Our past work has seen a detailed exposition of the antigenic glycoconjugates of many Mycobacterium spp. The purpose of this present proposal is to extend an expanded version of this chemical approach to M. tuberculosis; to isolate, purify and characterize its cell wall and """"""""export"""""""" protein antigens; to work with selected investigators on their application to human tuberculosis; and to apply them to our own murine model of tuberculosis. The antigens that are targeted for chemical resolution and immunological application are new and old, the new peptidoglycan-bound 23 kD protein and relatives and the highly immunogenic=250 kD """"""""cell wall-protein,"""""""" individual polypeptides from early culture filtrates, Seibert Protein Fractions A, B and C, antigen -5 and -6, purified protein derivative, lipoarabinomannan, lipomannan, etc. Many of the protocols will be those in common use by us in the context of other mycobacteria, but governed by the knowledge of the stable association between key protein immunogens and mycobacterial lipopolysaccharide. Pure antigens will be available for a host of studies, by others, to identify those being recognized with highest frequency by T lymphocytes from human pleural fluid. The murine immunological studies to be conducted by ourselves will attempt to define the precise antigens that result in the generation of acquired protective immunity to living M. tuberculosis and distinguish them from those implicated in delayed type hypersensitivity response (DTH). In this respect, short-lived protective T-cell populations and cloned T-cell lines to the defined antigens will be generated for use in determining which are expressed by macrophages containing the living infection. Efforts will be made to clone DTH effector T cells in order to learn the identity of the antigens that result in the sensitization of this discrete population. Experiments are proposed, with others, to gauge the effect of individual bacterial entities in the evolution of tissue necrosis and in the suppression of macrophage activation. Throughout, the parameters of T-cell mediated immunity and pathogenesis evoked by the living bacillus will be the criteria by which individual native M. tuberculosis components are selected, purified, and chemically defined.
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