1
|
Carlini F, Lusi V, Rizzi C, Assogna F, Laroni A. Cladribine Tablets Mode of Action, Learning from the Pandemic: A Narrative Review. Neurol Ther 2023; 12:1477-1490. [PMID: 37421556 PMCID: PMC10444742 DOI: 10.1007/s40120-023-00520-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 06/16/2023] [Indexed: 07/10/2023] Open
Abstract
Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system, characterized by chronic, inflammatory, demyelinating, and neurodegenerative processes. MS management relies on disease-modifying drugs that suppress/modulate the immune system. Cladribine tablets (CladT) have been approved by different health authorities for patients with various forms of relapsing MS. The drug has been demonstrated to deplete CD4+ and CD8+ T-cells, with a higher effect described in the former, and to decrease total CD19+, CD20+, and naive B-cell counts. COVID-19 is expected to become endemic, suggesting its potential infection risk for immuno-compromised patients, including MS patients treated with disease-modifying drugs. We report here the available data on disease-modifying drug-treated-MS patients and COVID-19 infection and vaccination, with a focus on CladT. MS patients treated with CladT are not at higher risk of developing severe COVID-19. While anti-SARS-CoV-2 vaccination is recommended in all MS patients with guidelines addressing vaccination timing according to the different disease-modifying drugs, no vaccination timing restrictions seem to be necessary for cladribine, based on its mechanism of action and available evidence. Published data suggest that CladT treatment does not impact the production of anti-SARS-CoV-2 antibodies after COVID-19 vaccination, possibly due to its relative sparing effect on naïve B-cells and the rapid B-cell reconstitution following treatment. Slightly lower specific T-cell responses are likely not impacting the risk of breakthrough COVID-19. It could be stated that cladribine's transient effect on innate immune cells likely contributes to maintaining an adequate first line of defense against the SARS-CoV-2 virus.
Collapse
Affiliation(s)
- Federico Carlini
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genoa, Italy
| | - Valeria Lusi
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genoa, Italy
| | - Caterina Rizzi
- Merck Serono S.P.A., Italy an Affiliate of Merck KGaA, Piazza del Pigneto 9, Rome, Italy
| | - Francesco Assogna
- Merck Serono S.P.A., Italy an Affiliate of Merck KGaA, Piazza del Pigneto 9, Rome, Italy
| | - Alice Laroni
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genoa, Italy.
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Largo Daneo 3, Genoa, Italy.
| |
Collapse
|
2
|
Yu X, Sun R, Yang X, He X, Guo H, Ou C. The NT5DC family: expression profile and prognostic value in pancreatic adenocarcinoma. J Cancer 2023; 14:2274-2288. [PMID: 37576396 PMCID: PMC10414034 DOI: 10.7150/jca.85811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 07/12/2023] [Indexed: 08/15/2023] Open
Abstract
Pancreatic adenocarcinoma (PAAD) is a malignant tumor with high morbidity and mortality rates. The NT5DC family is an evolutionarily-conserved family of 5'-nucleosidases that catalyze the intracellular hydrolysis of nucleotides. Although the NT5DC family has been linked to the initiation and growth of several cancers, its function in PAAD remains unclear. A series of bioinformatic analyses was used to ascertain the expression, prognosis, gene changes, functional enrichment, and immune regulatory functions of the NT5DC family in PAAD. NT5C2 and NT5DC1/2 mRNA and protein levels are increased in PAAD. Furthermore, the high mRNA expressions of NT5C2, NT5DC2, and NT5DC4 indicate a poor prognosis in patients with PAAD. The enrichment of biological processes and gene expression in the NT5DC family in PAAD were investigated using Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses. Further investigations into immune infiltration revealed a close relationship between NT5DC gene expression and immune cell infiltration. These findings provide new insights into the biological function and prognostic value of the NT5DC gene family in PAAD.
Collapse
Affiliation(s)
- Xiaoqian Yu
- Department of Pathology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Ru Sun
- Department of blood transfusion, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, Sichuan, China
| | - Xuejie Yang
- Department of Pathology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Xiaoyun He
- Departments of Ultrasound Imaging, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Hongbin Guo
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
| | - Chunlin Ou
- Department of Pathology, Xiangya Hospital, Central South University, Changsha 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
3
|
Aglas-Leitner FT, Juillard P, Juillard A, Byrne SN, Hawke S, Grau GE, Marsh-Wakefield F. Mass cytometry reveals cladribine-induced resets among innate lymphoid cells in multiple sclerosis. Sci Rep 2022; 12:20411. [PMID: 36437270 PMCID: PMC9701791 DOI: 10.1038/s41598-022-24617-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/17/2022] [Indexed: 11/29/2022] Open
Abstract
Here we present a comprehensive mass cytometry analysis of peripheral innate lymphoid cell (ILC) subsets in relapsing/remitting MS (RRMS) patients prior to and after onset of cladribine tablets (CladT). ILC analysis was conducted on CyTOF data from peripheral blood mononuclear cells (PBMC) of MS patients before, 2 and 6 months after onset of CladT, and non-MS controls. Dimensionality reduction was used for immunophenotyping ILC subsets. CladT reduced all ILC subsets, except for CD56bright NK cells and ILC2. Furthermore, CD38+ NK cell and CCR6+ ILC3 were excluded from CladT-induced immune cell reductions. Post-CladT replenishment by immature ILC was noted by increased CD5+ ILC1 proportions at 2 months, and boosted CD38-CD56bright NK cell numbers at 6 months. CladT induce immune cell depletion among ILC but exclude CD56bright NK cells and ILC2 subsets, as well as CD38+ NK cell and CCR6+ ILC3 immunophenotypes. Post-CladT ILC expansions indicate ILC reconstitution towards a more tolerant immune system phenotype.
Collapse
Affiliation(s)
- F. T. Aglas-Leitner
- grid.1013.30000 0004 1936 834XVascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia ,grid.22937.3d0000 0000 9259 8492Medical University of Vienna, Spitalgasse 23, Vienna, Austria
| | - P. Juillard
- grid.1013.30000 0004 1936 834XVascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - A. Juillard
- grid.1013.30000 0004 1936 834XVascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - S. N. Byrne
- grid.452919.20000 0001 0436 7430Centre for Immunology and Allergy Research, The Westmead Institute for Medical Research, Sydney, Australia ,grid.1013.30000 0004 1936 834XFaculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, Australia
| | - S. Hawke
- grid.1013.30000 0004 1936 834XVascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia ,Central West Neurology and Neurosurgery, Orange, Australia
| | - G. E. Grau
- grid.1013.30000 0004 1936 834XVascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia
| | - F. Marsh-Wakefield
- grid.1013.30000 0004 1936 834XVascular Immunology Unit, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia ,grid.248902.50000 0004 0444 7512Liver Injury & Cancer Group, Centenary Institute, Sydney, Australia ,grid.1013.30000 0004 1936 834XHuman Cancer & Viral Immunology Laboratory, The University of Sydney, Sydney, Australia ,grid.248902.50000 0004 0444 7512Centenary Institute, Sydney, NSW Australia
| |
Collapse
|
4
|
Schroeter CB, Rolfes L, Gothan KSS, Gruchot J, Herrmann AM, Bock S, Fazio L, Henes A, Narayanan V, Pfeuffer S, Nelke C, Räuber S, Huntemann N, Duarte-Silva E, Dobelmann V, Hundehege P, Wiendl H, Raba K, Küry P, Kremer D, Ruck T, Müntefering T, Budde T, Cerina M, Meuth SG. Cladribine treatment improves cortical network functionality in a mouse model of autoimmune encephalomyelitis. J Neuroinflammation 2022; 19:270. [DOI: 10.1186/s12974-022-02588-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Cladribine is a synthetic purine analogue that interferes with DNA synthesis and repair next to disrupting cellular proliferation in actively dividing lymphocytes. The compound is approved for the treatment of multiple sclerosis (MS). Cladribine can cross the blood–brain barrier, suggesting a potential effect on central nervous system (CNS) resident cells. Here, we explored compartment-specific immunosuppressive as well as potential direct neuroprotective effects of oral cladribine treatment in experimental autoimmune encephalomyelitis (EAE) mice.
Methods
In the current study, we compare immune cell frequencies and phenotypes in the periphery and CNS of EAE mice with distinct grey and white matter lesions (combined active and focal EAE) either orally treated with cladribine or vehicle, using flow cytometry. To evaluate potential direct neuroprotective effects, we assessed the integrity of the primary auditory cortex neuronal network by studying neuronal activity and spontaneous synaptic activity with electrophysiological techniques ex vivo.
Results
Oral cladribine treatment significantly attenuated clinical deficits in EAE mice. Ex vivo flow cytometry showed that cladribine administration led to peripheral immune cell depletion in a compartment-specific manner and reduced immune cell infiltration into the CNS. Histological evaluations revealed no significant differences for inflammatory lesion load following cladribine treatment compared to vehicle control. Single cell electrophysiology in acute brain slices was performed and showed an impact of cladribine treatment on intrinsic cellular firing patterns and spontaneous synaptic transmission in neurons of the primary auditory cortex. Here, cladribine administration in vivo partially restored cortical neuronal network function, reducing action potential firing. Both, the effect on immune cells and neuronal activity were transient.
Conclusions
Our results indicate that cladribine exerts a neuroprotective effect after crossing the blood–brain barrier independently of its peripheral immunosuppressant action.
