Stimulation of the murine mixed leukocyte reaction: optimal proliferation of responders requires activation of stimulators.
In characterizing the functional properties of the stimulators in a mixed leukocyte reaction (MLR) we have established that the optimally effective stimulators must themselves be capable of undergoing the early stages of proliferative activation. We treated the stimulators with sublytic doses of a variety of agents (ouabain, ultra-violet radiation, 5-fluorouracil and colchicine), which have been reported to inhibit their stimulating capacity, and then in parallel experiments, we examined the treated cells for their capacity to stimulate allogeneic cells and their ability to respond to Con A. A direct correlation was found between the capacity of mitomycin C-treated splenocytes to stimulate allogeneic cells in an MLR and their ability to undergo changes characteristic of pre-S phase activation, namely, increases in K+ influx and in cell size, in response to Con A. This correlation also existed in the case of metabolically active but immunosuppressed splenocytes from mice undergoing late graft-versus-host (GVH) reaction: these cells did not show increase in potassium influx in response to Con A and their stimulating ability was inhibited. Using fluorescein labelled anti-Thy 1.2 as a marker for T cells in the stimulating population, it was shown that a considerable fraction (up to one third) of the blasts in a mixed leukocyte culture (MLC) originated in the mitomycin C-treated stimulating population. These data are consistent with the hypothesis that induction of maximal proliferation, in MLR, requires that certain of the cells (mainly T cells) of the stimulating population undergo the early stages of activation.
Roy
C
C
Lapp
W S
WS
Brown
D L
DL
Kaplan
J G
JG
D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D006183:H-2 Antigens / Q000276:immunology; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008815:Mice, Inbred Strains; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
D006183:H-2 Antigens; D008937:Mitomycins; D003208:Concanavalin A; D016685:Mitomycin; D004247:DNA