SEPPIC vaccine adjuvants for poultry.

Two inactivated antigens (Newcastle and Pasteurella Multocida) were formulated with different adjuvants and tested in two separate experiments in poultry. Oil formulations constituting water in oil (W/O) or water in oil in water (W/O/W) emulsions were assessed for antibody response, protection, local reactions, and vaccine physicochemical parameters. Robust, efficacious, and safe formulations were obtained with W/O formulations whereas W/O/W was especially safe with maintained efficacy. Results show that it is possible to improve traditional Tween Span formulations for safety and efficacy parameters by using Montanide ISA 70 for W/O formulations and Montanide ISA 206 for W/O/W when safety is the priority.

Montanide ISA 720 and 51: a new generation of water in oil emulsions as adjuvants for human vaccines.

The development of adjuvants will represent a major challenge for this century. Indeed the need for safer vaccines leads to the development of a new generation of antigens like synthetic peptide, recombinant proteins or even vectored DNA. However, this is to the detriment of their immunogenicity. The addition of adjuvant is becomes necessary to enhance immune responses and improve vaccine potency. However, adjuvants can be responsible for the apparition of secondary reactions and they must be adapted according to various criteria such as the route of immunization, the type of the immune response, the duration of immunity, or the quality of the antigen, in order to get the best balance between efficacy and safety.

Regulation by macromolecules of calcium oxalate crystal aggregation in stone formers.

Based on the structure of kidney stones, it is likely that they form as aggregations of preformed crystals, mostly calcium oxalate monohydrate (COM). In this study, we examined the ability of a macromolecular mixture isolated from the urine of normal individuals and stone formers to inhibit aggregation of preformed COM seed crystals in a simple ionic solution using measurements of changes in the particle size distribution (PSD) of preformed COM crystal aggregates. We also examined the effect in this assay of a number of synthetic homopolymers, naturally occurring urine macromolecules, and binary mixtures thereof. The macromolecular mixtures from urine of normals and most stone formers reduced the degree of aggregation of the seed crystals, whereas 22% of stone former urine macromolecules either did not disaggregate or actually promoted further aggregation. Stone formers within one family shared this property, but a non-stone forming sibling did not. Polyanions, either synthetic or naturally occurring, induced disaggregation to an extent similar to that exhibited by normal urine macromolecules, while polycations had no effect on the PSD. However, mixing a polyanion, either poly-aspartate or osteopontin, with the polycation poly-arginine, changed their behavior from disaggregation to aggregation promotion. The disaggregating behavior of normal urinary macromolecules provides a defense against aggregation, but a minority of stone forming individuals lacks this defense, which may contribute to stone formation.

Application of statistical design of experiments to the optimization of factor VIII expression by CHO cells.

Selection and optimization of the concentrations of chemically defined components effective on recombinant factor VIII:C production by CHO cells have been performed with statistically designed experiments. Screening of efficient compounds on factor VIII expression was performed by using HADAMARD method, while a precise optimization of the concentrations of two components was achieved with the help of DOEHLERT method. Increased specific activity of factor VIII and reduced cost medium have been obtained with a fewer number of experiments than compared to a less rational approach.

Adjuvants designed for veterinary and human vaccines.

Adjuvants play an important role in the efficacy of vaccines as the antigens become more and more purified. Indeed recombinant proteins or synthetic peptides are safer than crude inactivated micro-organism, but less immunogenic. This can be balanced by specific adjuvants. But there is no universal adjuvants and their action is not yet clear and rely on different mechanisms. Then, they must be adapted according to several criteria, like the target species, the antigens, the type of immune response, the route of inoculation, or the duration of immunity. For this purpose different type of emulsions have been developed. Water in oil (W/O) emulsions induce a strong and long term immune response. Those based on mineral oils are known to be very efficient but can sometimes induce local reactions with reactive antigens. Non mineral oils are well tolerated but less efficient with poor immunogens. Multiphasic (W/O/W) emulsions can induce short and long term immune responses with various antigens and oil in water (O/W) emulsions are well tolerated and induce a short term immune response. New generation of adjuvants are based on a new concept called 'immunosol' and stem from the association of nanoparticles with a new immunostimulant. They can be used when emulsions are not suitable to obtain a good balance between safety and immunogenicity.

Enhancement of the efficacy of a replication-defective adenovirus-vectored vaccine by the addition of oil adjuvants.

We previously constructed a recombinant adenovirus with a defective E1A gene, which expresses high levels of the pseudorabies virus gp50 in non-transcomplementing cells. The virus is unable to replicate in mice. It elicited the production of anti-gp50 antibodies only when high concentrations (10(8) TCID50 per dose) of the virus were used and it gave mice little protection. The combination of the recombinant adenovirus at several concentrations (10(8), 10(7.4), 10(6.4) TCID50 per dose) with certain oil adjuvants in different galenic forms (water-in-oil, oil-in-water, water-in-oil-in-water) led to an increase in specific antibody responses and protection for the host when challenged with a virulent pseudorabies virus under very severe conditions, i.e. where 100% of unvaccinated mice died. A water-in-oil-in-water formulation induced a very high level of anti-gp50 antibodies even with a low concentration of adenovirus. These results could be correlated to the induction of cytokines, such as IL6, which is observed with this galenic form. The oil-adjuvanted emulsions induced IL2, suggesting that they were able to activate T-helper cells. Different oil formulations elicited the different IgG subclasses (IgG1, IgG2a, IgG2b, IgG3). These results can be extended to other live replication-defective vaccines expressing different proteins.

Production of recombinant Von Willebrand factor by CHO cells cultured in macroporous microcarriers.

Recombinant Chinese hamster ovary cells producing Von Willebrand factor have been successfully grown in gelatin macroporous microcarriers (Cultispher-G). Serum-free cultures were maintained in 1, 4, and 10 liter fermentors for more than two months. Comparative studies with Cytodex-3 microcarriers have been performed in 1 liter fermentors. The lower specific Von Willebrand factor productivity of CHO cells cultivated on Cultispher-G were offset by higher cell densities (10(7) - 2 x 10(7) cells/ml). Volumetric Von Willebrand factor productivity was influenced by oxygen concentration, and remained stable during scale-up from 1 to 10 liter fermentors.