1. |
- Beziat, Vivien, et al.
(author)
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NK cell responses to cytomegalovirus infection lead to stable imprints in the human KIR repertoire and involve activating KIRs
- 2013
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In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 121:14, s. 2678-2688
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Journal article (peer-reviewed)abstract
- Human natural killer (NK) cells are functionally regulated by killer cell immunoglobulin-like receptors (KIRs) and their interactions with HLA class I molecules. As KIR expression in a given NK cell is genetically hard-wired, we hypothesized that KIR repertoire perturbations reflect expansions of unique NK-cell subsets and may be used to trace adaptation of the NK-cell compartment to virus infections. By determining the human KIR-ome at a single-cell level in more than 200 donors, we were able to analyze the magnitude of NK cell adaptation to virus infections in healthy individuals. Strikingly, infection with human cytomegalovirus (CMV), but not with other common herpesviruses, induced expansion and differentiation of KIR-expressing NK cells, visible as stable imprints in the repertoire. Education by inhibitory KIRs promoted the clonal-like expansion of NK cells, causing a bias for self-specific inhibitory KIRs. Furthermore, our data revealed a unique contribution of activating KIRs (KIR2DS4, KIR2DS2, or KIR3DS1), in addition to NKG2C, in the expansion of human NK cells. These results provide new insight into the diversity of KIR repertoire and its adaptation to virus infection, suggesting a role for both activating and inhibitory KIRs in immunity to CMV infection.
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2. |
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3. |
- Giang, Kim Anh, et al.
(author)
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Affibody-based hBCMA x CD16 dual engagers for NK cell-mediated killing of multiple myeloma cells
- 2023
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In: New Biotechnology. - : Elsevier BV. - 1871-6784 .- 1876-4347. ; 77, s. 139-148
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Journal article (peer-reviewed)abstract
- We describe the development and characterization of the (to date) smallest Natural Killer (NK) cell re-directing human B Cell Maturation Antigen (hBCMA) x CD16 dual engagers for potential treatment of multiple myeloma, based on combinations of small 58 amino acid, non-immunoglobulin, affibody affinity proteins. Affibody molecules to human CD16a were selected from a combinatorial library by phage display resulting in the identification of three unique binders with affinities (KD) for CD16a in the range of 100 nM–3 µM. The affibody exhibiting the highest affinity demonstrated insensitivity towards the CD16a allotype (158F/V) and did not interfere with IgG (Fc) binding to CD16a. For the construction of hBCMA x CD16 dual engagers, different CD16a binding arms, including bi-paratopic affibody combinations, were genetically fused to a high-affinity hBCMA-specific affibody. Such 15–23 kDa dual engager constructs showed simultaneous hBCMA and CD16a binding ability and could efficiently activate resting primary NK cells and trigger specific lysis of a panel of hBCMA-positive multiple myeloma cell lines. Hence, we report a novel class of uniquely small NK cell engagers with specific binding properties and potent functional profiles.
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4. |
- Bengnér, Malin, et al.
(author)
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Independent skewing of the T cell and NK cell compartments associated with cytomegalovirus infection suggests division of labor between innate and adaptive immunity.
- 2014
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In: Age (Omaha). - : Springer Science and Business Media LLC. - 0161-9152 .- 1574-4647. ; 36:2, s. 571-582
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Journal article (peer-reviewed)abstract
- Cytomegalovirus (CMV) infection induces profound changes in different subsets of the cellular immune system. We have previously identified an immune risk profile (IRP) where CMV-associated changes in the T cell compartment, defined as a CD4/CD8 ratio < 1, are associated with increased mortality in elderly people. Since natural killer (NK) cells have an important role in the defense against viral infections, we examined whether the expansion of CD8 + T cells seen in individuals with CD4/CD8 ratio < 1 is coupled to a parallel skewing of the NK cell compartment. A number of 151 subjects were examined with CMV serology and a flow cytometry panel for assessment of T cell and NK cell subsets. CMV-seropositive individuals had higher frequencies of CD57 + and NKG2C + NK cells and lower frequencies of NKG2A + NK cells, in line with a more differentiated NK cell compartment. Intriguingly, however, there was no correlation between CD4/CD8 ratio and NK cell repertoires among CMV-seropositive donors, despite the profound skewing of the T cell compartment in the group with CD4/CD8 ratio < 1. Conversely, donors with profound expansion of NK cells, defined as NKG2C + NK cells with high expression of CD57 and ILT-2, did not display more common changes in their T cell repertoire, suggesting that NK cell expansion is independent of the T cell-defined IRP. Altogether, these results indicate that the effect of CMV on CD8 T cells and NK cells is largely nonoverlapping and independent.
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6. |
- Björkström, Niklas K, et al.
(author)
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Characterization of natural killer cell phenotype and function during recurrent human HSV-2 infection.
