Abstract
Generation of human monocyte-derived dendritic cells (DCs) for cancer vaccination involves ex vivo maturation in the presence of proinflammatory cytokines and prostaglandin E(2) (PGE2). Although the inclusion of PGE2 during maturation is imperative for the induction of DC migration, PGE2 has unfavorable effects on the immunostimulatory capacity of these cells. Like PGE2, leukotrienes (LTs) are potent mediators of DC migration. We therefore sought to characterize the migratory and immunologic properties of DCs that matured in the presence of LTB4, LTC4, LTD4, and PGE2. Here, we demonstrate that DCs matured in the presence of LTC4, but not LTB4 or LTD4, are superior to PGE2-matured DCs in stimulating CD4+ T-cell responses and in inducing antigen-specific cytotoxic T lymphocytes (CTLs) in vitro without concomitant induction or recruitment of regulatory T cells (Tregs). LTC4-matured DCs migrate efficiently through layers of extracellular matrix and secrete higher levels of immunostimulatory IL-12p70 while producing reduced levels of immuneinhibitory IL-10, IL12p40, indoleamine-2,3-dioxidase, and TIMP-1 (tissue inhibitor of matrix metalloproteinases). Intracellular calcium mobilization and receptor antagonist studies reveal that, in contrast to LTD4, LTC4 did not signal through CysLTR1 in DCs. Collectively, our data suggest that LTC4 represents a promising candidate to replace PGE 2 in DC maturation protocols for cancer vaccination.