scholarly journals Dendritic cell progenitors phagocytose particulates, including bacillus Calmette-Guerin organisms, and sensitize mice to mycobacterial antigens in vivo.

1993 ◽  
Vol 178 (2) ◽  
pp. 479-488 ◽  
Author(s):  
K Inaba ◽  
M Inaba ◽  
M Naito ◽  
R M Steinman
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Antigen Processing ◽  
Blood Stream ◽  
Active Immunization ◽  
Bacillus Calmette Guerin ◽  
Antigen Uptake ◽  
Gm Csf ◽  
Mycobacterial Antigens

Dendritic cells, while effective in sensitizing T cells to several different antigens, show little or no phagocytic activity. To the extent that endocytosis is required for antigen processing and presentation, it is not evident how dendritic cells would present particle-associated peptides. Evidence has now been obtained showing that progenitors to dendritic cells can internalize particles, including Bacillus Calmette-Guerin (BCG) mycobacteria. The particulates are applied for 20 h to bone marrow cultures that have been stimulated with granulocyte/macrophage colony-stimulating factor (GM-CSF) to induce aggregates of growing dendritic cells. Cells within these aggregates are clearly phagocytic. If the developing cultures are exposed to particles, washed, and "chased" for 2 d, the number of major histocompatibility complex class II-rich dendritic cells increases substantially and at least 50% contain internalized mycobacteria or latex particles. The mycobacteria-laden, newly developed dendritic cells are much more potent in presenting antigens to primed T cells than corresponding cultures of mature dendritic cells that are exposed to a pulse of organisms. A similar situation exists when the BCG-charged dendritic cells are injected into the footpad or blood stream of naive mice. Those dendritic cells that have phagocytosed organisms induce the strongest T cell responses to mycobacterial antigens in draining lymph node and spleen. The administration of antigens to GM-CSF-induced, developing dendritic cells (by increasing both antigen uptake and cell numbers) will facilitate the use of these antigen-presenting cells for active immunization in situ.

scholarly journals P01.02 TLR-mediated suppression of the CCL22-CCR4 axis as a new target for tumor immunotherapy

2021 ◽  
Vol 9 (Suppl 1) ◽  
pp. A3.2-A4
Author(s):  
J Grün ◽  
I Piseddu ◽  
C Perleberg ◽  
N Röhrle ◽  
S Endres ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
Regulatory T Cells ◽  
Type I ◽  
List Type ◽  
Gm Csf

BackgroundUnmethylated CpG-DNA is a potent ligand for the endosomal Toll-like-receptor-9, important for the immune activation to pathogen-associated molecules.1 CpG and other TLR-ligands show effective immunotherapeutic capacities in cancer treatment by inducing an antitumorigenic immunity.2 They are able to reduce tumor progression by reduction of intratumoral secretion of the immunoregulating chemokine CCL223 and subsequent recruitment of immunosuppressive regulatory T cells (Treg), which express CCR4 the only so far known receptor for CCL22.4 Our recent work has shown that CCL22 secretion by dendritic cells (DC) in the lymph node, mediates tolerance by inducing DC-Treg contacts.5 Indeed, in the absence of CCL22, immune responses to vaccination were stronger and resulted in tumor rejection.6 Therefore, we are aiming to investigate the effects of TLR-ligands on systemic CCL22 levels, elucidating all involved mechanisms to identify new targets for cancer immunotherapy.Materials and MethodsT, B and CD11c+ DCs of wildtype (wt) and RAG1-/- mice were isolated from splenocytes by magnetic-activated cell sorting for in vitro assays. Different co-cultures were incubated with CpG and GM-CSF, known as an CCL22 inducer.5 For in vivo experiments, wt mice were treated with CpG, R484 or poly(I:C) alone and in combination with GM-CSF. CCL22-levels in a number of organs were analyzed.ResultsAnalyzing the different immune cell compartments in vitro, we found that DCs in whole splenocytes secrete CCL22 during culture while DC cultured alone showed no CCL22 secretion. When treated with CpG, CCL22-levels were reduced in splenocytes, while it was induced in DC culture alone. The same results were seen when RAG splenocytes, that lack functional B and T cells, were cultured with CpG. CpG treated B cells were able to suppress CCL22 secretion by DC unlike T cells alone. Co-cultures of T and B cells treated with CpG, however, induced the strongest CCL22 suppression in DC. In vivo, we could show that all TLR ligands tested reduced CCL22 in a number of organs significantly. Furthermore, CpG showed the strongest suppression of CCL22 even in the presence of the CCL22 inducer GM-CSF.5ConclusionsWe could show that B cells with T cells mediate CCL22 suppression by TLR ligands. The fact that CpG was able to reduce CCL22 levels even in the presence of the inducer GM-CSF demonstrates the potent CCL22 suppressive capacity of TLR ligands.ReferencesO’Neill LA, et al. The history of toll-like receptors – redefining innate immunity. Nat Rev Immunol 2013;13(6):453–60.Rothenfusser S, et al. Recent advances in immunostimulatory CpG oligonucleotides. Curr Opin Mol Ther 2003;5(2):98–106.Wang S, et al. Intratumoral injection of a CpG oligonucleotide reverts resistance to PD-1 blockade by expanding multifunctional CD8+ T cells. Proc Natl Acad Sci U S A 2016;113(46): E7240–E7249.Rapp M, et al. CCL22 controls immunity by promoting regulatory T cell communication with dendritic cells in lymph nodes. J Exp Med 2019;216(5):1170–1181.Piseddu I, et al. Constitutive expression of CCL22 is mediated by T cell-derived GM-CSF. J Immunol 2020;205(8):2056–2065.Anz D, et al. Suppression of intratumoral CCL22 by type i interferon inhibits migration of regulatory T cells and blocks cancer progression. Cancer Res 2015;75(21):4483–93.Disclosure InformationJ. Grün: None. I. Piseddu: None. C. Perleberg: None. N. Röhrle: None. S. Endres: None. D. Anz: None.

Leukemic blasts fail to differentiate into mature antigen presenting cells, and may hinder dendritic cell maturation in vitro and in vivo

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 10556-10556
Author(s):  
J. Rosenblatt ◽  
R. Stone ◽  
C. Lenahan ◽  
Z. Wu ◽  
B. Vasir ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Tumor Vaccine ◽  
Leukemia Cells ◽  
Phenotypic Characteristics ◽  
Gm Csf ◽  
Maturation In Vitro ◽  
Dc Maturation

10556 Background: Dendritic cells (DC) play a key role in the development of tumor specific immune responses. Dendritic cells differentiated from leukemic blasts (LDC) are being explored as a tumor vaccine in AML. We examined the phenotypic and functional characteristics of LDC, the phenotypic characteristics of native DC in AML patients, and the effect of leukemic blasts on the phenotype of DC generated from normal donors. Methods: Leukemia blasts were isolated from peripheral blood of 24 patients with AML. LDC were generated by culturing blasts in the presence of GM-CSF, IL-4 and TNFa for 7 days. The phenotype of circulating DC1 (CD11C+/lin-) and DC2 (CD123+/ lin-) in AML patients was assessed by multichannel FACS analysis. To assess the effect of blasts on DC maturation, adherent mononuclear cells were isolated from normal donors, combined with leukemia cells in a 10:1 ratio, and cultured with GM-CSF, IL-4, and TNFa. Results: LDC demonstrate only modest expression of the costimulatory molecules CD80 and CD86 (mean expression 10% and 32%) and poorly express the maturation marker CD83 (mean expression 4%). Interferon gamma production by autologous T cells was not higher after stimulation with LDC than with blasts. LDC stimlation resulted in a 2 fold increase in both CD4+/CD25+/CD69+ (activated) and CD4+/CD25+/FOXP3+ (regulatory) T cells. Given the inability of leukemia progenitors to differentiate into phenotypically mature DC, we assessed whether leukemia cells directly inhibit differentiation of DC from normal progenitors. Expression of costimulatory molecules was decreased in DC differentiated in the presence of blasts. Mean expression of CD80, CD83, and CD86 was 16%, 2%, 83% and 49%, 10%, 99% for DCs generated in the presence or absence blasts respectively. Phenotypic characteristics of native DC in patients with AML were examined. In 3 experiments, a predominance of DC2 was seen (ratio DC2/DC1 5), and both DC1 and DC2 poorly expressed CD83 (mean expression 9% DC1, 0.9% DC2). Conclusions: LDC have phenotypic and functional deficiencies, limiting their efficacy as a tumor vaccine. Contact with leukemic blasts may inhibit DC maturation in vitro and in vivo, which may contribute to the lack of effective antitumor immunity in AML patients. No significant financial relationships to disclose.

