1
|
Ebrahimi N, Abdulwahid AHRR, Mansouri A, Karimi N, Bostani RJ, Beiranvand S, Adelian S, Khorram R, Vafadar R, Hamblin MR, Aref AR. Targeting the NF-κB pathway as a potential regulator of immune checkpoints in cancer immunotherapy. Cell Mol Life Sci 2024; 81:106. [PMID: 38418707 PMCID: PMC10902086 DOI: 10.1007/s00018-023-05098-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 10/01/2023] [Accepted: 10/29/2023] [Indexed: 03/02/2024]
Abstract
Advances in cancer immunotherapy over the last decade have led to the development of several agents that affect immune checkpoints. Inhibitory receptors expressed on T cells that negatively regulate the immune response include cytotoxic T‑lymphocyte antigen 4 (CTLA4) and programmed cell death protein 1 (PD1), which have been studied more than similar receptors. Inhibition of these proteins and other immune checkpoints can stimulate the immune system to attack cancer cells, and prevent the tumor from escaping the immune response. However, the administration of anti-PD1 and anti-CTLA4 antibodies has been associated with adverse inflammatory responses similar to autoimmune diseases. The current review discussed the role of the NF-κB pathway as a tumor promoter, and how it can govern inflammatory responses and affect various immune checkpoints. More precise knowledge about the communication between immune checkpoints and NF-κB pathways could increase the effectiveness of immunotherapy and reduce the adverse effects of checkpoint inhibitor therapy.
Collapse
Affiliation(s)
- Nasim Ebrahimi
- Genetics Division, Department of Cell and Molecular Biology and Microbiology, Faculty of Science and Technology, University of Isfahan, Isfahan, Iran
| | | | - Atena Mansouri
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Nasrin Karimi
- Department of Biology, Faculty of Basic Science, Islamic Azad University Damghan Branch, Damghan, Iran
| | | | - Sheida Beiranvand
- Department of Biology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Samaneh Adelian
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Roya Khorram
- Bone and Joint Diseases Research Center, Department of Orthopedic Surgery, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Reza Vafadar
- Department of Orthopeadic Surgery, Kerman University of Medical Sciences, Kerman, Iran
| | - Michael R Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein, 2028, South Africa.
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Amir Reza Aref
- Xsphera Biosciences, Translational Medicine Group, 6 Tide Street, Boston, MA, 02210, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA.
| |
Collapse
|
2
|
Effects of Reticuloendotheliosis virus on TLR-3/IFN-Β pathway in specific pathogen-free chickens. Res Vet Sci 2023; 156:36-44. [PMID: 36774696 DOI: 10.1016/j.rvsc.2023.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 07/17/2022] [Accepted: 01/24/2023] [Indexed: 01/31/2023]
Abstract
Birds infected by Reticuloendotheliosis virus (REV) are vulnerable to other microorganisms. This immunosuppression is related to the immune organs (thymus, bursa of Fabricius, and spleen) damaged by REV. The regulation of IFN-β greatly depends on pattern recognition receptor TLR-3 and nuclear factors IRF-7, NF-κB. To address if and how the TLR-3/IFN-β pathway is disturbed by REV, 60 one-day-old specific-pathogen-free chickens were intraperitoneally injected with RE virus dilution (n = 30) or stroke-physiological saline solution (n = 30). At 1, 3, 7, 21, and 28 days post-infection, after collecting thymuses, bursas, and spleens, we monitor the kinetics of TLR-3, IFN-β, NF-κB p65, and IRF-7 at transcriptional and translational levels using qPCR, Western blotting, and ELISA separately. As a result, compared with control chickens, the mRNA levels of TLR-3, IRF-7, and NF-κB p65 showed increasingly differences in the early period of REV infection. Synchronal changes occurred at translation levels. In the latter infection period, a decrease of NF-κB p65 was contemporaneous with a fall in IFN-β at both transcriptional and translational levels in the thymuses and bursas. These data suggest that the changes of IFN-β content are closely related to NF-κB p65 when REV invades chicken central immune organs. That reveals new insights into the immunosuppression mechanism of REV in avian.
