Augmentation of type-1 polarizing ability of monocyte-derived dendritic cells from chronically immunosuppressed organ-transplant recipients.
BACKGROUND
Chronic immunosuppressive (IS) therapy impairs normal T-cell immune surveillance and may predispose to opportunistic infections and malignancies that represent life-threatening complication of solid-organ transplantation (SOTx). Our study was designed to ascertain the impact of chronic in vivo administration of IS on the ability of monocyte-derived dendritic cells (MoDC) to differentiate, mature, and function ex vivo. The potential of these cells to be implemented for DC-based adoptive immunotherapy was also considered.


METHODS
MoDCs were propagated by conventional procedures, their phenotype was analyzed by flow cytometry, and their function was assessed by mixed leukocyte reaction, enzyme-linked immunoadsorbent assay, and ELISPOT assays. Nuclear translocation of nuclear factor (NF)-kB was analyzed by electrophoretic mobility shift assay.


RESULTS
Circulating DC1s in peripheral blood were reduced in SOTx patients. MoDCs generated from patients displayed higher endocytic activity versus normal DCs, indicating their comparative immaturity. Patients' DCs exposed to pro-inflammatory cytokines (tumor necrosis factor-alpha, interleukin [IL]-1beta, and IL-6) were less able to mature, to stimulate recall antigen (Ag)- or allo-Ag-induced proliferation responses, or to secrete IL-12p70. These deficiencies were associated with a decrease in NF-kB translocation. In contrast, combination of pro-inflammatory cytokines and interferon (IFN)-gamma (a Th1-polarizing factor) augmented patients' DC1-type function and IL-12p70 production by way of an NF-kB-independent mechanism.


CONCLUSIONS
Chronic IS restrains DC differentiation, maturation, and function at a transcriptional level; however, type-1 polarizing potential of patients' DC1 can be augmented ex vivo by a two-signal stimulation provided by pro-inflammatory cytokines and IFN-gamma. These results may have implications for DC-based immunotherapy of malignancies in the transplantation setting.
Macedo
Camila
C
The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, E1551 Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15261, USA.
Popescu
Iulia
I
Abu-Elmagd
Kareem
K
Reyes
Jorge
J
Shapiro
Ron
R
Zeevi
Adriana
A
Berghaus
Jan Mueller
JM
Wang
Lian Fu
LF
Lu
Lina
L
Thomson
Angus W
AW
Storkus
Walter J
WJ
Fung
John J
JJ
Metes
Diana
D
D021581:Active Transport, Cell Nucleus; D000328:Adult; D015703:Antigens, CD; D039521:CD11c Antigen / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D016764:Cell Polarity; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000187:drug effects* / Q000502:physiology*; D006683:HLA-DQ Antigens / Q000378:metabolism; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D016219:Immunotherapy, Adoptive; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000032:analysis; D009000:Monocytes / Q000166:cytology; D016328:NF-kappa B / Q000378:metabolism; D016377:Organ Transplantation; D000097802:CD83 Antigen
D015703:Antigens, CD; D039521:CD11c Antigen; D016207:Cytokines; D006683:HLA-DQ Antigens; D007136:Immunoglobulins; D007166:Immunosuppressive Agents; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D000097802:CD83 Antigen