Liver Cell Transplantation Research Articles

Therapeutic liver cell transplantation to treat murine PKU.

For gene therapy of the liver, in vivo applications based on adeno-associated virus are the most advanced vectors despite limitations, including low efficacy and episomal loss, potential integration and safety issues, and high production costs. Alternative vectors and/or delivery routes are of high interest. The regenerative ability of the liver bears the potential for ex vivo therapy using liver cell transplantation for disease correction if provided with a selective advantage to expand and replace the existing cell mass. Here we present such treatment of a mouse model of human phenylketonuria (PKU). Primary hepatocytes from wild-type mice were gene modified in vitro (with a lentiviral vector) that carries a gene editing system (CRISPR) to inhibit Cypor. Cypor inactivation confers paracetamol (or acetaminophen) resistance to hepatocytes and thus a growth advantage to eliminate the pre-existing liver cells upon grafting (via the spleen) and exposure to repeated treatment with paracetamol. Grafting Cypor-inactivated wild-type hepatocytes into inbred young adult enu2 (PKU) mice, followed by selective expansion by paracetamol dosing, resulted in replacing up to 5% of cell mass, normalization of blood phenylalanine, and permanent correction of PKU. Hepatocyte transplantation offers thus an armamentarium of novel therapy options for genetic liver defects.

Defining the Landscape of Educational Experiences in Transplant Infectious Diseases: A National Survey of Infectious Diseases Fellows in the United States.

Transplant infectious diseases (TID) is a growing area of expertise within infectious diseases (ID), but TID training is not standardized. Previous surveys of fellows identified opportunities to improve TID education resources but did not explore didactic, clinical, and nonclinical experiences comprehensively. The American Society of Transplantation ID Community of Practice surveyed adult and pediatric fellows in US-based general ID or dedicated TID training programs to explore their didactic exposure, clinical experiences, and non-direct patient care activities in TID. A total of 234 fellows initiated the survey, and 195 (83%) (190 general ID and 19 TID fellows, including 125 adult, 76 pediatric, and 8 combined adult-pediatric fellows) completed the entire survey. More than half of the fellows described receiving no formal curricular content on most foundational topics in transplant medicine. Almost all respondents (>90%) had some inpatient TID experience, but for >60% of fellows this was <12 weeks annually. Clinical exposure varied by fellow and patient type-in an average month rotating on an inpatient TID service, more than half of adult fellows had evaluated ≥10 kidney, liver, or hematopoietic stem cell transplant recipients but <10 heart, lung, pancreas, or intestinal recipients; pediatric fellows saw <10 of all patient types. Nearly half (46%) of general ID fellows had not spent any time in the dedicated TID clinic at their program. Few fellows had participated in protocol development, organ selection meetings, or donor evaluations. This survey highlights important gaps in TID training. Given the increasing need for TID specialists, updated curricula and educational resources are needed.

Integration of a clinical pharmacist practitioner-led pharmacogenomics service in a Veterans Affairs hematology/oncology clinic.

This article describes the implementation and evaluation of pharmacogenomic testing within the hematology/oncology ambulatory care clinic at the William S. Middleton Memorial Veterans Hospital in Madison, WI. The Pharmacogenomic Testing for Veterans (PHASER) program provides preemptive pharmacogenomic testing for veterans nationally. Program implementation at the Madison Veterans Affairs site began in the hematology/oncology clinic with the goal of integrating the offer for pharmacogenomic testing, testing completion, and review of the results by the hematology/oncology clinical pharmacist practitioner (CPP) into current workflows to create a sustainable process for PHASER. The hematology/oncology CPP designed workflows outlining how testing would be offered to patients, how results would be reported and to whom, and how documentation would occur in the electronic medical record. Veterans are offered preemptive PHASER testing, before needing therapy requiring pharmacogenomic results. Exceptions to pharmacogenomic testing were patients with a history of liver or allogeneic hematopoietic stem cell transplantation. This article provides a summary of the role of the hematology/oncology CPP in the implementation of a pharmacogenomics service and the impact on medication management in a hematology/oncology clinic.