- 2011
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In: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 6:11
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Journal article (peer-reviewed)abstract
- Human natural killer (NK) cell differentiation, characterized by a loss of NKG2A in parallel with the acquisition of NKG2C, KIRs, and CD57 is stimulated by a number of virus infections, including infection with human cytomegalovirus (CMV), hantavirus, chikungunya virus, and HIV-1. Here, we addressed if HSV-2 infection in a similar way drives NK cell differentiation towards an NKG2A(-)NKG2C(+)KIR(+)CD57(+) phenotype. In contrast to infection with CMV, hantavirus, chikungunya virus, and HIV-1, recurrent HSV-2 infection did not yield an accumulation of highly differentiated NK cells in human peripheral blood. This outcome indicates that human HSV-2 infection has no significant imprinting effect on the human NK cell repertoire.
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7. |
- Björkström, Niklas K, et al.
(author)
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Rapid expansion and long-term persistence of elevated NK cell numbers in humans infected with hantavirus
- 2011
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In: Journal of Experimental Medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 208:1, s. 13-21
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Journal article (peer-reviewed)abstract
- Natural killer (NK) cells are known to mount a rapid response to several virus infections. In experimental models of acute viral infection, this response has been characterized by prompt NK cell activation and expansion followed by rapid contraction. In contrast to experimental model systems, much less is known about NK cell responses to acute viral infections in humans. We demonstrate that NK cells can rapidly expand and persist at highly elevated levels for >60 d after human hantavirus infection. A large part of the expanding NK cells expressed the activating receptor NKG2C and were functional in terms of expressing a licensing inhibitory killer cell immunoglobulin-like receptor (KIR) and ability to respond to target cell stimulation. These results demonstrate that NK cells can expand and remain elevated in numbers for a prolonged period of time in humans after a virus infection. In time, this response extends far beyond what is considered normal for an innate immune response.
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9. |
- Curbo, Sophie, et al.
(author)
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Regulation of interleukin-4 signaling by extracellular reduction of intramolecular disulfides
- 2009
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In: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 390:4, s. 1272-1277
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Journal article (peer-reviewed)abstract
- Interleukin-4 (IL-4) contains three structurally important intramolecular disulfides that are required for the bioactivity of the cytokine. We show that the cell surface of HeLa cells and endotoxin-activated monocytes can reduce IL-4 intramolecular disulfides in the extracellular space and inhibit binding of IL-4 to the IL-4R alpha receptor. IL-4 disulfides were in vitro reduced by thioredoxin 1 (Trx1) and protein disulfide isomerase (PDI). Reduction of IL-4 disulfides by the cell surface of HeLa cells was inhibited by auranofin, an inhibitor of thioredoxin reductase that is an electron donor to both Trx1 and PDI. Both Trx1 and PDI have been shown to be located at the cell surface and our data suggests that these enzymes are involved in catalyzing reduction of IL-4 disulfides. The pro-drug N-acetylcysteine (NAC) that promotes T-helper type 1 responses was also shown to mediate the reduction of IL-4 disulfides. Our data provides evidence for a novel redox dependent pathway for regulation of cytokine activity by extracellular reduction of intramolecular disulfides at the cell surface by members of the thioredoxin enzyme family.
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10. |
- Enqvist, Monika, et al.
(author)
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Systemic and Intra-Nodal Activation of NK Cells After Rituximab Monotherapy for Follicular Lymphoma.
- 2019
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In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Journal article (peer-reviewed)abstract
- Monotherapy with the anti-CD20 monoclonal antibody rituximab can induce complete responses (CR) in patients with follicular lymphoma (FL). Resting FcRγIII+ (CD16+) natural killer (NK) cells respond strongly to rituximab-coated target cells in vitro. Yet, the contribution of NK cells in the therapeutic effect in vivo remains unknown. Here, we followed the NK cell repertoire dynamics in the lymph node and systemically during rituximab monotherapy in patients with FL. At baseline, NK cells in the tumor lymph node had a naïve phenotype albeit they were more differentiated than NK cells derived from control tonsils as determined by the frequency of CD56dim NK cells and the expression of killer cell immunoglobulin-like receptors (KIR), CD57 and CD16. Rituximab therapy induced a rapid drop in NK cell numbers coinciding with a relative increase in the frequency of Ki67+ NK cells both in the lymph node and peripheral blood. The Ki67+ NK cells had slightly increased expression of CD16, CD57 and higher levels of granzyme A and perforin. The in vivo activation of NK cells was paralleled by a temporary loss of in vitro functionality, primarily manifested as decreased IFNγ production in response to rituximab-coated targets. However, patients with pre-existing NKG2C+ adaptive NK cell subsets showed less Ki67 upregulation and were refractory to the loss of functionality. These data reveal variable imprints of rituximab monotherapy on the NK cell repertoire, which may depend on pre-existing repertoire diversity.
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