Early bifurcation of the common hepatic artery: A pitfall that should be known and recognized.

Early bifurcation of the common hepatic artery (EBCHA) is a rare anatomical variation (1%), that is often overlooked but can lead to accidental ligation of the right branch of the hepatic artery with consequent arterial ischemia of the right liver and potentially very serious complications during pancreaticoduodenectomy, partial hepatectomy, or liver harvesting for transplantation. It may be difficult to diagnose EBCHA using transverse imaging sections. However, on standard CT sections with intravenous contrast injection, three warning signs should allow the image reader to suspect it: presence of two hepatic arteries to the right of the celiac trunk, presence of a retro-portal hepatic artery, and absence of a right hepatic artery arising from the superior mesenteric artery. Analysis of the CT with reconstruction then allows for definitive diagnosis and limits the risk of accidental arterial injury or ligation.

Initial laparoscopic liver resection is associated with reduced adhesions and transfusions at the time of salvage liver transplantation.

BACKGROUND: Laparoscopic liver resection (LLR) has been associated with improved patient recovery as well as reduced postoperative adhesions compared to open LR (OLR) and could therefore facilitate redo liver surgery. LLR prior to liver transplantation (LT) is increasingly performed, LT being saved for HCC recurrence. LT is still performed by open surgery due to vascular reconstructions and underlying liver chronic disease. We evaluated the impact of laparoscopic approach for LR prior to LT in terms of intraoperative transfusions, adhesions severity and outcome. METHODS: Data from all patients who underwent a LT after LR in two French high-volume tertiary centers were retrospectively reviewed. The impact of LLR on per operative and postoperative outcome was assessed using logistic regression. RESULTS: 170 patients were included, 43 patients in the LLR group and 127 in the OLR group. Preoperative characteristics were comparable between both groups, except LLR group included more patients with "very early-stage" BCLC tumors than OLR group (51% vs. 33%, p = 0.02) and less anatomical resections (54% vs. 75%, p = 0.015). During LT, the transfusion rate was significantly higher in the OLR group (71.4% vs 44.2%, p = 0.002) as well as the proportion of type III adhesions according to OLSG classification (p < 0.001). Multivariate analysis found LLR to be an independent protective factor for adhesions and transfusion (p = 0.001 and p = 0.03 respectively). CONCLUSION: Laparoscopic liver resection was associated with reduced postoperative adhesions and transfusion requirements during subsequent liver transplantation.

Right Ex-situ split grafts for adult liver transplantation - A Multicenter Benchmarking Analysis.

OBJECTIVE: To analyse outcomes after adult right ex-situ split graft liver transplantations (RSLT) and compare with available outcome benchmarks from whole liver transplantation (WLT). SUMMARY BACKGROUND DATA: Ex-situ SLT may be a valuable strategy to tackle the increasing graft shortage. Recently established outcome benchmarks in WLT offer a novel reference to perform a comprehensive analysis of results after ex-situ RSLT. METHODS: This retrospective multicenter cohort study analyzes all consecutive adult SLT performed using right ex-situ split grafts from 01.01.2014 to 01.06.2022. Study endpoints included 1 year graft and recipient survival, overall morbidity expressed by the comprehensive complication index (CCI©) and specific post-LT complications. Results were compared to the published benchmark outcomes in low-risk adult WLT scenarii. RESULTS: In 224 adult right ex-situ SLT, 1y recipient and graft survival rates were 96% and 91.5%, within the WLT benchmarks. The 1y overall morbidity was also within the WLT benchmark (41.8 CCI points vs. <42.1). Detailed analysis, revealed cut surface bile leaks (17%, 65.8% Grade IIIa) as a specific complication without a negative impact on graft survival. There was a higher rate of early hepatic artery thrombosis (HAT) after SLT, above the WLT benchmark (4.9% vs. ≤4.1%), with a significant impact on early graft but not patient survival. CONCLUSION: In this multicentric study of right ex-situ split graft LT, we report 1-year overall morbidity and mortality rates within the published benchmarks for low-risk WLT. Cut surface bile leaks and early HAT are specific complications of SLT and should be acknowledged when expanding the use of ex-situ SLT.

European validation of the classification for the anticipated difficulty of liver transplantation.

