Abstract
Hypersensitivity responses to two highly purified and well characterized mycobacterial proteins and a preparation of mycobacterial arabinogalactanarabinomannan were studied by using guinea pig skin tests and in vitro-cultured human lymphocyte mitogenesis stimulation assays. The purified proteins were found to elicit delayed-type hypersensitivity skin test reactions and to stimulate mitogenesis in cultured lymphocytes. The polysaccharide preparation was found to evoke delayed skin tests but not to stimulate cultured lymphocytes.