SARS-CoV-2-specific immune responses converge in kidney disease patients and controls with hybrid immunity

Healthy individuals with hybrid immunity, due to a SARS-CoV-2 infection prior to first vaccination, have stronger immune responses compared to those who were exclusively vaccinated. However, little is known about the characteristics of antibody, B- and T-cell responses in kidney disease patients with hybrid immunity. Here, we explored differences between kidney disease patients and controls with hybrid immunity after asymptomatic or mild coronavirus disease-2019 (COVID-19). We studied the kinetics, magnitude, breadth and phenotype of SARS-CoV-2-specific immune responses against primary mRNA-1273 vaccination in patients with chronic kidney disease or on dialysis, kidney transplant recipients, and controls with hybrid immunity. Although vaccination alone is less immunogenic in kidney disease patients, mRNA-1273 induced a robust immune response in patients with prior SARS-CoV-2 infection. In contrast, kidney disease patients with hybrid immunity develop SARS-CoV-2 antibody, B- and T-cell responses that are equally strong or stronger than controls. Phenotypic analysis showed that Spike (S)-specific B-cells varied between groups in lymph node-homing and memory phenotypes, yet S-specific T-cell responses were phenotypically consistent across groups. The heterogeneity amongst immune responses in hybrid immune kidney patients warrants further studies in larger cohorts to unravel markers of long-term protection that can be used for the design of targeted vaccine regimens.</p

SARS-CoV-2-specific immune responses converge in kidney disease patients and controls with hybrid immunity

Healthy individuals with hybrid immunity, due to a SARS-CoV-2 infection prior to first vaccination, have stronger immune responses compared to those who were exclusively vaccinated. However, little is known about the characteristics of antibody, B- and T-cell responses in kidney disease patients with hybrid immunity. Here, we explored differences between kidney disease patients and controls with hybrid immunity after asymptomatic or mild coronavirus disease-2019 (COVID-19). We studied the kinetics, magnitude, breadth and phenotype of SARS-CoV-2-specific immune responses against primary mRNA-1273 vaccination in patients with chronic kidney disease or on dialysis, kidney transplant recipients, and controls with hybrid immunity. Although vaccination alone is less immunogenic in kidney disease patients, mRNA-1273 induced a robust immune response in patients with prior SARS-CoV-2 infection. In contrast, kidney disease patients with hybrid immunity develop SARS-CoV-2 antibody, B- and T-cell responses that are equally strong or stronger than controls. Phenotypic analysis showed that Spike (S)-specific B-cells varied between groups in lymph node-homing and memory phenotypes, yet S-specific T-cell responses were phenotypically consistent across groups. The heterogeneity amongst immune responses in hybrid immune kidney patients warrants further studies in larger cohorts to unravel markers of long-term protection that can be used for the design of targeted vaccine regimens.</p

PRMT3 inhibitor SGC707 reduces triglyceride levels and induces pruritus in Western-type diet-fed LDL receptor knockout mice

Protein arginine methyltransferase 3 (PRMT3) is a co-activator of liver X receptor capable of selectively modulating hepatic triglyceride synthesis. Here we investigated whether pharmacological PRMT3 inhibition can diminish the hepatic steatosis extent and lower plasma lipid levels and atherosclerosis susceptibility. Hereto, male hyperlipidemic low-density lipoprotein receptor knockout mice were fed an atherogenic Western-type diet and injected 3 times per week intraperitoneally with PRMT3 inhibitor SGC707 or solvent control. Three weeks into the study, SGC707-treated mice developed severe pruritus and scratching-associated skin lesions, leading to early study termination. SGC707-treated mice exhibited 50% lower liver triglyceride stores as well as 32% lower plasma triglyceride levels. Atherosclerotic lesions were virtually absent in all experimental mice. Plasma metabolite analysis revealed that levels of taurine-conjugated bile acids were ~ threefold increased (P < 0.001) in response to SGC707 treatment, which was paralleled by systemically higher bile acid receptor TGR5 signalling. In conclusion, we have shown that SGC707 treatment reduces hepatic steatosis and plasma triglyceride levels and induces pruritus in Western-type diet-fed LDL receptor knockout mice. These findings suggest that pharmacological PRMT3 inhibition can serve as therapeutic approach to treat non-alcoholic fatty liver disease and dyslipidemia/atherosclerosis, when unwanted effects on cholesterol and bile acid metabolism can be effectively tackled

