The LRRK2 kinase has emerged as a priority therapeutic target due to its well-documented role in Parkinson-s diseases (PD). One of LRRK2 key partners is the phosphatase PP1, which dephosphorylates LRRK2. Therefore, modulating this protein/protein interaction represents a promising therapeutic strategy for PD. We have developed a bi-functional peptide, PEP 3, capable of crossing the blood-brain barrier (BBB) and disrupting the LRRK2/PP1 interaction. In vitro competition assays confirmed that PEP 3 specifically targets this interaction. The in vivo imaging demonstrated that the peptide remains detectable in the mouse brain up to 6 hours or retro-orbital vein post-injection. The PEP 3 peptide does not show chronic toxicity in CD1 mice and is resistant to degradation by mouse, human, dog and monkey serum proteases. In mouse models overexpressing alpha-synuclein, repeated intraperitoneal injections of PEP 3 for 15 and 30 days were well tolerated. Immunohistochemistry revealed a significant reduction of dopaminergic cell death in the substantia nigra, and quantification of phosphorylated pathological alpha-synuclein showed decreased levels in the PEP 3-treated group compared to controls. These findings support the potential of PEP 3 as a therapeutic agent for Parkinson-s disease.

Background Patients with systemic lupus erythematosus (SLE) with inadequate responses to standard therapies have unmet therapeutic needs. The immunomodulatory, proangiogenic, and antifibrotic properties of mesenchymal stromal cells support their use in treating patients with SLE. We aimed to assess the safety of a single intravenous infusion of allogeneic umbilical cord-derived mesenchymal stromal cells in patients with severe SLE. Methods This prospective, single-centre, open-label, dose-escalation, Bayesian phase 1 study was done at the SaintLouis University Hospital (Paris, France). Eligible patients were aged 18-70 years, were diagnosed with SLE according to American College of Rheumatology criteria with positive antinuclear antibodies, had a baseline Safety of Estrogens in Lupus Erythematosus National Assessment-SLE Disease Activity Index (SELENA-SLEDAI) score of 6 or more, and had disease that was refractory to first and second line SLE therapies. Patients were to receive a single intravenous infusion of 1 x 106, 2 x 106, or 4 x 106 umbilical cord-derived mesenchymal stromal cells per kg (manufactured from a single umbilical cord) in cohorts of five patients per dose, starting at 2 x 106 cells per kg. The primary endpoint was the rate of treatment-related severe adverse events (grade >= 3) in the first 10 days after infusion of umbilical cord-derived mesenchymal stromal cells. People with lived experience were involved in study design, patient enrolment, and dissemination of the study findings. This study is registered with ClinicalTrials.gov, NCT03562065, and the EU Clinical Trials Register, EudraCT2017-001400-29. Findings From May 14, 2019, to March 6, 2023, 29 patients were screened for eligibility, eight of whom were enrolled in the study. Enrolment was terminated early after inclusion of eight patients and no patients received the 1 x 106 dose of umbilical cord-derived mesenchymal stromal cells. Seven (88%) of eight participants were cisgender women and one (13%) was a cisgender man. The median age was 35 years (range 26-57) and the median SLE disease duration was 12 years (5-19). All patients received at least 2 x 106 cells per kg (range 2 x 106 to 4 x 106). No severe adverse events and three infusion-related adverse events (two grade 1 and one grade 2) occurred in two patients in the first 10 days after infusion. After 124 months (range 12-13) of follow-up, no treatment-related severe adverse events and three non-treatment-related severe adverse events occurred in one patient after relapse. Interpretation Our results suggest that a single infusion of 2 x 106 cells per kg or 4 x 106 cells per kg of allogeneic umbilical cord-derived mesenchymal stromal cells was safe in patients with severe SLE. Placebo-controlled trials are needed to confirm clinical efficacy and the role of B-cell modifications in clinical benefit. Copyright (c) 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.

