scholarly journals 693 Mucosal-associated invariant T (MAIT) cell regulation networks in anti-tumor immunity

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A721-A721
Author(s):  
Benjamin Ruf ◽  
Vanessa Catania ◽  
Noemi Kedei ◽  
Simon Wabitsch ◽  
Chi Ma ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Cell Fate ◽  
Mouse Strains ◽  
Murine Models ◽  
Humoral Factors ◽  
Mait Cells ◽  
Novel Target ◽  
Anti Tumor Activity ◽  
Mait Cell

BackgroundMAIT cells are MR1-restricted innate-like T cells that recognize non-peptide antigens including riboflavin derivates. They account for up to 10 % of circulating T cells, but they are further enriched at mucosal sites and the liver. On one hand, altered MAIT number and function have been reported in liver cancer with MAITs correlating with poor clinical outcome. On the other hand, we recently demonstrated that MAIT cells can potentially have anti-tumor activity suggesting them as a novel target for cancer immunotherapy. Yet, the cellular and humoral factors that determine MAIT cell fate in the context of malignancies remain largely unknown.MethodsHighly multiplexed immunofluorescence-based CODEX imaging and high-dimensional flow cytometry was used to analyze MAIT cell infiltration and phenotype in human HCC samples. We recently developed an experimental framework to manipulate MAIT cells in vivo using VitaminB2 synthesis pathway-derived antigen 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU) in combination with Toll-like receptor 9 agonist CpG. Next, we used murine models of orthotopic primary liver cancer and liver metastasis across two different mouse strains, to assess anti-tumor activity of MAIT cells. A series of pharmacological depletion experiments and genomic knockout mouse strains were used to identify additional effector immune cells and humoral factors mediating the anti-tumor effect.ResultsUsing flow cytometry and spatially resolved analysis of multiplexed CODEX microscopy images, we found impaired infiltration and altered phenotype of MAIT cells in human HCC tumors compared to unaffected liver tissue. Thus, we sought out to experimentally increase MAIT cell infiltration into liver cancers using murine models. Co-administration of 5-OP-RU + CpG induced a strong systemic in vivo expansion and activation of MAIT cells with Th1/NK-like polarization. We found MAIT cells to be potent orchestrators of anti-tumor function in vivo when activated by a combination of 5-OP-RU + CpG. MAIT-directed 5-OP-RU/CpG showed pronounced and consistent anti-tumor activity against different models of liver cancer and prolonged mouse survival. Importantly, such tumor inhibition was absent in MAIT-deficient MR1 k.o. mice but nor dependent on MR1 expression on tumor cells. Additional pharmacological depletion studies/genomic k.o. models helped to identify antigen presenting cells, downstream effector cells as well as co-stimulatory cytokines as critical components needed for MAIT-induced tumor suppression.ConclusionsMAIT cells are important players in cancer immunology and represent an attractive novel target for cancer immunotherapy. Fine-tuned, context-dependent mechanisms determine MAIT-cell fate in vivo as they undergo a phenotypic switch upon 5-OP-RU and CpG treatment enabling them to exert potent anti-tumor function.

scholarly journals MAIT cells regulate NK cell-mediated tumor immunity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Emma V. Petley ◽  
Hui-Fern Koay ◽  
Melissa A. Henderson ◽  
Kevin Sek ◽  
Kirsten L. Todd ◽  
...  
Keyword(s):  
Nk Cells ◽  
Tumor Immunity ◽  
Nk Cell ◽  
Prognostic Significance ◽  
Human Tumor ◽  
Gene Signature ◽  
Mouse Tumor ◽  
Mait Cells ◽  
Mait Cell