Collapse
|
3
|
Wargasetia TL, Ratnawati H, Widodo N. Sea Cucumber Compounds Targeting NF-κB in Cancer Treatment. Bioinform Biol Insights 2022; 16:11779322221091740. [PMID: 35462875 PMCID: PMC9019350 DOI: 10.1177/11779322221091740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 03/16/2022] [Indexed: 01/19/2023] Open
Abstract
Cancer is a major health problem worldwide and the leading cause of death in many countries. It remains challenging to find anticancer treatments that work efficiently for varying types of cancer cells. Several studies revealed that nuclear factor kappa B (NF-κB) is a family of dimeric transcription factors that induce tumor promotion, progression, and therapeutic resistance, providing evidence that NF-kB may be a promising target for cancer drugs. Some research has found that sea cucumber biocompounds have anticancer properties, but further research is essential to confirm anticancer targets. This manuscript discusses the mechanisms of anticancer targeting the NF-κB signaling pathway induced by sea cucumber-derived compounds. Additional database analysis showed the protein targeted by the compounds involved in several pathways related to the NF-κB network. Moreover, SwissADME predicted druglikeliness properties of the active compounds of sea cucumber. The discussion is expected to provide new insight into the promising potential of these marine natural products for the treatment of many different types of cancers.
Collapse
Affiliation(s)
- Teresa Liliana Wargasetia
- Faculty of Medicine, Universitas Kristen Maranatha (Maranatha Christian University), Bandung, Indonesia
| | - Hana Ratnawati
- Faculty of Medicine, Universitas Kristen Maranatha (Maranatha Christian University), Bandung, Indonesia
| | - Nashi Widodo
- Department of Biology, Faculty of Mathematics and Natural Sciences, The University of Brawijaya, Indonesia
| |
Collapse
|
4
|
de Jesús TJ, Ramakrishnan P. NF-κB c-Rel Dictates the Inflammatory Threshold by Acting as a Transcriptional Repressor. iScience 2020; 23:100876. [PMID: 32062419 PMCID: PMC7031323 DOI: 10.1016/j.isci.2020.100876] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 01/11/2020] [Accepted: 01/28/2020] [Indexed: 12/14/2022] Open
Abstract
NF-κB/Rel family of transcription factors plays a central role in initiation and resolution of inflammatory responses. Here, we identified a function of the NF-κB subunit c-Rel as a transcriptional repressor of inflammatory genes. Genetic deletion of c-Rel substantially potentiates the expression of several TNF-α-induced RelA-dependent mediators of inflammation. v-Rel, the viral homologue of c-Rel, but not RelB, also possesses this repressive function. Mechanistically, we found that c-Rel selectively binds to the co-repressor HDAC1 and competitively binds to the DNA mediating HDAC1 recruitment to the promoters of inflammatory genes. A specific point mutation at tyrosine25 in c-Rel's DNA-binding domain, for which a missense single nucleotide variation (Y25H) exists in humans, completely abrogated its ability to bind DNA and repress TNF-α-induced, RelA-mediated transcription. Our findings reveal that the transactivator NF-κB subunit c-Rel also plays a role as a transcriptional repressor in the maintenance of inflammatory homeostasis.
Collapse
Affiliation(s)
- Tristan James de Jesús
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 6526, Wolstein Research Building, 2103 Cornell Road, Cleveland, OH 44106, USA
| | - Parameswaran Ramakrishnan
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 6526, Wolstein Research Building, 2103 Cornell Road, Cleveland, OH 44106, USA; Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; The Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| |
Collapse
|
5
|
Asatryan A, Bazan NG. Molecular mechanisms of signaling via the docosanoid neuroprotectin D1 for cellular homeostasis and neuroprotection. J Biol Chem 2017; 292:12390-12397. [PMID: 28615451 PMCID: PMC5535015 DOI: 10.1074/jbc.r117.783076] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Docosahexaenoic acid, enriched in the brain and retina, generates docosanoids in response to disruptions of cellular homeostasis. Docosanoids include neuroprotectin D1 (NPD1), which is decreased in the CA1 hippocampal area of patients with early-stage Alzheimer's disease (AD). We summarize here how NPD1 elicits neuroprotection by up-regulating c-REL, a nuclear factor (NF)-κB subtype that, in turn, enhances expression of BIRC3 (baculoviral inhibitor of apoptosis repeat-containing protein 3) in the retina and in experimental stroke, leading to neuroprotection. Elucidating the mechanisms of action of docosanoids will contribute to managing diseases, including stroke, AD, age-related macular degeneration, traumatic brain injury, Parkinson's disease, and other neurodegenerations.
