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Brüggemann Y, Klöhn M, Wedemeyer H, Steinmann E. Hepatitis E virus: from innate sensing to adaptive immune responses. Nat Rev Gastroenterol Hepatol 2024:10.1038/s41575-024-00950-z. [PMID: 39039260 DOI: 10.1038/s41575-024-00950-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 07/24/2024]
Abstract
Hepatitis E virus (HEV) infections are a major cause of acute viral hepatitis in humans worldwide. In immunocompetent individuals, the majority of HEV infections remain asymptomatic and lead to spontaneous clearance of the virus, and only a minority of individuals with infection (5-16%) experience symptoms of acute viral hepatitis. However, HEV infections can cause up to 30% mortality in pregnant women, become chronic in immunocompromised patients and cause extrahepatic manifestations. A growing body of evidence suggests that the host immune response to infection with different HEV genotypes is a critical determinant of distinct HEV infection outcomes. In this Review, we summarize key components of the innate and adaptive immune responses to HEV, including the underlying immunological mechanisms of HEV associated with acute and chronic liver failure and interactions between T cell and B cell responses. In addition, we discuss the current status of vaccines against HEV and raise outstanding questions regarding the immune responses induced by HEV and treatment of the disease, highlighting areas for future investigation.
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Affiliation(s)
- Yannick Brüggemann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Mara Klöhn
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Partner Sites Hannover-Braunschweig, Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany.
- German Center for Infection Research (DZIF), External Partner Site, Bochum, Germany.
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Molecular and therapeutic insights of rapamycin: a multi-faceted drug from Streptomyces hygroscopicus. Mol Biol Rep 2023; 50:3815-3833. [PMID: 36696023 PMCID: PMC9875782 DOI: 10.1007/s11033-023-08283-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023]
Abstract
The advancement in pharmaceutical research has led to the discovery and development of new combinatorial life-saving drugs. Rapamycin is a macrolide compound produced from Streptomyces hygroscopicus. Rapamycin and its derivatives are one of the promising sources of drug with broad spectrum applications in the medical field. In recent times, rapamycin has gained significant attention as of its activity against cytokine storm in COVID-19 patients. Rapamycin and its derivatives have more potency when compared to other prevailing drugs. Initially, it has been used exclusively as an anti-fungal drug. Currently rapamycin has been widely used as an immunosuppressant. Rapamycin is a multifaceted drug; it has anti-cancer, anti-viral and anti-aging potentials. Rapamycin has its specific action on mTOR signaling pathway. mTOR has been identified as a key regulator of different pathways. There will be an increased demand for rapamycin, because it has lesser adverse effects when compared to steroids. Currently researchers are focused on the production of effective rapamycin derivatives to combat the growing demand of this wonder drug. The main focus of the current review is to explore the origin, development, molecular mechanistic action, and the current therapeutic aspects of rapamycin. Also, this review article revealed the potential of rapamycin and the progress of rapamycin research. This helps in understanding the exact potency of the drug and could facilitate further studies that could fill in the existing knowledge gaps. The study also gathers significant data pertaining to the gene clusters and biosynthetic pathways involved in the synthesis and production of this multi-faceted drug. In addition, an insight into the mechanism of action of the drug and important derivatives of rapamycin has been expounded. The fillings of the current review, aids in understanding the underlying molecular mechanism, strain improvement, optimization and production of rapamycin derivatives.
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3
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Decourt B, Lahiri DK, Sabbagh MN. Targeting Tumor Necrosis Factor Alpha for Alzheimer's Disease. Curr Alzheimer Res 2017; 14:412-425. [PMID: 27697064 DOI: 10.2174/1567205013666160930110551] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/10/2016] [Accepted: 09/22/2016] [Indexed: 01/06/2023]
Abstract
Alzheimer's disease (AD) affects an estimated 44 million individuals worldwide, yet no therapeutic intervention is available to stop the progression of the dementia. Neuropathological hallmarks of AD are extracellular deposits of amyloid beta (Aβ) peptides assembled in plaques, intraneuronal accumulation of hyperphosphorylated tau protein forming tangles, and chronic inflammation. A pivotal molecule in inflammation is the pro-inflammatory cytokine TNF-α. Several lines of evidence using genetic and pharmacological manipulations indicate that TNF-α signaling exacerbates both Aβ and tau pathologies in vivo. Interestingly, preventive and intervention anti-inflammatory strategies demonstrated a reduction in brain pathology and an amelioration of cognitive function in rodent models of AD. Phase I and IIa clinical trials suggest that TNF-α inhibitors might slow down cognitive decline and improve daily activities in AD patients. In the present review, we summarize the evidence pointing towards a beneficial role of anti-TNF-α therapies to prevent or slow the progression of AD. We also present possible physical and pharmacological interventions to modulate TNF-α signaling in AD subjects along with their limitations.
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Affiliation(s)
- Boris Decourt
- Banner Sun Health Research Institute, 10515 W. Santa Fe Dr., Sun City AZ 85351, United States
| | - Debomoy K Lahiri
- Institute of Psychiatry Research, Department of Psychiatry, School of Medicine, Indiana University-Purdue University, Indianapolis, IN, United States
| | - Marwan N Sabbagh
- Alzheimer's and Memory Disorders Division, Barrow Neurological Institute, 240 West Thomas, Ste 301, Phoenix, AZ 85013, United States
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4
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Liu SQ, Zhao JP, Fan XX, Liu GH, Jiao HC, Wang XJ, Sun SH, Lin H. Rapamycin, a specific inhibitor of the target of rapamycin complex 1, disrupts intestinal barrier integrity in broiler chicks. J Anim Physiol Anim Nutr (Berl) 2015; 100:323-30. [PMID: 26249793 DOI: 10.1111/jpn.12375] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/10/2015] [Indexed: 12/16/2022]
Abstract
To uncover the molecular mechanisms underlying the intestinal barrier integrity, this study determined whether the rapamycin (RAPA)-sensitive target of rapamycin complex 1 (TORC1) pathway was involved in this process. Three groups of 4-day-old male chicks were randomly subjected to one of the following treatments for 6 days: high-dose RAPA [a specific inhibitor of TORC1; an intraperitoneal injection of 1.0 mg/kg body weight (BW), once daily at 09:00 hours], low-dose RAPA (0.4 mg/kg BW) and RAPA vehicle (control). Results showed that the RAPA treatment increased mortality, while decreasing villus height (p < 0.01), claudin 1 expression, content of immunoglobulin A (IgA), extent of TORC1 phosphorylation (p < 0.05), ratio of villus height to crypt depth (p < 0.01), and population of IgA-positive B cells in intestinal mucosa, particularly for the jejunum. Some aspects of these responses were dose dependent and appeared to result from weight loss. Together, RAPA exerts the expected inhibition of small intestinal development and IgA production in birds, suggesting the important role of TORC1 in gut barrier integrity.
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Affiliation(s)
- S Q Liu
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - J P Zhao
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - X X Fan
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - G H Liu
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - H C Jiao
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - X J Wang
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - S H Sun
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
| | - H Lin
- Shandong Key Lab for Animal Biotechnology and Disease Control, Department of Animal Science, Shandong Agricultural University, Tai'an, China
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Han B, Cai H, Chen Y, Hu B, Luo H, Wu Y, Wu J. The role of TGFBI (βig-H3) in gastrointestinal tract tumorigenesis. Mol Cancer 2015; 14:64. [PMID: 25889002 PMCID: PMC4435624 DOI: 10.1186/s12943-015-0335-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 03/09/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND TGFβ-induced (TGFBI/βig-H3) is a protein inducible by TGFβ1 and secreted by many types of cells. It binds to collagen, forms part of the extracellular matrix (ECM), and interacts with integrins on cell surfaces. In this study, we investigated the role of TGFBI in tumorigenesis and the underlying mechanisms. METHODS Patient serum TGFBI levels were determined by ELISA. TGFBI transgenic and gene knockout mice and TGFBI-overexpressing liver cells were used for mechanistic studies. RESULTS We demonstrated that patients with cholangiocarcinomas, hepatic carcinomas or gastric carcinomas presented significantly elevated serum TGFBI levels, and the excess TGFBI was derived from the tumor masses. TGFBI overexpression in mice resulted in increased incidence of spontaneous tumors and N,N-diethylnitrosamine (DEN)-induced liver tumor nodules, compared to that in wild type (WT) mice, while TGFBI knockout mice were comparable to WT controls in these 2 aspects. TGFBI promoted the survival of Aml-12 liver cells with DNA damage after irradiation, and augmented their post-irradiation proliferation. It activated the FAK/AKT/AKT1S1/PRS6/EIF4EBP pathway, which is known to modulate cell survival and proliferation. CONCLUSIONS Our data suggest that TGFBI functions as a promoter of certain gastrointestinal tract cancers. It provides a survival advantage to cells with DNA damage. Over a long time span, this advantage could translate into increased tumor risks.
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Affiliation(s)
- Bing Han
- Laboratory of Immunology and Cardiovascular Research, Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Stain-Denis Street, Montreal, Quebec, Canada.
| | - Haolei Cai
- Department of Surgery, The Second Affiliated Hospital of Zhejiang University, 88 Jiefang Road, Hangzhou, China.
| | - Ying Chen
- Department of Surgery, The Second Affiliated Hospital of Zhejiang University, 88 Jiefang Road, Hangzhou, China.
| | - Bing Hu
- Anatomic Pathology, AmeriPath Central Florida, 8150 Chancellor Dr, Orlando, FL, USA.
| | - Hongyu Luo
- Laboratory of Immunology and Cardiovascular Research, Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Stain-Denis Street, Montreal, Quebec, Canada.
| | - Yulian Wu
- Department of Surgery, The Second Affiliated Hospital of Zhejiang University, 88 Jiefang Road, Hangzhou, China.
| | - Jiangping Wu
- Laboratory of Immunology and Cardiovascular Research, Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Stain-Denis Street, Montreal, Quebec, Canada. .,Nephrology Service, Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Stain-Denis Street, Montreal, Quebec, Canada.