scholarly journals Direct Expansion of Functional CD25+ CD4+ Regulatory T Cells by Antigen-processing Dendritic Cells

2003 ◽  
Vol 198 (2) ◽  
pp. 235-247 ◽  
Author(s):  
Sayuri Yamazaki ◽  
Tomonori Iyoda ◽  
Kristin Tarbell ◽  
Kara Olson ◽  
Klara Velinzon ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cd4 T Cells ◽  
Antigen Processing ◽  
Specific Antigen ◽  
Cell Receptor ◽  
Cd4 T Cell

An important pathway for immune tolerance is provided by thymic-derived CD25+ CD4+ T cells that suppress other CD25− autoimmune disease–inducing T cells. The antigen-presenting cell (APC) requirements for the control of CD25+ CD4+ suppressor T cells remain to be identified, hampering their study in experimental and clinical situations. CD25+ CD4+ T cells are classically anergic, unable to proliferate in response to mitogenic antibodies to the T cell receptor complex. We now find that CD25+ CD4+ T cells can proliferate in the absence of added cytokines in culture and in vivo when stimulated by antigen-loaded dendritic cells (DCs), especially mature DCs. With high doses of DCs in culture, CD25+ CD4+ and CD25− CD4+ populations initially proliferate to a comparable extent. With current methods, one third of the antigen-reactive T cell receptor transgenic T cells enter into cycle for an average of three divisions in 3 d. The expansion of CD25+ CD4+ T cells stops by day 5, in the absence or presence of exogenous interleukin (IL)-2, whereas CD25− CD4+ T cells continue to grow. CD25+ CD4+ T cell growth requires DC–T cell contact and is partially dependent upon the production of small amounts of IL-2 by the T cells and B7 costimulation by the DCs. After antigen-specific expansion, the CD25+ CD4+ T cells retain their known surface features and actively suppress CD25− CD4+ T cell proliferation to splenic APCs. DCs also can expand CD25+ CD4+ T cells in the absence of specific antigen but in the presence of exogenous IL-2. In vivo, both steady state and mature antigen-processing DCs induce proliferation of adoptively transferred CD25+ CD4+ T cells. The capacity to expand CD25+ CD4+ T cells provides DCs with an additional mechanism to regulate autoimmunity and other immune responses.

scholarly journals Dramatic increase in the numbers of functionally mature dendritic cells in Flt3 ligand-treated mice: multiple dendritic cell subpopulations identified.

1996 ◽  
Vol 184 (5) ◽  
pp. 1953-1962 ◽  
Author(s):  
E Maraskovsky ◽  
K Brasel ◽  
M Teepe ◽  
E R Roux ◽  
S D Lyman ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Class Ii ◽  
Terminal State ◽  
T Cell Response ◽  
Daily Injection ◽  
Flt3 Ligand ◽  
Cd11b Expression ◽  
Gm Csf

Dendritic cells (DC) are the most efficient APC for T cells. The clinical use of DC as vectors for anti-tumor and infectious disease immunotherapy has been limited by their trace levels and accessibility in normal tissue and terminal state of differentiation. In the present study, daily injection of human Flt3 ligand (Flt3L) into mice results in a dramatic numerical increase in cells co-expressing the characteristic DC markers-class II MHC, CD11c, DEC205, and CD86. In contrast, in mice treated with either GM-CSF, GM-CSF plus IL-4, c-kit ligand (c-kitL), or G-CSF, class II+ CD11c+ cells were not significantly increased. Five distinct DC subpopulations were identified in the spleen of Flt3L-treated mice using CD8 alpha and CD11b expression. These cells exhibited veiled and dendritic processes and were as efficient as rare, mature DC isolated from the spleens of untreated mice at presenting allo-Ag or soluble Ag to T cells, or in priming an Ag-specific T cell response in vivo. Dramatic numerical increases in DC were detected in the bone marrow, gastro-intestinal lymphoid tissue (GALT), liver, lymph nodes, lung, peripheral blood, peritoneal cavity, spleen, and thymus. These results suggest that Flt3L could be used to expand the numbers of functionally mature DC in vivo for use in clinical immunotherapy.

scholarly journals Immortalized dendritic cell line fully competent in antigen presentation initiates primary T cell responses in vivo.