Collapse
Affiliation(s)
- Aram Asatryan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana 70112-2223.
| |
Collapse
|
6
|
|
7
|
Hancarova M, Simandlova M, Drabova J, Mannik K, Kurg A, Sedlacek Z. A patient with de novo 0.45 Mb deletion of 2p16.1: The role ofBCL11A,PAPOLG,REL, andFLJ16341in the 2p15-p16.1 microdeletion syndrome. Am J Med Genet A 2013; 161A:865-70. [DOI: 10.1002/ajmg.a.35783] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 10/27/2012] [Indexed: 12/25/2022]
|
8
|
Chan JK, Greene WC. Dynamic roles for NF-κB in HTLV-I and HIV-1 retroviral pathogenesis. Immunol Rev 2012; 246:286-310. [DOI: 10.1111/j.1600-065x.2012.01094.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
9
|
Wood MA, Mukherjee P, Toocheck CA, Walker WH. Upstream stimulatory factor induces Nr5a1 and Shbg gene expression during the onset of rat Sertoli cell differentiation. Biol Reprod 2011; 85:965-76. [PMID: 21734262 DOI: 10.1095/biolreprod.111.093013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Within the testis, each Sertoli cell can support a finite number of developing germ cells. During development, the cessation of Sertoli cell proliferation and the onset of differentiation establish the final number of Sertoli cells and, thus, the total number of sperm that can be produced. The upstream stimulatory factors 1 and 2 (USF1 and USF2, respectively) differentially regulate numerous Sertoli cell genes during differentiation. To identify genes that are activated by USF proteins during differentiation, studies were conducted in Sertoli cells isolated from 5- and 11-day-old rats, representing proliferating and differentiating cells, respectively. Usf1 mRNA and USF1 protein levels were increased between 5 and 11 days after birth. In vitro studies revealed that USF1 and USF2 DNA-binding activity also increased at 11 days for the promoters of four potential target genes, Fshr, Gata4, Nr5a1, and Shbg. Chromatin immunoprecipitation assays confirmed that USF recruitment increased in vivo between 5 and 11 days after birth at the Fshr, Gata4, and Nr5a1 promoters. Expression of Nr5a1 and Shbg, but not of Fshr or Gata4, mRNAs was elevated in 11-day-old Sertoli cells compared with 5-day-old Sertoli cells. Transient transfection of USF1 and USF2 expression vectors up-regulated Nr5a1 and Shbg promoter activity. RNA interference assays demonstrated that USF1 and USF2 contribute to Nr5a1 and Shbg expression in differentiating cells. Together, these data indicate that increased USF levels induce the expression of Nr5a1 and Shbg during the differentiation of Sertoli cells, whereas Fshr and Gata4 expression is not altered by USF proteins during differentiation.
Collapse
Affiliation(s)
- Michelle A Wood
- Center for Research in Reproductive Physiology, Department of Obstetrics, Gynecology, and Reproduction Services, Magee Women's Research Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | |
Collapse
|
10
|
Fraser-Pitt DJ, Cameron P, McNeilly TN, Boyd A, Manson EDT, Smith DGE. Phosphorylation of the epidermal growth factor receptor (EGFR) is essential for interleukin-8 release from intestinal epithelial cells in response to challenge with Escherichia coli O157 : H7 flagellin. MICROBIOLOGY-SGM 2011; 157:2339-2347. [PMID: 21546588 DOI: 10.1099/mic.0.047670-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Enterohaemorrhagic Escherichia coli O157 : H7 is a major foodborne and environmental pathogen responsible for both sporadic cases and outbreaks of food poisoning, which can lead to serious sequelae, such as haemolytic uraemic syndrome. The structural subunit of E. coli O157 : H7 flagella is flagellin, which is both the antigenic determinant of the H7 serotype, an important factor in colonization, and an immunomodulatory protein that has been determined to be a major pro-inflammatory component through the instigation of host cell signalling pathways. Flagellin has highly conserved N- and C-terminal regions that are recognized by the host cell pattern recognition receptor Toll-like receptor (TLR) 5. Activation of this receptor triggers cell signalling cascades, which are known to activate host cell kinases and transcription factors that respond with the production of inflammatory mediators such as the chemokine interleukin-8 (IL-8), although the exact components of this pathway are not yet fully characterized. We demonstrate that E. coli O157 : H7-derived flagellin induces rapid phosphorylation of the epidermal growth factor receptor (EGFR), as an early event in intestinal epithelial cell signalling, and that this is required for the release of the pro-inflammatory cytokine IL-8.
Collapse
Affiliation(s)
- Douglas J Fraser-Pitt
- Biomedical Sciences and Microbiology Group, School of Life, Sport and Social Sciences, Faculty of Health, Life and Social Sciences, Sighthill Campus, Edinburgh Napier University, Edinburgh EH11 4BN, UK
| | - Pamela Cameron
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Amanda Boyd
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Erin D T Manson
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - David G E Smith
- Institute for Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK.,Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| |
Collapse
|
11
|
Drawid A, Gupta N, Nagaraj VH, Gélinas C, Sengupta AM. OHMM: a Hidden Markov Model accurately predicting the occupancy of a transcription factor with a self-overlapping binding motif. BMC Bioinformatics 2009; 10:208. [PMID: 19583839 PMCID: PMC2718928 DOI: 10.1186/1471-2105-10-208] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 07/07/2009] [Indexed: 12/29/2022] Open
Abstract
Background DNA sequence binding motifs for several important transcription factors happen to be self-overlapping. Many of the current regulatory site identification methods do not explicitly take into account the overlapping sites. Moreover, most methods use arbitrary thresholds and fail to provide a biophysical interpretation of statistical quantities. In addition, commonly used approaches do not include the location of a site with respect to the transcription start site (TSS) in an integrated probabilistic framework while identifying sites. Ignoring these features can lead to inaccurate predictions as well as incorrect design and interpretation of experimental results. Results We have developed a tool based on a Hidden Markov Model (HMM) that identifies binding location of transcription factors with preference for self-overlapping DNA motifs by combining the effects of their alternative binding modes. Interpreting HMM parameters as biophysical quantities, this method uses the occupancy probability of a transcription factor on a DNA sequence as the discriminant function, earning the algorithm the name OHMM: Occupancy via Hidden Markov Model. OHMM learns the classification threshold by training emission probabilities using unaligned sequences containing known sites and estimating transition probabilities to reflect site density in all promoters in a genome. While identifying sites, it adjusts parameters to model site density changing with the distance from the transcription start site. Moreover, it provides guidance for designing padding sequences in gel shift experiments. In the context of binding sites to transcription factor NF-κB, we find that the occupancy probability predicted by OHMM correlates well with the binding affinity in gel shift experiments. High evolutionary conservation scores and enrichment in experimentally verified regulated genes suggest that NF-κB binding sites predicted by our method are likely to be functional. Conclusion Our method deals specifically with identifying locations with multiple overlapping binding sites by computing the local occupancy of the transcription factor. Moreover, considering OHMM as a biophysical model allows us to learn the classification threshold in a principled manner. Another feature of OHMM is that we allow transition probabilities to change with location relative to the TSS. OHMM could be used to predict physical occupancy, and provides guidance for proper design of gel-shift experiments. Based upon our predictions, new insights into NF-κB function and regulation and possible new biological roles of NF-κB were uncovered.
Collapse
Affiliation(s)
- Amar Drawid
- BioMAPS Institute for Quantitative Biology, Rutgers University, Piscataway, NJ, USA.
| | | | | | | | | |
Collapse
|
12
|
Castro I, Wright JA, Damdinsuren B, Hoek KL, Carlesso G, Shinners NP, Gerstein RM, Woodland RT, Sen R, Khan WN. B cell receptor-mediated sustained c-Rel activation facilitates late transitional B cell survival through control of B cell activating factor receptor and NF-kappaB2. THE JOURNAL OF IMMUNOLOGY 2009; 182:7729-37. [PMID: 19494297 DOI: 10.4049/jimmunol.0803281] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Signaling from the BCR and B cell activating factor receptor (BAFF-R or BR3) differentially regulates apoptosis within early transitional (T1) and late transitional (T2; CD21(int)-T2) B cells during selection processes to generate mature B lymphocytes. However, molecular mechanisms underlying the differential sensitivity of transitional B cells to apoptosis remain unclear. In this study, we demonstrate that BCR signaling induced more long-term c-Rel activation in T2 and mature than in T1 B cells leading to increased expression of anti-apoptotic genes as well as prosurvival BAFF-R and its downstream substrate p100 (NF-kappaB2). Sustained c-Rel activation required de novo c-Rel gene transcription and translation via Btk-dependent mechanisms. Like T1 cells, mature B cells from Btk- and c-Rel-deficient mice also failed to activate these genes. These findings suggest that the gain of survival potential within transitional B cells is dependent on the ability to produce a long-term c-Rel response, which plays a critical role in T2 B cell survival and differentiation in vivo by inducing anti-apoptotic genes, BAFF-R and NF-kappaB2, an essential component for BAFF-R survival signaling. Thus, acquisition of resistance to apoptosis during transitional B cell maturation is achieved by integration of BCR and BAFF-R signals.
