Prepared and screened a modified TNF-α molecule as TNF-α autovaccine to treat LPS induced endotoxic shock and TNF-α induced cachexia in mouse

Overexpression of TNF-alpha in the body is critically involved in many diseases. A strategy to construct TNF-alpha autovaccine by introducing a T cell helper epitope to the protein has been developed and may be an alternative because it is cheaper and highly efficient. However, the induction of high level anti-TNF-alpha neutralizing autoantibodies by TNF-alpha autovaccine is depend on a proper T cell help epitope. In order to evaluate the effect of different T helper cell epitopes on the immunogenicity of mouse TNF-alpha (mTNF-alpha), three T helper cell epitopes, TT (QYIKANSKFIGITEL), HEL (NTDGSTDYGILQINSR), and PADRE (AKFVAAWTLKA), were chosen for this study. The sequence (amino acids 126-140) of mTNF-alpha was replaced with those of the T cell help epitopes, respectively. The three fusion proteins (mTNF-TT, mTNF-HEL, mTNF-PADRE) were expressed in Escherichia coli and purified with a simple strategy. The abilities of the proteins elicited TNF-alpha autoantibodies in BALB/c mice were investigated. The results showed that mTNF-PADRE is the most effective among the three modified TNF-alpha molecules. In the absence of adjuvant, the therapeutic effect of TNF-PADRE on LPS induced endotoxic shock mice and mTNF-alpha induced cachexia mice was observed. This study suggests that mTNF-PADRE may be a better candidate of mTNF-alpha autovaccine.

Intranasal delivery: physicochemical and therapeutic aspects

Interest in intranasal (IN) administration as a non-invasive route for drug delivery continues to grow rapidly. The nasal mucosa offers numerous benefits as a target issue for drug delivery, such as a large surface area for delivery, rapid drug onset, potential for central nervous system delivery, and no first-pass metabolism. A wide variety of therapeutic compounds can be delivered IN, including relatively large molecules such as peptides and proteins, particularly in the presence of permeation enhancers. The current review provides an in-depth discussion of therapeutic aspects of IN delivery including consideration of the intended indication, regimen, and patient population, as well as physicochemical properties of the drug itself. Case examples are provided to illustrate the utility of IN dosing. It is anticipated that the present review will prove useful for formulation scientists considering IN delivery as a delivery route.

Cationic supported lipid bilayers for antigen presentation

Polystyrene sulfate (PSS) particles (301 nm mean diameter) were covered with single cationic dioctadecyldimethylammonium bromide (DDA) bilayers and used for antigen adsorption and presentation. The antigen was a mixture of purified 18/14 Taenia crassiceps proteins (18/14-Tcra). Firstly, the DDA/PSS assembly was characterized at 1mM NaCl and 5 x 10(9) PSS particles/mL over a range of DDA concentrations (0.001-1mM) by means of dynamic light scattering for particle sizing and zeta-potential analysis. 0.01 mM DDA is enough to produce homodisperse and cationic bilayer-covered particles. Secondly, under these experimental conditions, 18/14-Tcra adsorption isotherms onto biomimetic particles or aluminium hydroxide (Al(OH)3) yield limiting adsorption of 0.36 and 1.32 mg protein/mg biomimetic particles or Al(OH)3, respectively. Finally, in mice, superior humoral and cellular immunoresponse from serum IgG and footpad swelling was obtained for antigen/biomimetic particles in comparison to conventional Al(OH)3. Cationic bilayer-covered particles are a novel, highly organized and, possibly, general immunoadjuvant for antigen presentation and subunit vaccine design.