1993 ◽  
Vol 178 (6) ◽  
pp. 1893-1901 ◽  
Author(s):  
P Paglia ◽  
G Girolomoni ◽  
F Robbiati ◽  
F Granucci ◽  
P Ricciardi-Castagnoli
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
Cell Line ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Gm Csf ◽  
Antigen Presenting

Dendritic cells (DC) can provide all the known costimulatory signals required for activation of unprimed T cells and are the most efficient and perhaps the critical antigen presenting cells in the induction of primary T cell-mediated immune responses. It is now shown that mouse cell lines with many of the features of DC can be generated using the MIB phi 2-N11 retroviral vector transducing a novel envAKR-mycMH2 fusion gene. The immortalized dendritic cell line (CB1) displays most of the morphologic, immunophenotypic, and functional attributes of DC, including constitutive expression of major histocompatibility complex (MHC) class II molecules, costimulatory molecules B7/BB1, heat stable antigen, intracellular adhesion molecule 1, and efficient antigen-presenting ability. Granulocyte/macrophage colony-stimulating factor (GM-CSF) proved to be effective in increasing MHC class II molecule expression and in enhancing presentation of native protein antigens. In comparison with macrophages, CB1 dendritic cells did not exhibit phagocytic and chemotactic activity in response to various stimuli and lipopolysaccharide activation was ineffective in inducing tumor necrosis factor alpha or interleukin 1 beta production. CB1 cells, pulsed with haptens in vitro and injected into naive mice were able to induce delayed-type hypersensitivity responses, further increased with pretreatment with GM-CSF, indicating that these cells may represent an immature, rather than a mature DC. The ability of CB1 to prime T cells in vivo could provide a tool to design novel immunization strategies.

scholarly journals Constitutive Presentation of a Natural Tissue Autoantigen Exclusively by Dendritic Cells in the Draining Lymph Node

2002 ◽  
Vol 196 (8) ◽  
pp. 1079-1090 ◽  
Author(s):  
Clemens Scheinecker ◽  
Rebecca McHugh ◽  
Ethan M. Shevach ◽  
Ronald N. Germain
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Lymph Node ◽  
Mhc Class Ii ◽  
Tissue Destruction ◽  
Antigen Uptake ◽  
Autoreactive T Cells ◽  
Gastric Parietal Cell ◽  
Tissue Specific

The major histocompatibility complex (MHC)-dependent presentation of processed tissue-specific self-antigens can contribute to either peripheral (extrathymic) tolerance or the differentiation of autoreactive T cells. Here, we have studied the MHC class II molecule presentation of gastric parietal cell (PC)-specific H+/K+-ATPase, which induces a destructive autoimmune gastritis in BALB/c mice lacking CD4+ CD25+ regulatory T cells. Immunofluorescence microscopy showed physical association of CD11c+ dendritic cells (DCs) with PCs in the gastric mucosa. H+/K+-ATPase protein was found within vesicular compartments of a few CD11c+ DCs only in the draining gastric lymph node (LN) and these antigen-containing DCs increased markedly in number with the onset of tissue destruction in autoimmune animals. Both CD8αhi and CD8αlo gastric DCs, but not peripheral or mesenteric DCs, showed evidence of constitutive in vivo processing and presentation of H+/K+-ATPase. These data provide direct support for a widely held model of local tissue antigen uptake and trafficking by DCs in normal animals and demonstrate that DCs in the draining LN can present a tissue-specific self-antigen under noninflammatory conditions without fully deleting autoreactive T cells or inducing active autoimmunity.

scholarly journals In Vivo Irradiation of Mice Induces Activation of Dendritic Cells

2018 ◽  
Vol 19 (8) ◽  
pp. 2391 ◽  
Author(s):  
Eszter Persa ◽  
Tünde Szatmári ◽  
Géza Sáfrány ◽  
Katalin Lumniczky
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Ionizing Radiation ◽  
Fold Increase ◽  
High Dose ◽  
Antigen Uptake ◽  
Dose Irradiation

