Effect of Corynebacterium parvum on human T-lymphocyte interferon production and T-lymphocyte proliferation in vitro.

Heat-killed, preservatIve-free preparations of strain CN 6134 Cosynebacterlum parvum have been demonstrated to Induceinterferonin culturesof normaladufthuman1lymphocytes.C. parvumwas also shownto inducehuman T-lymphocytes to proliferate In vitro. The maximum inter feron and proliferative response was observed 7 days after initiationof cultureat a finalC. parvumconcentration of 140 @&g/mb. Humanmonocyte-derivedmacrophagesdid not produce Interferon in response to C. par.'um or in response to products of C. parvum-stlmulated T-lympho cytes. The addition of macrophagesto cuftures of T lymphocytes did not significantly enhance the production of interferonby the T-lymphocytes;however,it did slgnft icantlyenhance the proliferativeresponseto C. parvum. C. parvum can also enhancethe productionof Interferon by T-lymphocytesstimulatedwith phytohemagglutininin the presence of macrophages,and the amountof inter feron produced in the presence of both agents was greater than the sum of the amounts of Interferon stImu bated by each agent acting alone. The type of interferon produced by T-Iymphocytes in response to C. parium is similar to type II or immune interferon, because it was labile to low pH and heat. Thus, a link has been found between two agents, C. parvum and interferon, both of which have in common antitumor properties and the abilityto modulatethe Immuneresponse.