scholarly journals Liposomal TLR9 Agonist Combined with TLR2 Agonist-Fused Antigen Can Modulate Tumor Microenvironment through Dendritic Cells

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 810 ◽  
Author(s):  
Kuan-Yin Shen ◽  
Hsin-Yu Liu ◽  
Wan-Lun Yan ◽  
Chiao-Chieh Wu ◽  
Ming-Hui Lee ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Tumor Microenvironment ◽  
T Cell Activation ◽  
Antitumor Immunity ◽  
Cell Activation ◽  
Cpg Oligodeoxynucleotides ◽  
Maturation In Vitro ◽  
Immunosuppressive Cells

Dendritic cells (DCs) are antigen-presenting cells involved in T cell activation and differentiation to regulate immune responses. Lipoimmunogens can be developed as pharmaceutical lipoproteins for cancer immunotherapy to target DCs via toll-like receptor 2 (TLR2) signaling. Previously, we constructed a lipoimmunogen, a lipidated human papillomavirus (HPV) E7 inactive mutant (rlipoE7m), to inhibit the growth of HPV16 E7-expressing tumor cells in a murine model. Moreover, this antitumor effect could be enhanced by a combinatory treatment with CpG oligodeoxynucleotides (ODN). To improve safety, we developed a rlipoE7m plus DOTAP liposome-encapsulated native phosphodiester CpG (POCpG/DOTAP) treatment to target DCs to enhance antitumor immunity. We optimized the formulation of rlipoE7m and POCpG/DOTAP liposomes to promote conventional DC and plasmacytoid DC maturation in vitro and in vivo. Combination of rlipoE7m plus POCpG/DOTAP could activate conventional DCs and plasmacytoid DCs to augment IL-12 production to promote antitumor responses by intravenous injection. In addition, the combination of rlipoE7m plus POCpG/DOTAP could elicit robust cytotoxic T lymphocytes (CTLs) by intravenous immunization. Interestingly, the combination of rlipoE7m plus POCpG/DOTAP could efficiently inhibit tumor growth via intravenous immunization. Moreover, rlipoE7m plus POCpG/DOTAP combined reduced the number of tumor-infiltrating regulatory T cells dramatically due to downregulation of IL-10 production by DCs. These results showed that the combination of rlipoE7m plus POCpG/DOTAP could target DCs via intravenous delivery to enhance antitumor immunity and reduce the number of immunosuppressive cells in the tumor microenvironment.

scholarly journals In Vivo Role of Dendritic Cells in a Murine Model of Pulmonary Cryptococcosis

2006 ◽  
Vol 74 (7) ◽  
pp. 3817-3824 ◽  
Author(s):  
Karen L. Wozniak ◽  
Jatin M. Vyas ◽  
Stuart M. Levitz
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Mouse Lung

ABSTRACT Dendritic cells (DC) have been shown to phagocytose and kill Cryptococcus neoformans in vitro and are believed to be important for inducing protective immunity against this organism. Exposure to C. neoformans occurs mainly by inhalation, and in this study we examined the in vivo interactions of C. neoformans with DC in the lung. Fluorescently labeled live C. neoformans and heat-killed C. neoformans were administered intranasally to C57BL/6 mice. At specific times postinoculation, mice were sacrificed, and lungs were removed. Single-cell suspensions of lung cells were prepared, stained, and analyzed by microscopy and flow cytometry. Within 2 h postinoculation, fluorescently labeled C. neoformans had been internalized by DC, macrophages, and neutrophils in the mouse lung. Additionally, lung DC from mice infected for 7 days showed increased expression of the maturation markers CD80, CD86, and major histocompatibility complex class II. Finally, ex vivo incubation of lung DC from infected mice with Cryptococcus-specific T cells resulted in increased interleukin-2 production compared to the production by DC from naïve mice, suggesting that there was antigen-specific T-cell activation. This study demonstrated that DC in the lung are capable of phagocytosing Cryptococcus in vivo and presenting antigen to C. neoformans-specific T cells ex vivo, suggesting that these cells have roles in innate and adaptive pulmonary defenses against cryptococcosis.

scholarly journals Dendritic Cell Responses to Early Murine Cytomegalovirus Infection

2003 ◽  
Vol 197 (7) ◽  
pp. 885-898 ◽  
Author(s):  
Marc Dalod ◽  
Tanya Hamilton ◽  
Rachelle Salomon ◽  
Thais P. Salazar-Mather ◽  
Stanley C. Henry ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Lymphocyte Activation ◽  
Murine Cytomegalovirus ◽  
Cell Responses ◽  
Dc Maturation

