[Biochemical and immunological properties of the fractions of tubercle bacilli]

In 1954, Dr. Yuichi Yamamura and his coassociates, National Sanatorium Toneyama Hospital, has reported the formation of experimental tuberculous cavity in rabbits. This work was a milestone of the researches in the field of cellular immunology. In 1960, I have started my scientific carrier in Kyushu University Medical School as the post-graduate student under the guidance of Prof. Yamamura. Since then, I have worked on the field of biochemical and immunological properties of tubercle bacilli. The arabinose mycolate, polysaccharides, cell-wall skeleton (CWS) and trehalose dimycolate (TDM) were purified from tubercle bacilli and their Chemical structures and biological activities were investigated in detail in our laboratory. In 1971, we have reported that adjuvant active principle of tubercle bacilli was a CWS fraction, and the details of chemical structure and adjuvantity of mycobacterial CWS were investigated in our research group. The application of BCG-CWS to cancer immunotherapy was also studied. In 1974, Prof. E. Lederer and his coworkers, University of Paris, have reported that N-acetyl muramyl-L-alanyl-D-isoglutamine (MDP) was the minimum adjuvant-active structure of bacterial cell wall. We have synthesized several hundreds of MDP derivatives and selected, MDP-Lys(L18), romurtide, as the candidate of cytokine inducer for the clinical application. Romurtide is applied in cancer patients for the recovery of the number and functions of monocytes, neutrophils and platelets. These results suggest that the tubercle bacilli, especially, CWS and related synthetic MDP derivatives, are effective for the potentiation of host resistance against infectious diseases and cancer.