Mechanism of action of mineral oil adjuvants. I. Conditions influencing the in vitro stability of water-in-oil emulsions

Genetic analysis of the influence of neuroantigen-complete Freund's adjuvant emulsion structures on the sexual dimorphism and susceptibility to experimental allergic encephalomyelitis

The induction of organ-specific autoimmune diseases, such as experimental allergic encephalomyelitis (EAE) the principal animal model of multiple sclerosis (MS), relies on the use of complete Freund's adjuvant (CFA) emulsions. In this study we report that the physical structure of the particles comprising neuroantigen-CFA emulsions significantly influences the genetic control of the incidence and sexual dimorphism seen in EAE. Immunization of (B10.S/SgMcdJ x SJL/J) F(2) mice segregating the quantitative trait loci (QTL) controlling EAE in susceptible SJL/J and resistant B10.S/SgMcdJ mice with emulsions consisting of particles where the Mycobacterium tuberculosis and neuroantigens are localized on the phase surfaces led to severe EAE in 98.8% of the mice, overriding all sex-specific and non-sex-specific genetic checkpoints. In contrast, F(2) mice immunized with emulsions where the bacterial products and encephalitogens are buried inside the water/oil vesicles exhibited a significant reduction in disease incidence (7.5%) and a sexual dimorphism (5% male versus 10% female). A genome scan identified QTL on chromosomes 7 and 11 controlling the sexual dimorphism as a function of the physical structure of the emulsion. The chromosome 11 QTL co-localizes with eae6b, and with Il12b and heptatitis A virus cellular receptor 2 (Havcr2, formerly known as Timd3), both of which are candidate genes for this QTL. Sequence analysis of the SJL/J and B10.S/SgMcdJ alleles indicates that both gene products are structurally monomorphic. Expression analysis also excluded both as candidates for this sex-specific QTL. These results reinforce the importance of gene-environment interactions in initiating and propagating autoimmune disease of the central nervous system, particularly in the context of susceptibility to MS and disease heterogeneity.

Vitamin C metabolism and atopic allergy

The procedure for carrying out the Leucocyte Ascorbic Acid Uptake Direct Antigen Challenge Test (LAADACT) is described. Leucocytes from normal individuals, when incubated in a buffered medium containing ascorbic acid, increase their ascorbic acid concentration by about 80%. When leucocytes from atopic individuals are incubated in a medium containing the antigen to which they are sensitive, as shown by positive skin tests, the leucocyte uptake of ascorbic acid is significantly reduced. Addition of antigen, to which atopic or normal individuals are not sensitive, to the incubation mixture does not reduce leucocyte ascorbic acid uptake. Measurement of ascorbic acid uptake into leucocytes is a relatively simple, routine, laboratory procedure. The LAADACT, therefore, provides a quick and accurate blood test for diagnosing sensitivity to specific antigens, and measuring relative antigenic sensitivities. The underlying mechanism of the LAADACT is discussed.