Bsc, Leiden University, The Netherlands, Biomedical Sciences (2008)
Msc, Leiden University, The Netherlands, Biomedical Sciences (2011)
PhD, University of Cambridge, UK, Immunology (2017)
TNF-alpha+ CD4+ Tcells dominate the SARS-CoV-2 specific T cell response in COVID-19 outpatients and are associated with durable antibodies.
Cell reports. Medicine
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific CD4+ Tcells are likely important in immunity against coronavirus 2019 (COVID-19), but our understanding of CD4+ longitudinal dynamics following infection and of specific features that correlate with the maintenance of neutralizing antibodies remains limited. Here, we characterize SARS-CoV-2-specific CD4+ Tcells in a longitudinal cohort of 109 COVID-19 outpatients enrolled during acute infection. The quality of the SARS-CoV-2-specific CD4+ response shifts from cells producing interferon gamma (IFNgamma) to tumor necrosis factor alpha (TNF-alpha) from 5days to 4months post-enrollment, with IFNgamma-IL-21-TNF-alpha+ CD4+ Tcells the predominant population detected at later time points. Greater percentages of IFNgamma-IL-21-TNF-alpha+ CD4+ Tcells on day 28 correlate with SARS-CoV-2-neutralizing antibodies measured 7months post-infection (⍴= 0.4, p= 0.01). mRNA vaccination following SARS-CoV-2 infection boosts both IFNgamma- and TNF-alpha-producing, spike-protein-specific CD4+ Tcells. These data suggest that SARS-CoV-2-specific, TNF-alpha-producing CD4+ Tcells may play an important role in antibody maintenance following COVID-19.
View details for DOI 10.1016/j.xcrm.2022.100640
View details for PubMedID 35588734
MALARIA-DRIVEN EXPANSION OF MATURE, SHORT-LIVED FUNCTIONAL CD56NEG NK CELLS CORRELATES WITH CLINICAL IMMUNITY TO MALARIA
AMER SOC TROP MED & HYGIENE. 2021: 16-17
View details for Web of Science ID 000778105601048
HLA-A alleles influencing NK cell function impact AML relapse following allogeneic hematopoietic cell transplantation
2020; 4 (19): 4955-4964
HLA-B allotypes exhibiting the Bw4 epitope trigger variable inhibitory signaling of KIR3DL1 receptor types, where strong inhibitory HLA-B and KIR3DL1 allele combinations are associated with increased risk for relapse of acute myelogenous leukemia (AML) following allogeneic hematopoietic cell transplantation (HCT). Several HLA-A allotypes also exhibit the Bw4 epitope. Studies with natural killer (NK) cell clones have demonstrated NK inhibition via KIR3DL1 by HLA-A Bw4+ allotypes, but did not delineate strengths of inhibition or hierarchies of NK education. Using primary NK cells from healthy donors, we demonstrate that HLA-A*23, HLA-A*24, and HLA-A*32 proteins are expressed at different densities and exhibit different capacities to educate and inhibit KIR3DL1-expressing NK cells in vitro. Among the HLA-A Bw4+ allotypes, HLA-A*24 and HLA-A*32 demonstrate the strongest inhibitory capacity. To determine if HLA-A allotypes with strong inhibitory capacity have similar negative impact in allogeneic HCT as HLA-B Bw4+ allotypes, we performed a retrospective analysis of 1729 patients with AML who received an allogeneic HCT from a 9/10 or 10/10 HLA allele-matched unrelated donor. Examination of the donor-recipient pairs whose Bw4 epitope was exclusively contributed from HLA-A*24 and A*32 allotypes revealed that patients with HLA-A*24 who received an allograft from a KIR3DL1+ donor experienced a higher risk of disease relapse (hazard ratio, 1.65; 95% confidence interval, 1.17-2.32; P = .004) when compared with patients without a Bw4 epitope. These findings indicate that despite weak affinity interactions with KIR3DL1, common HLA-A allotypes with the Bw4 epitope can interact with KIR3DL1+ donor NK cells with clinically meaningful impact and provide additional insight to donor NK alloreactivity in HLA-matched HCT.