It is becoming clear that ionizing radiation positively influences certain immune parameters, which opens the possibility for combining radio- and immunotherapies in cancer treatment. The presence of functionally competent dendritic cells (DCs) is crucial in mounting a successful antitumor immune response. While it has been shown that DCs are relatively radioresistant, few and contradictory data are available on how ionizing radiation alters the functional integrity of these cells. Therefore, our objective was to investigate the effect of whole-body irradiation on the function of splenic DCs. C57Bl/6 mice were irradiated with 0.1, 0.25, and 2 Gy X-rays and changes in the phenotype of splenic DCs were compared to unirradiated controls. An increase was seen in DC surface markers influencing DC-T cell interactions. In vivo cytokine production was determined by direct intracellular cytokine staining. Irradiation with 2 Gy induced a 1.6-fold increase in IL-1α production, while the combination of irradiation and lipopolysaccharide (LPS) treatment induced a 3.9-fold increase, indicating a strong synergism between irradiation and LPS stimulation. Interaction of DCs with effector and regulatory T cells was investigated in a mixed lymphocyte reaction. While DCs from control animals induced stronger proliferation of regulatory T cells, DCs from animals irradiated with 2 Gy induced stronger proliferation of effector T cells. Antigen uptake and presentation was investigated by measuring the capacity of DCs to internalize and present ovalbumine (OVA)-derived peptides on their major histocompatibility complex (MHCI) molecules. Irradiation with 2 Gy did not influence antigen uptake or presentation, while low doses stimulated antigen uptake and reduced the level of antigen presentation. In conclusion, high-dose in vivo irradiation induced increased expression of T cell costimulatory markers, enhanced production of proinflammatory cytokines and a stronger stimulation of effector T cell proliferation than that of regulatory T cells. However, it did not influence DC antigen uptake or presentation. On the other hand, low-dose irradiation increased antigen uptake and lowered antigen presentation of DCs, indicating that low- and high-dose irradiation act on different pathways in DCs.

scholarly journals Alpha-Fetoprotein- and CD40Ligand-Expressing Dendritic Cells for Immunotherapy of Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3375
Author(s):  
Annabelle Vogt ◽  
Farsaneh Sadeghlar ◽  
Tiyasha H. Ayub ◽  
Carlo Schneider ◽  
Christian Möhring ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Dendritic Cells ◽  
Tumor Regression ◽  
Combined Therapy ◽  
Term Survival ◽  
Effector Cells ◽  
Tumor Environment ◽  
The Impact

Dendritic cells (DC) as professional antigen presenting cells are able to prime T-cells against the tumor-associated antigen α-fetoprotein (AFP) for immunotherapy of hepatocellular carcinoma (HCC). However, a strong immunosuppressive tumor environment limits their efficacy in patients. The co-stimulation with CD40Ligand (CD40L) is critical in the maturation of DC and T-cell priming. In this study, the impact of intratumoral (i.t.) CD40L-expressing DC to improve vaccination with murine (m)AFP-transduced DC (Ad-mAFP-DC) was analyzed in subcutaneous (s.c.) and orthotopic murine HCC. Murine DC were adenovirally transduced with Ad-mAFP or Ad-CD40L. Hepa129-mAFP-cells were injected into the right flank or the liver of C3H-mice to induce subcutaneous (s.c.) and orthotopic HCC. For treatments, 106 Ad-mAFP-transduced DC were inoculated s.c. followed by 106 CD40L-expressing DC injected intratumorally (i.t.). S.c. inoculation with Ad-mAFP-transduced DC, as vaccine, induced a delay of tumor-growth of AFP-positive HCC compared to controls. When s.c.-inoculation of Ad-mAFP-DC was combined with i.t.-application of Ad-CD40L-DC synergistic antitumoral effects were observed and complete remissions and long-term survival in 62% of tumor-bearing animals were achieved. Analysis of the tumor environment at different time points revealed that s.c.-vaccination with Ad-mAFP-DC seems to stimulate tumor-specific effector cells, allowing an earlier recruitment of effector T-cells and a Th1 shift within the tumors. After i.t. co-stimulation with Ad-CD40L-DC, production of Th1-cytokines was strongly increased and accompanied by a robust tumor infiltration of mature DC, activated CD4+-, CD8+-T-cells as well as reduction of regulatory T-cells. Moreover, Ad-CD40L-DC induced tumor cell apoptosis. Intratumoral co-stimulation with CD40L-expressing DC significantly improves vaccination with Ad-mAFP-DC in pre-established HCC in vivo. Combined therapy caused an early and strong Th1-shift in the tumor environment as well as higher tumor apoptosis, leading to synergistic tumor regression of HCC. Thus, CD40L co-stimulation represents a promising tool for improving DC-based immunotherapy of HCC.

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