BACKGROUND: Appropriate risk stratification for the difficulty of liver transplantation (LT) is essential to guide the selection and acceptance of grafts and avoid morbidity and mortality. METHODS: Based on 987 LTs collected from 5 centers, perioperative outcomes were analyzed across the 3 difficulty levels. Each LT was retrospectively scored from 0 to 10. Scores of 0-2, 3-5 and 6-10 were then translated into respective difficulty levels: low, moderate and high. Complications were reported according to the comprehensive complication index (CCI). RESULTS: The difficulty level of LT in 524 (53%), 323 (32%), and 140 (14%) patients was classified as low, moderate and high, respectively. The values of major intraoperative outcomes, such as cold ischemia time (p = 0.04) and operative time (p < 0.0001) increased gradually with statistically significant values among difficulty levels. There was a corresponding increase in CCI (p = 0.04), severe complication rates (p = 0.05) and length of ICU (p = 0.01) and hospital (p = 0.004) stays across the different difficulty levels. CONCLUSION: The LT difficulty classification has been validated.

Preclinical validation of a customized circuit for ex situ uninterrupted cold-to-warm prolonged perfusion of the liver.

CONTEXT: Clinical adoption of ex situ liver perfusion is growing. While hypothermic perfusion protects against ischemia-reperfusion injury in marginal grafts, normothermic perfusion enables organ viability assessment and therefore selection of borderline grafts. The combination of hypothermic and normothermic perfusion, known as "cold-to-warm," may be the optimal sequence for organ preservation, but is difficult to achieve with most commercial perfusion systems. We developed an adaptable customized circuit allowing uninterrupted "cold-to-warm" perfusion and conducted preclinical studies on healthy porcine livers and discarded human livers to demonstrate the circuit's efficacy. METHODS: In collaboration with bioengineers, we developed a customized circuit that adapts to extracorporeal circulation consoles used in cardiovascular surgery and includes a proprietary reservoir enabling easy perfusate change without interrupting perfusion. This preclinical study was conducted on porcine and human livers. Perfusion parameters (pressures, flows, oxygenation) and organ viability were monitored. RESULTS: The customized circuit was adapted to a LivaNova S5® console, and the perfusions were flow-driven with real-time pressure monitoring. Ten porcine liver and 12 discarded human liver perfusions were performed during 14 to 18 h and 7 to 25 h, respectively. No hyperpressure was observed (porcine and human portal pressure 2-6 and 2-8 mm Hg; arterial pressure 10-65 and 20-65 mm Hg, respectively). No severe histological tissue injury was observed (Suzuki score ≤ 3 at the end of perfusion). Seven (70%) porcine livers and five (42%) human livers met the UK viability criteria. CONCLUSION: The customized circuit and system design enables smooth uninterrupted "cold-to-warm" perfusion not present in current commercial perfusion systems.

Feasibility of Liver Transplantation after 90Y Radioembolization: Lessons from a Radiation Protection Incident.

ABSTRACT: Radioembolization using 90Y is a growing procedure in nuclear medicine for treating hepatocellular carcinoma. Current guidelines suggest postponing liver transplantation or surgical resection for a period of 14 to 30 d after radioembolization to minimize surgeons' exposure to ionizing radiation. In light of a radiation protection incident, we reevaluated the minimum delay required between radioembolization and subsequent liver transplantation. A patient with a hepatocellular carcinoma underwent a liver transplantation 44 h after undergoing radioembolization using 90Y (860 MBq SIR-Spheres). No specific radioprotection measures were followed during surgery and pathological analysis. We subsequently (1) evaluated the healthcare professionals' exposure to ionizing radiation by conducting dose rate measurements from removed liver tissue and (2) extrapolated the recommended interval to be observed between radioembolization and surgery/transplantation to ensure compliance with the radiation dose limits for worker safety. The surgeons involved in the transplantation procedure experienced the highest radiation exposure, with whole-body doses of 2.4 mSv and extremity doses of 24 mSv. The recommended delay between radioembolization and liver transplantation was 8 d when using SIR-Spheres and 15 d when injecting TheraSphere. This delay can be reduced further when considering the specific 90Y activity administered during radioembolization. This dosimetric study suggests the feasibility of shortening the delay for liver transplantation/surgery after radioembolization from the 8th or 15th day after using SIR-Spheres or TheraSphere, respectively. This delay can be decreased further when adjusted to the administrated activity while upholding radiation protection standards for healthcare professionals.

Recent outcomes of liver transplantation for Budd-Chiari syndrome: A study of the European Liver Transplant Registry (ELTR) and affiliated centers.

BACKGROUND AND AIMS: Management of Budd-Chiari syndrome (BCS) has improved over the last decades. The main aim was to evaluate the contemporary post-liver transplant (post-LT) outcomes in Europe. APPROACH AND RESULTS: Data from all patients who underwent transplantation from 1976 to 2020 was obtained from the European Liver Transplant Registry (ELTR). Patients < 16 years, with secondary BCS or HCC were excluded. Patient survival (PS) and graft survival (GS) before and after 2000 were compared. Multivariate Cox regression analysis identified predictors of PS and GS after 2000. Supplemental data was requested from all ELTR-affiliated centers and received from 44. In all, 808 patients underwent transplantation between 2000 and 2020. One-, 5- and 10-year PS was 84%, 77%, and 68%, and GS was 79%, 70%, and 62%, respectively. Both significantly improved compared to outcomes before 2000 ( p < 0.001). Median follow-up was 50 months and retransplantation rate was 12%. Recipient age (aHR:1.04,95%CI:1.02-1.06) and MELD score (aHR:1.04,95%CI:1.01-1.06), especially above 30, were associated with worse PS, while male sex had better outcomes (aHR:0.63,95%CI:0.41-0.96). Donor age was associated with worse PS (aHR:1.01,95%CI:1.00-1.03) and GS (aHR:1.02,95%CI:1.01-1.03). In 353 patients (44%) with supplemental data, 33% had myeloproliferative neoplasm, 20% underwent TIPS pre-LT, and 85% used anticoagulation post-LT. Post-LT anticoagulation was associated with improved PS (aHR:0.29,95%CI:0.16-0.54) and GS (aHR:0.48,95%CI:0.29-0.81). Hepatic artery thrombosis and portal vein thrombosis (PVT) occurred in 9% and 7%, while recurrent BCS was rare (3%). CONCLUSIONS: LT for BCS results in excellent patient- and graft-survival. Older recipient or donor age and higher MELD are associated with poorer outcomes, while long-term anticoagulation improves both patient and graft outcomes.

Legionnaires Disease in Solid Organ Transplant Recipients: A Decade-Long Nationwide Study in France.

BACKGROUND: Legionnaires disease (LD) is a rare, life-threatening opportunistic bacterial infection that poses a significant risk to patients with impaired cell-mediated immunity such as solid organ transplant recipients. However, the epidemiologic features, clinical presentation, and outcomes of LD in this population are poorly described. RESEARCH QUESTION: What are the clinical manifestations, radiologic presentation, risk factors for severity, treatment, and outcome of LD in solid organ transplant recipients? STUDY DESIGN AND METHODS: In this 10-year multicenter retrospective cohort study in France, where LD notification is mandatory, patients were identified by hospital discharge databases. Diagnosis of LD relied on positive culture findings from any respiratory sample, positive urinary antigen test (UAT) results, positive specific serologic findings, or a combination thereof. Severe LD was defined as admission to the ICU. RESULTS: One hundred one patients from 51 transplantation centers were eligible; 64 patients (63.4%) were kidney transplant recipients. Median time between transplantation and LD was 5.6 years (interquartile range, 1.5-12 years). UAT results were positive in 92% of patients (89/97). Among 31 patients with positive culture findings in respiratory samples, Legionella pneumophila serogroup 1 was identified in 90%. Chest CT imaging showed alveolar consolidation in 98% of patients (54 of 57), ground-glass opacity in 63% of patients (36 of 57), macronodules in 21% of patients (12 of 57), and cavitation in 8.8% of patients (5 of 57). Fifty-seven patients (56%) were hospitalized in the ICU. In multivariate analysis, severe LD was associated with negative UAT findings at presentation (P = .047), lymphopenia (P = .014), respiratory symptoms (P = .010), and pleural effusion (P = .039). The 30-day and 12-month mortality rates were 8% (8 of 101) and 20% (19 of 97), respectively. In multivariate analysis, diabetes mellitus was the only factor associated with 12-month mortality (hazard ratio, 3.2; 95% OR, 1.19-8.64; P = .022). INTERPRETATION: LD is a late and severe complication occurring in solid organ transplant recipients that may present as pulmonary nodules on which diabetes impacts its long-term prognosis.

Perceptions of surgical difficulty in liver transplantation: A European survey and development of the Pitié-Salpêtrière classification.

BACKGROUND: Significant variations exist regarding the definition of difficult liver transplantation. The study goals were to investigate how liver transplant surgeons evaluate the surgical difficulty of liver transplantation and to use the identified factors to classify liver transplantation difficulty. METHODS: A Web-based online European survey was presented to liver transplant surgeons. The survey was divided into 3 parts: (1) participant demographics and practices; (2) various situations based on recipient, liver disease, tumor treatment, and technical factors; and (3) 8 real-life clinical vignettes with different levels of complexity. In part 3 of the survey, respondents were asked whether they would perform liver transplantation but were not aware that these patients eventually underwent liver transplantation. RESULTS: A total of 143 invites were sent out, and 97 (67.8%) participants completed the survey. Most participants considered previous spontaneous bacterial peritonitis, previous supra-mesocolic surgery, hypertrophy of segment I, and obesity to be recipient factors for high-difficulty liver transplantation. Most participants considered liver transplantation to be challenging in patients with Budd-Chiari syndrome, Kasai surgery, polycystic liver disease, diffuse portal vein thrombosis, and a history of open hepatectomy. The proportion of participants indicating that liver transplantation was warranted varied across the 8 cases, from 69% to 100%. Our classification of the surgical difficulty of liver transplantation employed these recipient-related, surgical history-related, and liver disease-related variables and 3 difficulty groups were identified: low, intermediate, and high difficulty groups. CONCLUSION: This survey provides an overview of the surgical difficulty of various situations in liver transplantation that could be useful for further benchmark and textbook outcome studies.

Patients' perceptions of the definition of a textbook outcome following liver transplantation.

BACKGROUND: A textbook outcome (TO) describes the results of a successful liver transplantation (LT) in which all aspects of the LT and posttransplant courses were uneventful. We compared patient perceived experience of a TO with clinically defined TO. METHODS: This was a single-institution cohort study with retrospective chart review including patients who underwent LT from 2019 to 2021. Patients were asked to complete the survey at a scheduled posttransplant visit. The survey was designed to assess their viewpoints on the definition of a TO. A clinically defined TO was defined as no mortality, no severe complications, no need for reintervention, no prolonged hospital and intensive care unit stays, and no readmission. RESULTS: Of the 182 patients who were contacted, 132 (72.5%) completed the survey. Overall, 98 patients (74%) considered that they had experienced a TO. The clinically defined TO rate was 22.0%. Multivariate analysis showed that patients who did not experience severe complications were more likely to consider that they had a TO (P = 0.01; odds ratio: 3.2; 95% confidence interval: 1.3-7.9). CONCLUSIONS: From patients' perspectives, survival and avoidance of complications were the major characteristics of a TO.

Strategy for Oligometastatic Recurrence of Cardia Adenocarcinoma: Liver Radiofrequency Ablation Associated with PIPAC Inducing Response Permitting Cytoreductive Surgery and HIPEC.

Management of oligometastatic disease (OMD) in esophagogastric junction cancer is complex due to anatomical location and adenocarcinoma pathway. Specific curative strategy is mandatory to increase survival. A multimodal approach combining surgery, systemic and peritoneal chemotherapy, radiotherapy, and radiofrequency could be envisaged. We report a strategy proposed for a 61-year-old male with cardia adenocarcinoma, initially treated with chemotherapy and superior polar esogastrectomy. He developed at later stage an OMD with peritoneal metastasis, single liver metastasis, and single lung metastasis. Considering that peritoneal metastases were unresectable at first, he was given multiple Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) with oxaliplatin, associated with intravenous docetaxel. Percutaneous radiofrequency ablation was performed during the first PIPAC procedure. Peritoneal response allowed a secondary Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy.

Binding and Kinetic Analysis of Human Protein Phosphatase PP2A Interactions with Caspase 9 Protein and the Interfering Peptide C9h.

The serine/threonine phosphatase PP2A and the cysteine protease Caspase 9 are two proteins involved in physiological and pathological processes, including cancer and apoptosis. We previously demonstrated the interaction between Caspase 9 and PP2A and identified the C9h peptide, corresponding to the binding site of Caspase 9 to PP2A. This interfering peptide can modulate Caspase 9/PP2A interaction leading to a strong therapeutic effect in vitro and in vivo in mouse models of tumor progression. In this manuscript, we investigate (I) the peptide binding to PP2A combining docking with molecular dynamics and (II) the secondary structure of the peptide using CD spectroscopy. Additionally, we compare the binding affinity, using biolayer interferometry, of the wild-type protein PP2A with Caspase 9 and vice versa to that observed between the PP2A protein and the interfering peptide C9h. This result strongly encourages the use of peptides as new therapeutics against cancer, as shown for the C9h peptide already in clinical trial.

In situ normothermic regional perfusion versus ex situ normothermic machine perfusion in liver transplantation from donation after circulatory death.

