Lactoferrin derived from neutrophils inhibits the mixed lymphocyte reaction
K Slater and J Fletcher
The effects of the products of phagocytosing neutrophils on lymphocyte
transcriptional activity have been investigated using allogeneic mixed
lymphocyte cultures (MLC). When MLCs are grown crowded in round- bottomed
wells, uptake of tritiated uridine is inhibited by the presence of
neutrophil products. Similarly, inhibitory activity is shown by purified
lactoferrin. The inhibitory factor released by neutrophils is positively
identified as lactoferrin, since its activity is lost in the presence of
specific antibody. In addition, inhibitory activity is lost when
lactoferrin is removed by a monoclonal antibody (MoAb) column and is
recovered with lactoferrin from the column. The active form of lactoferrin
carries iron and the apoprotein is inactive. MLCs crowded in round-bottomed
wells take up considerably more uridine than when spread in flat-bottomed
wells, and it is this enhanced transcriptional activity that is inhibited
by neutrophil-derived lactoferrin. Enhanced uridine uptake by crowded
cultures is due to factors that can be transferred in the supernatants to
promote uridine uptake by spread cultures. Neutrophil lactoferrin inhibits
both production and effect of the transferable factor(s).
Volume 69,
Issue 5,
pp. 1328-1333,
05/01/1987
Copyright © 1987 by The American Society of Hematology
