T-cell hybridoma-produced lymphokine that activates macrophages to suppress intracellular growth of Histoplasma capsulatum

Supernatants from concanavalin A-stimulated T-cell hybridomas activated macrophages to suppress the intracellular growth of Histoplasma capsulatum and to kill tumor cells. The supernatants had high interferon activity and were pH 2 sensitive and heat resistant. Gamma interferon is suggested to be among the active substances in the supernatants. Neither alpha interferon nor beta interferon activated macrophages for the Histoplasma growth inhibitory activity.