Organ Donation and Transplantation Registries Across the Globe: A Review of the Current State.

The current landscape of organ donation and transplantation (ODT) registries is not well established. This narrative review sought to identify and characterize the coverage, structure, and data capture of ODT registries globally. We conducted a literature search using Ovid Medline and web searches to identify ODT registries from 2000 to 2023. A list of ODT registries was compiled based on publications of registry design, studies, and reports. Extracted data elements included operational features of registries and the types of donor and recipient data captured. We identified 129 registries encompassing patients from all continents except Antarctica. Most registries were active, received funding from government or professional societies, were national in scope, included both adult and pediatric patients, and reported patient-level data. Registries included kidney (n = 99), pancreas (n = 32), liver (n = 44), heart (n = 35), lung (n = 30), intestine (n = 15), and islet cell (n = 5) transplants. Most registries captured donor data (including living versus deceased) and recipient features (including demographics, cause of organ failure, and posttransplant outcomes) but there was underreporting of other domains (eg, donor comorbidities, deceased donor referral rates, waitlist statistics). This review highlights existing ODT registries globally and serves as a call for increased visibility and transparency in data management and reporting practices. We propose that standards for ODT registries, a common data model, and technical platforms for collaboration, will enable a high-functioning global ODT system responsive to the needs of transplant candidates, recipients, and donors.

Molecular force-induced liberation of transforming growth factor-beta remodels the spleen for ectopic liver regeneration

Ectopic liver regeneration in the spleen is a promising alternative to organ transplantation for treating liver failure. To accommodate transplanted liver cells, the splenic tissue must undergo structural changes to increase extracellular matrix content, demanding a safe and efficient approach for tissue remodelling. We synthesised sulphated hyaluronic acid (sHA) with an affinity for the latent complex of transforming growth factor-β (TGF-β) and cross-linked it into a gel network (sHA-X) via click chemistry. We injected this glycan into the spleens of mice to induce splenic tissue remodelling via supraphysiological activation of endogenous TGF-β. sHA-X efficiently bound to the abundant latent TGF-β in the spleen. It provided the molecular force to liberate the active TGF-β dimers from their latent complex, mimicking the 'bind-and-pull' mechanism required for physiological activation of TGF-β and reshaping the splenic tissue to support liver cell growth. Hepatocytes transplanted into the remodelled spleen developed into liver tissue with sufficient volume to rescue animals with a metabolic liver disorder (Fah-/- transgenic model) or following 90% hepatectomy, with no adverse effects observed and no additional drugs required. Our findings highlight the efficacy and translational potential of using sHA-X to remodel a specific organ by mechanically activating one single cytokine, representing a novel strategy for the design of biomaterials-based therapies for organ regeneration. Cell transplantation may provide a lifeline to millions of patients with end-stage liver diseases, but their severely damaged livers being unable to accommodate the transplanted cells is a crucial hurdle. Herein, we report an approach to restore liver functions in another organ - the spleen - by activating one single growth factor in situ. This approach, based on a chemically designed polysaccharide that can mechanically liberate the active transforming growth factor-β to an unusually high level, promotes the function of abundant allogenic liver cells in the spleen, rescuing animals from lethal models of liver diseases and showing a high potential for clinical translation.

The role of natural killer T cells in liver transplantation.

Natural killer T cells (NKTs) are innate-like lymphocytes that are abundant in the liver and participate in liver immunity. NKT cells express both NK cell and T cell markers, modulate innate and adaptive immune responses. Type I and Type II NKT cells are classified according to the TCR usage, while they recognize lipid antigen in a non-classical major histocompatibility (MHC) molecule CD1d-restricted manner. Once activated, NKT cells can quickly produce cytokines and chemokines to negatively or positively regulate the immune responses, depending on the different NKT subsets. In liver transplantation (LTx), the immune reactions in a series of processes determine the recipients' long-term survival, including ischemia-reperfusion injury, alloresponse, and post-transplant infection. This review provides insight into the research on NKT cells subpopulations in LTx immunity during different processes, and discusses the shortcomings of the current research on NKT cells. Additionally, the CD56-expressing T cells are recognized as a NK-like T cell population, they were also discussed during these processes.

Therapeutic monitoring of pediatric transplant patients with conversion to generic tacrolimus

ObjectiveTherapeutic monitoring during interchange of tacrolimus commercial formulations is essential to ensure similar exposure in transplant patients. However, there are limited data in the pediatric transplant population. This study aims to evaluate exposure, safety and efficacy in maintenance pediatric transplant patients under generic tacrolimus substitution. MethodPediatric patients who underwent interchange of tacrolimus formulations were detected by the Service of Pharmacy and included in this study. Tacrolimus trough levels (C0), laboratory parameters and clinical characteristics were recorded before and after the switch. Statistical analysis was performed using Wilcoxon matched pair t-test. ResultsIn total, 10 patients with kidney, liver, heart and hematopoietic stem cell transplantation received the innovator and switched to the generic product. The median (range) of the C0 normalized by the dose before and after switch was 74.8 [(ng/ml)/(mg/kg)] (13.8-518.4) and 65.1 [(ng/ml)/(mg/kg)] (13.5-723.5), respectively (p>0.05). Tacrolimus dose was 0.070(mg/kg) (0.024-0.461) and 0.069(mg/kg) (0.017-0.571) for the innovator and generic formulation, respectively, with no difference when comparing both values (p>0.05). Laboratory parameters did not change after conversion (p>0.05). Adverse events, acute rejection, death and graft loss were not observed. ConclusionsIn our study population, no significant differences in terms of laboratory parameters, drug exposure and dose were observed. We emphasize the need of close monitoring to ensure a safe interchange, especially in vulnerable populations such as the pediatric.

LIGHT (TNFSF14) promotes the differentiation of human bone marrow-derived mesenchymal stem cells into functional hepatocyte-like cells.

Liver transplantation is the most effective treatment option for patients with acute or chronic liver failure. However, the applicability and effectiveness of this modality are often limited by a shortage of donors, surgical complications, high medical costs, and the need for continuing immunosuppressive therapy. An alternative approach is liver cell transplantation. LIGHT (a member of the tumor necrosis factor superfamily) could be a promising candidate for promoting the differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) into hepatocyte-like cells. In this study, we investigated the effect of LIGHT on hBM-MSC differentiation into hepatocyte-like cells. Our previous results showed that LIGHT receptor lymphotoxin-β receptor (LTβR) is constitutively expressed on the surface of hBM-MSCs. Upon treatment with recombinant human LIGHT (rhLIGHT), the phenotype of hBM-MSCs changed to round or polygonal cells. In addition, the cells exhibited high levels of hepatocyte-specific markers, including albumin, cytokeratin-18 (CK-18), CK-19, cytochrome P450 family 1 subfamily A member 1 (CYP1A1), CYP1A2, CYP3A4, SRY-box transcription factor 17 (SOX17), and forkhead box A2 (FOXA2). These results indicate that rhLIGHT enhances the differentiation of hBM-MSCs into functional hepatocyte-like cells. Furthermore, rhLIGHT-induced hepatocyte-like cells showed a higher ability to store glycogen and uptake indocyanine green compared with control cells, indicating functional progression. Additionally, treatment with rhLIGHT increased the number, viability, and proliferation of cells by inducing the S/G2/M phase and upregulating the expression of various cyclin and cyclin dependent kinase (CDK) proteins. We also found that the hepatogenic differentiation of hBM-MSCs induced by rhLIGHT was mediated by the activation of signal transducer and activator of transcription 3 (STAT3) and STAT5 pathways. Overall, our findings suggest that LIGHT plays an essential role in promoting the hepatogenic differentiation of hBM-MSCs. Hence, LIGHT may be a valuable factor for stem cell therapy.

Role of Kupffer cells in tolerance induction after liver transplantation.

Currently, liver transplantation has reached a level of maturity where it is considered an effective treatment for end-stage liver disease and can significantly prolong the survival time of patients. However, acute and chronic rejection remain major obstacles to its efficacy. Although long-term use of immunosuppressants can prevent rejection, it is associated with serious side effects and significant economic burden for patients. Therefore, the investigation of induced immune tolerance holds crucial theoretical significance and socio-economic value. In fact, the establishment of immune tolerance in liver transplantation is intricately linked to the unique innate immune system of the liver. Kupffer cells, as a crucial component of this system, play a pivotal role in maintaining the delicate balance between inflammatory response and immune tolerance following liver transplantation. The important roles of different functions of Kupffer cells, such as phagocytosis, cell polarization, antigen presentation and cell membrane proteins, in the establishment of immune tolerance after transplantation is comprehensively summarized in this paper. Providing theoretical basis for further study and clinical application of Kupffer cells in liver transplantation.

The versatility of adipose derived stem cells in liver transplantation: a narrative review

The versatility of adipose derived stem cells in liver transplantation: a narrative review

Rescue of glutaric aciduria type I in mice by liver-directed therapies.

Glutaric aciduria type I (GA-1) is an inborn error of metabolism with a severe neurological phenotype caused by the deficiency of glutaryl-coenzyme A dehydrogenase (GCDH), the last enzyme of lysine catabolism. Current literature suggests that toxic catabolites in the brain are produced locally and do not cross the blood-brain barrier. In a series of experiments using knockout mice of the lysine catabolic pathway and liver cell transplantation, we uncovered that toxic GA-1 catabolites in the brain originated from the liver. Moreover, the characteristic brain and lethal phenotype of the GA-1 mouse model was rescued by two different liver-directed gene therapy approaches: Using an adeno-associated virus, we replaced the defective Gcdh gene or we prevented flux through the lysine degradation pathway by CRISPR deletion of the aminoadipate-semialdehyde synthase (Aass) gene. Our findings question the current pathophysiological understanding of GA-1 and reveal a targeted therapy for this devastating disorder.

Assessment of the effect of cell transplantation on DNA repair in rat hepatocytes exposed to carbon tetrachloride (CCl4) by DNA comet assay

Introduction. The effect of carbon tetrachloride (freon-10, asordin, hladon-10) is an organochlorine compound with the chemical formula CCl4 and the subsequent transplantation of fetal liver cells (FLC) on DNA degradation and repair in rat hepatocytes by means of alkaline single-cell gel electrophoresis (DNA comet assay) was assessed. Material and methods. Acute toxic damage to the rat liver was simulated by a single oral administration to female Wistar rats of CCl4 in an oil solution at a dose of 3000 mg/kg. As a protective agent, a suspension of FLC of E19 rat fetuses was used. Quantitative assessment of the degree of damage to the nuclear DNA of liver cells was performed by DNA comet assay on days 1, 3, 5, 7 and 16 of the experiment. Results. Intravenous injections of fetal liver cells 6 h after exposure to CCl4 induces DNA repair processes in rat hepatocytes in 5-7 days and led to a decrease in the intensity of nuclear DNA damage. The trend toward a decrease in the number of undamaged hepatocytes continued on the 16th day of the experiment, and, therewith, the enhancement of reparative processes after FLC injection revealed itself in in a significant decrease in the number of hepatocytes with a high intensity of nuclear DNA damage. Limitations. To prevent unwanted death of animals in the group, studies were limited to a dose of 3000 mg/kg of CCl4 in oil solution. Conclusion. The method of alkaline single-cell gel electrophoresis (DNA comet assay) allowed quantitative assessment of the degrees of genome damage and repair. The obtained positive results suggest that FLC exert a protective effect of the structure of the DNA of rat liver role after acute exposure to CCl4.

Psychosocial Risk Differences Among Veteran Organ Transplant Groups: Rehabilitation Targets to Promote Transplant Listing Outcomes

Research Objectives To investigate differences in psychosocial risk profiles among Veteran transplant groups during mental health (MH) pre-transplant evaluations to inform rehabilitation targets to promote transplant listing and general outcomes. Design Cross-sectional study. Setting VA Hospital. Participants 76 male Veterans ranging in age from 29–86 (M=62.9, SD=8.8) undergoing kidney (n=29), liver (n=31), or stem cell (SCT; n=16) transplantation work-up. Sixty-two percent identified as white, 30% Black, 5% Latinx, and 1% American Indian/Alaska Native (1% declined to answer). Interventions N/A. Main Outcome Measures Psychosocial risk assessed using the Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) to derive subscales of Patient's Readiness (PR), Social Support, Psychological Suitability and Psychopathology, and Lifestyle and Effect of Substance Use (LESU), with higher scores signifying greater psychosocial risk. Results Four ANOVA models were run (SIPAT subscale=dependent variable; transplant type=independent variable). Significant effects were found for PR, F(2, 73) = 3.98, p = .023, and LESU, F(2, 73) = 6.18, p = .003. Nonparametric bootstrapped t-tests using 10,000 resamples revealed higher mean scores for liver compared to kidney and SCT groups for PR (95% CI: 0.53 – 3.73, p = .009; 95% CI: 0.27 – 3.84, p = .025, respectively) as well as LESU (95% CI: 1.81 – 6.73, p < .001; 95% CI: 0.28 – 5.88, p = .030, respectively). Confidence intervals for differences among SCT and kidney groups contained zero (PR 95% CI: -1.45 – 1.58, LESU 95% CI: -1.85 – 1.98). Conclusions Patients from different transplant populations may require different rehabilitation/intervention needs to ensure potential listing and general success. Specifically, liver transplant patients may benefit from additional education on the transplant process and encouraging changes in substance use/lifestyle factors. Future research should investigate differences in psychosocial risk as well as the predictive validity of the SIPAT for long-term treatment outcomes (i.e., transplantation) across transplant groups. Author(s) Disclosures N/A. To investigate differences in psychosocial risk profiles among Veteran transplant groups during mental health (MH) pre-transplant evaluations to inform rehabilitation targets to promote transplant listing and general outcomes. Cross-sectional study. VA Hospital. 76 male Veterans ranging in age from 29–86 (M=62.9, SD=8.8) undergoing kidney (n=29), liver (n=31), or stem cell (SCT; n=16) transplantation work-up. Sixty-two percent identified as white, 30% Black, 5% Latinx, and 1% American Indian/Alaska Native (1% declined to answer). N/A. Psychosocial risk assessed using the Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) to derive subscales of Patient's Readiness (PR), Social Support, Psychological Suitability and Psychopathology, and Lifestyle and Effect of Substance Use (LESU), with higher scores signifying greater psychosocial risk. Four ANOVA models were run (SIPAT subscale=dependent variable; transplant type=independent variable). Significant effects were found for PR, F(2, 73) = 3.98, p = .023, and LESU, F(2, 73) = 6.18, p = .003. Nonparametric bootstrapped t-tests using 10,000 resamples revealed higher mean scores for liver compared to kidney and SCT groups for PR (95% CI: 0.53 – 3.73, p = .009; 95% CI: 0.27 – 3.84, p = .025, respectively) as well as LESU (95% CI: 1.81 – 6.73, p < .001; 95% CI: 0.28 – 5.88, p = .030, respectively). Confidence intervals for differences among SCT and kidney groups contained zero (PR 95% CI: -1.45 – 1.58, LESU 95% CI: -1.85 – 1.98). Patients from different transplant populations may require different rehabilitation/intervention needs to ensure potential listing and general success. Specifically, liver transplant patients may benefit from additional education on the transplant process and encouraging changes in substance use/lifestyle factors. Future research should investigate differences in psychosocial risk as well as the predictive validity of the SIPAT for long-term treatment outcomes (i.e., transplantation) across transplant groups.