Collapse
|
5
|
Ali SS, Raj R, Kaur T, Weadick B, Nayak D, No M, Protos J, Odom H, Desai K, Persaud AK, Wang J, Govindarajan R. Solute Carrier Nucleoside Transporters in Hematopoiesis and Hematological Drug Toxicities: A Perspective. Cancers (Basel) 2022; 14:cancers14133113. [PMID: 35804885 PMCID: PMC9264962 DOI: 10.3390/cancers14133113] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/18/2022] [Accepted: 06/22/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Anticancer nucleoside analogs are promising treatments that often result in damaging toxicities and therefore ineffective treatment. Mechanisms of this are not well-researched, but cellular nucleoside transport research in mice might provide additional insight given transport’s role in mammalian hematopoiesis. Cellular nucleoside transport is a notable component of mammalian hematopoiesis due to how mutations within it relate to hematological abnormities. This review encompasses nucleoside transporters, focusing on their inherent properties, hematopoietic role, and their interplay in nucleoside drug treatment side effects. We then propose potential mechanisms to explain nucleoside transport involvement in blood disorders. Finally, we point out and advocate for future research areas that would improve therapeutic outcomes for patients taking nucleoside analog therapies. Abstract Anticancer nucleoside analogs produce adverse, and at times, dose-limiting hematological toxicities that can compromise treatment efficacy, yet the mechanisms of such toxicities are poorly understood. Recently, cellular nucleoside transport has been implicated in normal blood cell formation with studies from nucleoside transporter-deficient mice providing additional insights into the regulation of mammalian hematopoiesis. Furthermore, several idiopathic human genetic disorders have revealed nucleoside transport as an important component of mammalian hematopoiesis because mutations in individual nucleoside transporter genes are linked to various hematological abnormalities, including anemia. Here, we review recent developments in nucleoside transporters, including their transport characteristics, their role in the regulation of hematopoiesis, and their potential involvement in the occurrence of adverse hematological side effects due to nucleoside drug treatment. Furthermore, we discuss the putative mechanisms by which aberrant nucleoside transport may contribute to hematological abnormalities and identify the knowledge gaps where future research may positively impact treatment outcomes for patients undergoing various nucleoside analog therapies.
Collapse
Affiliation(s)
- Syed Saqib Ali
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Ruchika Raj
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Tejinder Kaur
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Brenna Weadick
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Debasis Nayak
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Minnsung No
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Jane Protos
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Hannah Odom
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Kajal Desai
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Avinash K. Persaud
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
| | - Joanne Wang
- Department of Pharmaceutics, College of Pharmacy, University of Washington, Seattle, WA 98195, USA;
| | - Rajgopal Govindarajan
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; (S.S.A.); (R.R.); (T.K.); (B.W.); (D.N.); (M.N.); (J.P.); (H.O.); (K.D.); (A.K.P.)
- Translational Therapeutics, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
- Correspondence: ; Tel.: +1-614-247-8269; Fax: +1-614-292-2588
| |
Collapse
|
6
|
Giovannoni G, Mathews J. Cladribine Tablets for Relapsing-Remitting Multiple Sclerosis: A Clinician's Review. Neurol Ther 2022; 11:571-595. [PMID: 35318617 PMCID: PMC8940595 DOI: 10.1007/s40120-022-00339-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 02/25/2022] [Indexed: 01/22/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic neurodegenerative disease characterized by inflammation and demyelination for which there is currently no cure; therefore, the aim of therapy is to reduce the risk of relapse and disability progression. The treatment options for MS have increased greatly in recent years with the development of several disease-modifying therapies (DMTs) and the advent of immune reconstitution therapy (IRT). IRTs are administered in short-dosing periods to produce long-term effects on the immune system. Treatment with an IRT is based on the 3Rs: reduction, repopulation, and reconstitution of lymphocytes, which leads to restoration of immune effector functions. Cladribine tablets represent a selective, high-efficacy, oral form of IRT for patients with MS that targets lymphocytes and spares innate immune cells. Patients require only two weekly treatment courses, with each course comprising two treatment weeks, in Years 1 and 2; therefore, cladribine tablets are associated with a lower monitoring burden than many other DMTs, while short dosing periods can help to improve adherence. This review provides an overview of IRT and offers the clinician's perspective on the current MS treatment landscape, with a focus on practical advice for the management of patients undergoing treatment with cladribine tablets based on the most recent evidence available, including risks associated with COVID-19 and recommendations for vaccination in patients with MS.
