結核菌菌体成分(ロウD)によりひき起こされる生体反応

Relationship between adjuvant activity of a lipopolysaccharide fraction of tubercle bacilli, wax D, and its chemical structures has been investigated and the followi: conclusions were obtained: (1) the presence of the peptide moiety is important for the activity; (2) mycolic acid plays an important role in the activity; (3) hydroxyl groups are not important; (4) the size of the polysaccharide portion should be large enough for wax D to exert the activity. These findings together with the isolation of a unit structure identical with wax D (‘bound wax D’)from delipidated BCG cell walls led us to the assumption that the., imilarity of wax D to the cell surface of mycobacteria in chemical and physicochemical structures may be required for wax D to be active as adjuvant.<BR>Tubercle bacillary b odies which are usually used lot- Freund's complete adjuvant were shown to be disadvantageous particularly for a weak antigen, because the antigenicity f tubercle bacilli competes with that of an antigen incorporated, causing a negative effect on its adjuvant activity. In this connection, an acetylated and purified wax D subfraction, AD₆, was found to be a much better adjuvant in that it was virtually free from competing antigenic materials, exerting no negative effect. AD₆ was also found to be highly purified not only as a material but also in that it does not exert many other various biological activities and is considered to be advanta: eous as adjuvant for practical as well as research purposes.<BR>Statistically significant increases in plaque number and size were obtained with spleen cells derived from mice which had received sheep red blood cells plus wax D or other several adjuvants when measured by Jerne's plaque technique. This strongly ug'4-ests that the adjuvants exert the adjuvant effect through increasing the number of antibody-forming cells as well as enhancing the capacity of each cell. The adjuvant effect in terms of the increase in plaque size was long-lasting, while that in term, of the increase in plaque number transitory. Memory cells appeared to be able to 'memorize' the adjuvant effect when wax D was used in the primary immunization, while wax D exerted no adjuvant effect on memory cells which had been produced by the injection of sheep red blood cells alone.<BR>AD₆ was found to increase the phagocytic activity of the reticuloendothelial system in mice. This effect of AD₆ was long-lasting, while other several adjuvants or stimulants were found to increase the activity only for short periods. The fact that AD₆ which possesses no other biological activities so far tested except the adjuvant activity exerted the adjuvant acitivity and reticuloendothelial system-stimulating activity may suggest that these two activities may be closely related.