PRMT3 inhibitor SGC707 reduces triglyceride levels and induces pruritus in Western-type diet-fed LDL receptor knockout mice

Protein arginine methyltransferase 3 (PRMT3) is a co-activator of liver X receptor capable of selectively modulating hepatic triglyceride synthesis. Here we investigated whether pharmacological PRMT3 inhibition can diminish the hepatic steatosis extent and lower plasma lipid levels and atherosclerosis susceptibility. Hereto, male hyperlipidemic low-density lipoprotein receptor knockout mice were fed an atherogenic Western-type diet and injected 3 times per week intraperitoneally with PRMT3 inhibitor SGC707 or solvent control. Three weeks into the study, SGC707-treated mice developed severe pruritus and scratching-associated skin lesions, leading to early study termination. SGC707-treated mice exhibited 50% lower liver triglyceride stores as well as 32% lower plasma triglyceride levels. Atherosclerotic lesions were virtually absent in all experimental mice. Plasma metabolite analysis revealed that levels of taurine-conjugated bile acids were ~ threefold increased (P < 0.001) in response to SGC707 treatment, which was paralleled by systemically higher bile acid receptor TGR5 signalling. In conclusion, we have shown that SGC707 treatment reduces hepatic steatosis and plasma triglyceride levels and induces pruritus in Western-type diet-fed LDL receptor knockout mice. These findings suggest that pharmacological PRMT3 inhibition can serve as therapeutic approach to treat non-alcoholic fatty liver disease and dyslipidemia/atherosclerosis, when unwanted effects on cholesterol and bile acid metabolism can be effectively tackled.Analytical BioScience

SARS-CoV-2-specific immune responses converge in kidney disease patients and controls with hybrid immunity

Healthy individuals with hybrid immunity, due to a SARS-CoV-2 infection prior to first vaccination, have stronger immune responses compared to those who were exclusively vaccinated. However, little is known about the characteristics of antibody, B- and T-cell responses in kidney disease patients with hybrid immunity. Here, we explored differences between kidney disease patients and controls with hybrid immunity after asymptomatic or mild coronavirus disease-2019 (COVID-19). We studied the kinetics, magnitude, breadth and phenotype of SARS-CoV-2-specific immune responses against primary mRNA-1273 vaccination in patients with chronic kidney disease or on dialysis, kidney transplant recipients, and controls with hybrid immunity. Although vaccination alone is less immunogenic in kidney disease patients, mRNA-1273 induced a robust immune response in patients with prior SARS-CoV-2 infection. In contrast, kidney disease patients with hybrid immunity develop SARS-CoV-2 antibody, B- and T-cell responses that are equally strong or stronger than controls. Phenotypic analysis showed that Spike (S)-specific B-cells varied between groups in lymph node-homing and memory phenotypes, yet S-specific T-cell responses were phenotypically consistent across groups. The heterogeneity amongst immune responses in hybrid immune kidney patients warrants further studies in larger cohorts to unravel markers of long-term protection that can be used for the design of targeted vaccine regimens

An Implantable Artificial Atherosclerotic Plaque as a Novel Approach for Drug Transport Studies on Drug-Eluting Stents

Atherosclerotic arteries are commonly treated using drug-eluting stents (DES). However, it remains unclear whether and how the properties of atherosclerotic plaque affect drug transport in the arterial wall. A limitation of the currently used atherosclerotic animal models to study arterial drug distribution is the unpredictability of plaque size, composition, and location. In the present study, the aim is to create an artificial atherosclerotic plaque—of reproducible and controllable complexity and implantable at specific locations—to enable systematic studies on transport phenomena of drugs in stented atherosclerosis-mimicking arteries. For this purpose, mixtures of relevant lipids at concentrations mimicking atherosclerotic plaque are incorporated in gelatin/alginate hydrogels. Lipid-free (control) and lipid-rich hydrogels (artificial plaque) are created, mounted on DES and successfully implanted in porcine coronary arteries ex-vivo. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) is used to measure local drug distribution in the arterial wall behind the prepared hydrogels, showing that the lipid-rich hydrogel significantly hampers drug transport as compared to the lipid-free hydrogel. This observation confirms the importance of studying drug transport phenomena in the presence of lipids and of having an experimental model in which lipids and other plaque constituents can be precisely controlled and systematically studied

Endothelial Cell Replacement of Human Veins, Modeling Vascular Repair and Endothelial Cell Chimerism

