Multiparametric Immunoimaging Maps Inflammatory Signatures in Murine Myocardial Infarction Models.

In the past 2 decades, research on atherosclerotic cardiovascular disease has uncovered inflammation to be a key driver of the pathophysiological process. A pressing need therefore exists to quantitatively and longitudinally probe inflammation, in preclinical models and in cardiovascular disease patients, ideally using non-invasive methods and at multiple levels. Here, we developed and employed in vivo multiparametric imaging approaches to investigate the immune response following myocardial infarction. The myocardial infarction models encompassed either transient or permanent left anterior descending coronary artery occlusion in C57BL/6 and Apoe-/-mice. We performed nanotracer-based fluorine magnetic resonance imaging and positron emission tomography (PET) imaging using a CD11b-specific nanobody and a C-C motif chemokine receptor 2-binding probe. We found that immune cell influx in the infarct was more pronounced in the permanent occlusion model. Further, using 18F-fluorothymidine and 18F-fluorodeoxyglucose PET, we detected increased hematopoietic activity after myocardial infarction, with no difference between the models. Finally, we observed persistent systemic inflammation and exacerbated atherosclerosis in Apoe-/- mice, regardless of which infarction model was used. Taken together, we showed the strengths and capabilities of multiparametric imaging in detecting inflammatory activity in cardiovascular disease, which augments the development of clinical readouts.This work was supported by National Institute of Health grants R01HL143814 (to Dr Fayad), P01HL131478 (Drs Fayad and Mulder), P41EB025815 (Drs Liu and Gropler ), R35HL145212 (Dr Liu), and R35HL139598 (Dr Nahrendorf) and award K22CA226040 (Dr Rashidian). This work was also supported by an Innovation Research Fund Basic Research Award from the Dana-Farber Cancer Institute (Dr Rashidian). Dr Maier was supported by Deutsche Forschungsgemeinschaft grants (MA 7059/1 and MA 7059/3-1) and is part of SFB1425 funded by the Deutsche Forschungsgemeinschaft (project no. 422681845). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S

A modular approach toward producing nanotherapeutics targeting the innate immune system.

Immunotherapies controlling the adaptive immune system are firmly established, but regulating the innate immune system remains much less explored. The intrinsic interactions between nanoparticles and phagocytic myeloid cells make these materials especially suited for engaging the innate immune system. However, developing nanotherapeutics is an elaborate process. Here, we demonstrate a modular approach that facilitates efficiently incorporating a broad variety of drugs in a nanobiologic platform. Using a microfluidic formulation strategy, we produced apolipoprotein A1-based nanobiologics with favorable innate immune system-engaging properties as evaluated by in vivo screening. Subsequently, rapamycin and three small-molecule inhibitors were derivatized with lipophilic promoieties, ensuring their seamless incorporation and efficient retention in nanobiologics. A short regimen of intravenously administered rapamycin-loaded nanobiologics (mTORi-NBs) significantly prolonged allograft survival in a heart transplantation mouse model. Last, we studied mTORi-NB biodistribution in nonhuman primates by PET/MR imaging and evaluated its safety, paving the way for clinical translation.This work was supported by NIH grants R01 CA220234, R01 HL144072, P01 HL131478, and NWO/ZonMW Vici 91818622 (to W.J.M.M.); R01 HL143814 and P01HL131478 (to Z.A.F.); R01 AI139623 (to J.O.); and P30 CA008748 (to T.R.). M.M.T.v.L. was supported by the American Heart Association (grant 19PRE34380423). M.G.N. was supported by a Spinoza grant from the Netherlands Organization for Scientific Research and an ERC Advanced Grant (no. 833247); L.A.B.J. was supported by a Competitiveness Operational Programme grant of the Romanian Ministry of European Funds (P_37_762, MySMIS 103587).S

Resolving sepsis-induced immunoparalysis via trained immunity by targeting interleukin-4 to myeloid cells.

Immunoparalysis is a compensatory and persistent anti-inflammatory response to trauma, sepsis or another serious insult, which increases the risk of opportunistic infections, morbidity and mortality. Here, we show that in cultured primary human monocytes, interleukin-4 (IL4) inhibits acute inflammation, while simultaneously inducing a long-lasting innate immune memory named trained immunity. To take advantage of this paradoxical IL4 feature in vivo, we developed a fusion protein of apolipoprotein A1 (apoA1) and IL4, which integrates into a lipid nanoparticle. In mice and non-human primates, an intravenously injected apoA1-IL4-embedding nanoparticle targets myeloid-cell-rich haematopoietic organs, in particular, the spleen and bone marrow. We subsequently demonstrate that IL4 nanotherapy resolved immunoparalysis in mice with lipopolysaccharide-induced hyperinflammation, as well as in ex vivo human sepsis models and in experimental endotoxemia. Our findings support the translational development of nanoparticle formulations of apoA1-IL4 for the treatment of patients with sepsis at risk of immunoparalysis-induced complications.We thank M. Jaeger (Radboudumc) for kindly providing flourescein isothiocyanate-labelled Candida albicans. D. Williams (East Tennessee State University) provided the β-glucan we used in our initial experiments. H. Lemmers (Radboudumc) kindly prepared the purified lipopolysaccharide used for stimulation of primary human monocytes and macrophages. Part of the figures were prepared using (among other software) Biorender.com. B.N. is supported by a National Health and Medical Research Council (Australia) Investigator Grant (APP1173314). This work was supported by National Institutes of Health grants R01 HL144072, R01 CA220234 and P01 HL131478, as well as a Vici grant from the Dutch Research Council NWO and an ERC Advanced Grant (all to W.J.M.M.). M.G.N. was supported by a Spinoza grant from Dutch Research Council NWO and an ERC Advanced Grant (#833247).S

