Cytokine response to ischemia/reperfusion injury in an ex vivo perfused porcine liver model

Acute Lymphoblastic Leukemia Immunotherapy Treatment: Now, Next, and Beyond

Acute lymphoblastic leukemia (ALL) is a blood cancer that primarily affects children but also adults. It is due to the malignant proliferation of lymphoid precursor cells that invade the bone marrow and can spread to extramedullary sites. ALL is divided into B cell (85%) and T cell lineages (10 to 15%); rare cases are associated with the natural killer (NK) cell lineage (<1%). To date, the survival rate in children with ALL is excellent while in adults continues to be poor. Despite the therapeutic progress, there are subsets of patients that still have high relapse rates after chemotherapy or hematopoietic stem cell transplantation (HSCT) and an unsatisfactory cure rate. Hence, the identification of more effective and safer therapy choices represents a primary issue. In this review, we will discuss novel therapeutic options including bispecific antibodies, antibody-drug conjugates, chimeric antigen receptor (CAR)-based therapies, and other promising treatments for both pediatric and adult patients.

Direct CD32 T-cell cytotoxicity: implications for breast cancer prognosis and treatment

The FcγRII (CD32) ligands are IgFc fragments and pentraxins. The existence of additional ligands is unknown. We engineered T cells with human chimeric receptors resulting from the fusion between CD32 extracellular portion and transmembrane CD8α linked to CD28/ζ chain intracellular moiety (CD32-CR). Transduced T cells recognized three breast cancer (BC) and one colon cancer cell line among 15 tested in the absence of targeting antibodies. Sensitive BC cell conjugation with CD32-CR T cells induced CD32 polarization and down-regulation, CD107a release, mutual elimination, and proinflammatory cytokine production unaffected by human IgGs but enhanced by cetuximab. CD32-CR T cells protected immunodeficient mice from subcutaneous growth of MDA-MB-468 BC cells. RNAseq analysis identified a 42 gene fingerprint predicting BC cell sensitivity and favorable outcomes in advanced BC. ICAM1 was a major regulator of CD32-CR T cell-mediated cytotoxicity. CD32-CR T cells may help identify cell surface CD32 ligand(s) and novel prognostically relevant transcriptomic signatures and develop innovative BC treatments.

Effects of liver ischemia-reperfusion injury on respiratory mechanics and driving pressure during orthotopic liver transplantation

BACKGROUND

During orthotopic liver transplantation (OLT), liver graft ischemia-reperfusion injury (IRI) triggers a cytokine-mediated systemic inflammatory response, which impairs graft function and disrupts distal organ homeostasis. The objective of this prospective, observational trial was to assess the effects of IRI on lung and chest wall mechanics in the intraoperative period of patients undergoing OLT.

METHODS

In 26 patients undergoing OLT, we measured elastance of the respiratory system (ERS), partitioned into lung (EL) and chest wall (ECW), hemodynamics, and fluid and blood product intake before laparotomy (T1), after portal/caval surgical clamp (T2), and immediately (T3) and, at 90 and 180 minutes post-reperfusion (T4 and T5, respectively). Interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), IL-1β and tumor necrosis factor-α plasma concentrations were assessed at T1, T4 and T5.

RESULTS

EL significantly decreased from T1 to T2 (13.5±4.4 vs 9.7±4.8 cmH2O/L, P<0.05), remained stable at T3, while at T4 (12.3±4.4 cmH2O/L, P<0.05) was well above levels recorded at T2, reaching its highest value at T5 (15±3.9 cmH2O/L, P<0.05). Variations in ERS, EL, driving pressure (∆P) and trans-pulmonary pressure (∆PL) significantly correlated with changes in IL-6 and MCP-1 plasma concentrations, but not with changes in wedge pressure, fluid amounts, and red blood cells and platelets administered. No correlation was found between changes in cytokine concentrations and ECW.

CONCLUSIONS

We found that EL, ECW, ∆P and ∆PL underwent significant variations during the OLT procedure. Further, we documented a significant association between the respiratory mechanics changes and the inflammatory response following liver graft reperfusion.

Ex Vivo Porcine Organ Perfusion Models as a Suitable Platform for Translational Transplant Research

In transplantation surgery, extending the criteria for organ donation to include organs that may have otherwise been previously discarded has provided the impetus to improve organ preservation. The traditional method of cold static storage (CS) has been tried and tested and is suitable for organs meeting standard criteria donation. Ex vivo machine perfusion is, however, associated with evidence suggesting that it may be better than CS alone and may allow for organ donation criteria to be extended. Much of our knowledge of organ preservation is derived from animal studies. We review ex vivo porcine organ perfusion models and discuss the relevance to the field of transplantation surgery. Following a systematic literature search, only articles that reported on experimental studies with focus on any aspect(s) of ex vivo and porcine perfusion of organs yet limited to the context of organ transplantation surgery were included. The database search and inclusion/exclusion criteria identified 22 journal articles. All 22 articles discussed ex vivo porcine organ perfusion within the context of transplant preservation surgery: 8 liver, 3 kidney, 3 lung, 2 pancreas/islet, 4 discussed a combined liver-kidney multiorgan model, 1 small bowel, and 1 cardiac perfusion model systems. The ex vivo porcine perfusion model is a suitable, reliable, and safe translational research model. It has advantages to investigate organ preservation techniques in a reproducible fashion in order to improve our understanding and has implications to extend the criteria for organ donation.

Interleukin-6 concentration in the transgenic pig's liver preserved for 24 hours in Biolasol solution

INTRODUCTION

Increasing the human lifespan contributes to a higher number of patients with end-stage organ failure, which in turn stimulates the search for alternative sources. Xenotransplantation seems to be a promising approach in this respect.

OBJECTIVE

Analysis of changes in interleukin (IL)-6 concentration during 24-hour preservation of transgenic swine livers, depending on the kind of transgenesis and preservation solution used.

MATERIALS AND METHODS

The experiment was carried out in swine livers with transferred human genes that were divided into 5 groups. The following human genes were transferred: α1,2-fucosyltransferase (group I and II), α-galactosidase (III), combined α1,2-fucosyltransferase/α-galactosidase transgene (IV), and livers without modification (V). The livers were perfused and subsequently stored for 24 hours in Ringer's (group I) or Biolasol solutions (II-V). Reflush was then performed. IL-6 concentration was analyzed in the solution samples collected at the beginning and end of perfusion, and after 24 hours of preservation. ELISA was used to evaluate IL-6 concentration.

RESULTS

In liver homogenates from group I, IL-6 concentration after 24 hours of preservation increased by 8.24% compared to the levels observed after perfusion, whereas in the other groups IL-6 concentration decreased. The most significant decrease, 49.51%, was observed in group II; the least significant in group IV, 10.72%. In case of supernatants, a statistically significant increase of AUC0-30min level in relation to perfusion was observed in every group after 24-hour preservation and reperfusion. The highest values of AUC0-30min were observed in group I (α1,2-fucosyltransferase, Ringer's solution).

CONCLUSION

The study indicates the hepatoprotective action of Biolasol solution.

Volatile anaesthetics reduce neutrophil inflammatory response by interfering with CXC receptor-2 signalling

BACKGROUND

Growing evidence suggests a protective effect of volatile anaesthetics in ischaemia-reperfusion (I/R)-injury, and the accumulation of neutrophils is a crucial event. Pro-inflammatory cytokines carrying the C-X-C-motif including interleukin-8 (IL-8) and CXC-ligand 1 (CXCL1) activate CXC receptor-1 (CXCR1; stimulated by IL-8), CXC receptor-2 (CXCR2; stimulated by IL-8 and CXCL1), or both to induce CD11b-dependent neutrophil transmigration. Inhibition of CXCR1, CXCR2, or both reduces I/R-injury by preventing neutrophil accumulation. We hypothesized that interference with CXCR1/CXCR2 signalling contributes to the well-established beneficial effect of volatile anaesthetics in I/R-injury.

METHODS

Isolated human neutrophils were stimulated with IL-8 or CXCL1 and exposed to volatile anaesthetics (sevoflurane/desflurane). Neutrophil migration was assessed using an adapted Boyden chamber. Expression of CD11b, CXCR1, and CXCR2 was measured by flow cytometry. Blocking antibodies against CXCR1/CXCR2/CD11b and phorbol myristate acetate were used to investigate specific pathways.

RESULTS

Volatile anaesthetics reduced CD11b-dependent neutrophil transmigration induced by IL-8 by >30% and CD11b expression by 18 and 27% with sevoflurane/desflurane, respectively. This effect was independent of CXCR1/CXCR2 expression and CXCR1/CXCR2 endocytosis. Inhibition of CXCR1 signalling did not affect downregulation of CD11b with volatile anaesthetics. Blocking of CXCR2-signalling neutralized effects by volatile anaesthetics on CD11b expression. Specific stimulation of CXCR2 with CXCL1 was sufficient to induce upregulation of CD11b, which was impaired with volatile anaesthetics. No effect of volatile anaesthetics was observed with direct stimulation of protein kinase C located downstream of CXCR1/CXCR2.

CONCLUSION

Volatile anaesthetics attenuate neutrophil inflammatory responses elicited by CXC cytokines through interference with CXCR2 signalling. This might contribute to the beneficial effect of volatile anaesthetics in I/R-injury.

Steps for the autologous ex vivo perfused porcine liver-kidney experiment

The use of ex vivo perfused models can mimic the physiological conditions of the liver for short periods, but to maintain normal homeostasis for an extended perfusion period is challenging. We have added the kidney to our previous ex vivo perfused liver experiment model to reproduce a more accurate physiological state for prolonged experiments without using live animals. Five intact livers and kidneys were retrieved post-mortem from sacrificed pigs on different days and perfused for a minimum of 6 hr. Hourly arterial blood gases were obtained to analyze pH, lactate, glucose and renal parameters. The primary endpoint was to investigate the effect of adding one kidney to the model on the acid base balance, glucose, and electrolyte levels. The result of this liver-kidney experiment was compared to the results of five previous liver only perfusion models. In summary, with the addition of one kidney to the ex vivo liver circuit, hyperglycemia and metabolic acidosis were improved. In addition this model reproduces the physiological and metabolic responses of the liver sufficiently accurately to obviate the need for the use of live animals. The ex vivo liver-kidney perfusion model can be used as an alternative method in organ specific studies. It provides a disconnection from numerous systemic influences and allows specific and accurate adjustments of arterial and venous pressures and flow.

History, ethics, advantages and limitations of experimental models for hepatic ablation

Numerous techniques developed in medicine require careful evaluation to determine their indications, limitations and potential side effects prior to their clinical use. At present this generally involves the use of animal models which is undesirable from an ethical standpoint, requires complex and time-consuming authorization, and is very expensive. This process is exemplified in the development of hepatic ablation techniques, starting experiments on explanted livers and progressing to safety and efficacy studies in living animals prior to clinical studies. The two main approaches used are ex vivo isolated non-perfused liver models and in vivo animal models. Ex vivo non perfused models are less expensive, easier to obtain but not suitable to study the heat sink effect or experiments requiring several hours. In vivo animal models closely resemble clinical subjects but often are expensive and have small sample sizes due to ethical guidelines. Isolated perfused ex vivo liver models have been used to study drug toxicity, liver failure, organ transplantation and hepatic ablation and combine advantages of both previous models.

The autologous normothermic ex vivo perfused porcine liver-kidney model: improving the circuit's biochemical and acid-base environment

BACKGROUND

The ex vivo porcine liver perfused model isolates the organ from extrinsic regulatory mechanisms, facilitating an improved understanding of the organ physiology and reaction to various conditions. We have assessed the influence of the addition of a porcine kidney to the circuit.

METHODS

Eight livers were harvested and perfused for 6 hours. In 5 additional experiments a kidney also was connected in parallel. Hourly arterial blood gases were collected to analyze glucose, acid base, and renal parameters. The primary end point was an evaluation of the influence of the kidney on glucose, pH, and electrolyte levels.

RESULTS

In the combined porcine liver-kidney circuit all the parameters significantly improved compared with the liver circuit alone. This was particularly evident for glucose values because normoglycemia was reached by the end of the perfusion, and for pH and electrolyte values that were maintained at initial levels.

CONCLUSIONS

The addition of a porcine kidney to the perfusion circuit improves the biochemical milieu. This might produce more consistent and reliable results, particularly during studies requiring a steady-state environment.

Changes in acid-base balance during electrolytic ablation in an ex vivo perfused liver model

BACKGROUND

Electrolytic ablation (EA) destroys tissues through extreme pH changes in the local microenvironment. An ex vivo perfused liver model was used to assess the systemic effects of EA on the acid-base balance without the influence of compensatory organs (lungs and kidneys).

METHODS

Eleven pigs were perfused extracorporeally at 39°C with autologous blood; 4 also underwent EA after 1 hour of reperfusion. Arterial blood samples were obtained hourly.

RESULTS

pH and CO(2) levels did not change throughout the experiments. A significant increase of HCO(3)-, anion gap, base excess, and lactate was present after the third hour. No differences were observed between EA experiments and controls.

CONCLUSIONS

EA does not alter the acid-base balance even when the confounding influence of compensatory organs is removed. Such findings should be considered when planning ablations in patients with renal failure or respiratory diseases in which EA could avoid undesirable metabolic changes.

Patterns of histological changes following hepatic electrolytic ablation in an ex-vivo perfused model

Electrolytic ablation (EA) destroys the liver by releasing toxic radicles and producing modifications in the local pH without increasing the tissue temperature. We assessed the histological changes produced by EA using an ex-vivo perfused model. Five porcine livers were harvested, preserved in ice and reperfused for six hours in an extracorporeal circuit using autologous normothermic blood. One hour after reperfusion EA was performed and liver biopsies collected at the end of the experiments. The main necrotic zone consisted of coagulative necrosis, sinusoidal dilatation and haemorrhage with an unusual morphological pattern. The coagulative necrosis and haemorrhage affected mainly the peripheral area of the lobule with relative sparing of the area surrounding the centrilobular vein. Contrasting with this sinusoidal dilatation appeared to be more prominent in the centrilobular area. EA produces patterns of tissue destruction that have not been observed with the more commonly used thermal techniques. Further studies should obtain more information about the influence of adjacent biliary and vascular structures so that appropriate clinical trials can be designed.

Addition of a kidney to the normothermic ex vivo perfused porcine liver model does not increase cytokine response

The addition of a kidney to the ex vivo liver perfused model may facilitate the circuit homeostatic balance of important biochemical parameters (i.e. pH changes, urea and creatinine, or glucose levels) but might also increase the inflammatory reaction produced. In this study, we compared the production of various cytokines between liver-kidney and liver-alone circuits. Seven livers were harvested from female pigs and perfused for 6 h. In five additional experiments, a kidney was also harvested and connected in parallel. Blood samples for interleukins (IL) 1, 2, 4, 6, 8, 10, and 12, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were collected before perfusion and at hours 1, 2, 4 and 6 postperfusion. In the combined liver-kidney circuit, a significant increase was present only for IL-6 and IL-8, but this did not differ significantly from those recorded in the liver-alone circuit. All other cytokines were not modified from baseline levels. The addition of a kidney to the perfusion circuit does not stimulate a greater inflammatory reaction than that of the liver alone and therefore further confirms the safety of the experimental setups in view of more delicate experiments requiring strict homeostatic conditions.

Cytokine response of electrolytic ablation in an ex vivo perfused liver model

BACKGROUND

The inflammatory response following hepatic ablation depends on different factors including the method used, the duration and intensity of the treatment and the presence or absence of ischemia. Debate continues about the use of different modalities and whether some aspects of the response may be advantageous by releasing immunological active substances. Little data have been published concerning the cytokine response elicited by hepatic electrolytic ablation (EA). Study of an ex vivo liver model could allow for the evaluation of this response without the influence of confounding systemic factors.

METHODS

Livers explanted from 11 pigs were perfused extracorporeally with normothermic autologous blood. Four of them underwent EA after 1 h of reperfusion. Serum samples were obtained up to 6 h after the reperfusion and assayed for IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IFN-gamma, TNF-alpha.

RESULTS

Significant changes in the control group were observed for IL-6 after the second hour and IL-8 after the first hour compared with baseline levels (P < 0.001). In the EA group, IL-6 and IL-12 were raised after the second hour and IL-8 and IL-10 after the first hour (P < 0.001). The comparison between groups showed significant differences for IL-2, IL-4 (decreased in the EA group compared with controls), IL-10 and TNF-alpha (EA group increased compared with controls; P < 0.001).

CONCLUSIONS

The ex vivo perfused liver model demonstrated changes in levels of IL-2, IL-4, IL-10 and TNF-alpha following hepatic EA.

Changes in interleukin-1β and 6 after hepatic microwave tissue ablation compared with radiofrequency, cryotherapy and surgical resections

BACKGROUND

Cytokine changes after microwave tissue ablation (MTA) were compared with hepatic resection, cryotherapy (CRYO), and radiofrequency ablation (RFA). Cytokine production was measured at various ablation volumes for each modality and correlated with the transitional inflammatory zone produced by the ablation techniques.