View details for DOI 10.1182/bloodadvances.2020002086
View details for Web of Science ID 000581115700040
View details for PubMedID 33049053
View details for PubMedCentralID PMC7556125
Cytomegalovirus Infection Drives Avidity Selection of Natural Killer Cells
2019; 50 (6): 1381-+
The process of affinity maturation, whereby T and B cells bearing antigen receptors with optimal affinity to the relevant antigen undergo preferential expansion, is a key feature of adaptive immunity. Natural killer (NK) cells are innate lymphocytes capable of "adaptive" responses after cytomegalovirus (CMV) infection. However, whether NK cells are similarly selected on the basis of their avidity for cognate ligand is unknown. Here, we showed that NK cells with the highest avidity for the mouse CMV glycoprotein m157 were preferentially selected to expand and comprise the memory NK cell pool, whereas low-avidity NK cells possessed greater capacity for interferon-γ (IFN-γ) production. Moreover, we provide evidence for avidity selection occurring in human NK cells during human CMV infection. These results delineate how heterogeneity in NK cell avidity diversifies NK cell effector function during antiviral immunity, and how avidity selection might serve to produce the most potent memory NK cells.
View details for DOI 10.1016/j.immuni.2019.04.009
View details for Web of Science ID 000471876100010
View details for PubMedID 31103381
View details for PubMedCentralID PMC6614060
Modulation of Human Leukocyte Antigen-C by Human Cytomegalovirus Stimulates KIR2DS1 Recognition by Natural Killer Cells
FRONTIERS IN IMMUNOLOGY
2017; 8: 298
The interaction of inhibitory killer cell Ig-like receptors (KIRs) with human leukocyte antigen (HLA) class I molecules has been characterized in detail. By contrast, activating members of the KIR family, although closely related to inhibitory KIRs, appear to interact weakly, if at all, with HLA class I. KIR2DS1 is the best studied activating KIR and it interacts with C2 group HLA-C (C2-HLA-C) in some assays, but not as strongly as KIR2DL1. We used a mouse 2B4 cell reporter system, which carries NFAT-green fluorescent protein with KIR2DS1 and a modified DAP12 adaptor protein. KIR2DS1 reporter cells were not activated upon coculture with 721.221 cells transfected with different HLA-C molecules, or with interferon-γ stimulated primary dermal fibroblasts. However, KIR2DS1 reporter cells and KIR2DS1+ primary natural killer (NK) cells were activated by C2-HLA-C homozygous human fetal foreskin fibroblasts (HFFFs) but only after infection with specific clones of a clinical strain of human cytomegalovirus (HCMV). Active viral gene expression was required for activation of both cell types. Primary NKG2A-KIR2DS1+ NK cell subsets degranulated after coculture with HCMV-infected HFFFs. The W6/32 antibody to HLA class I blocked the KIR2DS1 reporter cell interaction with its ligand on HCMV-infected HFFFs but did not block interaction with KIR2DL1. This implies a differential recognition of HLA-C by KIR2DL1 and KIR2DS1. The data suggest that modulation of HLA-C by HCMV is required for a potent KIR2DS1-mediated NK cell activation.
View details for DOI 10.3389/fimmu.2017.00298
View details for Web of Science ID 000397490800001
View details for PubMedID 28424684
View details for PubMedCentralID PMC5372792
Membrane lipid saturation activates endoplasmic reticulum unfolded protein response transducers through their transmembrane domains
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2013; 110 (12): 4628-4633
Endoplasmic reticulum (ER) stress sensors use a related luminal domain to monitor the unfolded protein load and convey the signal to downstream effectors, signaling an unfolded protein response (UPR) that maintains compartment-specific protein folding homeostasis. Surprisingly, perturbation of cellular lipid composition also activates the UPR, with important consequences in obesity and diabetes. However, it is unclear if direct sensing of the lipid perturbation contributes to UPR activation. We found that mutant mammalian ER stress sensors, IRE1α and PERK, lacking their luminal unfolded protein stress-sensing domain, nonetheless retained responsiveness to increased lipid saturation. Lipid saturation-mediated activation in cells required an ER-spanning transmembrane domain and was positively regulated in vitro by acyl-chain saturation in reconstituted liposomes. These observations suggest that direct sensing of the lipid composition of the ER membrane contributes to the UPR.
View details for DOI 10.1073/pnas.1217611110
View details for Web of Science ID 000317521600051
View details for PubMedID 23487760
View details for PubMedCentralID PMC3606975