A reassessment of the energy requirements for neutrophil migration:
adenosine triphosphate depletion enhances chemotaxis
TA Lane and GE Lamkin
In view of previous studies demonstrating a significant correlation between
adenosine triphosphate (ATP) depletion and impairment of chemotaxis (CTX)
during granulocyte (PMN) storage, we sought to quantitate the relationship
between CTX and PMN energy metabolism. We incubated PMNs at 37 degrees C
with 2-deoxyglucose (2-dg) in the presence of 5 mmol/L glucose. As
expected, ATP inhibition by 2-dg was time-dependent (T 1/2, 18 minutes) and
dose-dependent, with half- maximal inhibition of ATP (ID50) with 1.3 +/- .3
mmol/L 2-dg. Similar concentrations of 2-dg inhibited lactate generation,
phagocytosis, superoxide anion generation, and degranulation. The random
migration of PMNs was inhibited by somewhat higher concentrations of 2-dg
(ID50, 12 mmol/L). In contrast, up to 40 mmol/L 2-dg did not inhibit CTX
toward synthetic peptides or activated serum. In fact, 2-dg consistently
increased the CTX of PMNs toward 10(-8) mol/L f-Met-Leu-Phe (fMLP), to a
maximum of 450% of control CTX using 15 mmol/L 2-dg. Half-maximal
stimulation (ED50) of CTX occurred at 6.3 +/- 1.0 mmol/L 2-dg. Although
maximal CTX toward optimal concentrations of fMLP was consistently
increased with 2-dg, the ED50 of CTX to fMLP was unchanged (ED50 with
glucose, 2.0 +/- 0.6 nmol/L fMLP; ED50 with 2-dg 2.2 +/- 0.7 nmol/L fMLP),
and 2-dg did not increase fMLP receptors. In the absence of glucose, 2-dg
exerted similar effects on ATP and CTX, but at doses 30- to 50-fold lower
than in the presence of glucose. Other glycolytic inhibitors (iodoacetamide
and sodium fluoride) exerted similar effects. Additional studies indicated
that CTX enhancement by 2-dg (a) required Mg++ but not Ca++, (b) occurred
with PMNs from a patient with chronic granulomatous disease, (c) was
unaltered in the presence of inhibitors of proteolysis, (d) was not due to
generation of a soluble agent, (e) was not due to alterations in PMN
adherence, and (f) was not due to inhibition of glycosylation. We conclude
that the chemotaxis, but not the random migration, of PMNs is surprisingly
resistant to inhibition of energy metabolism and depletion of ATP, since
concentrations of 2-dg that decreased ATP and other cell functions by more
than 50% not only did not inhibit, but actually stimulated, CTX. These
studies also indicate that the previously reported correlation between ATP
depletion and CTX impairment observed in stored PMNs are not causally
related.
Volume 64,
Issue 5,
pp. 986-993,
11/01/1984
Copyright © 1984 by The American Society of Hematology
