Culture of human peripheral blood leukocytes with interleukin 2 (IL-2) stimulates their differentiation into lymphokine-activated killer (LAK) cells, with a broad range of cytotoxicity against fresh tumor cells and tumor cell lines (Grimm et al., J. Exp. Med., 155: 1823-1841, 1982). We chose to utilize a molecular approach to determine whether IL-2 stimulates the expression of cytokine genes by the mixed cell population which may be involved in the generation or regulation of lytic activity. Northern blot analysis performed with total cellular RNA from LAK cells cultured for varying periods of time with IL-2 revealed that the genes which code for cytokines [interleukin 1 (IL-1)α and β, γ-interferon, tumor necrosis factor α, and lymphotoxin] were not spontaneously expressed. As soon as 2 h after IL-2 treatment, IL-1α and IL-1β mRNAs were expressed. Both nonadherent and adherent populations of LAK cells express IL-1β mRNA; however, the adherent population produced more IL-1β mRNA and maintained its expression for a prolonged period of time. Other cytokine mRNAs (γ-interferon, tumor necrosis factor α, and lymphotoxin) were expressed later than the IL-1 mRNAs with maximal levels between Days 2 through 7. Our results indicate that LAK cell populations can generate a variety of cytokines which may be involved in the generation of lytic activity.
|Number of pages||5|
|Publication status||Published - 1989|
ASJC Scopus subject areas
- Cancer Research