IL1B and infection: Double-knockout (KO) mice, deficient in both IL-1α and IL-1β, following infection with M. tuberculosis H37Rv, have been reported to develop larger granulomatous lesions (Yamada et al., 2000), whereas IL-1 type 1 receptor knockout mice were highly susceptible, showed greater mycobacterial load, and developed granulomas with fewer MΦs and lymphocytes, and abundant granulocytes (Juffermans et al., 2000).