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6
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Scotto G, Aucella F, Grandaliano G, Martinelli D, Querques M, Gesuete A, Infante B, Carri PD, Massa S, Salatino G, Bulla F, Fazio V. Hepatitis E in hemodialysis and kidney transplant patients in south-east Italy. World J Gastroenterol 2015; 21:3266-3273. [PMID: 25805933 PMCID: PMC4363756 DOI: 10.3748/wjg.v21.i11.3266] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/04/2014] [Accepted: 01/08/2015] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the serovirological prevalence and clinical features of hepatitis E virus (HEV) infection in end-stage renal failure patients and in the healthy population.
METHODS: HEV infection is a viral disease that can cause sporadic and epidemic hepatitis. Previous studies unexpectedly showed a high prevalence of HEV antibodies in immunosuppressed subjects, including hemodialysis (HD) patients and patients who had undergone kidney transplant. A cohort/case-control study was carried out from January 2012 to August 2013 in two hospitals in southern Italy (Foggia and S. Giovanni Rotondo, Apulia). The seroprevalence of HEV was determined in 801 subjects; 231 HD patients, 120 renal transplant recipients, and 450 health individuals. All HD patients and the recipients of renal transplants were attending the Departments of Nephrology and Dialysis at two hospitals located in Southern Italy, and were included progressively in this study. Serum samples were tested for HEV antibodies (IgG/IgM); in the case of positivity they were confirmed by a Western blot assay and were also tested for HEV-RNA, and the HEV genotypes were determined.
RESULTS: A total of 30/801 (3.7%) patients were positive for anti-HEV Ig (IgG and/or IgM) and by Western blot. The healthy population presented with a prevalence of 2.7%, HD patients had a prevalence of 6.0%, and transplant recipients had a prevalence of 3.3%. The overall combined HEV-positive prevalence in the two groups with chronic renal failure was 5.1%. The rates of exposure to HEV (positivity of HEV-IgG/M in the early samples) were lower in the healthy controls, but the difference among the three groups was not statistically significant (P > 0.05). Positivity for anti-HEV/IgM was detected in 4/30 (13.33%) anti-HEV Ig positive individuals, in 2/14 HD patients, in 1/4 transplant individuals, and in 1/12 of the healthy population. The relative risk of being HEV-IgM-positive was significantly higher among transplant recipients compared to the other two groups (OR = 65.4, 95%CI: 7.2-592.7, P < 0.001), but the subjects with HEV-IgM positivity were numerically too few to calculate a significant difference. No patient presented with chronic hepatitis from HEV infection alone.
CONCLUSION: This study indicated a higher, but not significant, circulation of HEV in hemodialysis patients vs the healthy population. Chronic hepatitis due to the HEV virus was not observed.
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Rapamycin represses myotube hypertrophy and preserves viability of C2C12 cells during myogenesis in vitro. Transplantation 2014; 98:139-47. [PMID: 24926828 DOI: 10.1097/tp.0000000000000175] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Rapamycin (RAPA) has been successfully used for myoblast allotransplantation in X chromosome-linked muscular dystrophy mice. However, the mechanism of skeletal myogenesis, particularly in starved condition by RAPA, remains elusive. For this reason, we investigated the effect of RAPA on C2C12 myogenesis in serum-starved condition. METHODS Serum-free treated C2C12 cells were mimicked as skeletal myogenesis in nutrition shortage microenvironment. A methylthiazoletetrazolium (MTT) assay was used to investigate different RAPA concentrations on serum-free treated C2C12 cells and the following assays were used to detect the characteristic of C2C12 myogenesis by RAPA in vitro. RESULTS We found that 150 ng/mL of RAPA did not significantly suppress the viability of C2C12 differentiated cells by MTT assay. The RAPA concentration could protect myoblast serum-starved cells effectively from apoptosis through flow cytometry and retain myogenic regulatory factors through quantitative polymerase chain reaction analysis. However, RAPA significantly suppressed cell migration in wound healing assay (P<0.05). Morphological analyses indicated that RAPA also significantly suppressed myotube hypertrophy in serum-starved C2C12 cells. Western blot analysis revealed that the ratio of phosphate extracellular signal-regulated kinase/extracellular signal-regulated kinase and the protein level of p-Akt decreased in the proliferation medium and in the differentiation medium, respectively. CONCLUSION These findings suggest that myoblast cells are sensitive to RAPA under a serum-starved microenvironment. As an immunosuppressive agent, RAPA shall be used as a considering dosage and as a safe strategy for future myoblast allotransplantation.
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Konstantinou GN, Asero R, Ferrer M, Knol EF, Maurer M, Raap U, Schmid-Grendelmeier P, Skol PS, Grattan CEH. EAACI taskforce position paper: evidence for autoimmune urticaria and proposal for defining diagnostic criteria. Allergy 2013; 68:27-36. [PMID: 23157716 DOI: 10.1111/all.12056] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2012] [Indexed: 12/26/2022]
Abstract
An autoimmune subset of chronic spontaneous urticaria is increasingly being recognized internationally, based on laboratory and clinical evidence that has accrued over the last 20 years. This evidence has been reviewed by a taskforce of the Dermatology section of the European Academy of Allergy and Clinical Immunology. Functional autoantibodies in chronic urticaria (CU) patient sera have been demonstrated against IgE and FcεRIα by basophil and mast cell histamine release assays and by basophil activation assays. Antibody specificity has been confirmed by immunoassay, but there is a poor correlation between functionality and immunoreactivity. Approximately 25% of CU patients have a positive basophil histamine release assay and show autoreactivity (a positive autologous serum skin test), whereas 50% are negative regarding both. Functionality of CU sera appears to be complement dependent on mast cells but not exclusively on basophils. Basophil activation by CU sera is predominantly restricted to IgG1 and IgG3 subclasses. Circumstantial evidence for CU being an autoimmune disease comes from an observed association with other autoimmune diseases, a strong association between serum functionality and HLA-DR4 haplotype and the good response of CU patients to immunotherapies. It was proposed that a study should be undertaken to prospectively validate potentially relevant clinical criteria (from the history, examination and routinely available clinical investigations) against a new 'gold standard' for the diagnosis of ACU (positive autoreactivity, functional bioassay and immunoassay) to define preliminary criteria sets for the diagnosis of ACU based on clinical and laboratory features with highest individual sensitivity and specificity.
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Affiliation(s)
- G. N. Konstantinou
- Department of Allergy and Clinical Immunology; 424 General Military Training Hospital; Thessaloniki; Greece
| | - R. Asero
- Ambulatorio di Allergologia; Clinica San Carlo; Paderno Dugnano; Millan; Italy
| | - M. Ferrer
- Department of Allergy; Clinica Universidad de Navarra; Pamplona; Spain
| | - E. F. Knol
- Department of Dermatology and Allergology; University Medical Center Utrecht; Utrecht; The Netherlands
| | - M. Maurer
- Department of Dermatology and Allergy; Charité - Universitätsmedizin Berlin; Berlin; Germany
| | - U. Raap
- Department of Dermatology and Allergy; Hannover Medical School; Hannover; Germany
| | | | - P. S. Skol
- Department of Dermatology; Odense University Hospital; Odense Area; Denmark
| | - C. E. H. Grattan
- Department of Dermatology; St John's Institute of Dermatology; London and Norfolk and Norwich University Hospital; Norwich; UK
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Legrand-Abravanel F, Kamar N, Sandres-Saune K, Lhomme S, Mansuy JM, Muscari F, Sallusto F, Rostaing L, Izopet J. Hepatitis E virus infection without reactivation in solid-organ transplant recipients, France. Emerg Infect Dis 2011; 17:30-7. [PMID: 21192851 PMCID: PMC3298369 DOI: 10.3201/eid1701.100527] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Kamar N, Abravanel F, Mansuy JM, Peron JM, Izopet J, Rostaing L. Infection par le virus de l’hépatite E en dialyse et après transplantation. Nephrol Ther 2010; 6:83-7. [DOI: 10.1016/j.nephro.2009.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2009] [Revised: 10/31/2009] [Accepted: 10/31/2009] [Indexed: 12/21/2022]
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Fischer R, Turnquist HR, Taner T, Thomson AW. Use of rapamycin in the induction of tolerogenic dendritic cells. Handb Exp Pharmacol 2009:215-32. [PMID: 19031028 DOI: 10.1007/978-3-540-71029-5_10] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Rapamycin (RAPA), a macrocyclic triene antibiotic pro-drug, is a clinically-utilized 'tolerance-sparing' immunosuppressant that inhibits the activity of T, B, and NK cells. Furthermore, maturation-resistance and tolerogenic properties of dendritic cells (DC) can be supported and preserved by conditioning with RAPA. Propagation of murine bone marrow (BM)-derived myeloid DC (mDC) in clinically relevant concentrations of RAPA (RAPA-DC) generates phenotypically immature DC with low levels of MHC and significantly reduced co-stimulatory molecules (especially CD86), even when exposed to inflammatory stimuli. RAPA-DC are weak stimulators of T cells and induce hyporesponsiveness and apoptosis in allo-reactive T cells. An interesting observation has been that RAPA-DC retain the ability to stimulate and enrich the regulatory T cells (Treg). Presumably as a result of these properties, alloantigen (alloAg)-pulsed recipient-derived DC are effective in subverting anti-allograft immune responses in rodent transplant models, making them an attractive subject for further investigation of their tolerance-promoting potential.
