Polymorphonuclear leukocytes (PMNLs) are thought to be terminally differentiated, short-lived, and unable to actively synthesize new proteins or to interact with T cells. In the current study, it was found that PMNLs incubated with supernatants of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PHA-sup) expressed high levels of CCR6 mRNA. Neutralization with IgG against several cytokines revealed that tumor necrosis factor (TNF)-α was largely responsible for the PHA-sup-induced CCR6 mRNA expression. Among recombinant cytokines, TNF-α induced high levels of CCR6 mRNA expression, whereas interferon (IFN)-γ induced low levels. The 2 cytokines together exhibited a considerable synergy. Cytokine-activated PMNLs expressed functional CCR6, as detected by the binding of sodium iodide I 125-labeled liver and activation-regulated chemokine (LARC) and dose-dependent migration toward LARC. The induction of CCR6 suggested that these cytokine-activated PMNLs have more similarities with dendritic cells (DCs) that express CCR6 in an immature stage. In fact, the activation of PMNLs with TNF-α and IFN-γ induced the expression of CD83, a dominant cell-surface marker of DCs. When PMNLs were activated with granulocyte macrophage-colony-stimulating factor, TNF-α, and IFN-γ, these cells expressed CD40 and HLA-DR in addition to CD83. Taken together, PMNLs, under appropriate conditions, can undergo a differentiation process characterized by the acquisition of new phenotypes and functions, and such differentiated PMNLs may play more active roles in the adaptive immune response. (C) 2000 by The American Society of Hematology.
ASJC Scopus subject areas
- Cell Biology