Effects of IL-7 and IL-2 on highly enriched CD56+ natural killer cells. A comparative study.
IL-7 has been shown to induce low levels of lymphokine-activated killer cell (LAK) activity in bulk PBMC populations. We report here that immunomagnetically purified CD56+ cells from peripheral blood generated high LAK activity in response to IL-7. The LAK activity induced by IL-7 was comparable to, or slightly lower than, the LAK activity induced by IL-2. When analyzing cells from the same donor, no detectable LAK-generating effect of IL-7 was registered in the PBMC population, in contrast to a substantial effect in the CD56+ population. IL-2 induced 8- to 15-fold higher proliferative activity in CD56+ cells, relative to IL-7. At suboptimal concentrations of IL-2, IL-7 had a synergistic effect on the proliferation. IL-2-neutralizing antibodies did not abrogate the IL-7-induced proliferation or LAK generation. Both IL-7 and IL-2 induced comparable levels of 75-kDa TNFR expression, whereas IL-2R alpha expression was higher in IL-7-stimulated CD56+ cells. Low levels of TNF were produced in response to IL-7 at day 5, as opposed to a 50-fold higher TNF production in response to IL-2. No IL-2 or IL-6 production was detected. Our data indicate that IL-7 has profound and direct effects on CD56+ cells.
Naume
B
B
Institute of Cancer Research, University of Trondheim, Norway.
Espevik
T
T
D015703:Antigens, CD / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D019002:CD56 Antigen; D002460:Cell Line; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D015851:Interleukin-7 / Q000494:pharmacology*; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects; D007694:Killer Cells, Natural / Q000187:drug effects*; D008213:Lymphocyte Activation / Q000187:drug effects; D011956:Receptors, Cell Surface / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000032:analysis; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D007376:Interleukin-2; D015851:Interleukin-7; D011956:Receptors, Cell Surface; D015375:Receptors, Interleukin-2; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha