Articles by Rubin N. Joshi in JoVE
In Vitro Differentiation of Human CD4+FOXP3+ Induced Regulatory T Cells (iTregs) from Naïve CD4+ T Cells Using a TGF-β-containing Protocol Angelika Schmidt1, Szabolcs Éliás*1, Rubin N. Joshi*1, Jesper Tegnér1 1Unit of Computational Medicine, Center for Molecular Medicine, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, & Science for Life Laboratory This protocol describes the reproducible generation and phenotyping of human induced regulatory T cells (iTregs) from naïve CD4+ T cells in vitro. Different protocols for FOXP3 induction allow for the study of specific iTreg phenotypes obtained with respective protocols.
Other articles by Rubin N. Joshi on PubMed
Human Plasmacytoid Dendritic Cells Are Equipped with Antigen-presenting and Tumoricidal Capacities Blood. Nov, 2012 | Pubmed ID: 22966165 Human plasmacytoid dendritic cells (pDCs) represent a highly specialized naturally occurring dendritic-cell subset and are the main producers of type I interferons (IFNs) in response to viral infections. We show that human pDCs activated by the preventive vaccine FSME specifically up-regulate CD56 on their surface, a marker that was thought to be specific for NK cells and associated with cytolytic effector functions. We observed that FSME-activated pDCs specifically lysed NK target cells and expressed cytotoxic molecules, such as tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and granzyme B. Elevated levels of these molecules coincided with the expression of CD56, indicative for skewing human pDCs toward an interferon-producing killer DC subset. Detailed phenotypical and functional analysis revealed that pDCs attained a mature phenotype, secreted proinflammatory cytokines, and had the capacity to present antigens and stimulate T cells. Here, we report on the generation of CD56(+) human interferon producing killer pDCs with the capacity to present antigens. These findings aid in deciphering the role for pDCs in antitumor immunity and present a promising prospect of developing antitumor therapy using pDCs.
Human Macrophages Induce CD4(+)Foxp3(+) Regulatory T Cells Via Binding and Re-release of TGF-β Immunology and Cell Biology. Sep, 2016 | Pubmed ID: 27075967 While pro-inflammatory immune responses are a requirement to combat microbes, uncontrolled self-directed inflammatory immune responses are the hallmark of autoimmune diseases. Restoration of immunological tolerance involves both suppression of ongoing tissue-destructive immune responses and re-education of the host immune system. Both functionally immunosuppressive macrophages (M2) and regulatory T cells (Tregs) are implicated in these processes. Their mutual interaction is synergistic in this context and adoptive transfer of each cell type has been functioning as immunotherapy in experimental models, being particularly effective when using M2 macrophages generated with an optimized interleukin-4 (IL-4)/interleukin-10 (IL-10)/transforming growth factor-β (TGF-β) combination. As a prerequisite for eventual translation of M2 therapy into clinical settings we herein studied the induction, stability and mechanism of generation of human induced Tregs (iTregs) by M2 macrophages generated with IL-4/IL-10/TGF-β. The supernatants of monocyte-derived human M2 macrophages robustly induced FOXP3 and other Treg signature molecules such as CTLA-4 and IKZF4 in human naïve CD4 T cells. M2-induced iTregs displayed enhanced FOXP3 stability and low expression of pro-inflammatory cytokines interferon-γ and IL-17, as well as functional immunosuppressive activity compared with control T cells. The FOXP3-inducing activity was dependent on TGF-β, which was both expressed and captured with re-release by M2 macrophages into the soluble supernatant fraction, in which the TGF-β was not confined to extracellular vesicles such as exosomes. We propose that adoptive transfer of human M2 macrophages may be exploited in the future to induce Tregs in situ by delivering TGF-β, which could be developed as a therapeutic strategy to target autoimmune and other inflammatory diseases.