Viral infections have been associated with the progression of atherosclerosis and CD8+ T-cells directed against common viruses, such as influenza, Epstein-Barr virus, and cytomegalovirus, have been... Show moreViral infections have been associated with the progression of atherosclerosis and CD8+ T-cells directed against common viruses, such as influenza, Epstein-Barr virus, and cytomegalovirus, have been detected inside human atherosclerotic lesions. These virus-specific CD8+ T-cells have been hypothesized to contribute to the development of atherosclerosis; however, whether they affect disease progression directly remains unclear. In this study, we aimed to characterize the activation status of virus-specific CD8+ T-cells in the atherosclerotic lesion.\nThe presence, clonality, tissue enrichment, and phenotype of virus-associated CD8+ T-cells in atherosclerotic lesions were assessed by exploiting bulk T-cell receptor-β sequencing and single-cell T-cell receptor (α and β) sequencing datasets on human endarterectomy samples and patient-matched blood samples. To investigate if virus-specific CD8+ T-cells can be activated through T-cell receptor stimulation in the atherosclerotic lesion, the immunopeptidome of human plaques was determined.\nVirus-associated CD8+ T-cells accumulated more in the atherosclerotic lesion (mean=2.0%), compared with patient-matched blood samples (mean=1.4%; P=0.05), and were more clonally expanded and tissue enriched in the atherosclerotic lesion in comparison with nonassociated CD8+ T-cells from the lesion. Single-cell T-cell receptor sequencing and flow cytometry revealed that these virus-associated CD8+ T-cells were phenotypically highly similar to other CD8+ T-cells in the lesion and that both exhibited a more activated phenotype compared with circulating T-cells. Interestingly, virus-associated CD8+ T-cells are unlikely to be activated through antigen-specific interactions in the atherosclerotic lesion, as no virus-derived peptides were detected on HLA-I in the lesion.\nThis study suggests that virus-specific CD8+ T-cells are tissue enriched in atherosclerotic lesions; however, their potential contribution to inflammation may involve antigen-independent mechanisms. Show less
Nagy, N.A.; Lozano Vigario, F.; Sparrius, R.; Capel, T.M.M. van; Ree, R. van; Tas, S.W.; ... ; Jong, E.C. de 2023
Cytotoxic CD4+ T cells have previously been found in peripheral blood of patients with coronary artery disease (1), however their occurrence in atherosclerotic plaques and their association with... Show moreCytotoxic CD4+ T cells have previously been found in peripheral blood of patients with coronary artery disease (1), however their occurrence in atherosclerotic plaques and their association with the pathophysiology of atherosclerosis has not been established. Single-cell RNA sequencing was performed on human carotid atherosclerotic plaques of 18 patients to identify specific T cell populations (2). Next, human femoral and carotid atherosclerotic plaques (n=95) and matched blood samples (n=49) were analyzed by flow cytometry for the presence of CD4+GZMB+ T cells. Plaque morphology was assessed by Movat’s Pentachrome staining. A distinct cytotoxic GZMB+ PRF1+ CD28- CD4+ T cell cluster was identified using single-cell RNA sequencing. Furthermore, flow cytometry analysis showed that the percentage of GZMB+CD4+ T cells was significantly elevated in plaque compared to blood (Blood: 12.17±2.0 vs. Plaque: 17.40±1.0; P=0.0002). Moreover, a significant positive correlation was observed between the percentage of GZMB+CD4+ T cells in blood versus plaque (P=0.031). In line with the proinflammatory character of these cells, we found a positive association of GZMB+CD4+ T cells (P=0.036) with necrotic core size, whereas no correlation was found with this subtype in the circulation. In this study we have shown an enrichment of cytotoxic CD4+ T cells in atherosclerotic lesions, which positively correlate with necrotic core size. Future studies are aimed at elucidating the role of these cells in advanced atherosclerosis. Show less
Dendritic cells (DCs) control adaptive immunity and are therefore attractive for in vivo targeting to either induce immune activation or tolerance, depending on disease. Liposomes, nanoparticles... Show moreDendritic cells (DCs) control adaptive immunity and are therefore attractive for in vivo targeting to either induce immune activation or tolerance, depending on disease. Liposomes, nanoparticles comprised of a lipid bi-layer, provide a nanoplatform for loading disease-relevant antigen, adjuvant and DC-targeting molecules simultaneously. However, it is yet not fully understood how liposomal formulations affect uptake by DCs and DC function. Here, we examined monocyte-derived DC (moDC) and skin DC uptake of six different liposomal formulations, together with their DC-modulating effect. Contrary to literature, we show using imaging flow cytometry that anionic or neutral liposomes are taken up more efficiently than cationic liposomes by moDCs, or by skin DCs after intradermal injection. None of the formulations yielded significant modulation of DC function as determined by the upregulation of maturation markers and cytokine production. These results suggest that anionic liposomes would be more suitable as vaccine carriers for a dermal application.(c) 2022 The Authors. Published by Elsevier Inc. on behalf of American Pharmacists Association. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Show less
