Leukotriene C4 induces migration of human monocyte-derived dendritic cells without loss of immunostimulatory function
BLOOD
Authors: Dannull, Jens; Schneider, Tristan; Lee, Walter T.; de Rosa, Nicole; Tyler, Douglas S.; Pruitt, Scott K.
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) (PGE(2)). Although the inclusion of PGE(2) during maturation is imperative for the induction of DC migration, PGE(2) has unfavorable effects on the immunostimulatory capacity of these cells. Like PGE(2), leukotrienes (LTs) are potent mediators of DC migration. We therefore sought to characterize the migratory and immunologic proper-ties of DCs that matured in the presence of LTB4, LTC4, LTD4, and PGE(2). Here, we demonstrate that DCs matured in the presence of LTC4, but not LTB4 or LTD4, are superior to PGE(2)-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 immune-inhibitory 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 CysLTR(1) in DCs. Collectively, our data suggest that LTC4 represents a promising candidate to replace PGE(2) in DC maturation protocols for cancer vaccination. (Blood.2012;119(13):3113-3122)
Temporal profiles of cerebrospinal fluid leukotrienes, brain edema and inflammatory response following experimental brain injury
NEUROLOGICAL RESEARCH
Authors: Schuhmann, MU; Mokhtarzadeh, M; Stichtenoth, DO; Skardelly, M; Klinge, PA; Gutzki, FM; Samii, M; Brinker, T
Abstract
The post-traumatic changes of leukotrienes LTC4, LTD4, LTE4, and LTB4 in cerebrospinal fluid of rats from 10 min to 7 days were investigated after controlled cortical impact in relation to brain edema and cellular inflammatory response. LTC4 increased five-fold at 4 h, normalized at 24 h, and showed another tour-told increase at 7 days. The same pattern was observed for LTD4 and LTE4. LTB4 however, behaved differently: concentrations were lower and levels peaked two-fold at 24 h. Edema in the injured hemisphere increased continuously up to 24 h without change contralaterally. Leukocyte infiltration, macrophage presence and microglia activation were most prominent at 24 h, 7 days and 24 h respectively. Leukotriene changes in CSF seem to reflect those in the affected tissue, with a time delay and in lower concentrations, and were not linearly correlated to brain edema. The initially high leukotriene levels are rather likely to contribute to the cytotoxic edema than to enhance a vasogenic edema component. The profile of LTB4 was parallel to the time course of leukocyte infiltration, indicating initiation of infiltration as well as prolonged production by leukocytes themselves. The second leukotriene peak at 7 days is likely to follow a different pathway and might be related to a production in macrophages or activated glia.