Characteristics of changes in double positive CD4+CD8+ T cells in liver transplantation

Although double positive CD4+CD8+ T (DPT) cells has been reported to be involved in some diseases, their trajectory and function as associated with liver transplantation (LT) remain unclear. In the present study, we found that the number of DPT cells was increased in the blood and liver tissue of LT patients. Meanwhile, we compared the distribution of DPT cells in peripheral blood samples and in penetrating liver tissue between liver rejection versus non-rejection patients, as well as the proportion of DPT cells as a function of the extent of liver rejection. The number of DPT cells in the rejection group was significantly increased. An analysis of the spatial distance and correlations between DPT and Treg cells, revealed that these cells showed a high degree of contiguity. In a mouse liver transplant model, the number of DPT cells were significantly increased in liver tissue, and the number of CD8+ T cells gradually increased, while CD4+ T cells decreased as a function of time post-transplantation. Expression level of PD-1 in DPT cells also increased in a temporally-dependent manner post liver transplantation and the changes of PD-1+ DPT cells were related to the degree of liver transplant rejection. In DPT cells interacting with Treg, there was an increased expression of PD-1, which enhanced cellular exhaustion. In conclusion, the capacity for DPT cells to induce immune tolerance may represent a new and important protocol for use in targeting treatments for the prevention of liver transplant rejection.

A Bibliometric Analysis of the Landscape of Pediatric Liver Transplantation.

BackgroundNowadays, pediatric liver transplantation (PLT) has become an effective strategy for treating various acute or chronic end-stage liver diseases and inherited metabolic diseases. Many experts have already concluded the current challenges and future directions of PLT. However, no detailed analysis of the publication landscape has substantiated these proposed opinions.MethodsThis study presents a bibliometric review of the articles related to PLT between 1997 and 2020. A total of 3,084 publications were analyzed mainly by CiteSpace and VOSviewer.ResultsThe field of PLT has evolved gradually in the past two decades. Articles increased at an average rate of 97 articles every 4 years. University of Pittsburgh (PITT) is the most prolific institution. The three most productive regions are North America, Europe, and East Asia. Currently, interdisciplinary studies on PLT are scarce. The main goal of PLT has shifted from survival rates to long-term outcome. The quality of life, living donor liver transplantation (LDLT), immunological biomarkers, perioperative hemodynamic management, expanding the indications of PLT, etc. are parts of the emerging research fronts. In the past two decades, articles that contain potentials that may lead to transformative discoveries are scarce, and obvious deficits can be seen in the field of new therapies.ConclusionsLong-term outcome and good quality of life represent the principal direction of work concerning PLT. Deficits in new therapies align with the shortage of intellectual milestones, which indicate possible subsequent intellectual milestones may occur as innovations in therapies such as new immunosuppression therapies or liver cell transplantation.

DDX41 is needed for pre- and postnatal hematopoietic stem cell differentiation in mice.

SummaryDDX41 is a tumor suppressor frequently mutated in human myeloid neoplasms, but whether it affects hematopoiesis is unknown. Using a knockout mouse, we demonstrate that DDX41 is required for mouse hematopoietic stem and progenitor cell (HSPC) survival and differentiation, particularly of myeloid lineage cells. Transplantation of Ddx41 knockout fetal liver and adult bone marrow (BM) cells was unable to rescue mice from lethal irradiation, and knockout stem cells were also defective in colony formation assays. RNA-seq analysis of Lin−/cKit+/Sca1+Ddx41 knockout cells from fetal liver demonstrated that the expression of many genes associated with hematopoietic differentiation were altered. Furthermore, differential splicing of genes involved in key biological processes was observed. Our data reveal a critical role for DDX41 in HSPC differentiation and myeloid progenitor development, likely through regulating gene expression programs and splicing.

Natural killer cells in liver transplantation: Can we harness the power of the immune checkpoint to promote tolerance?

