1
|
Bierling TEH, Gumann A, Ottmann SR, Schulz SR, Weckwerth L, Thomas J, Gessner A, Wichert M, Kuwert F, Rost F, Hauke M, Freudenreich T, Mielenz D, Jäck HM, Pracht K. GLUT1-mediated glucose import in B cells is critical for anaplerotic balance and humoral immunity. Cell Rep 2024; 43:113739. [PMID: 38340319 DOI: 10.1016/j.celrep.2024.113739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 12/14/2023] [Accepted: 01/19/2024] [Indexed: 02/12/2024] Open
Abstract
Glucose uptake increases during B cell activation and antibody-secreting cell (ASC) differentiation, but conflicting findings prevent a clear metabolic profile at different stages of B cell activation. Deletion of the glucose transporter type 1 (GLUT1) gene in mature B cells (GLUT1-cKO) results in normal B cell development, but it reduces germinal center B cells and ASCs. GLUT1-cKO mice show decreased antigen-specific antibody titers after vaccination. In vitro, GLUT1-deficient B cells show impaired activation, whereas established plasmablasts abolish glycolysis, relying on mitochondrial activity and fatty acids. Transcriptomics and metabolomics reveal an altered anaplerotic balance in GLUT1-deficient ASCs. Despite attempts to compensate for glucose deprivation by increasing mitochondrial mass and gene expression associated with glycolysis, the tricarboxylic acid cycle, and hexosamine synthesis, GLUT1-deficient ASCs lack the metabolites for energy production and mitochondrial respiration, limiting protein synthesis. We identify GLUT1 as a critical metabolic player defining the germinal center response and humoral immunity.
Collapse
Affiliation(s)
- Theresa E H Bierling
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Amelie Gumann
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Shannon R Ottmann
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Sebastian R Schulz
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Leonie Weckwerth
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Jana Thomas
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Arne Gessner
- Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Magdalena Wichert
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Frederic Kuwert
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Franziska Rost
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Manuela Hauke
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Tatjana Freudenreich
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Dirk Mielenz
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Hans-Martin Jäck
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Katharina Pracht
- Division of Molecular Immunology, Internal Medicine III, University Hospital Erlangen, Nikolaus-Fiebiger Center, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
| |
Collapse
|
2
|
Mett H, Hölscher K, Degen H, Esdar C, De Neumann BF, Flicke B, Freudenreich T, Holzer G, Schinzel S, Stamminger T, Stein-Gerlach M, Marschall M, Herget T. Identification of inhibitors for a virally encoded protein kinase by 2 different screening systems: in vitro kinase assay and in-cell activity assay. ACTA ACUST UNITED AC 2005; 10:36-45. [PMID: 15695342 DOI: 10.1177/1087057104270269] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The human cytomegalovirus (HCMV) protein kinase pUL97 represents an important determinant for viral replication and thus is a promising target for the treatment of HCMV. The authors screened a compound library of nearly 5000 entities based on known kinase inhibitors in 2 distinct ways. A radioactive in vitro kinase assay was performed with recombinant pUL97, purified from baculovirus-infected insect cells, on myelin basic protein-coated FlashPlates. About 20% of all compounds tested inhibited pUL97 kinase activity by more than 50% at a concentration of 10 microM. These hits belonged to various structural classes. To elucidate their potential to inhibit pUL97 in a cellular context, all compounds of the library were also tested in a cell-based activity assay. For this reason, a HEK293 cell line was established that ectopically expressed pUL97. When these cells were incubated with ganciclovir (GCV), pUL97 phosphorylated GCV to its monophosphate, which subsequently became phosphorylated to cytotoxic metabolites by cellular enzymes. Thereby, pUL97 converted cells into a GCV-sensitive phenotype. Inhibition of the pUL97 kinase activity resulted in protection of the cells against the cytotoxic effects of GCV. In total, 199 compounds of the library were cellular active at nontoxic concentrations, and 93 of them inhibited pUL97 in the in vitro kinase assay. Among these, promising inhibitors of HCMV replication were identified. The 2-fold screening system described here should facilitate the development of pUL97 inhibitors into potent drug candidates.
Collapse
|
3
|
Sommer MN, Bevec D, Klebl B, Flicke B, Hölscher K, Freudenreich T, Hauber I, Hauber J, Mett H. Screening assay for the identification of deoxyhypusine synthase inhibitors. J Biomol Screen 2004; 9:434-8. [PMID: 15296643 DOI: 10.1177/1087057104264031] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 1st step in the posttranslational hypusine [N(epsilon)-(4-amino-2-hydroxybutyl)lysine] modification of eukaryotic translation initiation factor 5A (eIF5A) is catalyzed by deoxyhypusine synthase (DHS). The eIF5A intermediate is subsequently hydroxylated by deoxyhypusine hydroxylase (DHH), thereby converting the eIF5A precursor into a biologically active protein. Depletion of eIF5A causes inhibition of cell growth, and the identification of eIF5A as a cofactor of the HIV Rev protein turns this host protein and therefore DHS into an interesting target for drugs against abnormal cell growth and/or HIV replication. The authors developed a 96-well format DHS assay applicable for the screening of DHS inhibitors. Using this assay, they demonstrate DHS inhibition by AXD455 (Semapimod, CNI-1493). This assay represents a powerful tool for the identification of new DHS inhibitors with potency against cancer and HIV.
Collapse
Affiliation(s)
- Marc-Nicola Sommer
- Department of Assay Development and Screening, Axxima Pharmaceuticals AG, Max-Lebsche-Platz 32, D-81377 München, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|