Differentiation of dendritic cells (DCs) into particular subsets may act to shape innate and adaptive immune responses, but little is known about how this occurs during infections. Plasmacytoid dendritic cells (PDCs) are major producers of interferon (IFN)-α/β in response to many viruses. Here, the functions of these and other splenic DC subsets are further analyzed after in vivo infection with murine cytomegalovirus (MCMV). Viral challenge induced PDC maturation, their production of high levels of innate cytokines, and their ability to activate natural killer (NK) cells. The conditions also licensed PDCs to efficiently activate CD8 T cells in vitro. Non-plasmacytoid DCs induced T lymphocyte activation in vitro. As MCMV preferentially infected CD8α+ DCs, however, restricted access to antigens may limit plasmacytoid and CD11b+ DC contribution to CD8 T cell activation. IFN-α/β regulated multiple DC responses, limiting viral replication in all DC and IL-12 production especially in the CD11b+ subset but promoting PDC accumulation and CD8α+ DC maturation. Thus, during defense against a viral infection, PDCs appear specialized for initiation of innate, and as a result of their production of IFN-α/β, regulate other DCs for induction of adaptive immunity. Therefore, they may orchestrate the DC subsets to shape endogenous immune responses to viruses.

Differentiation of myeloid dendritic cells into CD8α-positive dendritic cells in vivo

Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1865-1872 ◽  
Author(s):  
Miriam Merad ◽  
Lawrence Fong ◽  
Jakob Bogenberger ◽  
Edgar G. Engleman
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Wild Type Mouse ◽  
Interleukin 12 ◽  
Myeloid Dendritic Cells ◽  
Myeloid Antigens

Bone marrow-derived dendritic cells (DC) represent a family of antigen-presenting cells (APC) with varying phenotypes. For example, in mice, CD8α+ and CD8α− DC are thought to represent cells of lymphoid and myeloid origin, respectively. Langerhans cells (LC) of the epidermis are typical myeloid DC; they do not express CD8α, but they do express high levels of myeloid antigens such as CD11b and FcγR. By contrast, thymic DC, which derive from a lymphoid-related progenitor, express CD8α but only low levels of myeloid antigens. CD8α+ DC are also found in the spleen and lymph nodes (LN), but the origin of these cells has not been determined. By activating and labeling CD8α− epidermal LC in vivo, it was found that these cells expressed CD8α on migration to the draining LN. Similarly, CD8α− LC generated in vitro from a CD8 wild-type mouse and injected into the skin of a CD8αKO mouse expressed CD8α when they reached the draining LN. The results also show that CD8α+ LC are potent APC. After migration from skin, they localized in the T-cell areas of LN, secreted high levels of interleukin-12, interferon-γ, and chemokine-attracting T cells, and they induced antigen-specific T-cell activation. These results demonstrate that myeloid DC in the periphery can express CD8α when they migrate to the draining LN. CD8α expression on these DC appears to reflect a state of activation, mobilization, or both, rather than lineage.

scholarly journals Towards Identification of the Mechanisms of Action of Parasite-Derived Peptide GK1 on the Immunogenicity of an Influenza Vaccine

2009 ◽  
Vol 16 (9) ◽  
pp. 1338-1343 ◽  
Author(s):  
René Segura-Velázquez ◽  
Gladis Fragoso ◽  
Edda Sciutto ◽  
Adelaida Sarukhan
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Influenza Vaccine ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mechanisms Of Action ◽  
The Body ◽  
Vaccine Adjuvants

ABSTRACT Previous studies have shown that the synthetic peptide GK1, derived from Taenia crassiceps cysticerci, enhances the immunogenicity of the commercial inactivated influenza vaccine Fluzone in both young and aged mice. In particular, antibody responses were much improved. Since GK1 is a peptide and is rapidly cleared from the body, it offers the possibility to improve vaccine performance without undesirable effects. This study was therefore designed to understand the mechanisms of action involved in the adjuvant properties of GK1. For this, transgenic mice expressing a T-cell receptor specific for an epitope from the influenza virus hemagglutinin (HA) protein were employed. The GK1 peptide significantly increased the in vivo proliferative response of HA-specific CD4+ T cells when it was coimmunized with the HA epitope. Dendritic cells treated in vitro with GK1 were capable of enhancing T-cell activation. Furthermore, in synergy with lipopolysaccharide, GK1 enhanced the expression of major histocompatibility complex class II and costimulatory molecules of dendritic cells and promoted the secretion of proinflammatory cytokines and chemokines upon antigen-driven T-cell interaction. These data provide important insights into the mechanism that underlies the GK1 adjuvant capacity observed previously and underline the feasibility of using the transgenic mouse model described herein as a tool for investigation of the modes of action of different influenza vaccine adjuvants.