In situ normothermic regional perfusion (NRP) and ex situ normothermic machine perfusion (NMP) aim to improve the outcomes of liver transplantation (LT) using controlled donation after circulatory death (cDCD). NRP and NMP have not yet been compared directly. In this international observational study, outcomes of LT performed between 2015 and 2019 for organs procured from cDCD donors subjected to NRP or NMP commenced at the donor center were compared using propensity score matching (PSM). Of the 224 cDCD donations in the NRP cohort that proceeded to asystole, 193 livers were procured, resulting in 157 transplants. In the NMP cohort, perfusion was commenced in all 40 cases and resulted in 34 transplants (use rates: 70% vs. 85% [p = 0.052], respectively). After PSM, 34 NMP liver recipients were matched with 68 NRP liver recipients. The two cohorts were similar for donor functional warm ischemia time (21 min after NRP vs. 20 min after NMP; p = 0.17), UK-Donation After Circulatory Death risk score (5 vs. 5 points; p = 0.38), and laboratory Model for End-Stage Liver Disease scores (12 vs. 12 points; p = 0.83). The incidence of nonanastomotic biliary strictures (1.5% vs. 2.9%; p > 0.99), early allograft dysfunction (20.6% vs. 8.8%; p = 0.13), and 30-day graft loss (4.4% vs. 8.8%; p = 0.40) were similar, although peak posttransplant aspartate aminotransferase levels were higher in the NRP cohort (872 vs. 344 IU/L; p < 0.001). NRP livers were more frequently allocated to recipients suffering from hepatocellular carcinoma (HCC; 60.3% vs. 20.6%; p < 0.001). HCC-censored 2-year graft and patient survival rates were 91.5% versus 88.2% (p = 0.52) and 97.9% versus 94.1% (p = 0.25) after NRP and NMP, respectively. Both perfusion techniques achieved similar outcomes and appeared to match benchmarks expected for donation after brain death livers. This study may inform the design of a definitive trial.

Preservation of Organs to Be Transplanted: An Essential Step in the Transplant Process.

Organ transplantation remains the treatment of last resort in case of failure of a vital organ (lung, liver, heart, intestine) or non-vital organ (essentially the kidney and pancreas) for which supplementary treatments exist. It remains the best alternative both in terms of quality-of-life and life expectancy for patients and of public health expenditure. Unfortunately, organ shortage remains a widespread issue, as on average only about 25% of patients waiting for an organ are transplanted each year. This situation has led to the consideration of recent donor populations (deceased by brain death with extended criteria or deceased after circulatory arrest). These organs are sensitive to the conditions of conservation during the ischemia phase, which have an impact on the graft's short- and long-term fate. This evolution necessitates a more adapted management of organ donation and the optimization of preservation conditions. In this general review, the different aspects of preservation will be considered. Initially done by hypothermia with the help of specific solutions, preservation is evolving with oxygenated perfusion, in hypothermia or normothermia, aiming at maintaining tissue metabolism. Preservation time is also becoming a unique evaluation window to predict organ quality, allowing repair and/or optimization of recipient choice.

Donor eligibility criteria and liver graft acceptance criteria during normothermic regional perfusion: A systematic review.

Acceptance of liver grafts from donations after circulatory death (DCD) largely remains a "black box," particularly due to the unpredictability of the agonal phase. Abdominal normothermic regional perfusion (aNRP) can reverse ischemic injury early during the procurement procedure, and it simultaneously enables graft viability testing to unravel this black box. This review evaluates current protocols for liver viability assessment to decide upon acceptance or decline during aNRP. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used, and relevant literature databases were searched. The primary outcome consisted of criteria for liver graft viability assessment. Secondary outcomes included survival, primary nonfunction (PNF), early dysfunction, and biliary complications. A total of 14 articles were included in the analysis. In all protocols, a combination of criteria was used to assess suitability of the liver for transplantation. As many as 12 studies (86%) used macroscopic assessment, 12 studies (86%) used alanine transaminase (ALT) levels in perfusate, 9 studies (64%) used microscopic assessment, and 7 studies (50%) used lactate levels as assessment criteria. The organ utilization rate (OUR) was 16% for uncontrolled donation after circulatory death (uDCD) and 64% for controlled donation after circulatory death (cDCD). The most used acceptation criterion in uDCD is ALT level (31%), while in cDCD macroscopic aspect (48%) is most used. Regarding postoperative complications, PNF occurred in 13% (6%-25%) of uDCD livers and 3% (2%-4%) of cDCD livers. In uDCD, the 1-year graft and patient survival rates were 75% (66%-82%) and 82% (75%-88%). In cDCD, the 1-year graft and patient survival rates were 91% (89%-93%) and 93% (91%-94%), respectively. In conclusion, the currently used assessment criteria consist of macroscopic aspect and transaminase levels. The acceptance criteria should be tailored according to donor type to prevent an unacceptable PNF rate in uDCD and to increase the relatively modest OUR in cDCD.

