Interleukin 2 production in B cell chronic lymphocytic leukemia
JF Rossi, B Klein, T Commes and M Jourdan
Interleukin 2 (IL 2) production by phytohemagglutinin (PHA)-stimulated
peripheral blood mononuclear cells (PBMCs) was investigated in 22 patients
with active untreated B cell chronic lymphocytic leukemia (B- CLL) and in
15 healthy donors. PBMCs from healthy donors demonstrated an IL 2 synthesis
of 12.4 +/- 10 U/mL. B-CLL PBMCs produced a significant amount of IL 2 (8
+/- 6.6 U/mL) despite the low percentage of T cells (13% +/- 8%) associated
with this disease compared with that found in healthy donors (63% +/-
7.5%). If IL 2 production is expressed as units per milliliter per 10(4) T
cells, its level in patients with B- CLL (1.1 U/mL/10(4) T cells) is five
times greater than that of the controls (0.19 units). When expressed as
units per milliliter per liter of blood, the B-CLL patients produce
approximately 12 times as much IL 2 as controls. IL 2 production in normal
controls was doubled after irradiation of PBMCs or addition of
indomethacin. This increase was not seen with B-CLL PBMCs suggesting that
the latter have been devoid of prostaglandin-producing normal IL 2
suppressor cells. By mixing normal or B-CLL T cells with non-T cells we
found that T cells from patients with B-CLL stimulated by normal accessory
cells produced the same amount of IL 2 as normal T cells. Moreover, B-CLL
non-T cells (mainly B leukemic cells) produced no IL 2 themselves but
played a much more efficient role in IL 2 production than did non-T cells
from healthy donors. This was not due to detectable IL 1 production by
these cells. The IL 2 produced by B-CLL PBMCs was partially purified and
recovered in a 16,000 mol wt fraction, the same mol wt as IL 2 from normal
cells.
Volume 66,
Issue 4,
pp. 840-847,
10/01/1985
Copyright © 1985 by The American Society of Hematology
