CD8+ T cells are essential for adaptive immunity against infection and tumors. Their ability to proliferate after stimulation is crucial to their functionality. Dendritic cells (DCs) are professional antigen-presenting cells that induce their proliferation. Here, we show that thapsigargin-induced LAD2 mast cell (MC) line-released products can impair the ability of monocyte-derived DCs to induce CD8+ T-cell proliferation and the generation of Th1 cytokine-producing T cells. We found that culture medium conditioned with LAD2 MCs previously stimulated with thapsigargin (thapsLAD2) induces maturation of DCs as determined by the maturation markers CD80, CD83, CD86, and HLA-DR. However, thapsLAD2-matured DCs produced no detectable TNFα or IL-12 during the maturation. In addition, although their surface expression of PD-L1 was comparable with the immature or TLR7/8-agonist (R848)-matured DCs, their TIM-3 expression was significantly higher than in immature DCs and even much higher than in R848-matured DCs. In addition, contrary to R848-matured DCs, the thapsLAD2-matured DCs only tended to induce enhanced proliferation of CD4+ T cells than immature DCs. For CD8+ T cells, this tendency was not even detected because thapsLAD2-matured and immature DCs comparably induced their proliferation, which contrasted with the significantly enhanced proliferation induced by R848-matured DCs. Furthermore, these differences were comparably recapitulated in the ability of the tested DCs to induce IFNγ- and IFNγ/TNFα-producing T cells. These findings show a novel mechanism of MC-mediated regulation of adaptive immune responses.

• MeSH
• aktivace lymfocytů * účinky léků   imunologie   MeSH
• buněčná diferenciace * účinky léků   MeSH
• buněčné linie MeSH
• buněčný receptor 2 viru hepatitidy A metabolismus   MeSH
• CD8-pozitivní T-lymfocyty * imunologie   účinky léků   MeSH
• cytokiny metabolismus   MeSH
• dendritické buňky * imunologie   účinky léků   metabolismus   MeSH
• imidazoly farmakologie   MeSH
• lidé MeSH
• mastocyty * imunologie   účinky léků   metabolismus   MeSH
• monocyty imunologie   účinky léků   metabolismus   MeSH
• proliferace buněk * účinky léků   MeSH
• thapsigargin * farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• buněčný receptor 2 viru hepatitidy A MeSH
• cytokiny MeSH
• HAVCR2 protein, human MeSH Prohlížeč
• imidazoly MeSH
• thapsigargin * MeSH

The preparation of dendritic cells (DCs) for adoptive cellular immunotherapy (ACI) requires the maturation of ex vivo-produced immature(i) DCs. This maturation ensures that the antigen presentation triggers an immune response towards the antigen-expressing cells. Although there is a large number of maturation agents capable of inducing strong DC maturation, there is still only a very limited number of these agents approved for use in the production of DCs for ACI. In seeking novel DC maturation agents, we used differentially activated human mast cell (MC) line LAD2 as a cellular adjuvant to elicit or modulate the maturation of ex vivo-produced monocyte-derived iDCs. We found that co-culture of iDCs with differentially activated LAD2 MCs in serum-containing media significantly modulated polyinosinic:polycytidylic acid (poly I:C)-elicited DC maturation as determined through the surface expression of the maturation markers CD80, CD83, CD86, and human leukocyte antigen(HLA)-DR. Once iDCs were generated in serum-free conditions, they became refractory to the maturation with poly I:C, and the LAD2 MC modulatory potential was minimized. However, the maturation-refractory phenotype of the serum-free generated iDCs was largely overcome by co-culture with thapsigargin-stimulated LAD2 MCs. Our data suggest that differentially stimulated mast cells could be novel and highly potent cellular adjuvants for the maturation of DCs for ACI.

• Klíčová slova
• LAD2 human mast cells, adoptive cellular immunotherapy, dendritic cells, maturation,
• MeSH
• adjuvancia imunologická farmakologie   MeSH
• buněčná diferenciace účinky léků   MeSH
• buněčné kultury metody   MeSH
• dendritické buňky cytologie   účinky léků   imunologie   MeSH
• imunoterapie adoptivní * MeSH
• kokultivační techniky MeSH
• lidé MeSH
• mastocyty cytologie   účinky léků   imunologie   MeSH
• monocyty cytologie   účinky léků   imunologie   MeSH
• prezentace antigenu účinky léků   imunologie   MeSH
• thapsigargin farmakologie   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adjuvancia imunologická MeSH
• thapsigargin MeSH

The use of patient-derived dendritic cells (DCs) as a means to elicit therapeutically relevant immune responses in cancer patients has been extensively investigated throughout the past decade. In this context, DCs are generally expanded, exposed to autologous tumor cell lysates or loaded with specific tumor-associated antigens (TAAs), and then reintroduced into patients, often in combination with one or more immunostimulatory agents. As an alternative, TAAs are targeted to DCs in vivo by means of monoclonal antibodies, carbohydrate moieties or viral vectors specific for DC receptors. All these approaches have been shown to (re)activate tumor-specific immune responses in mice, often mediating robust therapeutic effects. In 2010, the first DC-based preparation (sipuleucel-T, also known as Provenge®) has been approved by the US Food and Drug Administration (FDA) for use in humans. Reflecting the central position occupied by DCs in the regulation of immunological tolerance and adaptive immunity, the interest in harnessing them for the development of novel immunotherapeutic anticancer regimens remains high. Here, we summarize recent advances in the preclinical and clinical development of DC-based anticancer therapeutics.

• Klíčová slova
• DC, dendritic cell, DC-based vaccination, FDA, Food and Drug Administration, IFN, interferon, MRC1, mannose receptor, C type 1, MUC1, mucin 1, TAA, tumor-associated antigen, TLR, Toll-like receptor, Toll-like receptor agonists, Treg, regulatory T cell, WT1, Wilms tumor 1, antigen cross-presentation, autophagy, iDC, immature DC, immunogenic cell death, mDC, mature DC, pDC, plasmacytoid DC, regulatory T cells,
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH