Liver transplantation (LT) is a successful treatment for patients with liver failure. However, organ shortage results in over 11% of patients losing their chance of a transplant attributed to liver ...decompensation (LD) and death. Ischemia/reperfusion injury (IRI) following conventional cold storage (CS) is a major cause of injury leading to graft loss after LT. Normothermic machine perfusion (NMP), a method of organ preservation, provides oxygen and nutrition during preservation and allows aerobic metabolism. NMP has recently been shown to enable improved organ utilization and posttransplant outcomes following a phase I and a phase III randomized trial. The aim of the present study is to assess the impact of NMP on reducing IRI and to define the underlying mechanisms. We transplanted and compared 12 NMP with 27 CS‐preserved livers by performing gene microarray, immunoprofiling of hepatic lymphocytes, and immunochemistry staining of liver tissues for assessing necrosis, platelet deposition, and neutrophil infiltration, and the status of steatosis after NMP or CS prereperfusion and postreperfusion. Recipients receiving NMP grafts showed significantly lower peak aspartate aminotransferase (AST) levels than those receiving CS grafts. NMP altered gene‐expression profiles of liver tissue from proinflammation to prohealing and regeneration. NMP also reduced the number of interferon gamma (IFN‐γ) and interleukin (IL)‐17–producing T cells and enlarged the CD4posCD25highCD127negFOXP3pos regulatory T cell (Treg) pool. NMP liver tissues showed less necrosis and apoptosis in the parenchyma and fewer neutrophil infiltration compared to CS liver tissues. Conclusion: Reduced IRI in NMP recipients was the consequence of the combination of inhibiting inflammation and promoting graft regeneration.
Acute liver failure (ALF) is characterised by overwhelming hepatocyte death and liver inflammation with massive infiltration of myeloid cells in necrotic areas. The mechanisms underlying resolution ...of acute hepatic inflammation are largely unknown. Here, we aimed to investigate the impact of Mer tyrosine kinase (MerTK) during ALF and also examine how the microenvironmental mediator, secretory leucocyte protease inhibitor (SLPI), governs this response.
Flow cytometry, immunohistochemistry, confocal imaging and gene expression analyses determined the phenotype, functional/transcriptomic profile and tissue topography of MerTK+ monocytes/macrophages in ALF, healthy and disease controls. The temporal evolution of macrophage MerTK expression and its impact on resolution was examined in APAP-induced acute liver injury using wild-type (WT) and Mer-deficient (Mer
) mice. SLPI effects on hepatic myeloid cells were determined in vitro and in vivo using APAP-treated WT mice.
We demonstrate a significant expansion of resolution-like MerTK+HLA-DR
cells in circulatory and tissue compartments of patients with ALF. Compared with WT mice which show an increase of MerTK+MHCII
macrophages during the resolution phase in ALF, APAP-treated Mer
mice exhibit persistent liver injury and inflammation, characterised by a decreased proportion of resident Kupffer cells and increased number of neutrophils. Both in vitro and in APAP-treated mice, SLPI reprogrammes myeloid cells towards resolution responses through induction of a MerTK+HLA-DR
phenotype which promotes neutrophil apoptosis and their subsequent clearance.
We identify a hepatoprotective, MerTK+, macrophage phenotype that evolves during the resolution phase following ALF and represents a novel immunotherapeutic target to promote resolution responses following acute liver injury.
Regulatory T cells (Tregs) play a pivotal role in maintaining immunological tolerance, but they can also play a detrimental role by preventing antitumor responses. Here, we characterized T helper ...(Th)-like Treg subsets to further delineate their biological function and tissue distribution, focusing on their possible contribution to disease states. RNA sequencing and functional assays revealed that Th2-like Tregs displayed higher viability and autocrine interleukin-2 (IL-2)-mediated activation than other subsets. Th2-like Tregs were preferentially found in tissues rather than circulation and exhibited the highest migratory capacity toward chemokines enriched at tumor sites. These cellular responses led us to hypothesize that this subset could play a role in maintaining a tumorigenic environment. Concurrently, Th2-like Tregs were enriched specifically in malignant tissues from patients with melanoma and colorectal cancer compared to healthy tissue. Overall, our results suggest that Th2-like Tregs may contribute to a tumorigenic environment due to their increased cell survival, higher migratory capacity, and selective T-effector suppressive ability.