Background & Aim: BackgroundPreclinical studies show Mesenchymal Stromal Cells (MSC) unique immunomodulatory, proangiogenic, and antifibrotic effects. Few clinical data report MSC use to treat Systemic Lupus (SLE) patients (pts) resistant to standard immunosuppressors and biologics, who suffer from high morbidity and increased mortality.AimsTo test the safety and preliminary efficacy of a single intravenous injection of allogeneic umbilical cord-derived (UC) MSC in severe SLE.Methods, Results & Conclusion: MethodsA prospective, single-center, Bayesian phase I/II study (NCT03562065) enrolled SLE pts (ACR criteria + antinuclear antibodies), aged 18–70 years (yr) with active disease (SELENA-SLEDAI-2K ≥6) at baseline and refractory to >2 immunosuppressive therapies for at least 3 months (M), including Prednisone ≥ 6 mg daily for ≥ 28 days, to receive a single infusion of 2 or 4.106 MSC(UC)/kg obtained from a single UC. Primary endpoint was the rate of treatment-related (TR) severe adverse events (SAE, grade ≥ 3) in the first 10 days post-MSC(UC) infusion. Secondary endpoints were adequacy of MSC(UC) production, all AE, clinical, HrQol and immune responses at M1 and quarterly for 1 yr post-infusion.ResultsFrom Sept 2019 to Feb 2023, 8 (7 female) pts, median age 35 [IQR 27-60] yrs after 12 [6-21] yrs SLE duration, were included with PGA 2 [1.5-2], SELENA-SLEDAI-2K 11.5 [8-14.2], BILAG A (50%), B (38%) or C (12%) and SLICC-ACR 1.5 [0-2.8] prior MSC(UC) infusion (median dose 2 [IQR 2-4]x106/kg). All pts received ≥2.106/kg MSC(UC) (5 assigned to 2.106/kg, 3 to 4.106/kg) with 1 batch released at lower than expected target dose. No SAE and 3 infusion-related AE (2 grade 1, 1 grade 2) in 2 pts occurred in the first 10 days. After 12.4 (min 9.6-max 13) months of follow-up, there were no TR SAE and 3 non-TR SAE after relapse in 1 pt. Improved clinical status (Table) in 7/8 pts at M3 persisted over 1 yr with 2 major and 2 partial clinical responses at M12. Donor-specific anti-HLA antibodies developed de novo in 1 pt at M3. While circulating T, B, NK and monocytes were unmodified by MSC(UC), CD24hiCD38hi transitional and CD27posCD38neg/loCD24hi memory B-cells frequencies, i.e. regulatory B-cell subsets, increased significantly and transiently at M1.ConclusionA single infusion of MSC(UC) was safe in 8 severe SLE pts. This proof of concept study showed clinical improvement. Placebo-controlled trials are needed to confirm clinical efficacy and explore the role of B-cell modifications in clinical benefit.

The combination of a tumor-penetrating peptide (TPP) with a peptide able to interfere with a given protein–protein interaction (IP) is a promising strategy with potential clinical application. Little is known about the impact of fusing a TPP with an IP, both in terms of internalization and functional effect. Here, we analyze these aspects in the context of breast cancer, targeting PP2A/SET interaction, using both in silico and in vivo approaches. Our results support the fact that state-of-the-art deep learning approaches developed for protein–peptide interaction modeling can reliably identify good candidate poses for the IP-TPP in interaction with the Neuropilin-1 receptor. The association of the IP with the TPP does not seem to affect the ability of the TPP to bind to Neuropilin-1. Molecular simulation results suggest that peptide IP-GG-LinTT1 in a cleaved form interacts with Neuropilin-1 in a more stable manner and has a more helical secondary structure than the cleaved IP-GG-iRGD. Surprisingly, in silico investigations also suggest that the non-cleaved TPPs can bind the Neuropilin-1 in a stable manner. The in vivo results using xenografts models show that both bifunctional peptides resulting from the combination of the IP and either LinTT1 or iRGD are effective against tumoral growth. The peptide iRGD-IP shows the highest stability to serum proteases degradation while having the same antitumoral effect as Lin TT1-IP, which is more sensitive to proteases degradation. Our results support the development of the TPP-IP strategy as therapeutic peptides against cancer.

Abstract Mesenchymal stromal cells (MSCs) have recently emerged as an interesting therapeutic approach for patients with progressive systemic sclerosis (SSc), a rare and life-threatening orphan autoimmune disease. Whereas MSC immunomodulatory potential is considered as a central mechanism for their clinical benefit, very few data are available on the impact of MSCs on immune cell subsets in vivo. In the current extended study of a phase I/II clinical trial exploring the injection of a single dose of allogeneic bone marrow-MSCs (alloBM-MSCs) in patients with severe SSc (NCT02213705), we performed a longitudinal in-depth characterization of circulating immune cells in 19 MSC-treated patients, including 14 responders and 5 non-responders. By a combination of flow cytometry and transcriptomic analyses, we highlighted an increase in circulating CD24hiCD27posCD38lo/neg memory B cells, the main IL-10-producing regulatory B cell (Breg) subset, and an upregulation of IL10 expression in ex-vivo purified B cells, specifically in responder patients, early after the alloBM-MSC infusion. In addition, a deeper alteration of the B-cell compartment before alloBM-MSC treatment, including a higher expression of profibrotic cytokines IL6 and TGFβ by sorted B cells was associated with a non-responder clinical status. Finally, BM-MSCs were able to directly upregulate IL-10 production in activated B cells in vitro. These data suggest that cytokine-producing B cells, in particular Breg, are pivotal effectors of BM-MSC therapeutic activity in SSc. Their quantification as activity biomarkers in MSC potency assays and patient selection criteria may be considered to reach optimal clinical benefit when designing MSC-based clinical trials.

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.

Background Systemic sclerosis rem ains an orphan life-threatening autoimmune disease. The unique immunomodulatory, proangiogenic, and antifibrotic properties of mesenchymal stromal cells provide a strong rationale for mesenchymal stromal cell-based therapy for systemic sclerosis, and treatment with mesenchymal stromal cells has shown benefits in preclinical models of this disease. The safety of allogeneic bone marrow-derived mesenchymal stromal cell administration in patients with severe systemic sclerosis has not yet been established. We aimed to test the safety and feasibility of a single intravenous injection of intrafamilial allogeneic bone marrow-derived mesenchymal stromal cells to treat severe diffuse systemic sclerosis. Methods We did an open-label, dose-escalation, proof-of-concept, phase 1/2 study at Saint-Louis-Hospital, Paris, France. Eligible patients were aged 18-70 years with severe diffuse systemic sclerosis, who fulfilled the 2013 American College of Rheumatology and European League Against Rheumatism systemic sclerosis criteria, had a minimum modified Rodnan skin score of 15 (range 0-51), had severe lung, heart, or kidney involvement, and had inadequate response or contraindications to conventional immunosuppressive therapy or autologous haematopoietic stem cell transplantation. Patients with severe comorbidities were excluded. The first ten recipients were to receive a single intravenous infusion of 1 x 10(6) bone marrow-derived mesenchymal stromal cells per kg bodyweight, and the subsequent ten recipients were to be infused with a single dose of 3 x 10(6) bone marrow-derived mesenchymal stromal cells per kg bodyweight. The primary endpoint was immediate tolerance during infusion and within the first 10 days after infusion, measured as the occurrence of serious adverse events (grade 3 or higher) in all infused patients. Safety was assessed in all participants during the 24-month follow-up period. This study is registered with ClinicalTrials.gov, NCT02213705. Findings Between March 24, 2014, and Jan 6, 2020, 20 cisgender individuals (13 women and seven men) with severe diffuse systemic sclerosis were enrolled. All 20 patients were included in the primary outcome analysis. No infusion-related severe adverse events and three infusion-related adverse events occurred in the first 10 days after treatment; one patient had grade 1 flushing and another patient had grade 1 nausea and grade 2 asthenia. After ten days and up to a median follow-up of 24.1 months (IQR 20.8-24.5), 36 non-treatment-related severe adverse events in 14 (70%) patients and no treatment- related adverse event were reported. Interpretation A single infusion of allogeneic bone marrow-derived mesenchymal stromal cells was safe in patients with severe diffuse systemic sclerosis. Future placebo-controlled trials will help to definitively ascertain the efficacy of mesenchymal stromal cell-based cell therapy from various tissue sources in larger number of patients with systemic sclerosis. Copyright (C) 2021 Elsevier Ltd. All rights reserved.

The therapeutic potential of culture-adapted adipose-derived stromal cells (ASCs) is largely related to their production of immunosuppressive factors that are inducible in vitro by priming with inflammatory stimuli, in particular tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ). In vivo, obesity is associated with chronic inflammation of white adipose tissue, including accumulation of neutrophils, infiltration by IFNγ/TNFα-producing immune cells, and ASC dysfunction. In the current study, we identified in obese patients a simultaneous upregulation of CD40Lin the adipose tissue stroma vascular fraction (AT-SVF), correlated with the Th1 gene signature, and an overexpression of CD40 by native ASCs. Moreover, activated CD4+ T cells upregulated CD40 on culture-expanded ASCs and triggered their production of IL-8 in a CD40L-dependent manner, leading to an increased capacity to recruit neutrophils. Finally, activation of ASCs by sCD40L or CD40L-expressing CD4+ T cells relies on both canonical and non-canonical NF-κB pathways, and IL-8 was found to be coregulated with NF-κB family members in AT-SVF. These data identify the CD40-CD40L axis as a priming mechanism of ASCs, able to modulate their cross talk with neutrophils in an inflammatory context, and their functional capacity for therapeutic applications.

