Evidence for the separate human T-lymphocyte subpopulations that
collaborate with autologous monocyte/macrophages in the elaboration of
colony-stimulating activity and those that suppress this collaboration
DS Verma, DA Johnston and KB McCredie
We investigated the interaction of monocyte/macrophages and autologous T
lymphocytes in the methanol extraction residue (MER) of BCG-induced
production of granulocyte-macrophage colony-stimulating activity (CSA).
Coincubation of monocyte/macrophages and T lymphocytes at a 1:3 ratio
produces an optimum collaboration; a change to a 1:9 ratio diminished this
collaboration. Coincubation of monocyte/macrophages and T lymphocytes
primed with lithium carbonate (2 meq/liter) for 40 hr synergistically
increased CSA elaboration and prevented the decline in CSA noted for the
1:9 monocyte/macrophage: T lymphocyte ratio. In contrast,
concanavalin-A-primed T lymphocytes did not enhance CSA elaboration at any
monocyte/macrophage:T lymphocyte ratio except, occasionally, at 1:9.
However, this was overcome if the T lymphocytes were primed with both
concanavalin-A and lithium carbonate before their coincubation with
monocyte/macrophages. Further cell-mixing experiments revealed that
concanavalin-A-primed T lymphocytes contained a subpopulation that
suppressed monocyte/macrophage and T-lymphocyte collaboration. Activation
of suppressor T lymphocytes could be effectively prevented by lithium
carbonate and, in a dose-dependent manner, by irradiation. Also, suppressor
T lymphocytes not only diminished the elaboration of colony-stimulating
factor(s), but also elaborated an inhibitor of granulocyte-macrophage
colony-forming cells. We further demonstrated that the respective
hemopoietic helper and suppressor T-lymphocyte activities could be enriched
with OKT8- (or OKT4+) and OKT8+ subpopulations.
Volume 62,
Issue 5,
pp. 1088-1099,
11/01/1983
Copyright © 1983 by The American Society of Hematology
