not detected in the sera of these birds. Because pigs might play a role as a "mixing vessel" for the generation of pandemic influenza viruses we explored the use of RCA-free adenovirus technology to immunize pigs against AI virus. Weanling piglets vaccinated intramuscularly with a single dose of RCA-free AdTW68.H5 developed strong systemic antibody responses 3 wk postvaccination. Intranasal application of AdTW68.H5 in piglets resulted in reduced vaccine coverage, i.e., 33% of pigs (2/6) developed an antibody response, but serum antibody levels in those successfully immunized animals were similar to intramuscularly vaccinated animals.

Non-replicating adenovirus vectors expressing avian influenza virus hemagglutinin and nucleocapsid proteins induce chicken specific effector, memory and effector memory CD8(+) T lymphocytes.

Avian influenza virus (AIV) specific CD8(+) T lymphocyte responses stimulated by intramuscular administration of an adenovirus (Ad) vector expressing either HA or NP were evaluated in chickens following ex vivo stimulation by non-professional antigen presenting cells. The CD8(+) T lymphocyte responses were AIV specific, MHC-I restricted, and cross-reacted with heterologous H7N2 AIV strain. Specific effector responses, at 10 days post-inoculation (p.i.), were undetectable at 2 weeks p.i., and memory responses were detected from 3 to 8 weeks p.i. Effector memory responses, detected 1 week following a booster inoculation, were significantly greater than the primary responses and, within 7 days, declined to undetectable levels. Inoculation of an Ad-vector expressing human NP resulted in significantly greater MHC restricted, activation of CD8(+) T cell responses specific for AIV. Decreases in all responses with time were most dramatic with maximum activation of T cells as observed following effector and effector memory responses.

Adenovirus as a carrier for the development of influenza virus-free avian influenza vaccines.

A long-sought goal during the battle against avian influenza is to develop a new generation of vaccines capable of mass immunizing humans as well as poultry (the major source of avian influenza for human infections) in a timely manner. Although administration of the currently licensed influenza vaccine is effective in eliciting protective immunity against seasonal influenza, this approach is associated with a number of insurmountable problems for preventing an avian influenza pandemic. Many of the hurdles may be eliminated by developing new avian influenza vaccines that do not require the propagation of an influenza virus during vaccine production. Replication-competent adenovirus-free adenovirus vectors hold promise as a carrier for influenza virus-free avian influenza vaccines owing to their safety profile and rapid manufacture using cultured suspension cells in a serum-free medium. Simple and efficient mass-immunization protocols, including nasal spray for people and automated in ovo vaccination for poultry, convey another advantage for this class of vaccines. In contrast to parenteral injection of adenovirus vector, the potency of adenovirus-vectored nasal vaccine is not appreciably interfered by pre-existing immunity to adenovirus.

Induction of mucosal immunity in the avian Harderian gland with a replication-deficient Ad5 vector expressing avian influenza H5 hemagglutinin.

The chicken Harderian gland (HG) plays an important role in adaptive immune responses upon ocular exposure to avian pathogens such as avian influenza (AI). To determine the role of HGs in generating immunity, chickens were immunized ocularly with an adenovirus (Ad5) vector expressing the AI hemagglutinin H5 gene. The Ad5-H5 vector induced H5 transgene expression and induced H5- and Ad5-specific IgA and IgG spot-forming cells (SFCs) in the HGs. The IgA and IgG SFC peaked on day 9 forAd5 and day 11 for the H5 protein. In addition, Ad5- and H5-specific antibodies were induced in serum. IgA in chicken tears was predominantly dimeric, while in serum monomeric IgA was most abundant. Analysis of HG mRNA confirmed expression of the polymeric immunoglobulin receptor (plgR). These data demonstrated the importance of HGs to generate mucosal and systemic immunity to AI following ocular Ad5-H5 administration to chickens.

Topical application of Escherichia coli particles over-producing pathogen-derived antigens as a simple vaccination modality in compliance with evolutionary medicine.

The development of a new generation of vaccines that can be produced rapidly at low costs and mass-administered noninvasively by non-medical personnel is crucial for boosting vaccine coverage in response to an escalation in demand. The demonstration that topical application of bioengineered nonreplicating Escherichia coli particles overproducing pathogen-derived antigens can mobilize the immune repertoire toward beneficial immune protection against relevant pathogens holds promise for enabling mass-immunization without pain, fear and perceivable tissue damage. Moreover, this noninvasive regimen using E. coli epitopes as a natural adjuvant is in compliance with evolutionary medicine.

Protection of chickens against avian influenza with non-replicating adenovirus-vectored vaccine.

Protective immunity against avian influenza (AI) virus was elicited in chickens by single-dose vaccination with a replication competent adenovirus (RCA)-free human adenovirus (Ad) vector encoding an H7 AI hemagglutinin (AdChNY94.H7). Chickens vaccinated in ovo with an Ad vector encoding an AI H5 (AdTW68.H5) previously described, which were subsequently vaccinated intramuscularly with AdChNY94.H7 post-hatch, responded with robust antibody titers against both the H5 and H7 AI proteins. Antibody responses to Ad vector in ovo vaccination follow a dose-response kinetic. The use of a synthetic AI H5 gene codon optimized to match the chicken cell tRNA pool was more potent than the cognate H5 gene. The use of Ad-vectored vaccines to increase resistance of chicken populations against multiple AI strains could reduce the risk of an avian-originating influenza pandemic in humans.

Automated mass immunization of poultry: the prospect for nonreplicating human adenovirus-vectored in ovo vaccines.

Automated in ovo vaccination is an efficient method for mass immunization of poultry. Although in ovo vaccination has been used to mass immunize chickens against several infectious diseases, there are common poultry diseases for which in ovo-compatible vaccines are not commercially available. It was recently demonstrated that in ovo administration of a nonreplicating human adenovirus vector encoding an avian influenza virus hemagglutinin induced protective immunity against highly pathogenic avian influenza. The advantages of this new class of poultry vaccine include in ovo delivery of a wide variety of pathogen-derived antigens, high potency in a single-dose regimen, rapid production in response to increased demand, no replication of the vector, no pre-existing immunity to human adenovirus in chickens, compatibility with automated in ovo administration and no interference with epidemiological surveys of natural infections.