Collapse
Affiliation(s)
- Iris Castro
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Quincozes-Santos A, Nardin P, de Souza DF, Gelain DP, Moreira JC, Latini A, Gonçalves CA, Gottfried C. The Janus Face of Resveratrol in Astroglial Cells. Neurotox Res 2009; 16:30-41. [DOI: 10.1007/s12640-009-9042-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 01/28/2009] [Accepted: 03/06/2009] [Indexed: 01/07/2023]
|
14
|
Wood MA, Walker WH. USF1/2 transcription factor DNA-binding activity is induced during rat Sertoli cell differentiation. Biol Reprod 2008; 80:24-33. [PMID: 18768914 DOI: 10.1095/biolreprod.108.070037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Each Sertoli cell can support a finite number of developing germ cells. During development of the testis, the cessation of Sertoli cell proliferation and the onset of differentiation determine the final number of Sertoli cells and, hence, the number of sperm that can be produced. We hypothesize that the transition from proliferation to differentiation is facilitated by E-box transcription factors that induce the expression of differentiation-promoting genes. The relative activities of E-box proteins were studied in primary Sertoli cells isolated from 5-, 11-, and 20-day-old rats, representing proliferating, differentiating, and differentiated cells, respectively. E-box DNA-binding activity is almost undetectable 5 days after birth but peaks with initiation of differentiation 11 days after birth and remains elevated. Upstream stimulatory factors 1 and 2 (USF1 and USF2) were found to be the predominant E-box proteins present within DNA-protein complexes formed after incubating E-box-containing probes with nuclear extracts from developing Sertoli cells. The known potentiator of Sertoli cell differentiation, thyroxine, increases USF DNA-binding activity in Sertoli cells before differentiation (5-day-old Sertoli cells) but not after differentiation is initiated (11- and 20-day-old Sertoli cells). The developmental-specific increase in USF1 and USF2 DNA-binding activity may facilitate the switch from proliferation to differentiation and, thus, determine the ultimate number of Sertoli cells present within the testes and the upper limit of fertility.
Collapse
Affiliation(s)
- Michelle A Wood
- Center for Research in Reproductive Physiology, Department of Cell Biology and Molecular Physiology, Magee Women's Research Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | |
Collapse
|
15
|
dos Santos NR, Williame M, Gachet S, Cormier F, Janin A, Weih D, Weih F, Ghysdael J. RelB-dependent stromal cells promote T-cell leukemogenesis. PLoS One 2008; 3:e2555. [PMID: 18596915 PMCID: PMC2440518 DOI: 10.1371/journal.pone.0002555] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 05/28/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The Rel/NF-kappaB transcription factors are often activated in solid or hematological malignancies. In most cases, NF-kappaB activation is found in malignant cells and results from activation of the canonical NF-kappaB pathway, leading to RelA and/or c-Rel activation. Recently, NF-kappaB activity in inflammatory cells infiltrating solid tumors has been shown to contribute to solid tumor initiation and progression. Noncanonical NF-kappaB activation, which leads to RelB activation, has also been reported in breast carcinoma, prostate cancer, and lymphoid leukemia. METHODOLOGY/PRINCIPAL FINDINGS Here we report a novel role for RelB in stromal cells that promote T-cell leukemogenesis. RelB deficiency delayed leukemia onset in the TEL-JAK2 transgenic mouse model of human T acute lymphoblastic leukemia. Bone marrow chimeric mouse experiments showed that RelB is not required in the hematopoietic compartment. In contrast, RelB plays a role in radio-resistant stromal cells to accelerate leukemia onset and increase disease severity. CONCLUSIONS/SIGNIFICANCE The present results are the first to uncover a role for RelB in the crosstalk between non-hematopoietic stromal cells and leukemic cells. Thus, besides its previously reported role intrinsic to specific cancer cells, the noncanonical NF-kappaB pathway may also play a pro-oncogenic role in cancer microenvironmental cells.
Collapse
Affiliation(s)
- Nuno R. dos Santos
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Maryvonne Williame
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Stéphanie Gachet
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Françoise Cormier
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Anne Janin
- INSERM Unité 728, Université Paris VII, Hôpital Saint-Louis, Paris, France
| | - Debra Weih
- Leibniz-Institute for Age Research – Fritz-Lipmann-Institute (FLI), Jena, Germany
| | - Falk Weih
- Leibniz-Institute for Age Research – Fritz-Lipmann-Institute (FLI), Jena, Germany
| | - Jacques Ghysdael
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
- * E-mail:
| |
Collapse
|
16
|
Palmieri C, Trimboli F, Scala G, Quinto I, Bressler PB. Regulation of the HIV promoter/enhancer. CURRENT PROTOCOLS IN IMMUNOLOGY 2008; Chapter 12:Unit 12.7. [PMID: 18432898 DOI: 10.1002/0471142735.im1207s54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This unit describes adaptations of two molecular techniques that can be used to study the regulation of HIV expression. The first two protocols describe the chloramphenicol acetyltransferase (CAT) assay, in which the CAT reporter gene is attached to an HIV-1 promoter and CAT activity is measured as an indication of the promoter's activity. The basic protocol is rapid, simple, and suited to analyzing multiple samples. An alternate protocol describes an assay for CAT function that involves separating the reaction products by thin-layer chromatography (TLC). The second basic protocol describes an electrophoretic mobility shift assay for detecting proteins present in cell extracts that can bind to the HIV-1 LTR (long terminal repeat). Such studies are central to current HIV research because it is important to know what agents induce and inhibit (or "down-regulate") HIV transcription.