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Affiliation(s)
- Ryan Fischer
- Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
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12
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Kamar N, Selves J, Mansuy JM, Ouezzani L, Péron JM, Guitard J, Cointault O, Esposito L, Abravanel F, Danjoux M, Durand D, Vinel JP, Izopet J, Rostaing L. Hepatitis E virus and chronic hepatitis in organ-transplant recipients. N Engl J Med 2008; 358:811-7. [PMID: 18287603 DOI: 10.1056/nejmoa0706992] [Citation(s) in RCA: 943] [Impact Index Per Article: 58.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hepatitis E virus (HEV) is considered an agent responsible for acute hepatitis that does not progress to chronic hepatitis. We identified 14 cases of acute HEV infection in three patients receiving liver transplants, nine receiving kidney transplants, and two receiving kidney and pancreas transplants. All patients were positive for serum HEV RNA. Chronic hepatitis developed in eight patients, as confirmed by persistently elevated aminotransferase levels, serum HEV RNA, and histologic features of chronic hepatitis. The time from transplantation to diagnosis was significantly shorter and the total counts of lymphocytes and of CD2, CD3, and CD4 T cells were significantly lower in patients in whom chronic disease developed.
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Affiliation(s)
- Nassim Kamar
- Department of Nephrology, Dialysis, and Multiorgan Transplantation, Centre Hospitalier Universitaire, Rangueil, France.
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Ołdakowska-Jedynak U, Paczek L, Mucha K, Foroncewicz B, Perkowska-Ptasińska A. Successful Reversal of Acute Vascular Rejection and Cyclosporine-Associated Nephrotoxicity in Renal Allograft With Combined Sirolimus and Mycophenolate Mofetil as Immunotherapy. Transplant Proc 2006; 38:66-8. [PMID: 16504666 DOI: 10.1016/j.transproceed.2005.12.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cyclosporine (CsA) has substantially improved patient and graft survival rates in solid organ transplantation. In clinical studies, sirolimus has been shown to be as effective as CsA to maintain survival of renal and cardiac allografts without causing nephrotoxicity. Herein we describe a patient with biopsy-proven CsA-associated nephrotoxicity and refractory renal allograft rejection who was converted from steroids, CsA, and azathioprine to steroids, sirolimus (RAPA), and low-dose mycophenolate mofetil (MMF). The follow-up period was 60 months. We observed substantial improvement, even normalization in renal function. Our patient did not give consent to repeat biopsy after conversion. We also observed a beneficial effect of CsA withdrawal on blood pressure control. The spectrum of adverse events induced by sirolimus seemed to be mild relative to the potency of the immunosuppressive effect. The excellent response to combined RAPA and MMF in this patient was probably due to "concerted actions" of these agents on both B- and T-cell functions. The combination enhanced therapeutic efficacy while minimizing the toxicity of individual drugs used in the regimen. These findings suggest that sirolimus, when used as a base therapy in combination with low-dose MMF in a renal allograft recipient, may be an alternative to CsA-based therapy, providing potent immunosuppression of a renal allograft. Sirolimus administration facilitated steroids dose reduction.
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Affiliation(s)
- U Ołdakowska-Jedynak
- Transplantation Institute, Department of Immunology, Transplantology and Internal Diseases, Warsaw Medical University, ul. Nowogrodzka 59, 02-006 Warsaw, Poland.
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Zachary AA, Montgomery RA, Leffell MS. Desensitization protocols improving access and outcome in transplantation. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.cair.2005.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Luo H, Yu G, Tremblay J, Wu J. EphB6-null mutation results in compromised T cell function. J Clin Invest 2005; 114:1762-73. [PMID: 15599401 PMCID: PMC535066 DOI: 10.1172/jci21846] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Accepted: 10/05/2004] [Indexed: 11/17/2022] Open
Abstract
So far, there is very limited knowledge about the role of Eph kinases, the largest family of receptor tyrosine kinases, in the immune system. Here, using EphB6(-/-) mice, we demonstrated that in vitro and in vivo T cell responses such as lymphokine secretion, proliferation, and the development of delayed-type skin hypersensitivity and experimental autoimmune encephalitis in EphB6(-/-) mice were compromised. On the other hand, humoral immune responses, such as serum levels of different Ig isotypes and IgG response to tetanus toxoid, were normal in these mice. Mechanistically, we showed that EphB6 migrated to the aggregated TCRs and rafts after TCR activation. Further downstream, in the absence of EphB6, ZAP-70 activation, LAT phosphorylation, the association of PLCgamma1 with SLP-76, and p44/42 MAPK activation were diminished. Thus, we have shown that EphB6 is pivotal in T cell function.
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MESH Headings
- Animals
- Antigens/metabolism
- Antigens, CD/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Biotinylation
- CD28 Antigens/biosynthesis
- CD3 Complex/biosynthesis
- Cell Proliferation
- Cytokines/biosynthesis
- Dose-Response Relationship, Drug
- Exons
- Female
- Flow Cytometry
- Gene Deletion
- Green Fluorescent Proteins/metabolism
- Immunoglobulin Class Switching
- Lectins, C-Type
- Leukocytes/metabolism
- Ligands
- Lymphocytes/metabolism
- Mice
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Models, Genetic
- Mutation
- Polymerase Chain Reaction
- Receptor, EphB6/genetics
- Receptor, EphB6/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Interleukin-2/biosynthesis
- Signal Transduction
- Spleen/metabolism
- T-Lymphocytes/metabolism
- Thymus Gland/metabolism
- Time Factors
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Affiliation(s)
- Hongyu Luo
- Laboratory of Immunology, Centre de Recherché, Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Pavilion DeSève, 1560 Sherbrooke Street East, Montréal, Quebec H2L 4M1, Canada
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Yu G, Luo H, Wu Y, Wu J. EphrinB1 Is Essential in T-cell-T-cell Co-operation during T-cell Activation. J Biol Chem 2004; 279:55531-9. [PMID: 15502157 DOI: 10.1074/jbc.m410814200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eph kinases are the largest family of receptor tyrosine kinases, and their ligands are ephrins (EFNs), which are also cell surface molecules. We have very limited knowledge about the expression and function of these kinases and their ligands in the immune system. In this study we investigated the effect of EFNB1 on mouse T-cells. EFNB1 and the Eph kinases it interacts with (collectively called EFNB1 receptors (EFNB1R)) were expressed on T-cells, B cells, and monocytes/macrophages. Some T-cells were double positive for EFNB1 and EFBB1R. Solid phase EFNB1 in the presence of suboptimal TCR ligation augmented T-cell responses in terms interferon-gamma secretion, proliferation, and cytotoxic T lymphocyte activity but not interleukin-2 production. After T-cell receptor (TCR) ligation, EFNB1R congregated to TCR caps, and then both of them translocated to raft caps. This provides a morphological basis for EFNB1R to enhance TCR signaling. Further downstream of the signaling pathway, EFNB1R stimulation led to increased LAT (linker for activation of T-cells) phosphorylation and p44/42 and p38 MAPK activation. Similar to CD28 costimulation, EFNB1R costimulation was insensitive to cyclosporin A inhibition. On the other hand, unlike the former, EFNB1R costimulation failed to activate Akt, which is essential in triggering interleukin-2 production. Our study suggests that EFNB1 is pivotal in T-cell-T-cell costimulation and in reducing T-cell response threshold to antigen stimulation.
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Affiliation(s)
- Guang Yu
- Laboratory of Immunology, Notre-Dame Hospital, Centre Hospitalier de l'Universite de Montreal, Pavilion DeSève, 1560 Sherbrooke Street East, Montreal H2L 4M1, Quebec, Canada
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Lorenz M, Regele H, Schillinger M, Exner M, Rasoul-Rockenschaub S, Wahrmann M, Kletzmayr J, Silberhumer G, Hörl WH, Böhmig GA. Risk Factors for Capillary C4d Deposition in Kidney Allografts: Evaluation of a Large Study Cohort. Transplantation 2004; 78:447-52. [PMID: 15316375 DOI: 10.1097/01.tp.0000128344.94808.03] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Capillary deposition of the complement split product C4d has turned out to be a valuable marker of antibody-mediated rejection. The impact of pre- and posttransplant variables including particular immunosuppressive regimens on the frequency of C4d deposition has not yet been systematically investigated in a large multivariate analysis. METHODS In this retrospective study, the authors evaluated the incidence of C4d deposition in 388 kidney transplant recipients subjected to diagnostic biopsy within the first 6 months and analyzed the influence of potential confounders on the rate of C4d-positive graft dysfunction by applying multivariate logistic regression. RESULTS Sixty-six recipients (17%) developed linear C4d deposits in at least a quarter of peritubular capillaries, a finding associated with inferior 1-year allograft survival (73% vs. 88% in C4d-negative patients, P=0.0003). A 50% reduction in the odds of C4d-positive graft dysfunction was found if calcineurin inhibitor or mycophenolate mofetil (MMF) therapy was started 2 to 4 hr before transplantation when compared with initiation after surgery (adjusted odds ratio [OR], 0.5; P=0.03). No differences with respect to C4d staining results were found for the use of tacrolimus, MMF, or sirolimus, or for cyclosporine C2 monitoring. Retransplantation (OR, 3.6; P<0.001) and presensitization (OR, 3.1; P=0.002) turned out to be strong independent risk factors for C4d deposition. CONCLUSIONS The authors' results suggest a reduced risk of C4d-positive graft dysfunction for patients receiving immunosuppression before transplantation. Apart from first dose timing, no influence of particular immunosuppressive strategies on C4d staining results was found.
