scholarly journals Autophagy-related protein Vps34 controls the homeostasis and function of antigen cross-presenting CD8α+ dendritic cells

2017 ◽  
Vol 114 (31) ◽  
pp. E6371-E6380 ◽  
Author(s):  
Vrajesh V. Parekh ◽  
Sudheer K. Pabbisetty ◽  
Lan Wu ◽  
Eric Sebzda ◽  
Jennifer Martinez ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mhc Class I ◽  
Critical Role ◽  
Class I ◽  
Apoptotic Cells ◽  
Class Iii ◽  
Cross Presentation ◽  
Vacuolar Protein ◽  
And Function

The class III PI3K Vacuolar protein sorting 34 (Vps34) plays a role in both canonical and noncanonical autophagy, key processes that control the presentation of antigens by dendritic cells (DCs) to naive T lymphocytes. We generated DC-specific Vps34-deficient mice to assess the contribution of Vps34 to DC functions. We found that DCs from these animals have a partially activated phenotype, spontaneously produce cytokines, and exhibit enhanced activity of the classic MHC class I and class II antigen-presentation pathways. Surprisingly, these animals displayed a defect in the homeostatic maintenance of splenic CD8α+ DCs and in the capacity of these cells to cross-present cell corpse-associated antigens to MHC class I-restricted T cells, a property that was associated with defective expression of the T-cell Ig mucin (TIM)-4 receptor. Importantly, mice deficient in the Vps34-associated protein Rubicon, which is critical for a noncanonical form of autophagy called “Light-chain 3 (LC3)-associated phagocytosis” (LAP), lacked such defects. Finally, consistent with their defect in the cross-presentation of apoptotic cells, DC-specific Vps34-deficient animals developed increased metastases in response to challenge with B16 melanoma cells. Collectively, our studies have revealed a critical role of Vps34 in the regulation of CD8α+ DC homeostasis and in the capacity of these cells to process and present antigens associated with apoptotic cells to MHC class I-restricted T cells. Our findings also have important implications for the development of small-molecule inhibitors of Vps34 for therapeutic purposes.

IFN-α enhances cross-presentation in human dendritic cells by modulating antigen survival, endocytic routing, and processing

Blood ◽  
2012 ◽  
Vol 119 (6) ◽  
pp. 1407-1417 ◽  
Author(s):  
Francesca Spadaro ◽  
Caterina Lapenta ◽  
Simona Donati ◽  
Laura Abalsamo ◽  
Vincenzo Barnaba ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Tumor Development ◽  
Class I ◽  
Cross Presentation ◽  
The Cross ◽  
Human Dendritic Cells

Abstract Cross-presentation allows antigen-presenting cells to present exogenous antigens to CD8+ T cells, playing an essential role in controlling infections and tumor development. IFN-α induces the rapid differentiation of human mono-cytes into dendritic cells, known as IFN-DCs, highly efficient in mediating cross-presentation, as well as the cross-priming of CD8+ T cells. Here, we have investigated the mechanisms underlying the cross-presentation ability of IFN-DCs by studying the intracellular sorting of soluble ovalbumin and nonstructural-3 protein of hepatitis C virus. Our results demonstrate that, independently from the route and mechanism of antigen entry, IFN-DCs are extraordinarily competent in preserving internalized proteins from early degradation and in routing antigens toward the MHC class-I processing pathway, allowing long-lasting, cross-priming capacity. In IFN-DCs, both early and recycling endosomes function as key compartments for the storage of both antigens and MHC-class I molecules and for proteasome- and transporter-associated with Ag processing–dependent auxiliary cross-presentation pathways. Because IFN-DCs closely resemble human DCs naturally occurring in vivo in response to infections and other danger signals, these findings may have important implications for the design of vaccination strategies in neoplastic or chronic infectious diseases.

scholarly journals Constitutive versus Activation-dependent Cross-Presentation of Immune Complexes by CD8+ and CD8− Dendritic Cells In Vivo

2002 ◽  
Vol 196 (6) ◽  
pp. 817-827 ◽  
Author(s):  
Joke M.M. den Haan ◽  
Michael J. Bevan
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Immune Complexes ◽  
Class I ◽  
Cross Presentation ◽  
Deficient Mice ◽  
Mhc Class I Molecules

Murine splenic dendritic cells (DCs) can be divided into two subsets based on CD8α expression, but the specific role of each subset in stimulation of T cells is largely unknown. An important function of DCs is the ability to take up exogenous antigens and cross-present them in the context of major histocompatibility complex (MHC) class I molecules to CD8+ T cells. We previously demonstrated that, when cell-associated ovalbumin (OVA) is injected into mice, only the CD8+ DC subset cross-presents OVA in the context of MHC class I. In contrast to this selectivity with cell-associated antigen, we show here that both DC subsets isolated from mice injected with OVA/anti-OVA immune complexes (OVA-IC) cross-present OVA to CD8+ T cells. The use of immunoglobulin G Fc receptor (FcγR) common γ-chain–deficient mice revealed that the cross-presentation by CD8− DCs depended on the expression of γ-chain–containing activating FcγRs, whereas cross-presentation by CD8+ DCs was not reduced in γ-chain–deficient mice. These results suggest that although CD8+ DCs constitutively cross-present exogenous antigens in the context of MHC class I molecules, CD8− DCs only do so after activation, such as via ligation of FcγRs. Cross-presentation of immune complexes may play an important role in autoimmune diseases and the therapeutic effect of antitumor antibodies.

scholarly journals Host ER–parasitophorous vacuole interaction provides a route of entry for antigen cross-presentation in Toxoplasma gondii–infected dendritic cells

