scholarly journals Induction of Anti-Tumour Immune Responses by Dendritic Cells Generated with Flt3-Ligand

2021 ◽  
Author(s):  
◽  
So Nai Lim

<p>Dendritic cells (DCs) are potent antigen presenting cells that are crucial for the initiation of an immune response. Due to this property, DCs have been used as the basis of cancer vaccines in immunotherapy. In clinical trials, DCs used for vaccination are commonly generated by culturing monocytes from each patients' blood with the growth factors GM-CSF and IL-4 (GMCSF/IL-4 DCs). The DCs generated are reportedly similar to those that arise in vivo during inflammation and trials using these DCs have been met with some success. A recently developed method of generating mouse or human DCs in vitro, involves the culture of bone marrow (BM) precursors with the cytokine Flt3-Ligand (Flt3L-DCs). Flt3L-DCs differ substantially in phenotype from GMCSF/IL-4 DCs and more closely resemble steady-state DCs in vivo. This thesis investigated the suitability of Flt3L-DCs for cancer immunotherapy. Murine BM cells cultured in Flt3L generated three DC subsets. These consisted of plasmacytoid DCs (pDCs) that were CD11c⁺B220⁺, and conventional DCs (cDCs) that were CD11c⁺B220⁻ and could be further subdivided into CD11bhigh and CD24high populations. We observed that cDCs responded to stimulation with a variety of Tolllike receptor (TLR) agonists, as evaluated by the up-regulation of activation markers. However pDCs responded to the agonist CpG at a higher extent compared to all other agonists used. In addition, combining TLR agonists could further enhance the activation of Flt3L-DCs. Among all combinations tested, Pam3Cys/Poly I:C was the most optimal at inducing the secretion of inflammatory cytokines IL-12p70 and TNF-α. Furthermore, Pam3Cys/Poly I:C stimulated Flt3L-cDCs exhibited a greater ability at inducing CD4⁺ T cell proliferation and cross-presentation of soluble antigen to CD8⁺ T cells, compared to Flt3L-cDCs activated with the respective individual agonists. Studies have shown that GM-CSF DCs are highly reliant on glycolytic metabolism during activation in order to up-regulate activation markers. Therefore, we also characterised Flt3L-cDCs for their ability to up-regulate activation markers following stimulation with the agonist LPS and treatment with the glycolysis inhibitor 2-Deoxy-D-glucose (2-DG). In line with previous reports, DCs generated in culture with GMCSF/IL-4 were unable to up-regulate activation markers at all the 2-DG concentrations used. In contrast, Flt3L-cDCs appeared to have a threshold level where only high concentrations of 2-DG inhibited their ability to up-regulate activation markers. This result indicates that steady-state and inflammatory DCs preferentially use different metabolic pathways upon activation. The ability of optimally activated Flt3L-cDCs and GMCSF/IL-4 DCs to confer tumour protection was also examined. While unstimulated Flt3L-cDCs or GMCSF/IL-4 DCs could protect mice from tumour growth, vaccination with activated DCs from either population was required for complete tumour protection. Furthermore, we found that even in optimal conditions of activation, 1x10⁵ Flt3LcDCs were required for maximal tumour protection, whereas 1x10⁴ GMCSF/IL-4 DCs provided sufficient protection. These findings indicate that Flt3L-cDCs can be used as the basis of a therapeutic cancer vaccine, but are not superior to GMCSF/IL- 4 DCs. Further studies are required to establish conditions that can enhance the efficacy of Flt3L-cDCs.</p>