AbstractThe function of MR1-restricted mucosal-associated invariant T (MAIT) cells in tumor immunity is unclear. Here we show that MAIT cell-deficient mice have enhanced NK cell-dependent control of metastatic B16F10 tumor growth relative to control mice. Analyses of this interplay in human tumor samples reveal that high expression of a MAIT cell gene signature negatively impacts the prognostic significance of NK cells. Paradoxically, pre-pulsing tumors with MAIT cell antigens, or activating MAIT cells in vivo, enhances anti-tumor immunity in B16F10 and E0771 mouse tumor models, including in the context of established metastasis. These effects are associated with enhanced NK cell responses and increased expression of both IFN-γ-dependent and inflammatory genes in NK cells. Importantly, activated human MAIT cells also promote the function of NK cells isolated from patient tumor samples. Our results thus describe an activation-dependent, MAIT cell-mediated regulation of NK cells, and suggest a potential therapeutic avenue for cancer treatment.

scholarly journals Influenza A Virus Infection v1

2020 ◽  
Author(s):  
Timothy S C Hinks ◽  
Bonnie van Wilgenburg ◽  
Huimeng Wang ◽  
Liyen Loh ◽  
Marios Koutsakos ◽  
...  
Keyword(s):  
Influenza A ◽  
Cell Activation ◽  
Viral Infections ◽  
Intracellular Cytokine Staining ◽  
Cell Receptor ◽  
Type I ◽  
Independent Manner ◽  
Mait Cells ◽  
Mait Cell

This is part 3.3 of the "Study of MAIT Cell Activation in Viral Infections In Vivo" collection of protocols. Collection Abstract: MAIT cells are abundant, highly evolutionarily conserved innate-like lymphocytes expressing a semi-invariant T cell receptor (TCR), which recognizes microbially derived small intermediate molecules from the riboflavin biosynthetic pathway. However, in addition to their TCR-mediated functions they can also be activated in a TCR-independent manner via cytokines including IL-12, -15, -18, and type I interferon. Emerging data suggest that they are expanded and activated by a range of viral infections, and significantly that they can contribute to a protective anti-viral response. Here we describe methods used to investigate these anti-viral functions in vivo in murine models. To overcome the technical challenge that MAIT cells are rare in specific pathogen-free laboratory mice, we describe how pulmonary MAIT cells can be expanded using intranasal bacterial infection or a combination of synthetic MAIT cell antigen and TLR agonists. We also describe protocols for adoptive transfer of MAIT cells, methods for lung homogenization for plaque assays, and surface and intracellular cytokine staining to determine MAIT cell activation.

scholarly journals MAIT cell-directed therapy of Mycobacterium tuberculosis infection

2020 ◽  
Vol 14 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Shunsuke Sakai ◽  
Keith D. Kauffman ◽  
Sangmi Oh ◽  
Christine E. Nelson ◽  
Clifton E. Barry ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Cd4 T Cell ◽  
Mycobacterium Tuberculosis Infection ◽  
Mait Cells ◽  
T Cell Priming ◽  
Draining Lymph Nodes ◽  
Mait Cell

AbstractMucosal-associated invariant T (MAIT) cells are potential targets of vaccination and host-directed therapeutics for tuberculosis, but the role of MAIT cells during Mycobacterium tuberculosis (Mtb) infection in vivo is not well understood. Here we find that following Mtb infection MAIT cells mount minimal responses, and MAIT cell-deficient MR1−/− mice display normal survival. Preinfection expansion of MAIT cells through 5-OP-RU vaccination fails to protect against subsequent Mtb challenge. In fact, 5-OP-RU vaccination delays Mtb-specific CD4 T cell priming in lung-draining lymph nodes, and conversely MR1 deficiency or blockade accelerates T cell priming. The MAIT cell-mediated delay in T cell priming is partly dependent on TGF-β. Surprisingly, 5-OP-RU treatment during chronic infection drives MAIT cell expansion and an IL-17A-dependent reduction in bacterial loads. Thus, during early infection MAIT cells directly contribute to the notoriously slow priming of CD4 T cells, but later during infection MAIT cell stimulation may be an effective host-directed therapy for tuberculosis.

scholarly journals The Good, the Bad, the Question–H19 in Hepatocellular Carcinoma

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1261 ◽  
Author(s):  
Lysann Tietze ◽  
Sonja M. Kessler
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cancer Therapy ◽  
Liver Cancer ◽  
Primary Liver Cancer ◽  
Human Patient ◽  
In Vivo Models ◽  
Study Results ◽  
Novel Target

