CELLULAR REACTIONS TO WAXES FROM MYCOBACTERIUM LEPRAE.

1. The waxes from the B. leprae, like those from tubercle bacilli, are remarkable stimulants of cells. 2. The crude wax separated from the B. leprae is a mixture of lipoids and other materials, and gives reactions that include the types of cells characteristic of the response to the tuberculo-polysaccharide, phosphatide, and wax. 3. The wax obtained from the purification of the lepra phosphatide shows similar cellular reactions but with a greater proportion of foreign body giant cells. 4. Leprosin, though a glyceride, corresponds in its physical properties to the unsaponifiable material from the tubercle bacillus. It stimulates two strains of cells, fibroblasts and monocytes. The monocytes fuse into foreign body giant cells to engulf the wax. 5. The cellular reaction to the leprosinic acid and to the crystalline alcohols is of one type only, represented by the foreign body giant cell.