Abstract
Dendritic cells (DCs) are potent antigen-presenting cells with a promising potential in cancer immunotherapy. Cbl proteins are E3 ubiquitin ligases and have been implicated in regulating the functional activity of various immune cells. As an example, c-Cbl negatively affects DC activation. We here describe that another member of the Cbl-protein family (i.e. Cbl-b) is highly expressed in murine bone-marrow-derived DCs (BMDCs). Differentiation of cblb-/- bone marrow mononuclear cells into classical BMDCs is unaltered, except enhanced induction of DEC-205 (CD205) expression. When tested in mixed-lymphocyte reaction (MLR), cblb-/- BMDCs exhibit increased allo-stimulatory capacity in vitro. BMDCs were next in vitro stimulated by various toll like receptor (TLR)-agonists (LPS, Poly(I:C), CpG) and exposed to FITC-labeled dextran. Upon TLR-stimulation, cblb-/- BMDCs produce higher levels of proinflammatory cytokines (IL-1α, IL-6 and TNF-α) and exhibit a slightly higher level of FITC-dextran uptake. To further characterize the functional significance of cblb-/- BMDCs we tested them in antigen-specific T cell responses against ovalbumin (OVA) protein and peptides, activating either CD8(+) OT-I or CD4(+) OT-II transgenic T cells. However, cblb-/- BMDCs are equally effective in inducing antigen-specific T cell responses when compared to wildtype BMDCs both in vitro and in vivo. The migratory capacity into lymph nodes during inflammation was similarly not affected by the absence of Cbl-b. In line with these observations, cblb-/- peptide-pulsed BMDCs are equally effective vaccines against OVA-expressing B16 tumors in vivo when compared to wildtype BMDCs. We conclude that in contrast to c-Cbl, Cbl-b plays only a limited role in the induction of Ag-specific T cell responses by murine BMDCs in vitro and in vivo.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adaptor Proteins, Signal Transducing / deficiency
-
Adaptor Proteins, Signal Transducing / genetics
-
Adaptor Proteins, Signal Transducing / immunology*
-
Animals
-
Antigens, CD / genetics
-
Antigens, CD / immunology
-
Biological Transport
-
Bone Marrow Cells / cytology
-
Bone Marrow Cells / drug effects
-
Bone Marrow Cells / immunology*
-
CD4-Positive T-Lymphocytes / cytology
-
CD4-Positive T-Lymphocytes / immunology*
-
CD8-Positive T-Lymphocytes / cytology
-
CD8-Positive T-Lymphocytes / immunology*
-
Cell Differentiation
-
Cytokines / biosynthesis
-
Cytokines / immunology
-
Dendritic Cells / cytology
-
Dendritic Cells / drug effects
-
Dendritic Cells / immunology*
-
Dextrans / metabolism
-
Fluorescein-5-isothiocyanate / analogs & derivatives
-
Fluorescein-5-isothiocyanate / metabolism
-
Gene Expression
-
Lectins, C-Type / genetics
-
Lectins, C-Type / immunology
-
Lipopolysaccharides / pharmacology
-
Lymphocyte Culture Test, Mixed
-
Melanoma, Experimental / drug therapy
-
Melanoma, Experimental / immunology
-
Melanoma, Experimental / pathology
-
Mice
-
Mice, Knockout
-
Minor Histocompatibility Antigens
-
Ovalbumin / immunology
-
Peptides / pharmacology
-
Poly I-C / pharmacology
-
Proto-Oncogene Proteins c-cbl / deficiency
-
Proto-Oncogene Proteins c-cbl / genetics
-
Proto-Oncogene Proteins c-cbl / immunology*
-
Receptors, Cell Surface / genetics
-
Receptors, Cell Surface / immunology
-
Skin Neoplasms / drug therapy
-
Skin Neoplasms / immunology
-
Skin Neoplasms / pathology
-
Ubiquitin-Protein Ligases / deficiency
-
Ubiquitin-Protein Ligases / genetics
-
Ubiquitin-Protein Ligases / immunology*
Substances
-
Adaptor Proteins, Signal Transducing
-
Antigens, CD
-
Cblb protein, mouse
-
Cytokines
-
DEC-205 receptor
-
Dextrans
-
Lectins, C-Type
-
Lipopolysaccharides
-
Minor Histocompatibility Antigens
-
Peptides
-
Receptors, Cell Surface
-
fluorescein isothiocyanate dextran
-
Ovalbumin
-
Proto-Oncogene Proteins c-cbl
-
Ubiquitin-Protein Ligases
-
Fluorescein-5-isothiocyanate
-
Poly I-C