Systemic sclerosis (SSc) is a rare chronic autoimmune disease characterized by vasculopathy, dysregulation of innate and adaptive immune responses, and progressive fibrosis. SSc remains an orphan disease, with high morbity and mortality in SSc patients. The mesenchymal stromal cells (MSC) demonstrate in vitro and in vivo pro-angiogenic, immuno-suppressive, and anti-fibrotic properties and appear as a promising stem cell therapy type, that may target the key pathological features of SSc disease. This review aims to summarize acquired knowledge in the field of :1) MSC definition and in vitro and in vivo functional properties, which vary according to the donor type (allogeneic or autologous), the tissue sources (bone marrow, adipose tissue or umbilical cord) or inflammatory micro-environment in the recipient; 2) preclinical studies in various SSc animal models , which showed reduction in skin and lung fibrosis after MSC infusion; 3) first clinical trials in human, with safety and early efficacy results reported in SSc patients or currently tested in several ongoing clinical trials.

In vitro-expanded mesenchymal stromal cells (MSC) represent a promising cell therapy product in regenerative medicine and in targeting dysimmune diseases, thanks to niche and immunological properties that can be impacted by numerous parameters. To improve clinical results, the main goal is to better understand their mechanisms of action and design relevant potency assays. Standardization of preclinical models and monitoring of treated patients will be a determinant to fully exploit MSC clinical potential. In this review, we will focus on the mechanisms sustaining MSC clinical activity, on the factors modulating such activity, and on the strategies under evaluation to foster their clinical use.

Autologous hematopoietic cell transplantation (AHCT) is a new treatment option for patients with severe autoimmune diseases (AD), based on the use of intensive or myeloablative chemotherapy to eradicate the pathogenic autoreactive immune cells and to allow the installation of a new and tolerant immune system during immune reconstitution process. Immune reconstitution analysis after AHCT is required for patients clinical follow-up and to further identify biological and immunological markers of the clinical response to develop individualized AHCT protocols. These MATHEC-SFGM-TC good clinical practice guidelines were developed by a multidisciplinary group of experts including members of the french reference center for stem Cell Therapy in Auto-immune Diseases (MATHEC), hematologists from the French speaking Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) and experts in immune monitoring and biobanking. The objectives are to provide practical recommandations for immune monitoring and biobanking of samples in patients with AD undergoing AHCT, for routine care purposes and investigational studies.

L’autogreffe de cellules hématopoïétiques (ACH) est une alternative thérapeutique validée pour les formes sévères d’un certain nombre de maladies auto-immunes (MAI). Le principe de l’ACH repose sur l’éradication du système immunitaire autoréactif, suite à l’administration d’une chimiothérapie intensive ou myéloablative, suivie d’une période d’aplasie, puis de reconstitution immunitaire associée à l’apparition d’une réponse immune de novo, avec l’acquisition d’un nouveau répertoire lymphocytaire naïf et tolérant aux antigènes du « soi ». L’analyse des données de reconstitution immunologique après ACH est nécessaire à la compréhension de l’évolution clinique des patients et à la recherche de facteurs prédictifs de la réponse clinique, dans le but de développer des protocoles d’ACH personnalisés. Ces recommandations de bonnes pratiques MATHEC-SFGM-TC ont été élaborées par un groupe d’experts aux spécialités complémentaires réunissant les membres du Centre de référence des maladies auto-immunes systémiques rares d’Île-de-France, filière FAI2R, et du réseau MATHEC (Maladies auto-immunes et thérapie cellulaire), des hématologues de la Société française de greffe de moelle osseuse et thérapie cellulaire (SFGM-TC) experts dans la procédure d’ACH dans les MAI, ainsi que des experts dans le suivi immunologique après thérapie cellulaire et dans l’établissement de collections biologiques. L’objectif est de guider les cliniciens dans le suivi immunologique minimal en soin courant des patients traités par ACH pour MAI et dans les modalités de collection d’échantillons biologiques destinés à la recherche.