Adaptations of nanoscale viruses and other protein cages for medical applications

Nanosized materials (5-100 nm) with multiple functionalities (cell targeting, drug delivery, and bio-imaging) have emerged over the recent years as promising therapeutic agents. Liposomal carriers, amphiphilic co-polymers, silica-based particles, colloidal systems, and dendrimer clusters are among the many available nanoscale scaffolds that have been explored for medical applications such as gene delivery, bio-imaging, and drug delivery. On the other hand, viruses, ferritin, and other protein cages for ages have self-organized in the nanometer range with biologically relevant functionalities. These bio-inspired systems form monodispersed units that are highly amendable through genetic and chemical modifications. In this review the expansion of these protein-based nanosystems, termed bionanoparticles (BNPs), beyond their native functionalities, and their application as building materials for nanomedicine will be discussed. The recent developments of biology-inspired systems with potential medical applications will be outlined, with particular emphasis on adaptations of protein-based nanostructures for gene delivery, bio-imaging, drug encapsulation, and vaccine development. Notable systems already streamlined for medical applications are recombinant virus-like particles derived from human papillomaviruses as multivalent vaccine carriers to immunize patients against genital infections, and vaccinia viruses to treat patients with established cancers.

Tolerance and immunological changes of chemically modified allergen vaccine of Parietaria judaica in accelerated schedules

The physicochemical modification of allergen vaccines provides a chance for administering higher doses in a shorter period of time. We sought to assess the safety and immunological changes of using a biologically standardized and modified Parietaria judaica pollen extract in accelerated schedules. Two accelerated schedules were tested in 45 P. judaica-allergic patients: 20 patients reached the maximum dose after two visits using two different concentrations and 25 patients reached the maximum dose after only one visit with two injections of the maximum concentration vial. The tolerance was assessed by recording all side effects related with immunotherapy. Specific antibody levels against native extract and rPar j 2 allergen were evaluated at the beginning and the end of the study. Allergenic potency determined by enzyme allergosorbent test (EAST) inhibition and skin prick test showed that modified P. judaica pollen had a 99.9% less allergenicity than native extract. After 650 doses administered, two clinically irrelevant local reactions (diameter<0 x 5 cm) and no systemic reactions were registered. Significant increases in allergen-specific IgG4 and IgG against P. judaica extract and rPar j 2 and significant decrease of specific IgE against Par j 2 were observed. The modified extract of P. judaica is safe to treat sensitive patients, even at accelerated regimens, and induces significant immunological changes.

Antibody-catalyzed anaerobic destruction of methamphetamine

Methamphetamine [(+)-2] abuse has emerged as a fast-rising global epidemic, with immunopharmacotherapeutic approaches being sought for its treatment. Herein, we report the generation and characterization of a monoclonal antibody, YX1-40H10, that catalyzes the photooxidation of (+)-2 into the nonpsychoactive compound benzaldehyde (14) under anaerobic conditions in the presence of riboflavin (6). Studies have revealed that the antibody facilitates the conversion of (+)-2 into 14 by binding the triplet photoexcited state of 6 in proximity to (+)-2. The antibody binds riboflavin (K(d) = 180 muM), although this was not programmed into hapten design, and the YX1-40H10-catalyzed reaction is inhibited by molecular oxygen via the presumed quenching of the photoexcited triplet state of 6. Given that this reaction is another highlight in the processing of reactive intermediates by antibodies, we speculate that this process may have future significance in vivo with programmed immunoglobulins that use flavins as cofactors to destroy selectable molecular targets under hypoxic or even anoxic conditions.

Mucosal vaccine targeting improves onset of mucosal and systemic immunity to botulinum neurotoxin A

Absence of suitable mucosal adjuvants for humans prompted us to consider alternative vaccine designs for mucosal immunization. Because adenovirus is adept in binding to the respiratory epithelium, we tested the adenovirus 2 fiber protein (Ad2F) as a potential vaccine-targeting molecule to mediate vaccine uptake. The vaccine component (the host cell-binding domain to botulinum toxin (BoNT) serotype A) was genetically fused to Ad2F to enable epithelial binding. The binding domain for BoNT was selected because it lies within the immunodominant H chain as a beta-trefoil (Hcbetatre) structure; we hypothesize that induced neutralizing Abs should be protective. Mice were nasally immunized with the Hcbetatre or Hcbetatre-Ad2F, with or without cholera toxin (CT). Without CT, mice immunized with Hcbetatre produced weak secretory IgA (sIgA) and plasma IgG Ab response. Hcbetatre-Ad2F-immunized mice produced a sIgA response equivalent to mice coimmunized with CT. With CT, Hcbetatre-Ad2F-immunized mice showed a more rapid onset of sIgA and plasma IgG Ab responses that were supported by a mixed Th1/Th2 cells, as opposed to mostly Th2 cells by Hcbetatre-dosed mice. Mice immunized with adjuvanted Hcbetatre-Ad2F or Hcbetatre were protected against lethal BoNT serotype A challenge. Using a mouse neutralization assay, fecal Abs from Hcbetatre-Ad2F or Hcbetatre plus CT-dosed mice could confer protection. Parenteral immunization showed that the inclusion of Ad2F enhances anti-Hcbetatre Ab titers even in the absence of adjuvant. This study shows that the Hcbetatre structure can confer protective immunity and that use of Hcbetatre-Ad2F gives more rapid and sustained mucosal and plasma Ab responses.