Collapse
Affiliation(s)
- Camillo Palmieri
- Department of Clinical and Experimental Medicine, University of Catanzaro, Magna Grecia, Cantazaro, Italy
| | | | | | | | | |
Collapse
|
17
|
Acevedo-Suárez CA, Kilkenny DM, Reich MB, Thomas JW. Impaired intracellular calcium mobilization and NFATc1 availability in tolerant anti-insulin B cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:2234-41. [PMID: 16887983 DOI: 10.4049/jimmunol.177.4.2234] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
B lymphocytes that recognize soluble self-Ags are routinely found in normal individuals in a functionally inactive or anergic state. Current models indicate that this tolerant state is maintained by interactions with self-Ags that uncouple the BCR from downstream signaling pathways and increase levels of free calcium. Contrary to this expectation, B cells that harbor anti-insulin Ig transgenes (125Tg) are maintained in a tolerant state even though free calcium levels remain normal and tyrosine kinase substrate phosphorylation is preserved following BCR stimulation. Under basal conditions, intracellular levels of inositol 1,4,5-trisphosphate are increased and NFATc1 levels are reduced in 125Tg B cells. The 125Tg B cells are markedly impaired in their ability to mobilize calcium upon stimulation with ionomycin, and BCR-induced calcium mobilization from internal stores is decreased. In contrast, poisoning intracellular calcium pumps with thapsigargin increases calcium mobilization in 125Tg B cells. Changes in calcium signaling are accompanied by a failure of 125Tg B cells to translocate NFATc1 into the nucleus following stimulation with either anti-IgM or ionomycin. Thus, disassociation of BCR from multiple signaling pathways is not essential for maintaining tolerance in anti-insulin 125Tg B cells. Rather, BCRs that are occupied by autologous insulin deliver signals that induce changes in intracellular calcium mobilization and maintain tolerance by preventing activation of key transcription factors such as NFAT.
Collapse
|
18
|
Mora AL, LaVoy J, McKean M, Stecenko A, Brigham KL, Parker R, Rojas M. Prevention of NF-kappaB activation in vivo by a cell-permeable NF-kappaB inhibitor peptide. Am J Physiol Lung Cell Mol Physiol 2005; 289:L536-44. [PMID: 15951331 DOI: 10.1152/ajplung.00164.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The NF-kappaB/Rel transcription factor family plays a central role in coordinating the expression of a variety of genes that regulate stress responses, immune cell activation, apoptosis, proliferation, differentiation, and oncogenic transformation. Interventions that target the NF-kappaB pathway may be therapeutic for a variety of pathologies, especially immune/inflammatory diseases. Using membrane translocating sequence (MTS) technology, we developed a cell-permeable dominant inhibitor of NF-kappaB activation, termed IkappaBalpha-(DeltaN)-MTS. This molecule contains a 12-amino acid MTS motif attached to the COOH-terminal region of a nondegradable inhibitor protein [IkappaBalpha-(DeltaN)]. The recombinant protein enters cells and localizes in the cytoplasm. Delivery of the IkappaBalpha-(DeltaN)-MTS to cell lines and primary cells inhibited nuclear translocation of NF-kappaB proteins induced by cell activation. The protein also effectively inhibited NF-kappaB activation in vivo in two different animal models: NF-kappaB activation in response to skin wounding in mice and NF-kappaB activation in lungs after endotoxin treatment in sheep. Inhibition of NF-kappaB by the IkappaBalpha-(DeltaN)-MTS in the endotoxin model attenuated physiological responses to endotoxemia. These data demonstrate that activation of NF-kappaB can be inhibited using a recombinant protein designed to penetrate into cells. This technology may provide a new approach to NF-kappaB pathway-targeted therapies.