Bone marrow microenvironment controls the in vivo differentiation of murine dendritic cells into osteoclasts

Blood ◽  
2008 ◽  
Vol 112 (13) ◽  
pp. 5074-5083 ◽  
Author(s):  
Abdelilah Wakkach ◽  
Anna Mansour ◽  
Romain Dacquin ◽  
Emmanuel Coste ◽  
Pierre Jurdic ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Bone Cells ◽  
Activated T Cells

Abstract Finding that activated T cells control osteoclast (OCL) differentiation has revealed the importance of the interactions between immune and bone cells. Dendritic cells (DCs) are responsible for T-cell activation and share common precursors with OCLs. Here we show that DCs participate in bone resorption more directly than simply through T-cell activation. We show that, among the splenic DC subsets, the conventional DCs have the higher osteoclastogenic potential in vitro. We demonstrate that conventional DCs differentiate into functional OCLs in vivo when injected into osteopetrotic oc/oc mice defective in OCL resorptive function. Moreover, this differentiation involves the presence of activated CD4+ T cells controlling a high RANK-L expression by bone marrow stromal cells. Our results open new insights in the differentiation of OCLs and DCs and offer new basis for analyzing the relations between bone and immune systems.

Differentiation of myeloid dendritic cells into CD8α-positive dendritic cells in vivo

Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1865-1872 ◽  
Author(s):  
Miriam Merad ◽  
Lawrence Fong ◽  
Jakob Bogenberger ◽  
Edgar G. Engleman
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Wild Type Mouse ◽  
Interleukin 12 ◽  
Myeloid Dendritic Cells ◽  
Myeloid Antigens

Abstract Bone marrow-derived dendritic cells (DC) represent a family of antigen-presenting cells (APC) with varying phenotypes. For example, in mice, CD8α+ and CD8α− DC are thought to represent cells of lymphoid and myeloid origin, respectively. Langerhans cells (LC) of the epidermis are typical myeloid DC; they do not express CD8α, but they do express high levels of myeloid antigens such as CD11b and FcγR. By contrast, thymic DC, which derive from a lymphoid-related progenitor, express CD8α but only low levels of myeloid antigens. CD8α+ DC are also found in the spleen and lymph nodes (LN), but the origin of these cells has not been determined. By activating and labeling CD8α− epidermal LC in vivo, it was found that these cells expressed CD8α on migration to the draining LN. Similarly, CD8α− LC generated in vitro from a CD8 wild-type mouse and injected into the skin of a CD8αKO mouse expressed CD8α when they reached the draining LN. The results also show that CD8α+ LC are potent APC. After migration from skin, they localized in the T-cell areas of LN, secreted high levels of interleukin-12, interferon-γ, and chemokine-attracting T cells, and they induced antigen-specific T-cell activation. These results demonstrate that myeloid DC in the periphery can express CD8α when they migrate to the draining LN. CD8α expression on these DC appears to reflect a state of activation, mobilization, or both, rather than lineage.

scholarly journals Effects of Filovirus Interferon Antagonists on Responses of Human Monocyte-Derived Dendritic Cells to RNA Virus Infection

2016 ◽  
Vol 90 (10) ◽  
pp. 5108-5118 ◽  
Author(s):  
Benjamin C. Yen ◽  
Christopher F. Basler
Keyword(s):  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ebola Virus ◽  
Human Monocyte ◽  
Marburg Virus ◽  
Innate Immune ◽  
Dc Maturation