Progress in the development of Fasciola hepatica vaccine using recombinant fatty acid binding protein with the adjuvant adaptation system ADAD

Fatty acid binding proteins (FABP) have been designed as a potential vaccine against fasciolosis. In this work, the immunoprophylaxis of the recombinant Fh15 FABP from F. hepatica (Fh15) in adjuvant/immunomodulator ADAD system was evaluated using mice and sheep challenged with F. hepatica. The ADAD system combines the Fh15 antigen with an immunomodulator (hydroalcoholic extract of Polypodium leucotomos; PAL) and/or an adjuvant (saponins of Quillaja saponaria; Qs) in a water/oil emulsion (30/70) with a non-mineral oil (Montanide). All the infected control mice died by 41-48 days post-infection. The mice vaccinated with ADAD only with PAL+Fh15 present a survival rate of 40-50% and those vaccinated with ADAD containing PAL+Qs+Fh15 had a survival rate of 50-62.5%. IgG1 antibodies were lower in surviving mice in comparison with non-surviving mice. The sheep vaccinated with ADAD PAL+Qs+Fh15 showed lower fluke recovery (43%), less hepatic lesions and higher post-infection daily weight gain than F. hepatica infected control animals. Thus, the ADAD system using recombinant fatty acid binding proteins from F. hepatica could be a good option to develop vaccines against F. hepatica.

Economic and practical challenges to the formulation of vaccines against endemic infectious diseases such as malaria

Herein, we analyze in general the current vaccine market and identify potential factors driving and modulating supply and demand for vaccines. An emphasis is placed on changes in regulation in the last 20 years which have led to increased indirect costs of production, and which can create a barrier against the timely use of technological advances to reduce direct costs. Other defining industry characteristics, such as firm numbers and sizes, cost and pricing strategies, nature extent and impact of Government involvement and international regulation are noted. These considerations, far from being removed from basic vaccine research, influence its ability to achieve aims that can be then progressed into effective vaccine products. We discuss specifically the development of particulate vaccines against malaria, a major lethal disease and health problem prevalent in Africa, including some key economic and methodological challenges and opportunities. We note some practical issues blocking the development of effective particulate vaccines for the Third World, mainly driven by the regulatory spiral noted above.

Drug evaluation: CYT-002-NicQb, a therapeutic vaccine for the treatment of nicotine addiction

Cytos Biotechnology AG is developing an intramuscular therapeutic vaccine, CYT-002-NicQb (also known as nicotine-Qbeta), based on its Immunodrug (formerly known as alpha vaccine) nicotine-specific antibody-generating technology, for the potential treatment of nicotine addiction. A phase II trial was initiated in Switzerland in January 2005 and in February 2006, Cytos Biotechnology announced that it planned to begin a phase IIb/III trial in 2007.

Pollinex® Quattro Ragweed: safety evaluation of a new allergy vaccine adjuvanted with monophosphoryl lipid A (MPL®) for the treatment of ragweed pollen allergy

