The relative immunodominance of haptenic determinants on a complex hapten phage conjugate

Immunodominance and Immunodomination: Critical Factors in Developing Effective CD8+ T‐Cell–Based Cancer Vaccines

The focusing of cellular immunity toward one, or just a few, antigenic determinant, even during immune responses to complex microorganisms or antigens, is known as immunodominance. Although described in many systems, the mechanisms of determinant immunodominance are only just beginning to be appreciated, especially in relation to the interplay between T cells of differing specificities and the interactions between T cells and the antigen-presenting cells (APCs). The outcome of these cellular interactions can lead to a form of immune suppression of one specificity by another-described as "immunodomination". The specific and detailed mechanisms involved in this process are now partly defined. A full understanding of all the factors that control immunodominance and influence immunodomination will help us to develop better viral and cancer vaccines.

Feasibility of an immunoassay for mevalonolactone

Mevalonic acid is a key intermediate in a broad spectrum of cellular biological processes and their regulation. Availability of a rapid, sensitive and accurate method for its assay would be highly useful. Therefore, the feasibility of developing an immunoassay for mevalonic acid in biological samples was explored. The strategy employed was to synthesize several racemic haptens structurally resembling R-mevalonolactone, the cyclic form of mevalonic acid present at lower pH and presumed to be more antigenic. Two of these haptens were coupled to keyhole limpet hemocyanin, and the resulting conjugates were used successfully to generate antibodies in rabbits. The first antiserum bound to R,S-mevalonolactone much more effectively at pH 4.0 than at pH 6.0, consistent with the structural resemblance of the haptens to the lactone form. This antiserum also bound the free hapten from which it was generated and two others of different structure with comparable effectiveness; and slightly better than it bound R,S-mevalonolactone at pH 4.0. Similar results were obtained with the antiserum to the second hapten. The binding of either antiserum to the natural enantiomer, R-mevalonolactone, was 20 times weaker than to R,S-mevalonolactone, suggesting that the nonbiological enantiomer was more antigenic. Nevertheless, the results demonstrate that an immunochemical approach to accurate quantitation of mevalonic acid in biological samples is feasible.