Protein–protein interactions are well recognized as therapeutic targets and therefore interfering peptides (IP) that block these interactions are receiving increasing attention. Four different tumor‐penetrating peptides (TPPs) (iRGD, RPARPAR, Linear TT1 (LinTT1), and cyclic TT1 (TT1)) are associated to an IP that blocks the interaction between the protein phosphatase PP2A and its binding protein SET, generating new bifunctional peptides able to intracellularly target the PP2A/SET interaction in malignant B cells and tumoral hepatocytes. The TPPs are able to penetrate into B cells of patients suffering chronic lymphocytic leukemia (CLL) and into tumoral hepatocytes but not into B cells from healthy donors and healthy hepatocytes. The association of cargo does not affect the penetration of the TPPs in CLL B cells. All the bifunctional peptides induce apoptosis in human CLL B cells and tumoral hepatocytes, and stability tests reveal that iRGD‐IP, RPARPAR‐IP, and TT1‐IP are stable after 24 h incubation in human serum. The iRGD associated with the IP significantly increases the survival of mice bearing xenograft models of CLL without any symptom of toxicity, suggesting that the bifunctional peptides may have a therapeutic application for selective tumoral targeting of PP2A/SET interaction, which is deregulated in several cancers, including CLL.

Background & AimAlthough native bone marrow-derived mesenchymal stromal cells (BM-MSC) have been described to express CD40, how CD40 is regulated on MSC, and whether CD40 signaling affects MSC activation and function remain unknown. We recently demonstrated that adipose-derived stromal cells (ASC) exhibit a stronger capacity to inhibit immune response than BM-MSC, supporting their use for clinical applications to treat inflammatory diseases and degenerative disorders. Moreover, obesity is associated with adipose tissue inflammation and recruitment of immune cells that could in turn affect the phenotype of native ASC in situ. We thus decided to explore CD40 regulation, signalization, and function on native and in vitro-expanded ASC.Methods, Results & ConclusionAdipose Tissue Stromal Vascular Fractions (ATSVF) were obtained from obese and non-obese donors during lipectomy. Comparison of gene expression was carried out by using RNA sequencing. Some gene expression levels were assessed by QPCR on the total cells or on the CD146− CD34+ Lin− purified ASC. Next, ASC isolated by adhesion in culture were submitted to various stimuli or co-culture with activated CD4+ T cells. Changes in gene expression and secretion profiles were studied by Q-PCR and ELISA. Neutrophil migration was measured through Transwell and involvement of the candidate pathways was assessed by using specific siRNAs.We first revealed through gene expression profiling that the inflammatory signature found in adipose tissue stromal vascular fractions from obese patients included an upregulation of CD40L and was associated with a simultaneous induction of CD40 expression on native ASC. We further confirmed that inflammatory cytokines and direct contact with activated CD4+ T cells upregulated membrane CD40 expression on in vitro-expanded ASC. Stimulation of ASC by CD40L induced a modification of their gene expression profile evaluated by RNAseq reflecting an activation of NF-kB pathway. In agreement, we confirmed by DNA-binding ELISA, the activation of NF-kB pathways by CD40L stimulation. More specifically we focused on the strong induction of inflammatory chemokines, in particular IL-8, triggered on ASC by CD4+ T cells in a CD40/CD40L-dependant manner. Accordingly, CD40L-stimulated ASC recruited more efficiently neutrophils. Overall, these data strongly suggest an interaction between CD4+ T cells, ASC, and neutrophils within inflammatory sites. This observation must be kept in mind when using ASC to treat inflammatory diseases.

Protein phosphatase 2A (PP2A) is known to be a negative regulator of several survival and proliferating pathways that are frequently altered in cancer. In addition to chemical enzymatic inhibitors of the PP2A activity, the oncoprotein SET has been described as a physiological PP2A inhibitor by forming a complex with PP2A catalytic subunit (PP2Ac). Increased SET protein levels therefore directly reduce the tumor suppressor function of PP2A and promote tumor progression. We have used the PEP-Scan approach to identify the binding site between the serine/threonine phosphatase PP2A and the oncoprotein SET. For in vivo validation of the peptides, we have used chronic lymphocytic leukemia (CLL) xenograft models. In this manuscript we describe the identification of amino acid sequences involved in the complex formation, both at the PP2Ac and SET sides. The amino acid sequences of the binding sites were coupled to an optimized penetrating peptide in order to generate chimeras (Mut3DPT-PP2A and Mut3DPT-SET) able to target the PP2A/SET interaction. We demonstrate that these peptides have an in vitro apoptotic effect on breast and lung cancer cell lines, as well as an antitumoral effect on CLL and lymphoma xenograft models. The new generated chimeric peptides allow the modulation of the PP2Ac/SET interaction and might have a potential as a new therapeutic approach for cancer treatment.