A novel allergy vaccine (Pollinex Quattro Ragweed) has been developed for the prevention or relief of allergic symptoms caused by pollen from Ambrosia spp. (ragweed). An extract from the pollen (chemically modified by glutaraldehyde) is adsorbed onto l-tyrosine with addition of the immunostimulatory adjuvant, monophosphoryl lipid A (MPL). A specific preclinical safety testing strategy was developed to support clinical use and comprised reference to preclinical data available for the marketed non-MPL adjuvanted form of the ragweed vaccine (Pollinex R) and a new repeat dose toxicity study in the rat. Studies with Pollinex R comprised single dose subcutaneous toxicity studies in mice and rats, repeat dose (10 injections over 20 days) parenteral toxicity studies in rats and dogs, an in vitro gene mutation assay along with single and multiple injection local tolerance studies in rats and dogs. The repeat dose subcutaneous toxicity study with Pollinex Quattro Ragweed involved seven injections over 3 weeks (which was more aggressive than the four weekly doses used in the clinic) with dose levels of up to 0.5 ml per animal used. Overall, the product showed no toxicological findings of significance at levels greatly in excess of those proposed for clinical use. As is a feature with vaccination, some dose site irritation was seen.

Targeting dendritic cells with biomaterials: developing the next generation of vaccines

Current vaccine and immunotherapy technology faces ongoing challenges in both efficacy and practicality: many chronic diseases cannot yet be addressed by vaccination, and several vaccines that do function well require multiple injections, which is a substantial limitation in various parts of the world. A possible key to developing the next generation of vaccines is the ability to deliver antigen to dendritic cells (DCs) more specifically and induce the subsequent activation of T-cell immunity. However, antigen delivery to, and activation of, DCs is a complex problem, involving antigen transport to DC-rich areas, DC binding and antigen uptake, and antigen processing and presentation. Addressing these challenges requires novel and multidisciplinary approaches, for example, the application of biomaterials to immunotechnology. Here, we review the latest advances in biomaterial drug vehicles, such as polymer microparticles and nanoparticles, and liposomes, that are being used to target DCs in new strategies for vaccination.

Novel vaccines and adjuvants for allergen-specific immunotherapy

Advances in genetic engineering and biotechnology, in parallel to increased understanding of disease processes and mechanisms of protective immunity, have facilitated the development of novel rational vaccination concepts for allergy. The spectrum ranges from utilizing recombinant proteins, peptides, new adjuvants, immunomodulatory therapy and DNA vaccines, to use of new application routes for both prophylaxis and treatment of allergic disease. New therapeutic concepts based on patient-tailored immunotherapy using recombinant allergens, anti-IgE and sublingual immunotherapies are slowly moving from the bench to the clinics. The additive value of new treatments above existing therapies must be, however, focused on the improvement of efficacy for long-term cure and increased patient compliance to warrant a broad applicability that has to compete with the symptomatic control of allergic and asthmatic diseases of currently available drugs.

Potentiation of the immune response to non-adsorbed antigens by aluminum-containing adjuvants

The degree of antigen adsorption by aluminum-containing adjuvants is considered an important characteristic of vaccines that is related to immunopotentiation by the adjuvant. This study examined immunopotentiation by aluminum phosphate adjuvant in three model vaccines in which the antigen was not adsorbed in the vaccine formulation nor when mixed in vitro with interstitial fluid. In the first model vaccine, aluminum phosphate adjuvant was pre-treated with 0.5 M KH2PO4 to minimize the adsorption of dephosphorylated alpha casein. The second model vaccine was composed of aluminum phosphate adjuvant and ovalbumin that was dephosphorylated by treatment with potato acid phosphatase. The third model vaccine consisted of aluminum phosphate adjuvant and lysozyme (LYS). In order to prevent adsorption of lysozyme, the aluminum phosphate adjuvant was pre-treated with fibrinogen, a protein present in interstitial fluid that binds strongly to aluminum phosphate adjuvant. Immunopotentiation was evaluated by measuring antibody production in mice. It was found that all three model vaccines induced antibody titers that were statistically higher than induced by a solution of antigen without adjuvant and similar to vaccines in which the antigens were adsorbed by aluminum phosphate adjuvant. Confocal microscopy experiments suggested that the antigens used in these experiments, even though not adsorbed to the aluminum phosphate adjuvant, were trapped in void spaces within the adjuvant aggregates, resulting in uptake of antigen by dendritic cells.