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Affiliation(s)
- Matthias Lorenz
- Department of Internal Medicine III, University of Vienna, Vienna, Austria
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18
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Wu Y, Han B, Luo H, Shi G, Wu J. Dipeptide Boronic Acid, a Novel Proteasome Inhibitor, Prevents Islet-Allograft Rejection. Transplantation 2004; 78:360-6. [PMID: 15316363 DOI: 10.1097/01.tp.0000128855.10397.db] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND We have demonstrated previously in vitro that proteasome inhibitors suppress the proliferation, and induce the apoptosis, of activated T cells. This implies that they could be used as a novel category of immunosuppressants to block allograft rejection. Therefore, in this study, dipeptide boronic acid (DPBA) was tested for its effect on mouse islet transplantation. METHODS First, DPBA was investigated in vitro for its effect on mouse mixed lymphocyte reaction (MLR) and cytotoxic T-lymphocyte (CTL) activity. DPBA was then used in vivo to treat mouse islet-allograft rejection. RESULTS Both MLR and CTL were dose dependently suppressed by the proteasome inhibitor. A 17-day DPBA regimen resulted in islet-allograft survival in 50% of the recipients for a duration of up to 60 days, whereas the control group without immunosuppressants rejected the islet graft in 7 days. DPBA showed moderate side effects according to blood biochemistry; the function of endogenous islets after treatment appeared normal on glucose challenge. CONCLUSIONS The proteasome inhibitor could inhibit islet-allograft rejection in mice without serious side effects at therapeutic dose levels. This has opened a new dimension in the development of better immunosuppression regimens for islet transplantation.
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Affiliation(s)
- Yulian Wu
- Laboratory of Immunology, Centre hospitalier de l'Universite de Montreal (CHUM)-Notre Dame Hospital, Montreal, Quebec, Canada
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Yu G, Luo H, Wu Y, Wu J. Mouse EphrinB3 Augments T-cell Signaling and Responses to T-cell Receptor Ligation. J Biol Chem 2003; 278:47209-16. [PMID: 13679370 DOI: 10.1074/jbc.m306659200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ephrins (EFN) are cell-surface ligands of Ephs, the largest family of cell-surface receptor tyrosine kinases. The function of EFNs in the immune system has not been well studied, although some EFNs and Ephs are expressed at high levels on certain leukocytes. We report here that EFNB3 and its receptors (collectively called EFNB3Rs, as EFNB3 binds to multiple EphBs) were expressed in peripheral T cells and monocytes/macrophages, with T cells being the dominant EFNB3+ and EFNB3R+ cell type. Solid-phase EFNB3-Fc in the presence of suboptimal anti-CD3 crosslinking enhanced T-cell responses in terms of proliferation, activation marker expression, interferon-gamma but not interleukin-2 production, and cytotoxic T-cell activity. EFNB3R costimulation in the presence of phorbol 12-myristate 13- acetate was insensitive to cyclosporin A, similar to CD28 costimulation, suggesting they might share a part of the signaling pathway. After crosslinking, T-cell receptor and EFNB3R congregated into aggregated rafts, and this provided a morphological basis for signaling pathways of T-cell receptor and EFNB3R to interact. Solid-phase EFNB3-Fc augmented p38 and p44/42 MAPK activation further downstream of the signaling pathway. These data suggest that EFNB3 is important in T-cell/T-cell and T-cell/antigen-presenting cell collaboration to enhance T-cell activation and function.
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Affiliation(s)
- Guang Yu
- Laboratory of Immunology and the Nephrology Service of Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Quebec H2L 4M1, Canada
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20
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Yu G, Luo H, Wu Y, Wu J. Ephrin B2 induces T cell costimulation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:106-14. [PMID: 12816988 DOI: 10.4049/jimmunol.171.1.106] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eph kinases form the largest family of receptor tyrosine kinases, and their ligands are ephrins (EFNs), which are cell surface proteins. Some Eph kinases and EFNs are expressed on T cells, B cells, and dendritic cells, but their functions in the immune system are largely unknown. In this study, we investigated the effect of EFNB2 on murine T cells. EFNB2 mRNA was expressed in the cortex of the thymus and white pulp of the spleen. At the protein level, it was expressed on T cells and monocytes/macrophages, but not on B cells. EFNB2Rs were expressed mainly on T cells. Solid-phase EFNB2 along with suboptimal anti-CD3 strongly stimulated T cell proliferation, with concomitant augmentation of IFN-gamma but not IL-2 or IL-4 secretion. The activity of cytotoxic T cells was also significantly enhanced in the presence of solid-phase EFNB2. These results indicate that EFNB2R cross-linking results in costimulation of T cells. EFNB2Rs were normally scattered on the T cell surface; after TCR cross-linking, they rapidly congregated to capped TCR complexes and then to patched rafts. This provides a morphological base for EFNB2Rs to participate in T cell costimulation. We also demonstrated that EFNB2R signaling led to augmented p38 and p44/42 mitogen-activated protein kinase activation. Our study shows that EFNB2 plays important roles in immune regulation.
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Affiliation(s)
- Guang Yu
- Laboratory of Immunology and. Nephrology Service, Notre Dame Hospital, Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montreal, Canada
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21
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Fernández-Fresnedo G, Pastor JM, López-Hoyos M, Ruiz JC, Zubimendi JA, Gonzalez-Cotorruelo J, Rodrigo E, De Francisco ALM, Arias M. Relationship of donor-specific class-I anti-HLA antibodies detected by ELISA after kidney transplantation on the development of acute rejection and graft survival. Nephrol Dial Transplant 2003; 18:990-5. [PMID: 12686676 DOI: 10.1093/ndt/gfg068] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The objective of this study was to evaluate the role of post-transplant donor-specific anti-HLA antibodies (DS-HLA Abs) detected by an ELISA method on long-term graft survival. METHODS The serum pre-/post-transplant profile of anti-HLA Abs was analysed in 71 renal transplant patients by ELISA. The HLA specificity of positive sera was analysed by a different ELISA method. According to the results, patients were classified into two different groups: those who either developed DS-HLA Abs or significantly increased their panel-reactive antibody (PRA) (group A) and those who did not (group B). RESULTS Thirteen out of 71 patients showed post-transplant DS-HLA Abs and were included in group A, whereas the remaining 58 were placed in group B. The incidence of acute rejection (AR) was significantly higher in group A than in group B (77 vs 10%). In addition, seven out of eight patients from group A had graft loss secondary to AR, whereas one of nine grafts lost in group B was due to AR. When analysing the clinical outcome according to HLA class specificity, only patients with HLA-I Abs lost their grafts due to vascular AR. The remaining patients with HLA-II Abs who lost their grafts also had HLA-I Abs. In four of the eight patients who lost their grafts, DS HLA-I Abs were detected several days before AR. CONCLUSIONS The detection of DS HLA-I Abs in the post-transplant period may provide a good marker for AR and graft loss due to immunological origin. Monitorization of these Abs by ELISA may be a useful tool for tailoring immunosuppression after kidney transplantation.
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Affiliation(s)
- Gema Fernández-Fresnedo
- Nephrology Unit, Marqués de Valdecilla University Hospital, University of Cantabria, E-39008 Santander, Spain
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22
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Wan X, Zhang J, Luo H, Shi G, Kapnik E, Kim S, Kanakaraj P, Wu J. A TNF family member LIGHT transduces costimulatory signals into human T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:6813-21. [PMID: 12471113 DOI: 10.4049/jimmunol.169.12.6813] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DcR3/TR6 is a secreted protein belonging to the TNFR family. It binds to Fas ligand, LIGHT, and TL1A, all of which are TNF family members. LIGHT is expressed on activated T cells. Its known receptors are TR2 and LTbetaR on the cell surface, and TR6 in solution. In the present study, we report soluble TR6-Fc or solid-phase TR6-Fc costimulated proliferation, lymphokine production, and cytotoxicity of human T cells in the presence of TCR ligation. These costimulating effects were blocked by soluble LIGHT but not by soluble Fas-Fc. TR6-Fc could also effectively costimulate gld/gld mouse T cells. We further demonstrated that TR6 bound to both Th1 and Th2 cells, according to flow cytometry, and that the association was inhibited by soluble LIGHT. Cross-linking Th1 and Th2 cells with solid-phase TR6-Fc along with a suboptimal concentration of anti-CD3 enhanced proliferation of both Th1 and Th2 cells, and augmented Th1 but not Th2 lymphokine production. These data suggest that TR6 delivers costimulation through its ligand(s) on the T cell surface, and at least the major part of such costimulation is via LIGHT.
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MESH Headings
- Adjuvants, Immunologic/metabolism
- Adjuvants, Immunologic/physiology
- Adult
- Animals
- Cell Differentiation/immunology
- Cells, Cultured
- Dose-Response Relationship, Immunologic
- Humans
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Ligands
- Lymphocyte Activation/immunology
- Lymphokines/biosynthesis
- Membrane Glycoproteins/metabolism
- Membrane Glycoproteins/physiology
- Membrane Proteins/biosynthesis
- Membrane Proteins/metabolism
- Membrane Proteins/physiology
- Mice
- Mice, Inbred C57BL
- Mitogens/pharmacology
- Protein Binding/immunology
- Receptors, Cell Surface/metabolism
- Receptors, Cell Surface/physiology
- Receptors, Tumor Necrosis Factor
- Receptors, Tumor Necrosis Factor, Member 6b
- Signal Transduction/immunology
- Solubility
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocytes, Cytotoxic/cytology
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Th2 Cells/immunology
- Th2 Cells/metabolism
- Tumor Necrosis Factor Ligand Superfamily Member 14
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/physiology
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Affiliation(s)
- Xiaochun Wan
- Laboratory of Transplantation Immunology, Center Hospitalier de l'Universite de Montreal, University of Montreal, Montreal, Quebec, Canada
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23
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Shi G, Luo H, Wan X, Salcedo TW, Zhang J, Wu J. Mouse T cells receive costimulatory signals from LIGHT, a TNF family member. Blood 2002; 100:3279-86. [PMID: 12384428 DOI: 10.1182/blood-2002-05-1404] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
LIGHT is a tumor necrosis factor (TNF) family member and is expressed on activated T cells. Its known receptors are TR2 and LTbetaR on the cell surface, and TR6/DcR3 in solution. TR6/DcR3 is a secreted protein belonging to the TNF receptor family. It binds to Fas ligand (FasL), LIGHT, and TL1A, all of which are TNF family members. In the present study, we report that solid-phase TR6-Fc costimulated proliferation, lymphokine production, and cytotoxicity of mouse T cells upon T-cell receptor (TCR) ligation. A monoclonal antibody against LIGHT similarly costimulated mouse T cells in their proliferation response to TCR ligation. These data suggest LIGHT, although a ligand, can receive costimulation when expressed on the T-cell surface. Mechanistically, when T cells were activated by TCR and CD28 co-cross-linking, TCR and rafts rapidly formed caps where they colocalized. LIGHT rapidly congregated and colocalized with the aggregated rafts. This provided a molecular base for the signaling machinery of LIGHT to interact with that of TCR. Indeed, LIGHT cross-linking enhanced p44/42 mitogen-activated protein kinase activation after TCR ligation. This study reveals a new function and signaling event of LIGHT.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- CD3 Complex/immunology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Cytotoxicity, Immunologic
- Enzyme Inhibitors/pharmacology
- Flavonoids/pharmacology
- Humans
- Interferon-gamma/metabolism
- Interleukin-2/metabolism
- Lymphocyte Activation
- MAP Kinase Signaling System
- Membrane Glycoproteins/metabolism
- Membrane Microdomains/immunology
- Membrane Proteins/immunology
- Membrane Proteins/physiology
- Mice
- Receptor Aggregation
- Receptors, Antigen, T-Cell/immunology
- Receptors, Cell Surface/metabolism
- Receptors, Tumor Necrosis Factor
- Receptors, Tumor Necrosis Factor, Member 6b
- Species Specificity
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- Tumor Necrosis Factor Ligand Superfamily Member 14
- Tumor Necrosis Factor-alpha/immunology
- Tumor Necrosis Factor-alpha/physiology
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Affiliation(s)
- Guixiu Shi
- Laboratory of Transplantation Immunology, Research Center, Centre hospitalier de l'Universite de Montreal (CHUM)-Notre Dame Hospital, Pavilion DeSeve, 1560 Sherbrooke Street E., Montreal, Quebec H2L 4M21, Canada
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24
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Luo H, Yu G, Wu Y, Wu J. EphB6 crosslinking results in costimulation of T cells. J Clin Invest 2002. [DOI: 10.1172/jci0215883] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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25
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Luo H, Yu G, Wu Y, Wu J. EphB6 crosslinking results in costimulation of T cells. J Clin Invest 2002; 110:1141-50. [PMID: 12393850 PMCID: PMC150798 DOI: 10.1172/jci15883] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Erythropoietin-producing hepatocyte (Eph) kinases represent the largest receptor tyrosine kinase family. Some of them are expressed in the T cell compartment, but their function in T cells is unknown. In peripheral blood, EphB6 was predominantly expressed on T cells, and was upregulated after culture. EphB6 crosslinking by anti-EphB6 mAb or ephrinB2 in the presence of suboptimal T cell receptor (TCR) stimulation led to drastic T cell proliferation, suggesting that EphB6 can co-stimulate T cells. The proliferation was accompanied by enhanced production of several lymphokines, such as IFN-gamma, IL-6, IL-10, TGF-beta, TNF-alpha, and GM-CSF, but not IL-2 and IL-4. Sorted EphB6(+) T cells had significantly stronger response to anti-CD3 and anti-CD28 stimulation than EphB6(-) T cells had. Taken together, these data suggest an important role of EphB6 in normal T cell activation. Within two minutes of anti-CD3 and anti-CD28 stimulation, EphB6 aggregated and colocalized with TCR, and this provides a morphological basis for EphB6 to enhance TCR signaling. The capping was followed by p38 MAPK activation, showing that EphB6 is capable of signaling, in spite of its lack of intrinsic kinase activity. This study demonstrates that interaction between EphB6 and its ligands facilitates T cell responses to antigen.
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Affiliation(s)
- Hongyu Luo
- Laboratory of Transplantation Immunology, Centre Hospitalier de l'Universite de Montreal, University of Montreal, Pavilion DeSève, 1560 Sherbrooke Street East, Montreal, Quebec H2L 4M1, Canada
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26
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Benito AI, Furlong T, Martin PJ, Anasetti C, Appelbaum FR, Doney K, Nash RA, Papayannopoulou T, Storb R, Sullivan KM, Witherspoon R, Deeg HJ. Sirolimus (rapamycin) for the treatment of steroid-refractory acute graft-versus-host disease. Transplantation 2001; 72:1924-9. [PMID: 11773890 DOI: 10.1097/00007890-200112270-00010] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND In a pilot trial we evaluated the toxicity and efficacy of sirolimus (rapamycin) as second-line therapy for the treatment of acute graft-versus-host disease (GVHD) in 21 patients (1-46 years of age) after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS All patients were treated with methylprednisolone at 2 mg/kg/day, but failed to respond satisfactorily. Sirolimus was started 19-78 (median 37) days after HSCT when 10 patients had grade III and 11 had grade IV GVHD. The first four patients received a loading dose (15 mg/m2) of oral sirolimus on day 1 followed by 5 mg/m2/day for 13 days. The next 17 patients received either 5 (n=7) or 4 (n=10) mg/m2/day for 14 days without a loading dose. Eleven patients completed the 14-day sirolimus course. Five patients were treated for 9-13 days, two for 6 days, and three for 1-3 days. RESULTS Sirolimus was discontinued early in 10 patients because of lack of improvement in GVHD (n=5), myelosuppression (n=2), seizure (n=2), and attending physician preference (n=1). The most common and significant adverse events were thrombocytopenia (n=7) and neutropenia (n=4). Other side effects included increased blood triglycerides (n=8) and cholesterol (n=3). Five patients had evidence of a hemolytic uremic syndrome concurrently with or after sirolimus treatment. Eighteen of the 21 patients received 6 or more doses of sirolimus and 12 responded, 5 with complete and 7 with partial responses. Six of the 12 responders (28% of all patients enrolled) and 1 nonresponder are currently alive at 400-907 days after HSCT, 3 with chronic GVHD. Fourteen of the 21 patients (66%) died 40-263 days after transplant. CONCLUSION These data suggest that sirolimus has activity in the treatment of steroid-refractory acute GVHD. However, there was considerable toxicity and further dose optimization studies seem warranted.
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Affiliation(s)
- A I Benito
- Clinical Research Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave., North, D1-100, P.O. Box 19204, Seattle, WA 98109-1204, USA
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27
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Luo H, Wan X, Wu Y, Wu J. Cross-linking of EphB6 resulting in signal transduction and apoptosis in Jurkat cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:1362-70. [PMID: 11466354 DOI: 10.4049/jimmunol.167.3.1362] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eph kinases are the largest family of receptor tyrosine kinases (RTK), and their ligands are cell surface molecules. The known functions of Eph kinases are mainly pattern formation in the CNS. Although several Eph kinases are expressed at high levels in hemopoietic cells and in the thymus, we have no knowledge of the functions of any Eph kinase in the immune system. In this study, we have demonstrated that an Eph kinase, EphB6, was expressed at high levels in Jurkat leukemic T cells. Co-cross-linking of EphB6 and CD3 led to an altered profile of lymphokine secretion along with proliferation inhibition of Jurkat cells. The cells subsequently underwent Fas-mediated apoptosis. Although EphB6 has no intrinsic kinase activity, its cross-linking triggered general protein tyrosine phosphorylation in Jurkat cells. EphB6 was found to associate with a number of molecules in the signaling pathways, notably Cbl. EphB6 cross-linking resulted in Cbl dephosphorylation and dissociation from Src homology 2 domain-containing tyrosine phosphatase-1 (SHP-1). Our results show that EphB6 has important functions in T cells, and it can transduce signals into the cells via proteins it associates with.
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Affiliation(s)
- H Luo
- Research Center, Notre-Dame Hospital, University of Montreal, 1560 Sherbrooke Street East, Montreal, Quebec H2l 4M1, Canada
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28
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Abstract
The proteasome is a multicatalytic complex of proteases involved in T lymphocyte proliferation and activation through multiple mechanisms. In this study, we investigated its role in lymphocyte aggregation. We found that blocking proteasome activity by a proteasome-specific inhibitor lactacystin (LAC) prevented clustering of T lymphocytes after stimulation with various mitogens. Expression of adhesion molecules ICAM-1 and LFA-1 at cell surfaces of activated T cells was decreased after treatment with LAC. Mechanisms by which the proteasome intervenes in the expression of these adhesion molecules were different. LAC inhibited ICAM-1 expression at the mRNA level, whereas LFA-1 inhibition was probably at a post-translational level. Downregulation of these molecules after proteasome inhibition likely contributes to the observed repression of T cell aggregation. Our results show that the proteasome plays an important role in cell-cell interaction during T cell activation.
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Affiliation(s)
- N Kanaan
- Research Center, Notre-Dame Hospital, CHUM, University of Montreal, Montreal, Canada
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29
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Cronin DC, Faust TW, Brady L, Conjeevaram H, Jain S, Gupta P, Millis JM. Modern immunosuppression. Clin Liver Dis 2000; 4:619-55, ix. [PMID: 11232165 DOI: 10.1016/s1089-3261(05)70130-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The current treatment of posttransplant lymphoproliferative disease (PTLD) includes prophylaxis at the time of transplant, decreasing or stopping immunosuppresion and initiation of antiviral therapy in patients with polymerase chain reaction or clinical evidence of PTLD, and judicial reintroduction of immunosuppression in patients who have cleared their PTLD and have begun to have rejection. The pharmacology, pharmacokinetics, notable side effects, and toxicities of the immunosuppressive agents are described in this article. At the conclusion of each section the author's current practice with these agents and treatment strategies are described.
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Affiliation(s)
- D C Cronin
- Section of Transplant Surgery, Department of Surgery, University of Chicago, Chicago, Illinois, USA
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30
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Chen H, Peng J, Luo H, Loubeau M, Wan X, Xu D, Qi S, Vu MD, Daloze P, Fitzsimmons WE, Bekersky I, Peets J, Sehgal SN, Wu J. Compromised kidney graft rejection response in Vervet monkeys after withdrawal of immunosuppressants tacrolimus and sirolimus. Transplantation 2000; 69:1555-61. [PMID: 10836361 DOI: 10.1097/00007890-200004270-00006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND In nonprimates, organ allografts are often not rejected after withdrawal of immunosuppression. In this study, we examined whether such a phenomenon also occurs in primates. METHODS Vervet monkeys were transplanted with renal allografts and treated for 60 days with tacrolimus, or tacrolimus plus sirolimus. The drugs were totally withdrawn on day 61. The survival of the monkeys was monitored, and their response to donor- or third party-derived alloantigens was examined in vivo and in vitro. RESULTS The majority (80-100%) of the grafts survived for at least additional 30 days with no signs of acute rejection. The compromised rejection is donor-specific, because recipient monkeys failed to reject a donor-derived skin graft, but a third-party skin graft was rejected. In vitro mixed lymphocyte reaction and interleukin-2 production in the mixed lymphocyte reaction between the recipients and their donors or between the recipients and a third party had no discernable patterns, and thus did not reflect the in vivo status of the immune system. Although the recipients could not reject the graft acutely after drug withdrawal, the kidney grafts and the donor-derived skin grafts had pathological findings of chronic rejection. CONCLUSIONS The rejection response of the monkeys to an established graft after withdrawal of immunosuppression is compromised. The compromised rejection is specific and is not due to a permanent alteration of the immune system by the initial drug treatment. The allografts are not inert but have low levels of interaction with the recipient immune system.
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Affiliation(s)
- H Chen
- The Research Center, CHUM, University of Montreal, Quebec, Canada
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Qi S, Xu D, Peng J, Vu MD, Wu J, Bekersky I, Fitzsimmons WE, Peets J, Sehgal S, Daloze P, Chen H. Effect of tacrolimus (FK506) and sirolimus (rapamycin) mono- and combination therapy in prolongation of renal allograft survival in the monkey. Transplantation 2000; 69:1275-83. [PMID: 10798741 DOI: 10.1097/00007890-200004150-00012] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Our previous studies confirmed that tacrolimus (FK506) and sirolimus [rapamycin (RAPA)], in combination, are not antagonistic but are synergistic in the prolongation of heart and small bowel grafts in the rodent. The aim of this study was to confirm further the synergistic effect of combined FK506 and RAPA in the more clinically relevant model, kidney transplantation in monkeys. METHODS A total of 60 male Vervet monkeys were randomly assigned to 10 groups (n> or =5). Monkeys with renal allografts were treated with different doses of FK506 and/or RAPA orally for 60 days. Graft survival, body weight, clinical biochemistry determinations, oral glucose tolerance test, trough levels of the two drugs, and histopathology were investigated. RESULTS Low doses of FK506 (1 or 4 mg/kg) combined with RAPA (0.5 mg/kg) produced synergistic effect in the prolongation of renal graft survival [combination index (CI) = 0.292, 0.565]. There were no additive or synergistic drug-associated toxicities such as hyperglycemia, nephrotoxicity, and hyperlipidemia. There also was no pharmacological antagonism. CONCLUSION Concomitant therapy of low-dose (drug-optimal) FK506 and RAPA produced a synergistic effect in the prolongation of kidney allograft survival in Vervet monkeys without additive drug-associated toxicities.
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Affiliation(s)
- S Qi
- Laboratories of Experimental Surgery and Transplantation Immunology, University of Montreal, Notre-Dame Hospital, Quebec, Canada
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Vu MD, Qi S, Xu D, Wu J, Peng J, Daloze P, Sehgal S, Leduc B, Chen H. Synergistic effects of mycophenolate mofetil and sirolimus in prevention of acute heart, pancreas, and kidney allograft rejection and in reversal of ongoing heart allograft rejection in the rat. Transplantation 1998; 66:1575-80. [PMID: 9884242 DOI: 10.1097/00007890-199812270-00002] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The effect of mycophenolate mofetil (MMF) and sirolimus (rapamycin, RAPA) mono- and combination-therapy was examined in prevention of acute heart, pancreas, and kidney allograft rejection and in reversal of ongoing heart allograft rejection in the rat. METHODS Both drugs were administered orally for up to 30 days. Eleven groups (n=6) were involved in the first part of the heart allografting model. Brown Norway (RT1n) to Lewis (RT1(1)) combination was used in the heart and pancreas transplantation models, whereas Buffalo (RT1b) to Wistar Furth (RT1u) was used in the kidney transplantation model. RESULTS The naive control group showed a mean survival time of 6.5+/-0.6 days. There were graded dose-responses to monotherapy of MMF 10 and 20 mg(kg/ day (12.5+/-2.6 days; 19.3+/-9.0 days) and RAPA 0.2, 0.4, 0.8, and 1.8 mg/kg/day (19.2+/-2.0 days; 30.0+/-7.3 days; 50.8+/-12.5 days; 51.2+/-2.6 days), respectively (P=0.001). Results with the combined use of drugs indicate that a synergistic or very strong synergistic interaction was produced when compared with monotherapy of MMF or RAPA: MMF 10 mg(kg/day+RAPA 0.2 mg/kg(day (52.7+/-5.7 days, combination index [CI] =0.189), MMF 20 mg(kg/day+RAPA 0.2 mg/kg/day (57.7+/-5.7 days, CI=0.084), MMF 10 mg/kg/day+RAPA 0.4 mg(kg/day (50.2+/-13.5 days, CI=0.453), and MMF 20 mg/kg(day+ RAPA 0.4 mg/kg(day (51.5+/-6.8 days, CI=0.439), respectively. These results were repeatable in the prevention of acute pancreas and kidney allograft rejection in the rat. In the second part of the study of reversal of ongoing acute heart allograft rejection model, the combined treatment of MMF 10 mg/kg(day+RAPA 0.2 mg/ kg(day (35.5+/-16.0 days, CI=0.794) and MMF 20 mg/kg day+RAPA 0.2 mg(kg/day (57.2+/-4.7 days, CI=0.310) represented synergistic interaction compared with monotherapy of MMF or RAPA. CONCLUSIONS Concomitant therapy of MMF and RAPA produces a synergistic effect in prevention of heart, pancreas, and kidney allograft rejection and in reversal of ongoing heart allograft rejection in the rat.
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Affiliation(s)
- M D Vu
- Laboratory of Experimental Surgery, Research Center of CHUM, Notre-Dame Hospital, University of Montreal, Quebec, Canada
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Trepanier DJ, Gallant H, Legatt DF, Yatscoff RW. Rapamycin: distribution, pharmacokinetics and therapeutic range investigations: an update. Clin Biochem 1998; 31:345-51. [PMID: 9721433 DOI: 10.1016/s0009-9120(98)00048-4] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Based on the findings above, a number of conclusions can be made regarding the distribution, pharmacokinetics, and therapeutic range investigations with RAPA: (a) the majority of the drug is sequestered in erythrocytes, resulting in whole blood concentrations being considerably higher than plasma concentrations; (b) the drug is metabolized by the same cytochrome P450 3A enzyme involved in the metabolism of CsA and FK506. Metabolites are primarily simple demethylations and hydroxylations with 41-O-demethyl RAPA being the major metabolite both in vivo and in vitro; (c) the drug has a relatively long half-life in both humans and animals with 24-h trough concentrations being within the analytical range of HPLC when immunosuppressive doses are administered; (d) the drug exhibits a degree of proportionality between trough concentrations and dose; (e) a strong correlation exists between area under the concentration-time curve and trough blood concentration at steady state; (f) trough concentrations of the drug appear to be related to immunosuppressive efficacy and drug-related side effects; (g) the nephro- and neurotoxic properties of CsA are not augmented by concurrent treatment with RAPA; and (h) phase IIB trial results have shown a decrease of acute rejection episodes from 40% to < 10% among patients treated with full-dose CsA plus RAPA. The studies described here should provide a basis for the establishment of therapeutic monitoring protocols for RAPA. In addition, new derivatives of RAPA, such as SDZ RAD, designed to overcome formulation problems associated with RAPA, while maintaining similar pharmacokinetics and in vivo activity, show promise as alternatives to RAPA.