METHODS

Live rats underwent MTA, surgical resection, CRYO or RFA of 15%, 33%, or 66% of the total hepatic volume. Serum samples were collected preoperatively and at 1, 3, 6, 24, and 48 hours after surgery and analyzed for pro-inflammatory cytokines interleukin (IL)-1β and IL-6.

RESULTS

Significantly higher levels of both cytokines were present after CRYO and RFA compared with MTA, hepatic resection, or controls (P < .001). All animals survived except those undergoing RFA or CRYO of 66% of the hepatic volume, which died within 6 hours. Transitional zones produced after RFA were larger than those after CRYO or MTA, but no correlation was present with the amount of cytokines.

CONCLUSIONS

Large-volume MTA is associated with a significant decreased cytokine response and is well tolerated compared with RFA and CRYO.

Pretreatment of vitamin D3 ameliorates lung and muscle injury induced by reperfusion of bilateral femoral vessels in a rat model

BACKGROUND

Peripheral arterial occlusive disease (PAOD) is a challenge in peripheral vascular disease. Clinical observations show reperfusion of occluded vessels may cause compartment syndrome or remote organ injury. Less well known is the role of vitamin D3 in tissue injury; therefore, we attempted to determine whether vitamin D3 could alleviate local and remote organ injury induced by reperfusion of occluded vessels in animal models.

METHODS

Twenty-four male Sprague-Dawley rats were randomized into four groups: saline + sham, saline + I/R, vitamin D3 + sham, and vitamin D3 + I/R group. After pretreatment for 5 d, the animals designed to I/R injury were subjected to 3 h of ischemia induced by bilateral femoral arteries clamp, followed by reperfusion of the vessels for 3 h on d 6. Left lung and left anterior tibial muscle tissue were harvested for wet/dry weight ratio and histopathologic analysis. Blood was collected for analysis of urea nitrogen (BUN), creatinine (Cr), aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), ionized calcium levels, and heme oxygenase-1 (HO-1).

RESULTS

Compared with the saline + sham group, there was a significant increase in plasma IL-6 level in both saline + I/R and vitamin D3 + I/R groups and muscle, lung wet/dry weight ratio in the saline + I/R group (P < 0.05). Compared with the saline + I/R group, there was a significant decrease in plasma IL-6 level, muscle and lung wet/dry weight ratio in both vitamin D3 + sham and vitamin D3 + I/R groups, and leukocyte HO-1 expression in vitamin D3 + sham group (P < 0.05). Compared with the vitamin D3 + sham group, there was a significant increase in plasma IL-6 levels in the vitamin D3 + I/R group, and leukocyte HO-1 expression in vitamin D3 + sham group (P < 0.05). BUN, Cr, AST, ALT, TNF-α, ionized calcium levels did not differ significantly among the groups.

CONCLUSIONS

Pretreatment of vitamin D3 ameliorates the systemic IL-6 levels, lung and muscle injury induced by ischemia followed by reperfusion of bilateral occluded vessels in a rat model.

The porcine hepatic arterial supply, its variations and their influence on the extracorporeal perfusion of the liver

BACKGROUND

Variations in the porcine hepatic vasculature may contribute to the outcome of experiments based on liver perfusion models. We studied the hepatic artery (HA), variations of its branches, and the correlation with the resultant perfusion.

MATERIALS AND METHODS

Nineteen animals were used. After 6 h of perfusion, dissection of the HA and its branches was conducted up to the insertion in the liver parenchyma. Data about the macroscopic appearance of lobes and the pattern of branching were recorded.

RESULTS

In all cases, the HA bifurcated into two constant branches, one for the LL/LM lobes (further divided in two vessels for each lobe) and one for the RM lobe. Five main patterns were identified involving vessels for the RL and the CL lobes. Two variations produced complete and uniform perfusion of the entire liver in all cases, while in the remaining cases, only part of them were completely perfused.

CONCLUSIONS

Some variants of the porcine HA and its branches are associated with the risk of incomplete perfusion if the perfusion cannula placement does not take the individual hepatic arterial anatomy into account. Understanding of the hepatic arteries branching patterns is essential when ex vivo perfusion models are being established.