2021 ◽  
Author(s):  
◽  
So Nai Lim

<p>Dendritic cells (DCs) are potent antigen presenting cells that are crucial for the initiation of an immune response. Due to this property, DCs have been used as the basis of cancer vaccines in immunotherapy. In clinical trials, DCs used for vaccination are commonly generated by culturing monocytes from each patients' blood with the growth factors GM-CSF and IL-4 (GMCSF/IL-4 DCs). The DCs generated are reportedly similar to those that arise in vivo during inflammation and trials using these DCs have been met with some success. A recently developed method of generating mouse or human DCs in vitro, involves the culture of bone marrow (BM) precursors with the cytokine Flt3-Ligand (Flt3L-DCs). Flt3L-DCs differ substantially in phenotype from GMCSF/IL-4 DCs and more closely resemble steady-state DCs in vivo. This thesis investigated the suitability of Flt3L-DCs for cancer immunotherapy. Murine BM cells cultured in Flt3L generated three DC subsets. These consisted of plasmacytoid DCs (pDCs) that were CD11c⁺B220⁺, and conventional DCs (cDCs) that were CD11c⁺B220⁻ and could be further subdivided into CD11bhigh and CD24high populations. We observed that cDCs responded to stimulation with a variety of Tolllike receptor (TLR) agonists, as evaluated by the up-regulation of activation markers. However pDCs responded to the agonist CpG at a higher extent compared to all other agonists used. In addition, combining TLR agonists could further enhance the activation of Flt3L-DCs. Among all combinations tested, Pam3Cys/Poly I:C was the most optimal at inducing the secretion of inflammatory cytokines IL-12p70 and TNF-α. Furthermore, Pam3Cys/Poly I:C stimulated Flt3L-cDCs exhibited a greater ability at inducing CD4⁺ T cell proliferation and cross-presentation of soluble antigen to CD8⁺ T cells, compared to Flt3L-cDCs activated with the respective individual agonists. Studies have shown that GM-CSF DCs are highly reliant on glycolytic metabolism during activation in order to up-regulate activation markers. Therefore, we also characterised Flt3L-cDCs for their ability to up-regulate activation markers following stimulation with the agonist LPS and treatment with the glycolysis inhibitor 2-Deoxy-D-glucose (2-DG). In line with previous reports, DCs generated in culture with GMCSF/IL-4 were unable to up-regulate activation markers at all the 2-DG concentrations used. In contrast, Flt3L-cDCs appeared to have a threshold level where only high concentrations of 2-DG inhibited their ability to up-regulate activation markers. This result indicates that steady-state and inflammatory DCs preferentially use different metabolic pathways upon activation. The ability of optimally activated Flt3L-cDCs and GMCSF/IL-4 DCs to confer tumour protection was also examined. While unstimulated Flt3L-cDCs or GMCSF/IL-4 DCs could protect mice from tumour growth, vaccination with activated DCs from either population was required for complete tumour protection. Furthermore, we found that even in optimal conditions of activation, 1x10⁵ Flt3LcDCs were required for maximal tumour protection, whereas 1x10⁴ GMCSF/IL-4 DCs provided sufficient protection. These findings indicate that Flt3L-cDCs can be used as the basis of a therapeutic cancer vaccine, but are not superior to GMCSF/IL- 4 DCs. Further studies are required to establish conditions that can enhance the efficacy of Flt3L-cDCs.</p>


1996 ◽  
Vol 184 (5) ◽  
pp. 1953-1962 ◽  
Author(s):  
E Maraskovsky ◽  
K Brasel ◽  
M Teepe ◽  
E R Roux ◽  
S D Lyman ◽  
...  

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.


2002 ◽  
Vol 6 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Yoav Peretz ◽  
Zheng Frank Zhou ◽  
Fawaz Halwani ◽  
Gérald J. Prud'homme
Keyword(s):  

Cytokine ◽  
2002 ◽  
Vol 17 (3) ◽  
pp. 119-130 ◽  
Author(s):  
Elizabeth Daro ◽  
Eric Butz ◽  
Jeffrey Smith ◽  
Mark Teepe ◽  
Charles R Maliszewski ◽  
...  

2000 ◽  
Vol 165 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Elizabeth Daro ◽  
Bali Pulendran ◽  
Kenneth Brasel ◽  
Mark Teepe ◽  
Dean Pettit ◽  
...  

