Production of immune interferon by murine T-cell clones from long-term cultures

Abstract

Production of leukocyte interferon (IFN-α) and fibroblast interferon (IFN-β) can be induced by a variety of agents¹ but immune interferon, IFN-γ, is only obtained when lymphoid cells are stimulated by specific antigens, allo-antigens or T-cell mitogens^2,3. Moreover, in bulk cultures, only small quantities of IFN-γ are produced. The type of cell producing IFN-γ has not been unambiguously defined^4–6 and so we set out to determine whether a pure T-cell population could produce it, exploiting the knowledge^7,8 that T cells can be maintained indefinitely in tissue culture by the addition of T-cell growth factors. Although not all T cells can found long-term cultures of this kind⁹, cultures of antigen-specific helper, suppressor and killer T cells have been obtained^10–15 in this way. We now describe the production of substantial amounts of INF-γ when some (but not all) murine T-cell clones derived from such cultures are stimulated by either concanavalin A (Con A) or phytohaemagglutinin (PHA).