Owing to their immunosuppressive properties, mesenchymal stromal cells (MSCs) obtained from bone marrow (BM-MSCs) or adipose tissue (ASCs) are considered a promising tool for cell therapy. However, important issues should be considered to ensure the reproducible production of efficient and safe clinical-grade MSCs. In particular, high expansion rate, associated with progressive senescence, was recently proposed as one of the parameters that could alter MSC functionality. In this study, we directly address the consequences of replicative senescence on BM-MSC and ASC immunomodulatory properties. We demonstrate that MSCs produced according to GMP procedures inhibit less efficiently T-cell, but not Natural Killer (NK)- and B-cell, proliferation after reaching senescence. Senescence-related loss-of-function is associated with a decreased indoleamine 2,3-dioxygenase (IDO) activity in response to inflammatory stimuli. In particular, although STAT-1-dependent IDO expression is transcriptionally induced at a similar level in senescent and nonsenescent MSCs, IDO protein is specifically degraded by the proteasome in senescent ASCs and BM-MSCs, a process that could be reversed by the MG132 proteasome inhibitor. These data encourage the use of appropriate quality controls focusing on immunosuppressive mechanisms before translating clinical-grade MSCs in the clinic. Stem Cells 2017;35:1431-1436.

The immunostimulatory properties of lenalidomide have been mostly described in vitro while in vivo studies performed in multiple myeloma or chronic lymphocytic leukemia have reported a poorly characterized T-cell activation. A better understanding of lenalidomide kinetics and mechanisms of action is mandatory to optimize its combination with other immunotherapeutic agents in particular for the treatment of non Hodgkin lymphomas.

Despite intensive effort, no effective pharmacological inhibitors of the Ras oncoprotein have been reached the clinic given the impression that Ras proteins are undruggable.However, progresses have been made in several directions to manipulate Ras.In this manuscript, we describe a novel and promising approach for specifically targeting the Ras/Raf interaction.We have identified the amino acid sequence involved in the binding of Ras to Raf.The amino acids of the binding site were coupled to an optimized penetrating peptide in order to generate a chimeric peptide, Mut3DPT-Ras, able to penetrate the cells and target Ras/Raf interaction.We demonstrate that this protease-resistant peptide has an in vitro apoptotic effect on several cancer cell lines and on primary cells isolated from chronic lymphocytic leukemia (CLL) as well as an antitumoral effect on chronic lymphocytic leukemialike and lymphoma xenograft model.The new generated peptide allows the modulation of the Ras/Raf interaction and might have a potential as a new therapeutic approach for cancer treatment.

CD4 and CD8 T lymphocyte activation requires the generation of sufficient energy to support new biosynthetic demands. Following T cell receptor (TCR) engagement, these requirements are met by an increased glycolysis, due, at least in part, to induction of the Glut1 glucose transporter. As Glut1 is upregulated on tumor cells in response to hypoxia, we assessed whether surface Glut1 levels regulate the antigen responsiveness of human T lymphocytes in both hypoxic and atmospheric oxygen conditions. Notably, Glut1 upregulation in response to TCR stimulation was significantly higher in T lymphocytes activated under hypoxic as compared to atmospheric oxygen conditions. Furthermore, TCR-stimulated human T lymphocytes sorted on the basis of Glut1-Lo and Glut1-Hi profiles maintained distinct characteristics, irrespective of the oxygen tension. While T cells activated in hypoxia divided less than those activated in atmospheric oxygen, Glut1-Hi lymphocytes exhibited increased effector phenotype acquisition, augmented proliferation and an inverted CD4/CD8 ratio in both oxygen conditions. Moreover, Glut1-Hi T lymphocytes exhibited a significantly enhanced ability to produce IFN-γ and this secretion potential was completely dependent on continued glycolysis. Thus, Glut1 surface levels identify human T lymphocytes with distinct effector functions in both hypoxic and atmospheric oxygen tensions.