Display omitted
•Memory Tregs can be classified as T helper-like Tregs (Th2, Th17, Th1, and Th1/17)•Human Th2-like Tregs exhibit the highest viability and IL-2-mediated activation•Th2-like Tregs are the subset with the highest chemotaxis toward CCL17/22•Th2-like Tregs are enriched at tumor sites in melanoma and colorectal cancer
Halim et al. provide a comprehensive transcriptomic and functional analysis of circulating Th-like Tregs, revealing unique features in Th2-like Tregs and a significant enrichment of this subset in patients with melanoma and colorectal cancer. This suggests that Th2-like Tregs play a major role in maintaining a tumorigenic environment.
This paper presents an acoustic transducer for fully implantable cochlear implants (FICIs), which can be implanted on the hearing chain to detect and filter the ambient sound in eight frequency bands ...between 250 and 6000 Hz. The transducer dimensions are conventional surgery compatible. The structure is formed with 3 × 3 × 0.36 mm active space for each layer and 5.2 mg total active mass excluding packaging. Characterization of the transducer is carried on an artificial membrane whose vibration characteristic is similar to the umbo vibration. On the artificial membrane, piezoelectric transducer generates up to 320.3 mVpp under 100 dB sound pressure level (SPL) excitation and covers the audible acoustic frequency. The measured signal‐to‐noise‐ratio (SNR) of the channels is up to 84.2 dB. Sound quality of the transducer for fully implantable cochlear implant application is graded with an objective qualification method (PESQ) for the first time in the literature to the best of the knowledge, and scored 3.42/4.5.
This study presents a middle ear implantable transducer for fully implantable cochlear implants. The transducer`s dimensions are compatible with routine cochlear implant procedures. The multi‐channel system covers the daily acoustic band with a high signal‐to‐noise ratio. Objective audiological evaluations of speech signals underscore the encouraging results, affirming the feasibility of the middle ear implantable multi‐channel transducer for the first time.
Autoimmune hepatitis (AIH) is a chronic liver disease caused by a perturbed immune system. The scarcity of short- and long-term immune monitoring of AIH hampered us to comprehend the interaction ...between immunosuppressive medication and immune homeostasis.
We recruited children with AIH at the time of diagnosis and at the 1st, 3rd, 6th, 12th, 18th, and 24th months of immunosuppression (IS). We also enrolled children with AIH being on IS for >2 years. Children with drug-induced liver injury (DILI), and those receiving tacrolimus after liver transplantation (LT), were enrolled as disease/IS control subjects. Healthy children (HC) were also recruited. Peripheral blood mononuclear cells (PBMCs) were isolated from all participants. Healthy liver tissue from adult donors and from livers without inflammation were obtained from children with hepatoblastoma. By using flow cytometry, we performed multi-parametric immune profiling of PBMCs and intrahepatic lymphocytes. Additionally, after IS with prednisolone, tacrolimus, rapamycin, or 6-mercaptopurine, we carried out an
cytokine stimulation assay. Finally, a Lifecodes SSO typing kit was used to type HLA-DRB1 and Luminex was used to analyze the results.
Untreated AIH patients had lower total CD8 T-cell frequencies than HC, but these cells were more naïve. While the percentage of naïve regulatory T cells (Tregs) (CD4
FOXP3
CD45RA
) and regulatory B cells (Bregs, CD20
CD24
CD38
) was similar, AIH patients had fewer activated Tregs (CD4
FOXP3
CD45RA
) compared to HC. Mucosal-associated-invariant-T-cells (MAIT) were also lower in these patients. Following the initiation of IS, the immune profiles demonstrated fluctuations. Bregs frequency decreased substantially at 1 month and did not recover anymore. Additionally, the frequency of intrahepatic Bregs in treated AIH patients was lower, compared to control livers, DILI, and LT patients. Following
IS drugs incubation, only the frequency of IL-10-producing total B-cells increased with tacrolimus and 6MP. Lastly, 70% of AIH patients possessed HLA-DR11, whereas HLA-DR03/DR07/DR13 was present in only some patients.
HLA-DR11 was prominent in our AIH cohort. Activated Tregs and MAIT cell frequencies were lower before IS. Importantly, we discovered a previously unrecognized and long-lasting Bregs scarcity in AIH patients after IS. Tacrolimus and 6MP increased IL-10+ B-cells
.
In this study, development of a wafer level, void free TSV fabrication process flow and feasibility study of TSV integration to MEMS piezoelectric resonator devices have been presented. TSV ...structures with 100 μm diameter and 350 μm depth were copper filled with via sealing and bottom-up electroplating process which is a two-step technique. Four-point Kelvin measurements showed 0.8 mΩ TSV resistance on fabricated TSVs. Furthermore, TSV frames were epoxy bonded to MEMS acoustic transducers, which showed 90% to the resonator signal from the TSV.
