Academic interests
- Immunology
- Intracellular signalling
- T cell biology and function
Background
- 2024-present Researcher in molecular immunology, Faculty of Medicine, University of Oslo, Norway
- 2018-2024 Doctoral research fellow in molecular immunology, Faculty of Medicine, University of Oslo, Norway
- 2017-2018 MSc Immunology, Imperial College London, UK. MSc thesis: “The Role of DYRK1A in B Cell Survival” at The Francis Crick Institute
- 2012-2016 BSc Biological Sciences, Nanyang Technological University, Singapore. BSc thesis: "Impact of Cutaneous Dendritic Cell Subsets on the Evolution of Lymphoid Cells in Response to Propionibacterium acnes" at Singapore Immunology Network
Tags:
Immunology,
T cells,
Signaling
Publications
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Huszenicza, Zsuzsa; Gilmour, Brian Christopher; Koll, Lise; Kjelstrup, Hanna; Chan, Hanna & Sundvold, Vibeke
[Show all 8 contributors for this article]
(2024).
Interaction of T-cell-specific adapter protein with Src- and Tec-family kinases.
Scandinavian Journal of Immunology.
ISSN 0300-9475.
99(5).
doi:
10.1111/sji.13358.
Full text in Research Archive
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Adapter proteins are flexible and dynamic modulators of cellular signalling that are important for immune cell function. One of these, the T-cell-specific adapter protein (TSAd), interacts with the non-receptor tyrosine kinases Src and Lck of the Src family kinases (SFKs) and Itk of the Tec family kinases (TFKs). Three tyrosine residues in the TSAd C-terminus are phosphorylated by Lck and serve as docking sites for the Src homology 2 (SH2) domains of Src and Lck. The TSAd proline-rich region (PRR) binds to the Src homology 3 (SH3) domains found in Lck, Src and Itk. Despite known interactors, the role TSAd plays in cellular signalling remains largely unknown. TSAd's ability to bind both SFKs and TFKs may point to its function as a general scaffold for both kinase families. Using GST-pulldown as well as peptide array experiments, we found that both the SH2 and SH3 domains of the SFKs Fyn and Hck, as well as the TFKs Tec and Txk, interact with TSAd. This contrasts with Itk, which interacts with TSAd only through its SH3 domain. Although our analysis showed that TSAd is both co-expressed and may interact with Fyn, we were unable to co-precipitate Fyn with TSAd from Jurkat cells, as detected by Western blotting and affinity purification mass spectrometry. This may suggest that TSAd-Fyn interaction in intact cells may be limited by other factors, such as the subcellular localization of the two molecules or the co-expression of competing binding partners.
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Borowicz, Pawel; Gjerstad, Vibeke Sundvold; Chan, Hanna; Abrahamsen, Greger; Kjelstrup, Hanna & Nyman, Tuula Anneli
[Show all 7 contributors for this article]
(2021).
Tyr192 Regulates Lymphocyte-Specific Tyrosine Kinase Activity in T Cells.
Journal of Immunology.
ISSN 0022-1767.
207(4),
p. 1128–1137.
doi:
10.4049/jimmunol.2001105.
Full text in Research Archive
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TCR signaling critically depends on the tyrosine kinase Lck (lymphocyte-specific protein tyrosine kinase). Two phosphotyrosines, the activating pTyr394 and the inhibitory pTyr505, control Lck activity. Recently, pTyr192 in the Lck SH2 domain emerged as a third regulator. How pTyr192 may affect Lck function remains unclear. In this study, we explored the role of Lck Tyr192 using CRISPR/Cas9-targeted knock-in mutations in the human Jurkat T cell line. Our data reveal that both Lck pTyr394 and pTyr505 are controlled by Lck Tyr192. Lck with a nonphosphorylated SH2 domain (Lck Phe192) displayed hyperactivity, possibly by promoting Lck Tyr394 transphosphorylation. Lck Glu192 mimicking stable Lck pTyr192 was inhibited by Tyr505 hyperphosphorylation. To overcome this effect, we further mutated Tyr505. The resulting Lck Glu192/Phe505 displayed strongly increased amounts of pTyr394 both in resting and activated T cells. Our results suggest that a fundamental role of Lck pTyr192 may be to protect Lck pTyr394 and/or pTyr505 to maintain a pool of already active Lck in resting T cells. This provides an additional mechanism for fine-tuning of Lck as well as T cell activity.
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Borowicz, Pawel; Chan, Hanna; Hauge, Anette & Spurkland, Anne
(2020).
Adaptor proteins: Flexible and dynamic modulators of immune cell signalling.
Scandinavian Journal of Immunology.
ISSN 0300-9475.
92(6).
doi:
10.1111/sji.12951.
