Systematic development of a block copolymer adjuvant for trivalent influenza virus vaccine

The current influenza virus vaccines induce systemic humoral immunity and short lived cellular immunity in young adults. Unfortunately these vaccines are only 50% efficacious in the elderly (> 65 years) and high risk groups of the very young. The use of a vaccine adjuvant to correct this deficit would therefore be very beneficial to these population groups. We have developed high molecular weight synthetic non-ionic block copolymers with adjuvant activity. These copolymers are compatible with, and active in, aqueous, physiological formulations in which they spontaneously assemble into 500-3000 nm particles. By varying both the molecular weight and the proportions of hydrophilic and hydrophobic components of the molecule, we have designed the optimal copolymer adjuvant for use with influenza hemagglutinin. This copolymer, termed CRL-1005, was investigated for its ability to augment the immune response of mice to the commercially-available human influenza vaccine, Fluogen. Co-formulation of CRL-1005 with the vaccine resulted in markedly increased antibody titres measured by both ELISA and the functional haemagglutination inhibition assay, indicating that critical immunogen epitopes were not destroyed. A single dose of copolymer and vaccine produced both long term rising antibody titres (six months) and primed for a potent secondary response. This high molecular weight copolymer is non-toxic and should therefore be well suited for widespread use.

Development of an adjuvant-active nonionic block copolymer for use in oil-free subunit vaccines formulations

Nonionic block copolymers, synthesized from repeating units of oxypropylene and oxyethylene, can be designed so that individual copolymers have unique physical properties with differential levels of adjuvant activity. We have designed high molecular weight block copolymers that spontaneously assemble into 500 nm-3 mum particles when formulated with protein antigens in aqueous solutions at physiological pH. The adjuvant activity of one of these copolymers, termed CRL1005, was compared to selected research adjuvants using ovalbumin (OVA) as the prototype vaccine antigen. Suboptimal doses of OVA were formulated with complete and incomplete. Freund's adjuvant (CFA/IFA), alum Quil-A saponins Ribi Adjuvant System (RAS) or the CRL1005 copolymer and these formulations were used to immunize C57BL/6 mice. The CRL1005 copolymer appeared to be more potent than either Quil-A or alum and comparable to the RAS formulation, based on the numbers of responding mice and the OVA-specific antibody titers. Alum. RAS and Quil-A all augmented the production of IgG1 and IgG2l, similarly whereas only the CFA/IFA boosted IgG2a levels significantly. The effect of adjuvants on relative antibody affinity was more variable with the CRL1005 and CFA/IFA inducing antibodies with the highest affinity scores. This high molecular weight nonionic copolymer is nontoxic in aqueous formulations and should therefore be compatible with a wide variety of protein or polysaccharide vaccine antigens.

Breeding and offspring rearing ability of C57BL/6J dystrophic mice

The antiepileptic drug phenytoin, administered in drinking water for 104 days, was used to reduce the neural overactivity (pseudomyotonia) of C57BL/6J dystrophic (dy2J/dy2J) male mice in an attempt to improve their breeding success over a 90-day period. Male dy2J/dy2J mice have difficulty in successfully mounting females due to the pseudomyotonia affecting their hindlimb musculature. Breeding success, as judged by litter frequency, of dy2J/dy2J males receiving phenytoin (5 micrograms/ml serum) was compared with untreated dy2J/dy2J and phenotypically normal (+/?) male and female mice. Phenytoin did not enhance male dy2J/dy2J breeding success. Based on dy2J/dy2J crosses with +/? animals, the dy2J/dy2J female was a more successful breeder than the dy2J/dy2J male. In terms of litter frequency, litter size, and offspring birth weight, dy2J/dy2J females (age 8-21 wks.) bred as efficiently as +/? females of the same age. Dystrophic females were deficient in offspring rearing capabilities as evidenced by lower offspring survival rates and weaning weights.

Chronic phenytoin administration alters the metabolic profile of superficial gastrocnemius muscle fibers in dystrophic mice

Phenytoin is known to reduce neural overactivity (pseudomyotonia) affecting the hind limb musculature in C57B1/6J dystrophic (dy2J/dy2J) mice. This study reports a change in the metabolic profile of superficial gastrocnemius muscle fibers from dy2J/dy2J animals after chronic phenytoin treatment. The superficial gastrocnemius muscle region from normal mice is composed of 98% fast-twitch glycolytic muscle fibers. In dystrophic mice these fibers (FG) show increased oxidative capacity without evidence of morphologic degeneration during the first few months ex utero. Many of these fibers also store abnormally large amounts of glycogen as determined by periodic acid-Schiff histochemistry. After 104 days of phenytoin treatment, the dy2J/dy2J FG muscle fibers showed a reduction in abnormally high oxidative capacity as monitored by succinic dehydrogenase activity; there was also a reduction of glycogen storage in a number of dy2J/dy2J fibers. One hypothesis suggests that the increase in oxidative capacity of the dy2J/dy2J superficial gastrocnemius muscle fibers is the expected result of overstimulation by the pseudomyotonia. Our experiments indicated that the abnormal metabolic profile observed in those fibers can be altered simply by a reduction in pseudomyotonia. These results mimic those seen after short-term denervation of the same dy2J/dy2J muscle. After phenytoin treatment the mean dy2J/dy2J superficial gastrocnemius muscle fiber cross-sectional area was significantly increased compared with untreated animals. Cursory examination of the degenerated deep region of this same muscle suggested that similar changes did not occur after drug treatment. This suggests that the pseudomyotonia was partially different from the factor(s) causing early degeneration of the oxidative muscle fibers in the dy2J/dy2J animals.