High-Density Lipoprotein Nanobiologics for Precision Medicine

Nature is an inspirational source for biomedical engineering developments. Particularly, numerous nanotechnological approaches have been derived from biological concepts. For example, among many different biological nanosized materials, viruses have been extensively studied and utilized, while exosome research has gained much traction in the 21st century. In our body, fat is transported by lipoproteins, intriguing supramolecular nanostructures that have important roles in cell function, lipid metabolism, and disease. Lipoproteins' main constituents are phospholipids and apolipoproteins, forming a corona that encloses a hydrophobic core of triglycerides and cholesterol esters. Within the lipoprotein family, high-density lipoprotein (HDL), primarily composed of apolipoprotein Al (apoA-I) and phospholipids, measuring a mere 10 nm, is the smallest and densest particle. Its endogenous character makes HDL particularly suitable as a nanocarrier platform to target a range of inflammatory diseases. For a decade and a half, our laboratories have focused on HDL's exploitation, repurposing, and reengineering for diagnostic and therapeutic applications, generating versatile hybrid nanomaterials, referred to as nanobiologics, that are inherently biocompatible and biodegradable, efficiently cross different biological barriers, and intrinsically interact with immune cells. The latter is facilitated by HDL's intrinsic ability to interact with the ATP-binding cassette receptor Al (ABCA1) and ABCG1, as well as scavenger receptor type B1 (SR-BI). In this Account, we will provide an up-to-date overview on the available methods for extraction, isolation, and purification of apoA-I from native HDL, as well as its recombinant production. ApoA-I's subsequent use for the reconstitution of HDL (rHDL) and other HDL-derived nanobiologics, including innovative microfluidic-based production methods, and their characterization will be discussed. The integration of different hydrophobic and amphiphilic imaging labels, including chelated radioisotopes and paramagnetic or fluorescent lipids, renders HDL nanobiologics suitable for diagnostic purposes. Nanoengineering also allows HDL reconstitution with core payloads, such as diagnostically active nanocrystals, as well as hydrophobic drugs or controlled release polymers for therapeutic purposes. The platform technology's specificity for inflammatory myeloid cells and methods to modulate specificity will be highlighted. This Account will build toward examples of in vivo studies in cardiovascular disease and cancer models, including diagnostic studies by magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET). A translational success story about the escalation of zirconium-89 radiolabeled HDL ("Zr-HDL) PET imaging from atherosclerotic mice to rabbits and pigs and all the way to cardiovascular disease patients is highlighted. Finally, recent advances in nanobiologic-facilitated immunotherapy of inflammation are spotlighted. Lessons, success stories, and perspectives on the use of these nature-inspired HDL mimetic are an integral part of this Accoun

Hoog tijd voor brede toepassing van 'opting-out'-strategie bij hiv-tests

--Despite the current active HIV test policy, the effects of the former policy are still visible, i.e. a relatively low number of individuals that have ever been tested for HIV. --The number of HIV tests and knowledge of current HIV status has increased among visitors to the STI clinic in Amsterdam. --Nevertheless, anonymous HIV surveillance among visitors to the STI clinic shows that a considerable proportion of HIV-infected individuals (24% of men who have sex with men (MSM) and 80% of heterosexuals) are unaware of the infection. --A new opting-out strategy for HIV testing in STI clinics is recommended. --The opting-out strategy may also be applicable to other medical settings, especially those that treat target populations such as MSM, heterosexuals with STI-related symptoms, and persons originating from AIDS-endemic regions. --The opting-out system was initiated in the Amsterdam STI clinic in 2007 in order to further reduce the number of undiagnosed HIV infection

Antibody-Mediated Inhibition of CTLA4 Aggravates Atherosclerotic Plaque Inflammation and Progression in Hyperlipidemic Mice

T cell-driven inflammation plays a critical role in the initiation and progression of atherosclerosis. The co-inhibitory protein Cytotoxic T-Lymphocyte Associated protein (CTLA) 4 is an important negative regulator of T cell activation. Here, we studied the effects of the antibody-mediated inhibition of CTLA4 on experimental atherosclerosis by treating 6-8-week-old Ldlr-/- mice, fed a 0.15% cholesterol diet for six weeks, biweekly with 200 μg of CTLA4 antibodies or isotype control for six weeks. 18F-fluorodeoxyglucose Positron Emission Tomography-Computed Tomography showed no effect of the CTLA4 inhibition of activity in the aorta, spleen, and bone marrow, indicating that monocyte/macrophage-driven inflammation was unaffected. Correspondingly, flow cytometry demonstrated that the antibody-mediated inhibition of CTLA4 did not affect the monocyte populations in the spleen. αCTLA4 treatment induced an activated T cell profile, characterized by a decrease in naïve CD44-CD62L+CD4+ T cells and an increase in CD44+CD62L- CD4+ and CD8+ T cells in the blood and lymphoid organs. Furthermore, αCTLA4 treatment induced endothelial activation, characterized by increased ICAM1 expression in the aortic endothelium. In the aortic arch, which mainly contained early atherosclerotic lesions at this time point, αCTLA4 treatment induced a 2.0-fold increase in the plaque area. These plaques had a more advanced morphological phenotype and an increased T cell/macrophage ratio, whereas the smooth muscle cell and collagen content decreased. In the aortic root, a site that contained more advanced plaques, αCTLA4 treatment increased the plaque T cell content. The short-term antibody-mediated inhibition of CTLA4 thus accelerated the progression of atherosclerosis by inducing a predominantly T cell-driven inflammation, and resulted in the formation of plaques with larger necrotic cores and less collagen. This indicates that existing therapies that are based on αCTLA4 antibodies may promote CVD development in patients