Acute granulomatous response produced in mice by trehalose-6,6-dimycolate.

Trehalose-6,6-dimycolate, a toxic lipid derived from tubercle bacilli, injected intravenously into mice in 10% emulsions of Bayol F caused a three- to fourfold increase in the weights of lungs compared with those of mice injected with emulsions of Bayol F alone or emulsions of Wax D. This change is due to a heavy infiltration of the lungs with granulocytes and large numbers of macrophages, with formation in some of the infiltrates of round foci, resembling granulomas.