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Wang X, Luo H, Chen H, Duguid W, Wu J. Role of Proteasomes in T Cell Activation and Proliferation. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.2.788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The role of proteasomes in T cell activation, proliferation, and apoptosis was investigated using a proteasome-specific inhibitor lactacystin (LAC). Inhibition of the proteasome activity by LAC repressed the mitogen-induced T cell proliferation. The proteasome activity was definitively required for the T cells to progress from the G0 to S phase. It was necessary to optimize the progress from the G1/S boundary to the G2/M phase, but not for the progress from the G2/M phase to the next G1 phase. Probably as a result of a blockage of cell cycle progress, the cycling, but not the resting, T cells underwent apoptosis when treated with LAC. Mechanistically, we have found that cyclin-dependent kinase-2 (CDK2) and the cyclin E-associated kinase (largely CDK2), but not CDK4, in the G1 phase were strongly inhibited by LAC. This could be an important mechanism for the proteasome to regulate the cell cycle. The degradation of cyclin E in the late G1 and early S phases was dependent on the proteasome, although it was unlikely that this accounted for the observed inhibition of T cell proliferation. There was a reduced decay of p27Kip1 in the late G1 phase when the proteasome activity was suppressed, and this might be a contributing mechanism for the observed inhibition of CDK2 activity. Interestingly, p21Cip1 was up-regulated during the G1 phase, and the up-regulation was inhibited by LAC. Our study shows that the proteasome plays pivotal roles in regulating T cell activation and proliferation, and its effect is probably exerted through multiple mechanisms.
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Affiliation(s)
- Xin Wang
- *Laboratory of Transplantation Immunology, Louis-Charles Simard Research Center, and
| | - Hongyu Luo
- *Laboratory of Transplantation Immunology, Louis-Charles Simard Research Center, and
| | - Huifang Chen
- *Laboratory of Transplantation Immunology, Louis-Charles Simard Research Center, and
| | | | - Jiangping Wu
- *Laboratory of Transplantation Immunology, Louis-Charles Simard Research Center, and
- †Nephrology Service, Notre-Dame Hospital, University of Montreal; and
- §Department of Surgery, McGill University, Montreal, Canada
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Akdis CA, Blesken T, Akdis M, Alkan SS, Heusser CH, Blaser K. Glucocorticoids inhibit human antigen-specific and enhance total IgE and IgG4 production due to differential effects on T and B cells in vitro. Eur J Immunol 1997; 27:2351-7. [PMID: 9341780 DOI: 10.1002/eji.1830270933] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Although anti-inflammatory properties of glucocorticoids (GC) are well documented, their activity in allergic diseases is still controversial. Recently, it has been reported that GC can increase, both in vivo and in vitro, the polyclonal production of total IgE. In this study we investigated the effects of GC on the antigen (Ag)-specific IgE response in a human in vitro system with peripheral blood mononuclear cells or B cells of bee venom-sensitized individuals that allows the production of bee venom phospholipase A2 (PLA)-specific IgE and IgG4 antibodies (Ab). PLA-specific Ab were induced by simultaneously activating T cells and B cells specifically with allergen and polyclonally with anti-CD2 and soluble CD40 ligand (sCD40L) in the presence of interleukin (IL)-4. Indeed, dexamethasone and prednisolone enhanced the formation of total IgE and IgG4 in PBMC, while the production of PLA-specific IgE and IgG4 Ab was selectively inhibited in a dose-dependent manner. The suppressive effect of GC was mediated during Ag-specific stimulation and T cell-B cell interaction. This was due to GC suppressing specific T cell proliferation and cytokine production, whereas neither allergen-specific nor total IgE and IgG4 production by sCD40L/IL-4-stimulated pure B cells was affected. In contrast to GC, cyclosporine A inhibited both total and PLA-specific IgE and IgG4 secretion in peripheral blood mononuclear cells and B cell cultures. Further experiments showed that increase in nonspecific total isotype response resulted from inhibition of IL-4 uptake by cells other than B cells and sufficient availability of IL-4 to B cells for isotype switch and synthesis. Furthermore, demonstration of opposite regulatory effects of GC on specific and total isotype formation in vitro, including the inhibition of allergy-relevant Ag-specific IgE response, may contribute to a better understanding of apparently controversial observations, and explain why most allergic patients benefit from GC therapy.
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Affiliation(s)
- C A Akdis
- Swiss Institute of Allergy and Asthma Research (SIAF), Davos, Switzerland.
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Smith AB, Condon SM, McCauley JA, Leazer JL, Leahy JW, Maleczka RE. A Unified Total Synthesis of the Immunomodulators (−)-Rapamycin and (−)-27-Demethoxyrapamycin: Construction of the C(21−42) Perimeters. J Am Chem Soc 1997. [DOI: 10.1021/ja963066w] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amos B. Smith
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Stephen M. Condon
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - John A. McCauley
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Johnnie L. Leazer
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - James W. Leahy
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Robert E. Maleczka
- Contribution from the Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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Abstract
Rapamycin (RAPA) strongly inhibits lymphocyte activation and proliferation, but does not affect most of the activation-related gene expression at the mRNA level. In order to understand the mechanism of action of RAPA and to gain further insights in lymphocyte signalling which is impaired by RAPA, we screened for RAPA-sensitive genes using differential hybridization. The expression of human aldolase A gene was found to be inducible during T and B cell activation, and the induction was repressed by RAPA at both the mRNA and enzymatic levels. The other two important immunosuppressants, cyclosporin A and FK506, also inhibited the mitogen-induced upregulation. However, none of these three drugs inhibited the constitutive expression. There was no fluctuation of aldolase A expression during the cell cycle, and RAPA failed to block the first cell cycle after synchronization in Jurkat cells. However, the second cycle was hampered by RAPA, and this was correlated with the inhibition of aldolase A expression during this later stage. Since aldolase A is a key enzyme in glycolysis and lymphocytes mainly depend on glycolysis for energy supply, the data from this study suggest that aldolase A might be one of the downstream targets of RAPA. The inhibition of the enzyme upregulation might deprive the cells of additional supply of energy, and prevent the cells from entering an optimal status for proliferation.
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Affiliation(s)
- X Wang
- Laboratory of Transplantation Immunology, Louis-Charles Simard Research Center, Notre-Dame Hospital, Montreal, Quebec, Canada
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Abstract
In the process of identifying genes involved in optimization of lymphocyte activation, we have cloned the human mitochondrial NADP-dependent isocitrate dehydrogenase (mNADP-IDH) cDNA. The cDNA and its deduced amino acid (AA) sequence had a high degree of homology with those of the porcine and bovine. The heart and muscle had the highest constitutive expression of the gene. The expression of steady-state mRNA in the resting T and B lymphocytes was low but was induced after mitogen stimulation. The mRNA levels peaked around 48 h and remained elevated at 72 h. At the protein level, the mitochondrial but not cytosolic NADP-IDH activity was augmented after the mitogen stimulation. There was no cell cycle-dependent fluctuation of mNADP-IDH expression in synchronized Jurkat cells. In T and B cells, rapamycin (RAPA) could repress the mitogen-stimulated mNADP-IDH expression, although most of the early or late phase activation-related genes including a G-protein beta subunit-related gene H12.3 were not affected by the drug. The restricted expression of the gene in certain tissues and the activation-related expression in lymphocytes suggest that this gene might be necessary for optimal functions in heart, muscle, and the activated lymphocytes.
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Affiliation(s)
- H Luo
- Laboratory of Nephrology and Transplantation Immunology, Notre-Dame Hospital Research Center, Montreal, Quebec, Canada
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Yang L, Luo H, Vinay P, Wu J. Molecular cloning of the cDNA of mouse mitochondrial NADP-dependent isocitrate dehydrogenase and the expression of the gene during lymphocyte activation. J Cell Biochem 1996; 60:400-10. [PMID: 8867815 DOI: 10.1002/(sici)1097-4644(19960301)60:3%3c400::aid-jcb11%3e3.0.co;2-o] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The current report documents the molecular cloning of the mouse mitochondrial NADP-dependent isocitrate dehydrogenase (mNADP-IDH) cDNA. The cDNA was 1,863 bp in length and contained one open reading frame encoding a 523-residue polypeptide with a predicted molecular weight of 58 kDa. The cDNA and the deduced amino acid (AA) sequence of the mouse mNADP-IDH had a high degree of homology with those of porcine, bovine, alfalfa, and yeast. The recombinant mNADP-IDH expressed in Escherichia coli had active enzymatic function, as well as an expected molecular weight. The heart had the highest constitutive expression of the steady-state mNADP-IDH mRNA, followed by the kidney, while the expression of the gene in other tissues was low. The enzymatic activity of different tissues was in agreement with their mNADP-IDH mRNA levels. The resting lymphocytes had low constitutive expression of the gene, but the steady-state mRNA could be induced 48 h after mitogen stimulation. At the protein level, the resting lymphocytes had low enzymatic activity of mNADP-IDH, but the activity was augmented fivefold after mitogen stimulation. The cytosolic NADP-IDH, on the contrary, remained low or undetectable before and after the mitogen stimulation. Based on our current findings as well as the known roles of the mNADP-IDH in anabolism and in the isocitrate shuttle, it is conceivable that the mNADP-IDH is necessary for optimizing proliferation in lymphocytes.