Full text in Research Archive
Show summary
To maintain homeostasis, all cells respond to environmental cues via a multitude of surface receptors. In order to act appropriately in their environment, cells are dependent on the transduction of the incoming signal through tightly regulated and interconnected signalling pathways to the cell nucleus. In particular, cells implicated in the immune system greatly depend on such systems to respond in a flexible and dynamic manner to environmental challenges. One major group of intracellular proteins that are involved in these signalling pathways are adaptor proteins. Although adaptor proteins are essential for normal immune cell operation, the functional role of this group of signalling proteins remains to be fully appreciated. So far, research on adaptor proteins has revealed their unique potential in building transient complexes in a reversible, dynamic and inducible manner. In this review, we explore the roles of adaptor proteins – in space and time of intracellular signalling – and their associations with human disease. Examples of adaptor proteins expressed in hematopoietic cells highlight their crucial role in the immune system. Lastly, we present challenges faced in elucidating roles of adaptor proteins, as illustrated by the T cell–specific adaptor (TSAd) protein encoded by the SH2D2A gene.
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Borowicz, Pawel; Chan, Hanna; Medina, Daniel Talmo; Gumpelmair, Simon; Kjelstrup, Hanna & Spurkland, Anne
(2019).
A simple and efficient workflow for generation of knock-in mutations in Jurkat T cells using CRISPR/Cas9.
Scandinavian Journal of Immunology.
ISSN 0300-9475.
doi:
10.1111/sji.12862.
Full text in Research Archive
Show summary
CRISPR/Cas9 is a powerful gene‐editing tool allowing for specific gene manipulation at targeted sites in the genome. Here, we used CRISPR/Cas9‐mediated gene editing to introduce single amino acid mutations into proteins involved in T cell receptor signalling pathways. Knock‐in mutations were introduced in Jurkat T cells by homologous directed repair using single‐stranded oligodeoxynucleotides. Specifically, we aimed to create targeted mutations at two loci within LCK, a constitutively expressed gene, and at three loci within SH2D2A, whose expression is induced upon T cell activation. Here, we present a simple workflow that can be applied by any laboratory equipped for cell culture work, utilizing basic flow cytometry, Western blotting and PCR techniques. Our data reveal that gene editing may be locus‐dependent and can vary between target sites, also within a gene. In our two targeted genes, on average 2% of the clones harboured homozygous mutations as assessed by allele‐specific PCR and subsequent sequencing. We highlight the importance of decreasing the clonal heterogeneity and developing robust screening methods to accurately select for correct knock‐in mutations. Our workflow may be employed in other immune cell lines and acts as a useful approach for decoding functional mechanisms of proteins of interest.
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Visser, Johan Georg; Borowicz, Pawel; Chan, Hanna; Hauge, Anette; Kjelstrup, Hanna & Spurkland, Anne
(2023).
Lck-SH2 domain superbinder for characterization of phosphotyrosine signaling in T-cell receptor pathway.
Full text in Research Archive
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Gilmour, Brian Christopher; Chan, Hanna; Borowicz, Pawel; Phuyal, Santosh; Lossius, Andreas & Spurkland, Anne
(2023).
β2, or not β2? Connecting the Lck-adaptor TSAd to integrin β2 via a combined wet lab & bioinformatic approach.
Full text in Research Archive
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Gilmour, Brian Christopher; Chan, Hanna; Borowicz, Pawel; Georg, Visser Johan; Lossius, Andreas & Spurkland, Anne
(2022).
Applying bioinformatics to pick-apart elusive protein functions: Focusing on TSAd/SH2D2A, an immune kinase adaptor.
Full text in Research Archive
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Gilmour, Brian Christopher; Chan, Hanna; Borowicz, Pawel; Kjelstrup, Hanna & Spurkland, Anne
(2021).
Application of bioinformatics to outstanding questions in immunology: TSAd (T cell adapter protein).
Full text in Research Archive
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Chan, Hanna & Spurkland, Anne
(2024).
TSAd as a target for therapy : TSAd-SH2 domain interactions in T cells.
Universitetet i Oslo.
ISSN 9788234803307.
Full text in Research Archive
Show summary
T cells play a crucial role in the immune system to combat infectious diseases and have been exploited for use in immunotherapies. Responding to incoming signals from their extracellular milieu, T cell activity is regulated by intracellular signalling pathways. These signalling networks, in which adaptor proteins bridge protein-protein interactions, ensure that T cells respond in an appropriate and sufficient manner. In this thesis, we characterised the interactome and explored the functional role of adaptor protein TSAd, which has been implicated in T cell intracellular signalling. Using affinity-purification mass spectrometry and biochemical methods, we identify two novel ligands of TSAd, namely DOK2 and PTPN11 and their interaction sites. Moreover, the phenotype of TSAd-deficient mice was revisited and discrepancies of the data in the field was addressed. Overall, our findings provide further insight into adaptor molecule biology, which may aid in future development of immunotherapies and elucidating mechanisms of T cell driven pathologies.
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Published
Dec. 19, 2018 7:55 PM
- Last modified
Mar. 22, 2024 9:46 AM
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