ABSTRACTDendritic cells (DCs) are major targets of filovirus infectionin vivo. Previous studies have shown that the filoviruses Ebola virus (EBOV) and Marburg virus (MARV) suppress DC maturationin vitro. Both viruses also encode innate immune evasion functions. The EBOV VP35 (eVP35) and the MARV VP35 (mVP35) proteins each can block RIG-I-like receptor signaling and alpha/beta interferon (IFN-α/β) production. The EBOV VP24 (eVP24) and MARV VP40 (mVP40) proteins each inhibit the production of IFN-stimulated genes (ISGs) by blocking Jak-STAT signaling; however, this occurs by different mechanisms, with eVP24 blocking nuclear import of tyrosine-phosphorylated STAT1 and mVP40 blocking Jak1 function. MARV VP24 (mVP24) has been demonstrated to modulate host cell antioxidant responses. Previous studies demonstrated that eVP35 is sufficient to strongly impair primary human monocyte-derived DC (MDDC) responses upon stimulation induced through the RIG-I-like receptor pathways. We demonstrate that mVP35, like eVP35, suppresses not only IFN-α/β production but also proinflammatory responses after stimulation of MDDCs with RIG-I activators. In contrast, eVP24 and mVP40, despite suppressing ISG production upon RIG-I activation, failed to block upregulation of maturation markers or T cell activation. mVP24, although able to stimulate expression of antioxidant response genes, had no measurable impact of DC function. These data are consistent with a model where filoviral VP35 proteins are the major suppressors of DC maturation during filovirus infection, whereas the filoviral VP24 proteins and mVP40 are insufficient to prevent DC maturation.IMPORTANCEThe ability to suppress the function of dendritic cells (DCs) likely contributes to the pathogenesis of disease caused by the filoviruses Ebola virus and Marburg virus. To clarify the basis for this DC suppression, we assessed the effect of filovirus proteins known to antagonize innate immune signaling pathways, including Ebola virus VP35 and VP24 and Marburg virus VP35, VP40, and VP24, on DC maturation and function. The data demonstrate that the VP35s from Ebola virus and Marburg virus are the major suppressors of DC maturation and that the effects on DCs of the remaining innate immune inhibitors are minor.

scholarly journals Deficiency of Bim in dendritic cells contributes to overactivation of lymphocytes and autoimmunity

Blood ◽  
2007 ◽  
Vol 109 (10) ◽  
pp. 4360-4367 ◽  
Author(s):  
Min Chen ◽  
Li Huang ◽  
Jin Wang
Keyword(s):  
Cell Death ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Autoantibody Production ◽  
Systemic Autoimmunity ◽  
Spontaneous Cell Death

Abstract Apoptosis in dendritic cells (DCs) can potentially regulate DC homeostasis and immune responses. We have previously observed that inhibition of the Fas signaling pathway in DCs results in spontaneous T-cell activation and the development of systemic autoimmunity in transgenic mice. However, the role for different apoptosis pathways in DCs in regulating DC homeostasis and immune tolerance remains to be determined. Bim, a BH3-only protein of the Bcl-2 family, was expressed at low levels in DCs and was significantly up-regulated by signaling from CD40 or toll-like receptors (TLRs). Because Bim−/− mice develop spontaneous systemic autoimmunity, we investigated whether Bim−/− DCs contributed to lymphoproliferation and autoimmunity in these mice. Bim−/− DCs showed decreased spontaneous cell death, and induced more robust T-cell activation in vitro and in vivo. Moreover, Bim−/− DCs induced autoantibody production after adoptive transfer. Our data suggest that Bim is important for regulating spontaneous cell death in DCs, and Bim-deficient DCs may contribute to the development of autoimmune diseases in Bim−/− mice.

scholarly journals Immune synapse instructs epigenomic and transcriptomic functional reprogramming in dendritic cells

2021 ◽  
Vol 7 (6) ◽  
pp. eabb9965
Author(s):  
Ana Alcaraz-Serna ◽  
Eugenio Bustos-Morán ◽  
Irene Fernández-Delgado ◽  
Diego Calzada-Fraile ◽  
Daniel Torralba ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Synapse ◽  
Capacity Change ◽  
Immune Synapses ◽  
Transcriptomic Signature

Understanding the fate of dendritic cells (DCs) after productive immune synapses (postsynaptic DCs) with T cells during antigen presentation has been largely neglected in favor of deciphering the nuances of T cell activation and memory generation. Here, we describe that postsynaptic DCs switch their transcriptomic signature, correlating with epigenomic changes including DNA accessibility and histone methylation. We focus on the chemokine receptor Ccr7 as a proof-of-concept gene that is increased in postsynaptic DCs. Consistent with our epigenomic observations, postsynaptic DCs migrate more efficiently toward CCL19 in vitro and display enhanced homing to draining lymph nodes in vivo. This work describes a previously unknown DC population whose transcriptomics, epigenomics, and migratory capacity change in response to their cognate contact with T cells.

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