Backtable preparation after liver harvesting with "en bloc" technique with video.

The aim of this didactical video is to show an easy and standardized technique of liver preparation after "en bloc" extraction and access a young surgeon to perform liver procurement. The technique entails five steps: beginning with the dissection of the vena cava, the superior mesenteric artery, and the coeliac trunk, followed by the common hepatic artery, the bile duct and finally the portal vein. This technique of liver graft preparation has high reproducibility while maintaining the safety of the procedure for young surgeons. The "en bloc" extraction with a standardized liver graft preparation is an easy and a reproducible technique.

Restrictive intraoperative fluid intake in liver surgery and postoperative renal function: A propensity score matched study.

BACKGROUND: Postoperative acute kidney injury (AKI) is a common complication in hepatic surgery. In hepatic surgery, relative hypovolemia may help to limit blood loss, but the consequences of restrictive fluid intake are unknown. The goal of this study was to determine the influence of intraoperative fluid intake on the incidence of AKI and its consequences. METHODS: Data from 397 consecutive patients who underwent liver resection were prospectively recorded and retrospectively analyszed. We compared the incidence of postoperative acute kidney failure in patients given restrictive (≤ 5 mL/kg/h) versus liberal (> 5 mL/kg/h) fluid therapy. We calculated a 1:1 match propensity score using logistic regression to estimate the likelihood of patients receiving restrictive or liberal intraoperative fluid intakes. The association between the intraoperative fluid intake strategy and occurrence of postoperative AKI were tested using a Cox frailty model on the database of matched patients. RESULTS: Postoperative AKI was diagnosed in 133 of the 397 patients. Fluid intake strategy was restrictive for 121 patients and liberal for 276 patients. After propensity score matching to balance confounding factors, the liberal strategy was associated with a significantly lower risk for postoperative AKI compared to the restrictive strategy (Hazard Ratio 0.40 [0.29; 0.56], P<0.001). Patients with postoperative AKI had longer hospital stays and higher mortality. There were no cases of further blood loss in the liberal fluid intake group. CONCLUSIONS: A restrictive fluid intake strategy is a risk factor for developing postoperative AKI, with serious consequences, without reducing blood loss in liver surgery.

Preclinical Validation of Tumor-Penetrating and Interfering Peptides against Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in adults. The disease is characterized by the accumulation of tumoral B cells resulting from a defect of apoptosis. We have in vitro and in vivo preclinically validated a tumor-penetrating peptide (named TT1) coupled to an interfering peptide (IP) that dissociates the interaction between the serine/threonine protein phosphatase 2A (PP2A) from its physiological inhibitor, the oncoprotein SET. This TT1-IP peptide has an antitumoral effect on CLL, as shown by the increased survival of mice bearing xenograft models of CLL, compared to control mice. The peptide did not show toxicity, as indicated by the mouse body weight and the biochemical parameters, such as renal and hepatic enzymes. In addition, the peptide-induced apoptosis in vitro of primary tumoral B cells isolated from CLL patients but not of those isolated from healthy patients. Finally, the peptide had approximately 5 h half-life in human serum and showed pharmacokinetic parameters compatible with clinical development as a therapeutic peptide against CLL.

Naive and memory CD4+ T cell subsets can contribute to the generation of human Tfh cells.

CD4+ T follicular helper cells (Tfh) promote B cell maturation and antibody production in secondary lymphoid organs. By using an innovative culture system based on splenocyte stimulation, we studied the dynamics of naive and memory CD4+ T cells during the generation of a Tfh cell response. We found that both naive and memory CD4+ T cells can acquire phenotypic and functional features of Tfh cells. Moreover, we show here that the transition of memory as well as naive CD4+ T cells into the Tfh cell profile is supported by the expression of pro-Tfh genes, including transcription factors known to orchestrate Tfh cell development. Using this culture system, we provide pieces of evidence that HIV infection differentially alters these newly identified pathways of Tfh cell generation. Such diversity in pathways of Tfh cell generation offers a new framework for the understanding of Tfh cell responses in physiological and pathological contexts.