| 1. |
- Bartsch, Yannic C, et al.
(författare)
-
IgG Fc sialylation is regulated during the germinal center reaction upon immunization with different adjuvants
- 2020
-
Ingår i: The Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 146:3, s. 652-666
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Effector functions of IgG antibodies (Abs) are regulated by their Fc N-glycosylation pattern. IgG Fc glycans that lack galactose and terminal sialic acid residues correlate with the severity of inflammatory (auto)immune disorders and have also been linked to the protection against viral infection and discussed in the context of vaccine-induced protection. In contrast, sialylated IgG Abs have shown immunosuppressive effects.OBJECTIVE: We sought to investigate IgG glycosylation programming during the germinal center (GC) reaction upon immunization of mice with a foreign protein antigen and different adjuvants.METHODS: Mice were analyzed for GC T, B cell and plasma cell responses as well as antigen-specific serum IgG subclass titers and Fc glycosylation patterns.RESULTS: Different adjuvants induce distinct IgG+ GC B cell responses with specific transcriptomes and expression levels of the α2,6-sialyltransferase responsible for IgG sialylation that correspond to distinct serum IgG Fc glycosylation patterns. Low IgG Fc sialylation programming in GC B cells was overall highly dependent on the T follicular helper (TFH) cell-inducing cytokine IL-6, especially induced by water-in-oil adjuvants and Mycobacterium tuberculosis (Mtb). Furthermore, low IgG Fc sialylation programming was dependent on adjuvants that induced IL-27R-dependent IFNγ+ TFH1 cells, IL-6/IL-23-dependent IL-17A+ TFH17 cells and high TFH/T follicular regulatory (TFR) cell ratios. The two latter were here dependent on Mtb and its cord factor.CONCLUSION: These findings on adjuvant-dependent GC responses and IgG glycosylation programming may aid the development of novel vaccination strategies to induce IgG Abs with both high affinity and defined Fc glycosylation patterns.
|
|
| 2. |
- Edwards, Steven J., et al.
(författare)
-
High-Resolution Imaging of Tumor Spheroids and Organoids Enabled by Expansion Microscopy
- 2020
-
Ingår i: Frontiers in Molecular Biosciences. - : Frontiers Media S.A.. - 2296-889X. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional cell cultures are able to better mimic the physiology and cellular environments found in tissuesin vivocompared to cells grown in two dimensions. In order to study the structure and function of cells in 3-D cultures, light microscopy is frequently used. The preparation of 3-D cell cultures for light microscopy is often destructive, including physical sectioning of the samples, which can result in the loss of 3-D information. In order to probe the structure of 3-D cell cultures at high resolution, we have explored the use of expansion microscopy and compared it to a simple immersion clearing protocol. We provide a practical method for the study of spheroids, organoids and tumor-infiltrating immune cells at high resolution without the loss of spatial organization. Expanded samples are highly transparent, enabling high-resolution imaging over extended volumes by significantly reducing light scatter and absorption. In addition, the hydrogel-like nature of expanded samples enables homogenous antibody labeling of dense epitopes throughout the sample volume. The improved labeling and image quality achieved in expanded samples revealed details in the center of the organoid which were previously only observable following serial sectioning. In comparison to chemically cleared spheroids, the improved signal-to-background ratio of expanded samples greatly improved subsequent methods for image segmentation and analysis.
|
|
| 3. |
- Sandoz, Patrick, et al.
(författare)
-
Modulation of lytic molecules restrain serial killing in γδ T lymphocytes
- 2023
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- γδ T cells play a pivotal role in protection against various types of infections and tumours, from early childhood on and throughout life. They consist of several subsets characterised by adaptive and innate-like functions, with Vγ9Vδ2 being the largest subset in human peripheral blood. Although these cells show signs of cytotoxicity, their modus operandi remains poorly understood. Here we explore, using live single-cell imaging, the cytotoxic functions of γδ T cells upon interactions with tumour target cells with high temporal and spatial resolution. While γδ T cell killing is dominated by degranulation, the availability of lytic molecules appears tightly regulated in time and space. In particular, the limited co-occurrence of granzyme B and perforin restrains serial killing of tumour cells by γδ T cells. Thus, our data provide new insights into the cytotoxic arsenal and functions of γδ T cells, which may guide the development of more efficient γδ T cell based adoptive immunotherapies.
|
|
| 4. |
- van Ooijen, Hanna, et al.
(författare)
-
Distinct mechanistic responses in serial-killing NK cells during natural and antibody-dependent cytotoxicity
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Natural Killer (NK) cells are potent cytotoxic immune cells, yet the population exhibits a large phenotypical and functional heterogeneity. Here we investigated the mechanisms underlying NK cell serial killing during natural and antibody-dependent cellular cytotoxicity (ADCC). We leveraged on our microwell chip platform to relate cellular function with organelle content and intracellular protein expression, in individual NK cells. We observed that highly potent serial-killing NK cells more often deployed degranulation and induced necrosis, and that they were multifunctional, producing INF-γ and TNF-α. We probed for intrinsic differences between NK cells that performed serial killing compared to other NK cells, yet found no distinction in the migration dynamics, nor in the lysosomal and mitochondrial load of the cells. However, when measuring the calcium signaling of the cells in consecutive interactions, we revealed that serial-killing NK cells were able to maintain calcium signaling longer than cells that interrupted their killing sequence. By staining the cells at the end of the cytotoxicity assay, we found that NK cells that had stopped killing still showed clear intracellular expression of granzyme B-positive granules. Thus, it appears that decreased signaling rather than depletion of lytic cargo is the reason for NK cell exhaustion in our assay. Our results motivate exploring ways to enhance the signaling machinery in NK cells to achieve sustained functional responses.
|
|