Anionic liposomal formulations have previously shown to have intrinsic tolerogenic capacity and these properties have been related to the rigidity of the particles. The combination of highly rigid... Show moreAnionic liposomal formulations have previously shown to have intrinsic tolerogenic capacity and these properties have been related to the rigidity of the particles. The combination of highly rigid anionic liposomes to deliver tolerogenic adjuvants and antigen peptides has potential applications for the treatment of autoimmune and inflammatory diseases. However, the preparation of these highly rigid anionic liposomes using traditional methods such as lipid film hydration presents problems in terms of scalability and loading efficiency of some costly tolerogenic adjuvants like 1-α,25-dihydroxyvitaminD3. Here we propose the use of an off-the-shelf staggered herringbone micromixer for the preparation of these formulations and performed a systematic study on the effect of temperature and flow conditions on the size and polydispersity index of the formulations. Furthermore, we show that the system allows for the encapsulation of a wide variety of peptides and significantly higher loading efficiency of 1-α,25-dihydroxyvitaminD3 compared to the traditional lipid film hydration method, without compromising their non-inflammatory interaction with dendritic cells. Therefore, the microfluidics method presented here is a valuable tool for the preparation of highly rigid tolerogenic liposomes in a fast, size-tuneable and scalable manner. Show less
Neonatal sepsis is a major cause of death and disability in newborns. Commonly used biomarkers for diagnosis and evaluation of treatment response lack sufficient sensitivity or specificity.... Show moreNeonatal sepsis is a major cause of death and disability in newborns. Commonly used biomarkers for diagnosis and evaluation of treatment response lack sufficient sensitivity or specificity. Additionally, new targets to treat the dysregulated immune response are needed, as are methods to effectively screen drugs for these targets. Available research methods have hitherto not yielded the breakthroughs required to significantly improve disease outcomes, we therefore describe the potential of zebrafish (Danio rerio) larvae as preclinical model for neonatal sepsis. In biomedical research, zebrafish larvae combine the complexity of a whole organism with the convenience and high-throughput potential of in vitro methods. This paper illustrates that zebrafish exhibit an immune system that is remarkably similar to humans, both in terms of types of immune cells and signaling pathways. Moreover, the developmental state of the larval immune system is highly similar to human neonates. We provide examples of zebrafish larvae being used to study infections with pathogens commonly causing neonatal sepsis and discuss known limitations. We believe this species could expedite research into immune regulation during neonatal sepsis and may hold keys for the discovery of new biomarkers and novel treatment targets as well as for screening of targeted drug therapies. Show less
Benne, N.; Leboux, R.J.T.; Glandrup, M.; Duijn, J. van; Lozano Vigario, F.; Neustrup, M.A.; ... ; Slütter, B. 2019
Regulatory T cells (Tregs) are vital for maintaining a balanced immune response and their dysfunction is oftenassociated with auto-immune disorders. We have previously shown that antigen-loaded... Show moreRegulatory T cells (Tregs) are vital for maintaining a balanced immune response and their dysfunction is oftenassociated with auto-immune disorders. We have previously shown that antigen-loaded anionic liposomescomposed of phosphatidylcholine (PC) and phosphatidylglycerol (PG) and cholesterol can induce strong antigenspecificTreg responses. We hypothesized that altering the rigidity of these liposomes while maintaining theirsize and surface charge would affect their capability of inducing Treg responses. The rigidity of liposomes isaffected in part by the length and saturation of carbon chains of the phospholipids in the bilayer, and in part bythe presence of cholesterol. We used atomic force microscopy (AFM) to measure the rigidity of anionic OVA323-containing liposomes composed of different types of PC and PG, with or without cholesterol, in a molar ratio of4:1(:2) distearoyl (DS)PC:DSPG (Young's modulus (YM) 3611 ± 1271 kPa), DSPC:DSPG:CHOL(1498 ± 531 kPa), DSPC:dipalmitoyl (DP)PG:CHOL (1208 ± 538), DPPC:DPPG:CHOL (1195 ± 348 kPa),DSPC:dioleoyl (DO)PG:CHOL (825 ± 307 kPa), DOPC:DOPG:CHOL (911 ± 447 kPa), and DOPC:DOPG(494 ± 365 kPa). Next, we assessed if rigidity affects the association of liposomes to bone marrow-deriveddendritic cells (BMDCs) in vitro. Aside from DOPC:DOPG liposomes, we observed a positive correlation betweenliposomal rigidity and cellular association. Finally, we show that rigidity positively correlates with Treg responsesin vitro in murine DCs and in vivo in mice. Our findings underline the suitability of AFM to measureliposome rigidity and the importance of this parameter when designing liposomes as a vaccine delivery system. Show less
Benne, N.; Duijn, J. van; Lozano Vigario, F.; Leboux, R.; Veelen, P. van; Jiskoot, W.; ... ; Slütter, B. 2019