Development of a novel vaccine delivery system based on Gantrez nanoparticles

The adjuvant capacity of a novel vaccine vector "Gantrez-nanoparticles" (NP) towards coated or encapsulated ovalbumin (OVA) was investigated. OVA nanoparticles were prepared by a solvent displacement method previously described. The protein was incorporated during the manufacturing process (OVA-encapsulated nanoparticles) or after the preparation (OVA-coated nanoparticles). The mean size of the different nanoparticle formulations was lower than 300 nm, and the OVA content ranged approximately from 67 microg/mg nanoparticles (for OVA-coated nanoparticles) to 30 microg/mg nanoparticles (for OVA-encapsulated nanoparticles). All the OVA-NP formulations were capable of amplifying the antibodies titres (IgG1 and IgG2a) in mice after a single subcutaneous inoculation with respect free OVA or OVA adsorbed to Alum. Furthermore, the elicited response was, for some formulations, predominantly Th1 subtype. Thus, the formulation that contained mainly the antigen inside, and with a low concentration of cross-linking agent, displayed the best potential to induce a Th1 response after 35 days post-immunisation. These results are highly suggestive for the use of Gantrez nanoparticles as an efficient antigen delivery system, especially when a long lasting Th1 cytokine response is required.

[Recent advances in liposomes and nanoparticles as drug carriers for drug delivery]

Liposomes and nanoparticles have been used as drug carriers to increase solubility, prolong drug duration in vivo, target drug delivery, reduce toxicity and combat multi-drug resistance. With major advances in the preparation techniques, preparation material, and surface modifiers in recent years, liposomes and nanoparticles delivery systems have achieved success in fields including cancer therapy, overcoming biological barriers, and biological drugs and vaccine carriage.

Emulsifier content and side effects of oil-based adjuvant vaccine in swine

Side effects caused by the excessive emulsifier in oil-based adjuvant vaccine were examined practically in swine using one oil-in-water type adjuvant vaccine against swine pleuropneumonia. The vaccine was prepared from cell-free-antigen of Actinobacillus pleuropneumoniae, liquid paraffin, and several polyoxyethylenesorbitan and sorbitan oleates. Based on findings about safety in mice and emulsion stability, 2 vaccines containing either 11.25% or 6.25% emulsifier content were injected intramuscularly twice in swine, as the highest and lowest limits, respectively, within the practical range. All pigs showed temporary fever and malaise with anorexia for several days after each injection. The fever of the higher emulsifier content group took significantly longer to recover than the lower. Malaise also showed a similar tendency. On the other hand, antibody response was sufficiently induced with no significant difference between the 2 groups. Lowering the emulsifier content is a very simple but effective solution for mitigation of side effects without the reduction of adjuvanticity. For safe and high-quality oil-based adjuvant vaccines, not only antigen and base-oil, but emulsifier content must be optimized.

Vaccination and anaphylaxis

The incidence of anaphylactic or severe allergic reactions to vaccines is very low, less than one case per million vaccine doses. Larger studies from later years report no deaths. The cause of the reaction is usually not the immunizing antigen itself, but rather some other vaccine ingredient such as egg protein from the production process or gelatin added as a stabilizer. Most people with egg allergy can be vaccinated without any reaction. Vasovagal reactions with or without hyperventilation are common after vaccination. They can be rather dramatic and are often mistaken for anaphylactic reactions. Correct diagnosis is important in making it possible to vaccinate those who might otherwise run the risk of serious infections.

Liposomes and Micro/Nanoparticles as Colloidal Carriers for Nasal Drug Delivery

The use of the nasal route for drug delivery has attracted much interest in recent years in the pharmaceutical field. Local and principally systemic drug delivery can be achieved by this route of administration. But the nasal route of delivery is not applicable to all drugs. Polar drugs and some macromolecules are not absorbed in sufficient concentration due to poor membrane permeability, rapid clearance and enzymatic degradation into the nasal cavity. Thus, alternative means that help overcome these nasal barriers are currently in development. Absorption enhancers such as phospholipids and surfactants are constantly used, but care must be taken in relation to their concentration. Drug delivery systems including liposomes, cyclodextrins, micro- and nanoparticles are being investigated to increase the bioavailability of drugs delivered intranasally. This review article discusses recent progress and specific development issues relating to colloidal drug delivery systems in nasal drug delivery.