2003 ◽  
Vol 198 (2) ◽  
pp. 305-313 ◽  
Author(s):  
Holger Karsunky ◽  
Miriam Merad ◽  
Antonio Cozzio ◽  
Irving L. Weissman ◽  
Markus G. Manz

Stimulation of Flt3 receptor tyrosine kinase through its cognate ligand expands early hematopoietic progenitor and dendritic cells (DCs) in humans and mice. The exact developmental stages at which hematopoietic progenitors express Flt3, are responsive to its ligand, and subsequently develop to DCs, are not known. Here we show that common lymphoid and common myeloid progenitors, as well as steady state DCs in thymus, spleen, and epidermis, express Flt3. The receptor is down-regulated once definitive B cell, T cell, and megakaryocyte/erythrocyte commitment occurs, and Flt3 is not detectable on other steady state hematopoietic cell populations. Upon in vivo Flt3 ligand (Flt3L) administration, Flt3+ progenitor cells and their progeny DCs are expanded, whereas Flt3− downstream progenitors are not, or are only slightly increased. Transplantation of common lymphoid and common myeloid progenitors and subsequent Flt3L injection increases progeny DCs of both precursor populations. These findings provide a definitive map of Flt3 expression in the hematopoietic hierarchy and directly demonstrate that Flt3L can drive DC development along both the lymphoid and myeloid developmental pathways from Flt3+ progenitors to Flt3+ DCs.


2005 ◽  
Vol 169 (4) ◽  
pp. 569-576 ◽  
Author(s):  
Clare L. Bennett ◽  
Erwin van Rijn ◽  
Steffen Jung ◽  
Kayo Inaba ◽  
Ralph M. Steinman ◽  
...  

Langerhans cells (LC) form a unique subset of dendritic cells (DC) in the epidermis but so far their in vivo functions in skin immunity and tolerance could not be determined, in particular in relation to dermal DC (dDC). Here, we exploit a novel diphtheria toxin (DT) receptor (DTR)/DT-based system to achieve inducible ablation of LC without affecting the skin environment. Within 24 h after intra-peritoneal injection of DT into Langerin-DTR mice LC are completely depleted from the epidermis and only begin to return 4 wk later. LC deletion occurs by apoptosis in the absence of inflammation and, in particular, the dDC compartment is not affected. In LC-depleted mice contact hypersensitivity (CHS) responses are significantly decreased, although ear swelling still occurs indicating that dDC can mediate CHS when necessary. Our results establish Langerin-DTR mice as a unique tool to study LC function in the steady state and to explore their relative importance compared with dDC in orchestrating skin immunity and tolerance.


2022 ◽  
Author(s):  
Michael Valente ◽  
Nils Collinet ◽  
Thien-Phong Vu Manh ◽  
Karima Naciri ◽  
Gilles Bessou ◽  
...  

Plasmacytoid dendritic cells (pDC) were identified about 20 years ago, based on their unique ability to rapidly produce copious amounts of all subsets of type I and type III interferon (IFN-I/III) upon virus sensing, while being refractory to infection. Yet, the identity and physiological functions of pDC are still a matter of debate, in a large part due to their lack of specific expression of any single cell surface marker or gene that would allow to track them in tissues and to target them in vivo with high specificity and penetrance. Indeed, recent studies showed that previous methods that were used to identify or deplete pDC also targeted other cell types, including pDC-like cells and transitional DC (tDC) that were proposed to be responsible for all the antigen presentation ability previously attributed to steady state pDC. Hence, improving our understanding of the nature and in vivo choreography of pDC physiological functions requires the development of novel tools to unambiguously identify and track these cells, including in comparison to pDC-like cells and tDC. Here, we report successful generation of a pDC-reporter mouse model, by using an intersectional genetic strategy based on the unique co-expression of Siglech and Pacsin1 in pDC. This pDC-Tomato mouse strain allows specific ex vivo and in situ detection of pDC. Breeding them with Zbtb46GFP mice allowed side-by-side purification and transcriptional profiling by single cell RNA sequencing of bona fide pDC, pDC-like cells and tDC, in comparison to type 1 and 2 conventional DC (cDC1 and cDC2), both at steady state and during a viral infection, revealing diverging activation patterns of pDC-like cells and tDC. Finally, by breeding pDC-Tomato mice with Ifnb1EYFP mice, we determined the choreography of pDC recruitment to the micro-anatomical sites of viral replication in the spleen, with initially similar but later divergent behaviors of the pDC that engaged or not into IFN-I production. Our novel pDC-Tomato mouse model, and newly identified gene modules specific to combinations of DC types and activations states, will constitute valuable resources for a deeper understanding of the functional division of labor between DC types and its molecular regulation at homeostasis and during viral infections.