Liver T-cells respond to the inflammatory insult generated during organ procurement and contribute to the injury following reperfusion. The mode of liver donation alters various metabolic and ...inflammatory pathways but the way it affects intrahepatic T-cells is still unclear.
We investigated the modifications occurring in the proportion and function of T-cells during liver procurement for transplantation. We isolated hepatic mononuclear cells (HMC) from liver perfusate of living donors (LD) and donors after brain death (DBD) or cardiac death (DCD) and assessed the frequency of T-cell subsets, their cytokine secretion profile and CD8 T-cell cytotoxicity function, responsiveness to a danger associated molecular pattern (High Mobility Group Box1, HMGB1) and association with donor and recipient clinical parameters and immediate graft outcome.
We found that T-cells in healthy human livers were enriched in memory CD8 T-cells exhibiting a phenotype of non-circulating tissue-associated lymphocytes, functionally dominated by more cytotoxicity and IFN-γ-production in DBD donors, including upon activation by HMGB1 and correlating with peak of post-transplant AST. This liver-specific pattern of CD8 T-cell was prominent in DBD livers compared to DCD and LD livers suggesting that it was influenced by events surrounding brain death, prior to retrieval.
Mode of liver donation can affect liver T-cells with increased liver damage in DBD donors. These findings may be relevant in designing therapeutic strategies aimed at organ optimization prior to transplantation.
Increasing evidence suggests that innate immunity plays an important role in alcohol-induced liver injury and most studies have focused on positive regulation of innate immunity. The main objective ...of this study was to investigate the negative regulator of innate immunity, IL-1/Toll-like receptor (TLR) signaling pathways and interleukin receptor-associated kinase-M (IRAK-M) in alcoholic liver injury. We established an alcohol-induced liver injury model using wild type and IRAK-M deficient B6 mice and investigated the possible mechanisms. We found that in the absence of IRAK-M, liver damage by alcohol was worse with higher alanine transaminase (ALT), more immune cell infiltration and increased numbers of IFNγ producing cells. We also found enhanced phagocytic activity in CD68(+) cells. Moreover, our results revealed altered gut bacteria after alcohol consumption and this was more striking in the absence of IRAK-M. Our study provides evidence that IRAK-M plays an important role in alcohol-induced liver injury and IRAK-M negatively regulates the innate and possibly the adaptive immune response in the liver reacting to acute insult by alcohol. In the absence of IRAK-M, the hosts developed worse liver injury, enhanced gut permeability and altered gut microbiota.
Immunocompromised patients may be at increased risk to develop COVID-19 during the 2019 β-coronavirus infection. We present the unique opportunity we had to monitor the liver, IL-6 and immune cell ...course before, during and after COVID-19 in a boy with autoimmune hepatitis (AIH) and type 1 diabetes (T1D). CD4 and CD8 T cells frequencies decreased because of prednisolone, followed by a plateauing increase whereas CD19CD20 B cell increased strongly and was unaffected by COVID-19 infection. Moreover, the percentage of activated CD8 T cells expressing HLA-DR (CD8HLA-DR) increased during COVID-19 and subsided after its clearance. Total regulatory T cells (Tregs: CD4CD25CD127FOXP3) remained stable. Although activated Tregs (CD4CD45RAFOXP3) strongly increased upon prednisolone, it decreased afterwards. Furthermore, regulatory B cells (Bregs: CD19CD20CD24CD38) declined sharply owing to prednisolone. Serum IL-6 remained undetectable at all times. We demonstrated for the first time immune monitoring in a child with AIH and T1D before, during and after COVID-19. We hypothesize that continuing with low level of prednisolone without azathioprine may have abrogated activated Tregs, Bregs and IL-6 production and therefore permitting the activation of CD8 T cells, clearing the virus.
Nylon fibres are commonly used in blends with elastane. One of the problems encountered in the printing of nylon/elastane blend fabrics is the necessity of long steaming times for fixation, which ...causes an increase in energy consumption. In this study, the possibility of printing polyamide fabrics with 1:2 metal complex dyes for short steaming times was investigated. For this aim, laboratory and sample scale trials were performed to develop a method of chemically modifying fibres so that polyamide fabrics can be printed in short steaming times. Based on the results obtained in both trials, it was noticed that the steaming time for fixation could be reduced from 30 minutes to 15 minutes by printing with 1:2 metal complex dyes without causing a loss of printing yield and without affecting the fastness adversly in case of applying cationisation pretreatment with a modified quaternary polyalkylamine compound based product.
PDF