Stable liquid vaccines and drugs for the 21st century

Cambridge Biostability Ltd has developed stable, dry formulations of vaccines and drugs that contain the actives stabilized in water-soluble glass, together with systems to automate their injection and reactivation. One generic process consists of stabilized actives in glass microspheres, which are suspended in biocompatible anhydrous liquids where they do not dissolve, forming two-phase liquids. When injected, the glass microspheres dissolve in body water, releasing potent vaccines, and the anhydrous liquids are either exhaled in the breath or rapidly metabolized. These stable liquid formulations can be stored at a high temperature for at least 3 years, are completely resistant to freeze damage and can be injected without any preparation at the point of use. This is facilitated by a simple, cheap, disposable injection device that requires no training to use yet safely injects the vaccine without a visible needle. This device can be used with conventional liquid vaccines as well as with the stable liquid vaccines described herein. A second process stores the vaccines in a delicate web of glass impregnated in a fibrous membrane in the hub of a hypodermic needle. The vaccine is automatically redissolved and flushed into the patient when the needle is attached to a syringe and 0.5 ml of sterile saline is injected. These products promise to radically improve the way vaccinations and therapeutic drugs are delivered worldwide.

Using TEM to couple transient protein distribution and release for PLGA microparticles for potential use as vaccine delivery vehicles

In the development of tunable PLGA microparticles as vaccine delivery vehicles, it is important to understand the drug distribution within the microparticle over time as well as the long-term release of the drug during polymer degradation. This study addresses the transient 3-D drug distribution in PLGA microparticles during in vitro degradation. Specifically, poly (lactide-co-glycolide) (PLGA 75:25) microparticles containing ovalbumin (OVA) as a model protein were fabricated by double-emulsion (w/o/w) method. The microparticles were incubated at 37 degrees C and 250 rpm in PBS buffer (pH 7.4) over a 100-day period. The in vitro polymer erosion, transient protein distribution profiles and protein release behaviors were investigated. Protein release profiles were determined via spectrophotometry using a BCA assay for the solution. Transmission electron microscopy (TEM) images were obtained for the OVA-loaded microparticles before and during degradation (0 day, 30 days and 60 days), and the corresponding 3-D constructions were developed. From the 3-D constructions, the overall protein distribution of the entire microparticle was vividly reflected. Pixel number analysis of the TEM images was used to quantify transient protein distribution. The transient protein release obtained from the TEM analysis was in good agreement with the BCA analysis. This technique provides an additional tool in helping develop polymer matrices for tunable delivery vehicles in vaccination and other drug delivery scenarios.

Dose sparing of CpG oligodeoxynucleotide vaccine adjuvants by nanoparticle delivery

The main objective of these studies was to investigate whether the nanoparticle delivery has any immunopotentiation effect at modest doses of a few micro- or nanograms of CpG oligodeoxynucleotide (CpG ODN) and what would be the influence on T cell responses at such low doses. Various doses (5 to 0.05 microg) of a model CpG ODN adjuvant (#1826) along with 2 Lf tetanus toxoid (TT) were formulated in either nanoparticles using poly(D,L-lactic-co-glycolic acid) (PLGA) 50:50 co-polymer, or saline. Strong antigen specific ex vivo T cell proliferation was observed for the Balb/c mice receiving immunogens in nanoparticles. At 5 microg dose of CpG ODN, the T cell stimulation index (SI) was 241 as compared with 74 for the same dose when given in saline. Comparable SI value of 78 was observed at 100-fold lower dose (0.05 microg) using nanoparticles. Similarly, significantly higher (P<0.01) cytokine secretion was observed for nanoparticles groups. A ten-fold lower dose (0.5 microg instead of 5 microg) of CpG ODN in nanoparticles was adequate to obtain levels of IFN-gamma, TNF-alpha, and IL-2 comparable to those observed following immunisations in saline. The immunopotentiation effect of the particulate delivery on antibody response (total IgG and subtypes) was not so marked. These studies emphasise that antigen delivery in biodegradable nanoparticles can facilitate induction of strong T cell responses, particularly of the Th1 type, at extremely lower doses of CpG ODN. Such reduction in the effective dose would be advantageous for minimising the potential side effects of these novel adjuvants.