Hepatocellular carcinoma (HCC), the most common primary liver cancer, is challenging to treat due to its typical late diagnosis, mostly at an advanced stage. Therefore, there is a particular need for research in diagnostic and prognostic biomarkers and therapeutic targets for HCC. The use of long noncoding (lnc) RNAs can widen the list of novel molecular targets improving cancer therapy. In hepatocarcinogenesis, the role of the lncRNA H19, which has been known for more than 30 years now, is still controversially discussed. H19 was described to work either as a tumor suppressor in vitro and in vivo, or to have oncogenic features. This review attempts to survey the conflicting study results and tries to elucidate the potential reasons for the contrary findings, i.e., different methods, models, or readout parameters. This review encompasses in vitro and in vivo models as well as studies on human patient samples. Although the function of H19 in HCC remains elusive, a short outlook summarizes some ideas of using the H19 locus as a novel target for liver cancer therapy.

scholarly journals Activation of MAIT cells plays a critical role in viral vector vaccine immunogenicity

2019 ◽  
Author(s):  
Nicholas M. Provine ◽  
Ali Amini ◽  
Lucy C. Garner ◽  
Christina Dold ◽  
Claire Hutchings ◽  
...  
Keyword(s):  
Cell Activation ◽  
Viral Vector ◽  
Critical Role ◽  
Vector Vaccine ◽  
Future Design ◽  
Mait Cells ◽  
Lethal Infection ◽  
Mait Cell

AbstractMucosal-associated invariant T (MAIT) cells can be activated by viruses through a cytokine-dependent mechanism, and thereby protect from lethal infection. Given this, we reasoned MAIT cells may have a critical role in the immunogenicity of replication-incompetent adenovirus vectors, which are novel and highly potent vaccine platforms. In vitro, ChAdOx1 (Chimpanzee Adenovirus Ox1) induced potent activation of MAIT cells. Activation required transduction of monocytes and plasmacytoid dendritic cells to produce IL-18 and IFN-α, respectively. IFN-α-induced monocyte-derived TNF-α was identified as a novel intermediate in this activation pathway, and activation required combinatorial signaling of all three cytokines. Furthermore, ChAdOx1-induced in vivo MAIT cell activation in both mice and human volunteers. Strikingly, MAIT cell activation was necessary in vivo for development of ChAdOx1-induced HCV-specific CD8 T cell responses. These findings define a novel role for MAIT cells in the immunogenicity of viral vector vaccines, with potential implications for future design.One sentence summaryRobust immunogenicity of candidate adenovirus vaccine vectors requires the activation of unconventional T cells.

scholarly journals Lung Homogenization v1

2020 ◽  
Author(s):  
Timothy S C Hinks ◽  
Bonnie van Wilgenburg ◽  
Huimeng Wang ◽  
Liyen Loh ◽  
Marios Koutsakos ◽  
...  
Keyword(s):  
Cell Activation ◽  
Viral Infections ◽  
Intracellular Cytokine Staining ◽  
Cell Receptor ◽  
Type I ◽  
Independent Manner ◽  
Mait Cells ◽  
Specific Pathogen ◽  
Mait Cell

This is part 3.4 of the "Study of MAIT Cell Activation in Viral Infections In Vivo" collection of protocols. Collection Abstract: MAIT cells are abundant, highly evolutionarily conserved innate-like lymphocytes expressing a semi-invariant T cell receptor (TCR), which recognizes microbially derived small intermediate molecules from the riboflavin biosynthetic pathway. However, in addition to their TCR-mediated functions they can also be activated in a TCR-independent manner via cytokines including IL-12, -15, -18, and type I interferon. Emerging data suggest that they are expanded and activated by a range of viral infections, and significantly that they can contribute to a protective anti-viral response. Here we describe methods used to investigate these anti-viral functions in vivo in murine models. To overcome the technical challenge that MAIT cells are rare in specific pathogen-free laboratory mice, we describe how pulmonary MAIT cells can be expanded using intranasal bacterial infection or a combination of synthetic MAIT cell antigen and TLR agonists. We also describe protocols for adoptive transfer of MAIT cells, methods for lung homogenization for plaque assays, and surface and intracellular cytokine staining to determine MAIT cell activation.