Collapse
Affiliation(s)
- Ana L Mora
- Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | | | | | | | |
Collapse
|
19
|
Sinha S, Perdomo G, Brown NF, O'Doherty RM. Fatty acid-induced insulin resistance in L6 myotubes is prevented by inhibition of activation and nuclear localization of nuclear factor kappa B. J Biol Chem 2004; 279:41294-301. [PMID: 15252018 DOI: 10.1074/jbc.m406514200] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies have implicated inhibitor of kappaB kinase (IKK) in mediating fatty acid (FA)-induced insulin resistance. How IKK causes these effects is unknown. The present study addressed the role of nuclear factor kappaB (NFkappaB), the distal target of IKK activity, in FA-induced insulin resistance in L6 myotubes, an in vitro skeletal muscle model. A 6-h exposure of myotubes to the saturated FA palmitate reduced insulin-stimulated glucose uptake by approximately 30%, phosphatidylinositol-3 kinase and protein kinase B phosphorylation by approximately 40%, and stimulated inhibitor of kappaBalpha degradation and the nuclear translocation of NFkappaB. On the other hand, the Omega-3 polyunsaturated FA linolenate neither induced insulin resistance nor promoted nuclear localization of NFkappaB. Supporting the hypothesis that IKK acts through NFkappaB to cause insulin resistance, the IKK inhibitors acetylsalicylate and parthenolide prevented FA-induced reductions in insulin-stimulated glucose uptake and NFkappaB nuclear translocation. Most importantly, NFkappaB SN50, a cell-permeable peptide that inhibits NFkappaB nuclear translocation downstream of IKK, was sufficient to prevent palmitate-induced reductions in insulin-stimulated glucose uptake. Acetylsalicylate, but not NFkappaB SN50, prevented FA effects on phosphatidylinositol-3 kinase activity and protein kinase B phosphorylation. We conclude that FAs induce insulin resistance and activates NFkappaB in L6 cells. Furthermore, inhibition of NFkappaB activation, indirectly by preventing IKK activation or directly by inhibiting NFkappaB nuclear translocation, prevents the detrimental effects of palmitate on the metabolic actions of insulin in L6 myotubes.
Collapse
Affiliation(s)
- Sandeep Sinha
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | | | | | |
Collapse
|
20
|
Liao G, Zhang M, Harhaj EW, Sun SC. Regulation of the NF-kappaB-inducing kinase by tumor necrosis factor receptor-associated factor 3-induced degradation. J Biol Chem 2004; 279:26243-50. [PMID: 15084608 DOI: 10.1074/jbc.m403286200] [Citation(s) in RCA: 369] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The NF-kappaB family of transcription factors plays a pivotal role in regulation of diverse biological processes, including immune responses, cell growth, and apoptosis. Activation of NF-kappaB is mediated by both canonical and noncanonical signaling pathways. Although the canonical pathway has been extensively studied, the mechanism mediating the noncanonical pathway is still poorly understood. Recent studies have identified the NF-kappaB-inducing kinase (NIK) as a key component of the noncanonical pathway of NF-kappaB activation; however, how the signaling function of NIK is regulated remains unknown. We report here that one important mechanism of NIK regulation is through its dynamic interaction with the tumor necrosis factor receptor-associated factor 3 (TRAF3). TRAF3 physically associates with NIK via a specific sequence motif located in the N-terminal region of NIK; this molecular interaction appears to target NIK for degradation by the proteasome. Interestingly, induction of noncanonical NF-kappaB signaling by extracellular signals involves degradation of TRAF3 and the concomitant enhancement of NIK expression. These results suggest that induction of noncanonical NF-kappaB signaling may involve the rescue of NIK from TRAF3-mediated negative regulation.
Collapse
Affiliation(s)
- Gongxian Liao
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | | | | | | |
Collapse
|
21
|
Scobey MJ, Fix CA, Walker WH. The Id2 transcriptional repressor is induced by follicle-stimulating hormone and cAMP. J Biol Chem 2004; 279:16064-70. [PMID: 14761970 DOI: 10.1074/jbc.m309298200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Id (inhibitor of DNA binding/differentiation) proteins repress differentiation and promote cell division by dimerizing with and inhibiting the action of basic helix-loop-helix transcription factors including those that bind to E-box motifs. Of the four characterized Id proteins, only Id2 is found in the nucleus of Sertoli cells that support the development of spermatozoa in the testis. Differential display analysis of rat primary Sertoli cell mRNA identified Id2 as being inducible by forskolin, a stimulator of cAMP production. Northern blot analysis confirmed that Id2 mRNA expression peaked in Sertoli cells 6-12 h after stimulation with forskolin or follicle-stimulating hormone (FSH), the major physiological stimulator of cAMP in Sertoli cells. Similarly, Id2 promoter activity in Sertoli cells was induced after forskolin or FSH stimulation as well as by overexpression of protein kinase A. Forskolin induction of the Id2 promoter required sequences located between positions -122 and -82. Protein(s) of 40-45 kDa were found to bind two activated transcription factor/cAMP-response element-like sites and a GATA motif within the regulatory region. The induction of the Id2 gene by FSH corresponded with a decrease in protein binding to an E-box consensus motif and decreased E-box-mediated transcription. Together, these findings raise the possibility that FSH-mediated induction of Id2 and resultant inhibition of basic helix-loop-helix transcription factor-regulated genes in Sertoli cells may contribute to the regulation of spermatogenesis.