Collapse
Affiliation(s)
- Gavin Giovannoni
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark St, Whitechapel, London, E1 2AT, UK.
| | - Joela Mathews
- Royal London Hospital, Barts Health NHS Trust, London, UK
| |
Collapse
|
7
|
2-Chlorodeoxyadenosine (Cladribine) preferentially inhibits the biological activity of microglial cells. Int Immunopharmacol 2022; 105:108571. [DOI: 10.1016/j.intimp.2022.108571] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/06/2022] [Accepted: 01/21/2022] [Indexed: 02/05/2023]
|
8
|
Hermann R, Krajcsi P, Fluck M, Seithel-Keuth A, Bytyqi A, Galazka A, Munafo A. Cladribine as a Potential Object of Nucleoside Transporter-Based Drug Interactions. Clin Pharmacokinet 2022; 61:167-187. [PMID: 34894346 PMCID: PMC8813788 DOI: 10.1007/s40262-021-01089-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2021] [Indexed: 12/15/2022]
Abstract
Cladribine is a nucleoside analog that is phosphorylated in its target cells (B and T-lymphocytes) to its active triphosphate form (2-chlorodeoxyadenosine triphosphate). Cladribine tablets 10 mg (Mavenclad®), administered for up to 10 days per year in 2 consecutive years (3.5-mg/kg cumulative dose over 2 years), are used to treat patients with relapsing multiple sclerosis. Cladribine has been shown to be a substrate of various nucleoside transporters (NTs). Intestinal absorption and distribution of cladribine throughout the body appear to be essentially mediated by equilibrative NTs (ENTs) and concentrative NTs (CNTs), specifically by ENT1, ENT2, ENT4, CNT2 (low affinity), and CNT3. Other efficient transporters of cladribine are the ABC efflux transporters, specifically breast cancer resistance protein, which likely modulates the oral absorption and renal excretion of cladribine. A key transporter for the intracellular uptake of cladribine into B and T-lymphocytes is ENT1 with ancillary contributions of ENT2 and CNT2. Transporter-based drug interactions affecting absorption and target cellular uptake of a prodrug such as cladribine are likely to reduce systemic bioavailability and target cell exposure, thereby possibly hampering clinical efficacy. In order to manage optimized therapy, i.e., to ensure uncompromised target cell uptake to preserve the full therapeutic potential of cladribine, it is important that clinicians are aware of the existence of NT-inhibiting medicinal products, various lifestyle drugs, and food components. This article reviews the existing knowledge on inhibitors of NT, which may alter cladribine absorption, distribution, and uptake into target cells, thereby summarizing the existing knowledge on optimized methods of administration and concomitant drugs that should be avoided during cladribine treatment.
Collapse
Affiliation(s)
- Robert Hermann
- Clinical Research Appliance (cr.appliance), Heinrich-Vingerhut-Weg 3, 63571, Gelnhausen, Germany.
| | | | | | | | | | - Andrew Galazka
- An Affiliate of Merck KGaA, Ares Trading SA, Eysins, Switzerland
| | - Alain Munafo
- An Affiliate of Merck KGaA, Merck Institute of Pharmacometrics, Lausanne, Switzerland
| |
Collapse
|
9
|
Immunomodulatory Effects Associated with Cladribine Treatment. Cells 2021; 10:cells10123488. [PMID: 34943995 PMCID: PMC8700070 DOI: 10.3390/cells10123488] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 12/29/2022] Open
Abstract
Cladribine is a synthetic deoxyadenosine analogue with demonstrated efficacy in patients with relapsing-remitting multiple sclerosis (MS). The main mechanism of action described for cladribine is the induction of a cytotoxic effect on lymphocytes, leading to a long-term depletion of peripheral T and B cells. Besides lymphocyte toxicity, the mode of action may include immunomodulatory mechanisms affecting other cells of the immune system. In order to induce its beneficial effects, cladribine is phosphorylated inside the cell by deoxycytidine kinase (DCK) to its active form. However, the mechanism of action of cladribine may also include immunomodulatory pathways independent of DCK activation. This in vitro study was designed to explore the impact of cladribine on peripheral blood mononuclear cells (PBMC) subsets, and to assess whether the immunomodulatory mechanisms induced by cladribine depend on the activation of the molecule. To this end, we obtained PBMCs from healthy donors and MS patients and performed proliferation, apoptosis and activation assays with clinically relevant concentrations of cladribine in DCK-dependent and -independent conditions. We also evaluated the effect of cladribine on myeloid lineage-derived cells, monocytes and dendritic cells (DCs). Cladribine decreased proliferation and increased apoptosis of lymphocyte subsets after prodrug activation via DCK. In contrast, cladribine induced a decrease in immune cell activation through both DCK-dependent and -independent pathways (not requiring prodrug activation). Regarding monocytes and DCs, cladribine induced cytotoxicity and impaired the activation of classical monocytes, but had no effect on DC maturation. Taken together, these data indicate that cladribine, in addition to its cytotoxic function, can mediate immunomodulation in different immune cell populations, by regulating their proliferation, maturation and activation.
Collapse
|