Allogeneic transplant organs are potentially highly immunogeneic. The endothelial cells (EC) located within the vascular system serve as the primary interface between the recipient's immune system and the donor organ, playing a key role in the allo-immune response. In this study, we investigated the potential use of recipient-derived ECs in a vein recellularization model. Here, human iliac veins underwent complete decellularization using a triton X-100 protocol. We demonstrated the feasibility of re-endothelializing acellular blood vessels using either HUVEC or human venous-derived ECs, with this re-endothelization being sustainable for up to 28 days in vitro. The re-endothelialized veins exhibited the restoration of vascular barrier function, along with the restoration of innate immune regulatory capabilities, evident through the facilitation of monocytic cell transmigration and their polarization towards a macrophage phenotype following trans-endothelial extravasation. Finally, we explored whether recellularization with EC of a different donor could prevent antibody-mediated rejection. We demonstrated that in chimeric vessels, allogeneic EC became a target of the humoral anti-donor response after activation of the classical immune complement pathway whereas autologous EC were spared, emphasizing their potential utility prior to transplantation. In conclusion, our study demonstrates that replacement of EC in transplants could reduce the immunological challenges associated with allogeneic grafts.</p

mRNA-based COVID-19 vaccination of lung transplant recipients with prior SARS-CoV-2 infection induces durable SARS-CoV-2-specific antibodies and T cells

Lung transplant recipients (LTRs) are particularly at risk of developing severe coronavirus disease-2019 (COVID-19), but are also difficult to protect by vaccination due to their immunocompromised state. Here, we investigated the immunogenicity of mRNA-based COVID-19 vaccines in LTRs who had a prior natural SARS-CoV-2 infection. At a median of 184 days after SARS-CoV-2 infection, LTRs were vaccinated twice with the mRNA-1273 COVID-19 vaccine, with a 28-day interval. Blood samples were obtained pre-vaccination, 28 days after the first dose, and 28 days and 6 months after the second dose. Spike (S-) and nucleocapsid (N-) specific antibodies were measured, as well as neutralization of the ancestral and Omicron BA.5 variant. S-specific T cell responses were evaluated using IFN-γ ELISpot，IGRA, and activation markers by flow cytometry. Phenotyping of T cells was performed by using high-resolution spectral flow cytometry. Most LTRs with prior infection had detectable S-specific antibodies and T cells at baseline. After the first vaccination, S-specific antibody levels increased significantly; an additional increase was observed after the second vaccination. N-specific antibodies decreased during the study period, indicative of the fact that no further breakthrough infections occurred. An increase in IFN-γ producing T cells was observed after the first vaccination, but no additional boost could be detected after the second vaccination. Antibody levels and virus-specific T cell responses remained significantly higher compared to pre-vaccination levels at 6 months post-vaccination, indicating an additive and durable effect of vaccination after infection in LTRs. Neutralizing antibodies were detected against the ancestral strain and retained cross-reactivity with Omicron BA.5, albeit at lower levels. Moreover, the quantity and phenotype of SARS-CoV-2 spike-specific T cells were similar in LTRs compared to controls with hybrid immunity. In conclusion, mRNA-based COVID-19 vaccines are immunogenic in LTRs with prior immunity, and antibody and T cell responses are durable up to 6 months post-vaccination.</p

Endothelial Cell Replacement of Human Veins, Modeling Vascular Repair and Endothelial Cell Chimerism

Allogeneic transplant organs are potentially highly immunogeneic. The endothelial cells (EC) located within the vascular system serve as the primary interface between the recipient's immune system and the donor organ, playing a key role in the allo-immune response. In this study, we investigated the potential use of recipient-derived ECs in a vein recellularization model. Here, human iliac veins underwent complete decellularization using a triton X-100 protocol. We demonstrated the feasibility of re-endothelializing acellular blood vessels using either HUVEC or human venous-derived ECs, with this re-endothelization being sustainable for up to 28 days in vitro. The re-endothelialized veins exhibited the restoration of vascular barrier function, along with the restoration of innate immune regulatory capabilities, evident through the facilitation of monocytic cell transmigration and their polarization towards a macrophage phenotype following trans-endothelial extravasation. Finally, we explored whether recellularization with EC of a different donor could prevent antibody-mediated rejection. We demonstrated that in chimeric vessels, allogeneic EC became a target of the humoral anti-donor response after activation of the classical immune complement pathway whereas autologous EC were spared, emphasizing their potential utility prior to transplantation. In conclusion, our study demonstrates that replacement of EC in transplants could reduce the immunological challenges associated with allogeneic grafts.</p