scholarly journals MAIT Cell Adoptive Transfer v1

2020 ◽  
Author(s):  
Timothy S C Hinks ◽  
Bonnie van Wilgenburg ◽  
Huimeng Wang ◽  
Liyen Loh ◽  
Marios Koutsakos ◽  
...  
Keyword(s):  
Adoptive Transfer ◽  
Cell Activation ◽  
Viral Infections ◽  
Intracellular Cytokine Staining ◽  
Cell Receptor ◽  
Type I ◽  
Independent Manner ◽  
Mait Cells ◽  
Mait Cell

This is part 3.2 of the "Study of MAIT Cell Activation in Viral Infections In Vivo" collection of protocols. Collection Abstract: MAIT cells are abundant, highly evolutionarily conserved innate-like lymphocytes expressing a semi-invariant T cell receptor (TCR), which recognizes microbially derived small intermediate molecules from the riboflavin biosynthetic pathway. However, in addition to their TCR-mediated functions they can also be activated in a TCR-independent manner via cytokines including IL-12, -15, -18, and type I interferon. Emerging data suggest that they are expanded and activated by a range of viral infections, and significantly that they can contribute to a protective anti-viral response. Here we describe methods used to investigate these anti-viral functions in vivo in murine models. To overcome the technical challenge that MAIT cells are rare in specific pathogen-free laboratory mice, we describe how pulmonary MAIT cells can be expanded using intranasal bacterial infection or a combination of synthetic MAIT cell antigen and TLR agonists. We also describe protocols for adoptive transfer of MAIT cells, methods for lung homogenization for plaque assays, and surface and intracellular cytokine staining to determine MAIT cell activation.

scholarly journals Interleukin-18 Is Critical for Mucosa-Associated Invariant T Cell Gamma Interferon Responses toFrancisellaSpeciesIn Vitrobut NotIn Vivo

2018 ◽  
Vol 86 (5) ◽  
Author(s):  
Eric Jesteadt ◽  
Irma Zhang ◽  
Huifeng Yu ◽  
Anda Meierovics ◽  
Wei-Jen Chua Yankelevich ◽  
...  
Keyword(s):  
Pulmonary Infection ◽  
Gamma Interferon ◽  
Interleukin 18 ◽  
Class I Mhc ◽  
Content Type ◽  
Mait Cells ◽  
Ifn Γ ◽  
Mait Cell

ABSTRACTMucosa-associated invariant T (MAIT) cells are a subset of innate T cells that express a semi-invariant Vα chain paired with limited Vβ chains. MAIT cells are activated by riboflavin metabolite derivatives presented by the nonpolymorphic major histocompatibility complex class I (MHC-I)-like molecule MR1. The precise mechanisms required to activate MAIT cells are an area of intense interest. Here we used two closely related intracellular pathogens with distinct inflammasome activation phenotypes to probe the role of innate cytokines in MAIT cell activation. Using anin vitroassay containing transgenic murine MAIT cells, we show that macrophages infected withFrancisella novicida, a strong inflammasome activator, released high levels of interleukin-18 (IL-18) and stimulated high levels of MAIT cell gamma interferon (IFN-γ) through a partially MR1-independent pathway. In contrast, macrophages infected withFrancisella tularensislive vaccine strain (LVS), a weak inflammasome activator, generated little IL-18 and stimulated low MAIT cell IFN-γ through an MR1-dependent pathway. By manipulating the quantities of IL-18 in these cultures, we show that the IL-18 concentration is sufficient to influence the magnitude of MAIT cell IFN-γ production. Correspondingly, infected IL-18-deficient macrophages failed to induce substantial MAIT cell IFN-γ. In contrast, we found that MAIT cell IFN-γ production in the lungs of IL-18-deficient mice was not significantly different from that in WT mice duringF. tularensisLVS pulmonary infection. Overall, we demonstrate that while IL-18 is essential for the MAIT cell IFN-γ responsein vitro, it is not essential for MAIT cell IFN-γ production duringin vivoLVS pulmonary infection, suggesting that additional signals can drive MAIT cell IFN-γ productionin vivo.

