Table 3.

In Vitro Effects of KL and FL in the Murine and Human Hematopoietic System

Cell Type Response KL FL
Primitive progenitors/candidate stem cells Growth Synergy Synergy
Viability + +
Adhesion + ND
Erythroid progenitors
 BFU-E Growth Synergy
Adhesion +
 CFU-E Growth +
Myeloid (GM) progenitors Growth SynergySynergy
Viability + +
Adhesion+ ND
Megakaryocytopoiesis
 BFU-Mk/CFU-Mk Growth+ +
Mk maturation +
Mast cells Growth +
Maturation +
Adhesion +
Migration+
Activation +
B lymphopoiesis
 Murine stem cells Growth/  commitmentWeak Strong
 Murine pro-B cells Growth SynergySynergy
 Human pro-B cells Growth Synergy
T lymphopoiesis
 Murine pro-T cells Growth SynergySynergy
 Human pro-T cellsStromadependent  growth Synergy Synergy
NK cells
 NK cell progenitors Growth Synergy Synergy
 NK cells Growth Synergy ND
Viability + ND
Dendritic cells
 DC progenitors Growth SynergySynergy
  • Cell types or responses in which neither KL nor FL are known to have an effect are not listed.

  • Abbreviations: −, no effect found on indicated response (in some cases not specifically investigated but cell type lacks receptor for indicated ligand); +, stimulatory effect of ligand alone on indicated response; synergy, effect predominantly through synergistic interaction with other cytokines; ND, not determined.