The roles that natural killer (NK) cells play in liver disease and transplantation remain ill‐defined. Reports on the matter are often contradictory, and the mechanisms elucidated are complex and dependent on the context of the model tested. Moreover, NK cell attributes, such as receptor protein expression and function differ among species, make study of primate or rodent transplant models challenging. Recent insights into NK function and NK‐mediated therapy in the context of cancer therapy may prove applicable to transplantation. Of specific interest are immune checkpoint molecules and the mechanisms by which they modulate NK cells in the tumor micro‐environment. In this review, we summarize NK cell populations in the peripheral blood and liver, and we explore the data regarding the expression and function of immune checkpoint molecules on NK cells. We also hypothesize about the roles they could play in liver transplantation and discuss how they might be harnessed therapeutically in transplant sciences.

Activation of reparative liver regeneration following the combined transplantation of multipotent mesenchymal stromal cells and hepatic stellate cells

Aim. To study the effect of combined transplantation of multipotent mesenchymal stromal and hepatic stellate cells on the reparative liver regeneration.&#x0D; Methods. Laboratory mice were given intravenous administration of multipotent mesenchymal stromal and hepatic stellate cells after partial hepatectomy. The mice were divided into four groups: control, experimental 1 (injection of multipotent mesenchymal stromal cells), experimental 2 (co-transplantation of multipotent mesenchymal stromal cells and hepatic stellate cells), the comparison group. Comparison of the experimental groups with the control group and the comparison group was carried out. Each group consisted of 14 animals. The control and experimental groups underwent partial hepatectomy. The experimental mice were injected with the cells into the lateral tail vein 1 hour after the operation. Multipotent mesenchymal stromal cells were administered at a dose of 4 million cells/kg (120 thousand cells/mouse), hepatic stellate cells in the amount of 9 million cells/kg (270 thousand cells/mouse), suspended in 0.2 ml 0.9% NaCl solution. The control group animals were injected with 0.2 ml 0.9% NaCl solution into the lateral tail vein. The comparison group consisted of mice without partial hepatectomy, injected with 0.2 ml 0.9% NaCl solution. To assess reparative regeneration of the liver, morphometric parameters of the liver, blood biochemical parameters on the 3rd and 7th days after partial hepatectomy were studied. The severity of apoptosis was assessed by the immunohistochemical method, the activity of deoxyribonucleic acid (DNA) repair enzymes of the poly (ADP-ribose) polymerases was determined by flow cytometry. The number of micronucleated hepatocytes was also determined. The hepatocyte growth factor (HGF) content was measured by using an enzyme-linked immunosorbent assay in serum. The significance of differences in the compared samples was determined by using the Student's t-test. Statistical data processing was performed by using the SPSS Statistics software version 17.0.&#x0D; Results. It was found that the combined transplantation of multipotent mesenchymal stromal and stellate liver cells causes restoration of the activity of alanine aminotransferase (a decrease of 30.3%, p=0.016), aspartate aminotransferase (a decrease of 27.7%, p=0.021), alkaline phosphatase (a decrease of 21.1%, p=0.036), an increase in the protein synthetic function of the liver (increase in albumin level by 36.6%, p=0.009), an increase in hepatocyte growth factor level by 74.3%. These changes were accompanied by the restoration of liver morphometric parameters: there was an increase in the mitotic activity of hepatocytes by 28.7% (p=0.008), the nuclear area of hepatocytes by 26.7% (p=0.006), the number of binucleated hepatocytes by 26.1% (p=0.004), which led to the restoration of liver mass. There was a decrease in the level of apoptosis by 28.8% (p=0.006) and a decrease in the number of micronucleated hepatocytes by 22.7% (p=0.001) compared with the control group, which may be related to an increase in the activity of Poly (ADP-ribose) polymerase repair enzymes detected in the study. The deviations were presented as a difference relative to the indicators of the control group (operated animals that were injected with 0.9% NaCl solution).&#x0D; Conclusion. Combined transplantation of multipotent mesenchymal stromal and hepatic stellate cells activates reparative liver regeneration after partial hepatectomy.Keywords: multipotent mesenchymal stromal cells, MSC, hepatic stellate cells, HSC, liver regeneration, partial hepatectomy.

