The growth of T lymphocyte colonies in agar is dependent on the cooperation of a number of different cell types and their products. Among these interacting cells are monocytes and/or macrophages. Monocytes are capable of producing both interleukin 1 (IL-1) and tumor necrosis factor (TNF). These two factors display a positive influence on T cell colony formation. Recombinant IL-1 and recombinant TNF were both shown to stimulate T cell colony growth in a dose-dependent manner, and this stimulation could be blocked by prior incubation with anti-IL-1 or anti-TNF, respectively. In addition, conditioned medium obtained from monocytes cultured in the presence of endotoxin also stimulated T cell colony formation. This stimulation by monocyte-conditioned medium was partially suppressed by incubation with anti-TNF or anti-IL-1, while incubation with both antibodies together displayed greater suppression. In conclusion, monocytes produce at least two factors, IL-1 and TNF, which can stimulate T cell colony formation by peripheral blood lymphocytes.
J R Zucali, G J Elfenbein, K C Barth, C A Dinarello
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.