2021 ◽  
Vol 9 (Suppl 1) ◽  
pp. A3.2-A4
Author(s):  
J Grün ◽  
I Piseddu ◽  
C Perleberg ◽  
N Röhrle ◽  
S Endres ◽  
...  

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.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A901-A901
Author(s):  
Jinho Kang ◽  
Eunkyo Joung ◽  
Hunwoo Shin ◽  
Byung cheol Ahn ◽  
Eunjung Jung ◽  
...  

BackgroundAST-021p, which is derived from HLA class II binding epitopes of human HSP90 protein, is an investigational therapeutic cancer vaccine for the malignant neoplasms. AST-021p is designed to demonstrate the immunologic efficacy by activating antigen-specific CD4+ Th1 cell in humans. Due to their ability to link the innate with the adaptive immune response, Toll-like receptor (TLR) agonists are highly promising as adjuvants in vaccines against life-threatening and complex diseases such as cancer, AIDS and malaria. In this study, AST-021p was investigated to evaluate the immunogenicity and tumor growth inhibitory effect under the condition of combining with various immune adjuvants derived from TLR agonists, using in-vivo model.MethodsThree different agonists of TLR (TLR-4, TLR-2/3, TLR-7/8) were assigned to investigate the immunogenicity in each group (4 FVB mice/group, total 4 groups). AST-021p was intradermally injected 3 times with different TLR-agonists and the immunogenicity was assessed from mouse splenocyte by HSP90-specific IFN-γ ELISpot method. We also examined the efficacy of AST-021p and selected TLR-agonist in MMTVneu Tg mice (4 mice/group, conducted twice and A total 8 mice was assigned to each group). The combination of AST-021p and TLR-2/3 agonist (AST-021p plus TLR-2/3 agonist) was injected 3 times every 10 days to mice followed by inoculated mouse mammary cancer cell line. The tumor volume change and immunogenicity were evaluated.ResultsThe most effective TLR-agonist as a potent immune adjuvant was a TLR-2/3 agonist (L-pampoTM, supplied by CHA Vaccine Institute). In MMTV-Neu transgenic mice, AST-021p (100 μg) plus TLR-2/3 agonist significantly enhanced immunogenicity by increasing up to 130±10 HSP-90 epitope specific T cells per 1x105 splenocytes (P<0.001). AST-021p plus TLR-2/3 agonist also showed higher tumor growth inhibitory effect (170±108 mm3) on post-implantation 35th day by suppressing mouse mammary cancer cell line (5x105)-derived tumor growth, compared with a TLR-2/3 agonist alone (1031±450 mm3).ConclusionsCombination regimen of AST-021p and TLR-2/3 agonist (as immune adjuvant) demonstrated significant immunogenicity and tumor prevention effect in in-vivo study. These data supported the clinical study of AST-021p combined with TLR-2/3 agonist as active immune adjuvant in certain tumor types, and phase 1/2 clinical program would be expected to be initiated.AcknowledgementsNot applicableTrial RegistrationNot applicableReferencesCsermely P, Schnaider T, Soti C, Prohaszka Z, Nardai G. The 90-kDa molecular chaperone family: structure, function, and clinical applications. A comprehensive review. Pharmacol Ther 1998;79,129–168.Wang H, Lu M, Yao M, Zhu W. Effects of treatment with an Hsp90 inhibitor in tumors based on 15 phase II clinical trials. Mol Clin Oncol 2016;5,326–334.Ramalingam S, Goss G, Rosell R. Schmid-Bindert G, Zaric B, Andric Z, Bondarenko I, Komov D, Ceric T, Khuri F. A randomized phase II study of ganetespib, a heat shock protein 90 inhibitor, in combination with docetaxel in second-line therapy of advanced non-small cell lung cancer (GALAXY-1). Ann Oncol Off J Eur Soc Med Oncol 2015,26,1741–1748.Ethics ApprovalAll experimental procedures involving mice were performed with the guidance protocols approved by the Institutional Animal Care and Use Committee of Korea University (IACUC, Approval number: KOREA-2019-129)ConsentIt is not an abstract containing sensitive or identifiable information.


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