Influence of combined transplantation of multipotent mesenchymal stromal cells and stellate liver cells on its morphofunctional state after partial hepatectomy

The aimof the study was to study the changes in the morphofunctional state of the liver after the combined transplantation of multipotent mesenchymal stromal (MMSC) and stellate liver cells (ZCP) in animals with partial hepatectomy.Materials and methods.The MMSC culture was isolated from the placental chorion of 5 laboratory animals f female mice aged 3-4 months, weighing 22-23 g, gestation period of 18 days. The mononuclear fraction of the cells was obtained by sequential mechanical and enzymatic treatment of the placental tissue. The cultivation of MMSCs was carried out in a CO2 incubator at a temperature of 370C with a carbon dioxide content of 5% and a humidity of 90%. ZCP was isolated by collagenase-pronase perfusion of the liver, followed by cell separation in the histodense density gradient. MMSCs of the 3rd passage were introduced, and ZKP was introduced immediately after isolation. MMSCs at a dose of 4 million cells/kg and ZCP at a dose of 9 million cells/ kg were used for transplantation to labotory animals. The cells were injected 1 hour after partial hepatectomy. The biochemical parameters of peripheral blood and morphometric parameters of the liver were evaluated on the 3rd, 7th day after the administration of MMSC.Results.As a result of the study, it was found that the combined transplantation of MMSC and ZCP after partial hepatectomy leads to the restoration of the level of enzymes that characterize cytolysis and cholestasis, normalization of the protein-synthetic function of the liver, normalization morphometric parameters of the liver. A significant mechanism for restoring the morphofunctional state of the liver can be considered the influence of transplanted MMSCs and ZCP on the cell repair system, which leads to a decrease in the severity of programmed cell death of hepatocytes and the level of pathological mitoses.Discussion.Combined transplantation of MMSCs and HCP after partial hepatectomy leads to an increase in the level of hepatocyte growth factor (HGF), thus contributing to an se in the mitotic activity of hepatocytes and the restoration of liver mass. The transplanted cells also, by increasing the activity of DNA repair enzymes of the PARP family, lead to a decrease in the level of pathological mitoses, inhibition of their programmed cell death.Conclusions.The conducted studies demonstrate the ability of combined MMSC and PCR transplantation to restore the morphofunctional state of the liver after partial hepatectomy and provide the basis for conducting pilot clinical studies

Development of T-cell immunity in a liver and hematopoietic stem cell transplant recipient following coronavirus disease 2019 infection

The outbreak of coronavirus disease 2019 (COVID-19) has disproportionately affected patients with comorbidities, including recipients of solid organ and hematopoietic stem cell transplants (SCT). Upon recovery from COVID-19, the degree of the immunological protection from reinfection remains unclear. Here we describe a 33-year-old patient with erythropoietic protoporphyria (EPP) who had undergone liver transplantation with splenectomy followed by allogeneic SCT in 2013 after an initial failed liver and umbilical cord transplant. The patient developed mild upper respiratory symptoms in the spring of 2020 and was found to have anti-SARS-CoV2 antibodies suggesting past infection. A comprehensive analysis of T cell functionality in peripheral blood from this patient revealed robust in vitro responses against SARS CoV2 antigens Spike (S) 1 and 2, membrane (M) and nucleoprotein (NP), comparable to the reactivity against common antigens from CMV, EBV, Ad and BK viruses, while only low reactivity was seen in healthy donors without documented history of COVID-19. Moreover, the patient displayed a marked recognition of counterpart antigens from related human coronaviruses (hCoVs) 229E, OC43, NL63 and HKU1. Thus, despite lifelong immunosuppression, this survivor of COVID-19 retained a remarkable degree of immunocompetence and showed broad-spectrum T cell memory specific for SARS-CoV2 and related hCoVs including less studied hCoV M and NP antigens. The study highlights the role of cellular immunity after natural COVID-19 infection, suggesting broader use of T cell assays as a tool for risk stratification, measurement of immunocompetence and/or post-infection or post-vaccination protection, and possible T cell-based adoptive immunotherapy strategies in high-risk patients.