scholarly journals African Salmonella Typhimurium sequence type 313 lineage 2 evades MAIT cell recognition by overexpressing RibB

2019 ◽  
Author(s):  
Lorena Preciado-Llanes ◽  
Anna Aulicino ◽  
Rocío Canals ◽  
Patrick Moynihan ◽  
Xiaojun Zhu ◽  
...  
Keyword(s):  
Invasive Disease ◽  
Multidrug Resistant ◽  
Sequence Type ◽  
Immune Recognition ◽  
Cell Recognition ◽  
Bacterial Gene ◽  
Mait Cells ◽  
Lineage 2 ◽  
Mait Cell

SUMMARYMucosal-associated invariant T (MAIT) cells are a subset of innate T lymphocytes activated by bacteria that produce vitamin B2 metabolites. Mouse models of infection have demonstrated a role for MAIT cells in antimicrobial defence. However, proposed protective roles of MAIT cells in human infections remain unproven and clinical conditions associated with a selective absence of MAIT cells have not been identified. We report that typhoidal and non-typhoidal S. enterica strains generally activate MAIT cells. However, African invasive disease-associated multidrug-resistant S. Typhimurium sequence type 313 lineage 2 strains escape MAIT cell recognition through overexpression of ribB, a bacterial gene that encodes the 4-dihydroxy-2-butanone 4-phosphate synthase enzyme of the riboflavin biosynthetic pathway. This MAIT cell-specific phenotype did not extend to other innate lymphocytes. We propose that ribB overexpression is an evolved trait that facilitates evasion from immune recognition by MAIT cells and contributes to the invasive pathogenesis of S. Typhimurium sequence type 313 lineage 2 in vivo.

scholarly journals Viral Plaque Assay v1

2020 ◽  
Author(s):  
Timothy S C Hinks ◽  
Bonnie van Wilgenburg ◽  
Huimeng Wang ◽  
Liyen Loh ◽  
Marios Koutsakos ◽  
...  
Keyword(s):  
Cell Activation ◽  
Viral Infections ◽  
Mdck Cells ◽  
Intracellular Cytokine Staining ◽  
Type I ◽  
Tissue Culture Dish ◽  
Mait Cells ◽  
Viral Plaque ◽  
Mait Cell

This is part 3.6 of the "Study of MAIT Cell Activation in Viral Infections In Vivo" collection of protocols. Collection Abstract: MAIT cells are abundant, highly evolutionarily conserved innate-like lymphocytes expressing a semi-invariant T cell receptor (TCR), which recognizes microbially derived small intermediate molecules from the riboflavin biosynthetic pathway. However, in addition to their TCR-mediated functions they can also be activated in a TCR-independent manner via cytokines including IL-12, -15, -18, and type I interferon. Emerging data suggest that they are expanded and activated by a range of viral infections, and significantly that they can contribute to a protective anti-viral response. Here we describe methods used to investigate these anti-viral functions in vivo in murine models. To overcome the technical challenge that MAIT cells are rare in specific pathogen-free laboratory mice, we describe how pulmonary MAIT cells can be expanded using intranasal bacterial infection or a combination of synthetic MAIT cell antigen and TLR agonists. We also describe protocols for adoptive transfer of MAIT cells, methods for lung homogenization for plaque assays, and surface and intracellular cytokine staining to determine MAIT cell activation. Abstract: Viral plaque assays are used to determine influenza viral titers. A diluted solution of egg-adapted Influenza A viruses/lung-infected tissue homogenates are applied to a six-well tissue culture dish containing a monolayer of Madin-Darby canine kidney (MDCK) cells. The infected MDCK cells grow under a semisolid overlay medium (agar) containing trypsin. A plaque is produced when a virus particle infects a cell, replicates, and then kills the cell. This process can be repeated several times as surrounding cells can be infected by newly replicated virus and killed. When visualized by eye, plaques appear as white spots. The assay is measured in PFU/mL.

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