2009 ◽  
Vol 206 (2) ◽  
pp. 399-410 ◽  
Author(s):  
Romina S. Goldszmid ◽  
Isabelle Coppens ◽  
Avital Lev ◽  
Pat Caspar ◽  
Ira Mellman ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Toxoplasma Gondii ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Parasitophorous Vacuole ◽  
Host Cells ◽  
Class I ◽  
Cross Presentation ◽  
Infected Cells

Toxoplasma gondii tachyzoites infect host cells by an active invasion process leading to the formation of a specialized compartment, the parasitophorous vacuole (PV). PVs resist fusion with host cell endosomes and lysosomes and are thus distinct from phagosomes. Because the parasite remains sequestered within the PV, it is unclear how T. gondii–derived antigens (Ag’s) access the major histocompatibility complex (MHC) class I pathway for presentation to CD8+ T cells. We demonstrate that recruitment of host endoplasmic reticulum (hER) to the PV in T. gondii–infected dendritic cells (DCs) directly correlates with cross-priming of CD8+ T cells. Furthermore, we document by immunoelectron microscopy the transfer of hER components into the PV, a process indicative of direct fusion between the two compartments. In strong contrast, no association between hER and phagosomes or Ag presentation activity was observed in DCs containing phagocytosed live or dead parasites. Importantly, cross-presentation of parasite-derived Ag in actively infected cells was blocked when hER retrotranslocation was inhibited, indicating that the hER serves as a conduit for the transport of Ag between the PV and host cytosol. Collectively, these findings demonstrate that pathogen-driven hER–PV interaction can serve as an important mechanism for Ag entry into the MHC class I pathway and CD8+ T cell cross-priming.

scholarly journals Dendritic Cells Cross-Present Latency Gene Products from Epstein-Barr Virus–Transformed B Cells and Expand Tumor-Reactive Cd8+ Killer T Cells

2001 ◽  
Vol 193 (3) ◽  
pp. 405-412 ◽  
Author(s):  
Marion Subklewe ◽  
Casper Paludan ◽  
Ming L. Tsang ◽  
Karsten Mahnke ◽  
Ralph M. Steinman ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mhc Class I ◽  
Cd8 T Cells ◽  
Epstein Barr Virus ◽  
Class I ◽  
Nuclear Antigen ◽  
Cross Presentation ◽  
Barr Virus ◽  
Epstein Barr

Dendritic cells (DCs) are not targets for infection by the transforming Epstein-Barr virus (EBV). To test if the adjuvant role of DCs could be harnessed against EBV latency genes by cross-presentation, DCs were allowed to process either autologous or human histocompatibility leukocyte antigen (HLA)-mismatched, transformed, B lymphocyte cell lines (LCLs) that had been subject to apoptotic or necrotic cell death. After phagocytosis of small numbers of either type of dead LCL, which lacked direct immune-stimulatory capacity, DCs could expand CD8+ T cells capable of killing LCLs that were HLA matched to the DCs. Necrotic EBV-transformed, major histocompatibility complex (MHC) class I–negative LCLs, when presented by DCs, also could elicit responses to MHC class II–negative, EBV-transformed targets that were MHC class I matched to the DCs, confirming efficient cross-presentation of LCL antigens via MHC class I on the DC. Part of this EBV-specific CD8+ T cell response, in both lytic and interferon γ secretion assays, was specific for the EBV nuclear antigen (EBNA)3A and latent membrane protein (LMP)2 latency antigens that are known to be expressed at low levels in transformed cells. The induced CD8+ T cells recognized targets at low doses, 1–10 nM, of peptide. Therefore, the capacity of DCs to cross-present antigens from dead cells extends to the expansion of high affinity T cells specific for viral latency antigens involved in cell transformation.

scholarly journals Mechanisms of antigen presentation to T cells in murine graft-versus-host disease: cross-presentation and the appearance of cross-presentation

Blood ◽  
2011 ◽  
Vol 118 (24) ◽  
pp. 6426-6437 ◽  
Author(s):  
Xiaojian Wang ◽  
Hongmei Li ◽  
Catherine Matte-Martone ◽  
Weiguo Cui ◽  
Ning Li ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Mhc Class I ◽  
Large Scale ◽  
Class I ◽  
Type I ◽  
Minor Histocompatibility Antigens ◽  
Cd8 Cells ◽  
Cross Presentation ◽  
Peptide Complexes

Abstract Recipient antigen-presenting cells (APCs) initiate GVHD by directly presenting host minor histocompatibility antigens (miHAs) to donor CD8 cells. However, later after transplantation, host APCs are replaced by donor APCs, and if pathogenic CD8 cells continue to require APC stimulation, then donor APCs must cross-present host miHAs. Consistent with this, CD8-mediated GVHD is reduced when donor APCs are MHC class I−. To study cross-presentation, we used hosts that express defined MHC class I Kb-restricted miHAs, crossed to Kb-deficient backgrounds, such that these antigens cannot be directly presented. Cross-priming was surprisingly efficient, whether antigen was restricted to the hematopoietic or nonhematopoietic compartments. Cross-primed CD8 cells were cytolytic and produced IFN-γ. CD8 cells were exclusively primed by donor CD11c+ cells, and optimal cross-priming required that they are stimulated by both type I IFNs and CD40L. In studying which donor APCs acquire host miHAs, we made the surprising discovery that there was a large-scale transfer of transmembrane proteins from irradiated hosts, including MHC class I–peptide complexes, to donor cells, including dendritic cells. Donor dendritic cells that acquired host MHC class I–peptide complexes were potent stimulators of peptide-specific T cells. These studies identify new therapeutic targets for GVHD treatment and a novel mechanism whereby donor APCs prime host-reactive T cells.

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