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Affiliation(s)
- L Yang
- Department of Medicine, Notre-Dame Hospital Research Center and Nephrology Service, Montreal, Québec, Canada
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Yang L, Luo H, Vinay P, Wu J. Molecular cloning of the cDNA of mouse mitochondrial NADP-dependent isocitrate dehydrogenase and the expression of the gene during lymphocyte activation. J Cell Biochem 1996. [DOI: 10.1002/(sici)1097-4644(19960301)60:3<400::aid-jcb11>3.0.co;2-o] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chen H, Qi S, Xu D, Wu J, Daloze P. The immunosuppressive effect of rapamycin on mouse small bowel transplantation. Transplantation 1996; 61:523-6. [PMID: 8610374 DOI: 10.1097/00007890-199602270-00001] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The efficacy of rapamycin (RAPA) was tested on small bowel transplantation in the mouse and compared with cyclosporine (CsA). Four groups were involved, each one included three combinations (n > or = 6) for evaluation of host-versus-graft (HVG, C57BL/6 X BALB/c F1 (CB6F1)-to-BALB/c), graft-versus-host (GVH, BALB/c-to-CB6F1), and combined HVG and GVH responses (C57BL/6-to-BALB/c). Grafts were transplanted to recipients heterotopically. Groups were as follows: group 1: naive controls; groups 2 and 3: recipient mice treated with RAPA 2 mg/kg/day and 4 mg/kg/day orally for 14 days, respectively; group 4: recipient mouse treated with CsA 4 mg/kg/day orally for 14 days. In the HVG model, the mean survival time (MST) of recipients was significantly longer in group 2 (32.9 +/- 17.7 days, P=0.006), group 3 (32.7 +/- 10.4 days, P=0.0001), and group 4 (37.9 +/- 11.8 days, P=0.0001), compared with naive controls in group 1 (8.5 +/- 1.6 days). In the GHV model, the MST of recipients in group 2 (41.8 +/- 19.9 days, P=0.002), group 3 (48.2 +/- 21.4 days, P=0.001) and group 4 (56.5 +/- 30.6 days, P=0.003) were significantly prolonged compared with control group 1 (8.5 +/- 1.6 days). In combined HVG and GVH responses, MST of recipient in group 2 (20.9 +/- 4.9 days, P=0.0001), group 3 (27.0 +/- 4.3 days, P=0.008), and group 4 (35.2 +/- 23.9 days, P=0.0001) were also significantly longer than that in controls (6.9 +/- 1.4 days), but in all three combinations, there were no statistically significant differences between groups 2 and 3, groups 2 and 4, or groups 3 and 4 (P>0.05). RAPA is a potent immunosuppressant able to significantly prolong small bowel allograft survival in mice using a short-term treatment. There is no statistically significant difference in recipient survival between low and high doses of RAPA treatment and the CsA standard dose used in this study.
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Affiliation(s)
- H Chen
- Laboratories of Experimental Surgery and Transplantation Immunology, Research Center, Notre-Dame Hospital, University of Montreal, Canada
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Aspeslet LJ, Chackowsky P, Sekhon H, Malcolm AJ, Mosleh Z, Koshal A, Yatscoff RW. Identification of porcine membrane antigens involved in the cytotoxic response mediated by human xenoreactive antibodies. Xenotransplantation 1996. [DOI: 10.1111/j.1399-3089.1996.tb00112.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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el-Asrar AM, Tabbara KF, Geboes K, Missotten L, Desmet V. An immunohistochemical study of topical cyclosporine in vernal keratoconjunctivitis. Am J Ophthalmol 1996; 121:156-61. [PMID: 8623884 DOI: 10.1016/s0002-9394(14)70579-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To determine the immunomodulating effects of topical cyclosporine on the immune cells in the conjunctival biopsy specimens obtained from patients with active vernal keratoconjunctivitis. METHODS We studied six patients who had severe active vernal keratoconjunctivitis. Each patient was given topical cyclosporine 2% eyedrops four times daily. A 2 x 2-mm limbal conjunctival biopsy specimen was obtained from each patient before and three weeks after treatment. Using a panel of monoclonal and polyclonal antibodies and immunohistochemical techniques, we analyzed the conjunctival immune cells before and after cyclosporine treatment. RESULTS Three weeks after topical cyclosporine treatment, there was marked clinical improvement and a statistically significant reduction in the number of epithelial and stromal class II MHC+ cells, UCHL1+ T cells, and stromal IgA+ and IgG+ plasma cells. The mean number of cells before and after therapy, respectively, were: class II MHC+ (epithelium), 31.5 +/- 13.1 and 8.3 +/- 5.6 (P = .031); class II MHC+ (stroma), 77.0 +/- 28.7 and 24.7 +/- 17.5 (P = .031); UCHL1+ T cells (epithelium), 24.5 +/- 14.1 and 4.2 +/- 2.9 (P = .031); UCHL1+ T cells (stroma), 78.7 +/- 31.1 and 44.5 +/- 27.5 (P = .031); IgA+ plasma cells, 66.7 +/- 32.1 and 22.2 +/- 7.8 (P = .031); and IgG+ plasma cells, 37.3 +/- 30.0 and 9.0 +/- 6.4 (P = .031). There was a statistically insignificant decrease in the epithelial class II MHC+ dendritic Langerhans cells, epithelial and stromal KP1+ macrophages, stromal OPD4+ helper/inducer T cells, and stromal L26+ B cells. The numbers of IgE+ plasma cells and mast cells were unaltered. CONCLUSION The clinical improvement in vernal keratoconjunctivitis after topical cyclosporine therapy may result from its immunomodulating effect on the components of cell-mediated and humoral immune responses. In contrast, the drug has no immunomodulatory effect on mast cells and IgE-mediated allergic response.
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Affiliation(s)
- A M el-Asrar
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Abstract
Rapamycin has potent immunosuppressive properties reflecting its ability to disrupt cytokine signaling that promotes lymphocyte growth and differentiation. In IL-2-stimulated T cells, rapamycin impedes progression through the G1/S transition of the proliferation cycle, resulting in a mid-to-late G1 arrest. Two major biochemical alterations underlie this mode of action. The first one affects the phosphorylation/activation of the p70 S6 kinase (p70s6k), an early event of cytokine-induced mitogenic response. By inhibiting this enzyme, whose major substrate is the 40S ribosomal subunit S6 protein, rapamycin reduces the translation of certain mRNA encoding for ribosomal proteins and elongation factors, thereby decreasing protein synthesis. A second, later effect of rapamycin in IL-2-stimulated T cells is an inhibition of the enzymatic activity of the cyclin-dependent kinase cdk2-cyclin E complex, which functions as a crucial regulator of G1/S transition. This inhibition results from a prevention of the decline of the p27 cdk inhibitor, that normally follows IL-2 stimulation. To mediate these biochemical alterations, rapamycin needs to bind to intracellular proteins, termed FKBP, thereby forming a unique effector molecular complex. However, neither(p70s6k) inhibition, nor p27-induced cdk2-cyclin E inhibition are directly caused by the FKBP-rapamycin complex. Instead, this complex physically interacts with a novel protein, designated "mammalian target of rapamycin" (mTOR), which has sequence homology with the catalytic domain of phosphatidylinositol kinases and may therefore be itself a kinase. mTOR may act upstream of (p70s6K) and cdk2-cyclin E in a linear or bifurcated pathway of growth regulation. Molecular dissection of this pathway should further unravel cytokine-mediated signaling processes and help devise new immunosuppressants.
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Affiliation(s)
- F J Dumont
- Department of Immunology, Merck Research Laboratories, Rahway, NJ 07065, USA
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Bundick RV, Craggs RI, Holness E. The effect of cyclosporin A, FK506, and rapamycin on the murine chronic graft-versus-host response--an in vivo model of Th2-like activity. Clin Exp Immunol 1995; 99:467-72. [PMID: 7533681 PMCID: PMC1534195 DOI: 10.1111/j.1365-2249.1995.tb05574.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We have evaluated the effects of three potent immunosuppressive agents: cyclosporin A, FK506, and rapamycin, on a murine chronic graft-versus-host response (chronic GVHR). The chronic GVHR has previously been described to be a Th2-like response, and is characterized by a marked splenomegaly and hyper-IgE production in the early stages of the response. The effects of the immunosuppressive agents on both splenomegaly and hyper-IgE were measured 3 weeks after the induction of the chronic GVHR. Rapamycin was found to inhibit both splenomegaly and the hyper-IgE response in a dose-dependent manner. Unexpectedly cyclosporin A and FK506 were found to potentiate markedly both the splenomegaly and hyper-IgE response at low doses before exhibiting an inhibitory effect at higher doses. We propose the differences of activity seen with rapamycin compared with cyclosporin A and FK506 may be explained by their different mechanisms of action, and also by the selectivity of low dose cyclosporin A and FK506 for Th1-like lymphocytes. The implications of these observations are discussed in relation to the use of these immunosuppressives for the treatment of Th2-like diseases.
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Affiliation(s)
- R V Bundick
- Department of Biochemistry, Fisons plc--Pharmaceutical Division, Loughborough, UK
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Rapamycin: Biological and therapeutic effects, binding by immunophilins and molecular targets of action. ACTA ACUST UNITED AC 1994. [DOI: 10.1007/bf02171742] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kim HS, Raskova J, Degiannis D, Raska K. Effects of cyclosporine and rapamycin on immunoglobulin production by preactivated human B cells. Clin Exp Immunol 1994; 96:508-12. [PMID: 8004821 PMCID: PMC1534564 DOI: 10.1111/j.1365-2249.1994.tb06058.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In order to assess the direct effects of cyclosporine A (CsA) and rapamycin on B cells, we utilized a two-segment culture system of highly purified B lymphocytes consisting of induction (activation) in the presence of the formalinized Staphylococcus aureus bacteria and IL-2, and differentiation, respectively, in the presence of various combinations of cytokines. Results show that rapamycin strongly inhibited production of both IgM and IgG measured at the end of the secondary culture supported by IL-2/IL-6, whereas CsA up-regulated the immunoglobulin production. The stimulatory effect of CsA was also observed when preactivated B cells were recultured in absence of any cytokines. These results show that rapamycin and CsA have clearly distinct effects on human B lymphocyte responses in vitro. Rapamycin is a more potent in vitro immunosuppressant of B lymphocytes than CsA. It is effective at significantly lower concentrations, and it does not stimulate either the proliferation or antibody production by preactivated B cells.
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Affiliation(s)
- H S Kim
- Department of Pathology, UMDNJ-Robert Wood Johnson Medical School, Piscataway
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