Collapse
Affiliation(s)
- M Joseph Scobey
- Department of Cell Biology and Physiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | | | |
Collapse
|
22
|
Schmitz ML, Henkel T, Baeuerle PA. Proteins controlling the nuclear uptake of NF-kappa B, Rel and dorsal. Trends Cell Biol 2004; 1:130-7. [PMID: 14731544 DOI: 10.1016/0962-8924(91)90118-s] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The two DNA-binding subunits of the transcription factor NF-kappa B, the products of the rel oncogene family and the product of the developmental control gene dorsal of Drosophila are homologous within a 300 amino acid region. This sequence represents a novel DNA-binding and dimerization domain. The access of the NF-kappa B/Rel/dorsal (NRD) transcription factor family to the cell nucleus is regulated. There is now evidence that functionally and structurally related accessory proteins of NF-kappa B, Rel and dorsal control the nuclear entry as well as DNA-binding activity of the transcription factors. This review summarizes current knowledge about the nuclear-uptake regulatory proteins (NURPs) I kappa B-alpha, I kappa B-beta/pp40 and cactus.
Collapse
Affiliation(s)
- M L Schmitz
- Laboratorium für Molekulare Biologie der Ludwig-Maximilians-Universität, Genzentrum, Am Klopferspitz, D-8033 Martinsried, FRG
| | | | | |
Collapse
|
23
|
Fan Y, Rayet B, Gélinas C. Divergent C-terminal transactivation domains of Rel/NF-κB proteins are critical determinants of their oncogenic potential in lymphocytes. Oncogene 2003; 23:1030-42. [PMID: 14647412 DOI: 10.1038/sj.onc.1207221] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
rel/nf-kappaB genes are amplified, overexpressed, or constitutively activated in many human hematopoietic tumors; however, the molecular mechanisms by which they contribute to tumorigenesis remain to be determined. Here, we explored the oncogenic potential of cellular Rel/NF-kappaB proteins in vitro and in vivo. We show that overexpression of wild-type mouse and human c-rel genes suffices to malignantly transform primary spleen cells in stringent soft agar assays and produce fatal tumors in vivo. In contrast relA and a constitutively active form of IKKbeta did not. Importantly, a hybrid RelA protein with its C-terminal transactivation domain substituted by that of v-Rel was potently oncogenic in vitro and in vivo. The transactivation domain of v-Rel selectively conferred an oncogenic phenotype upon the Rel homology domain (RHD) of RelA, but not to the more divergent RHDs of p50/NF-kappaB1, p52/NF-kappaB2, or RelB. Collectively, our results highlight important differences in the intrinsic oncogenic activity of mammalian c-Rel and RelA proteins, and indicate that critical determinants of their differential oncogenicity reside in their divergent transactivation domains. These findings provide experimental evidence for a role of mammalian Rel/NF-kappaB factors in leukemia/lymphomagenesis in an in vivo animal model, and are consistent with the implication of c-rel in many human lymphomas.
Collapse
Affiliation(s)
- Yongjun Fan
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ 08854-5638, USA
| | | | | |
Collapse
|
24
|
Delfino FJ, Boustead JN, Fix C, Walker WH. NF-kappaB and TNF-alpha stimulate androgen receptor expression in Sertoli cells. Mol Cell Endocrinol 2003; 201:1-12. [PMID: 12706288 DOI: 10.1016/s0303-7207(03)00005-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Germ cell development within the mammalian testis requires testosterone stimulation of somatic Sertoli cells via interaction with intracellular androgen receptors (AR). AR expression levels undergo marked changes during spermatogenesis suggesting that the modulation of AR expression is an important mechanism to regulate Sertoli cell responsiveness to testosterone. An analysis of the AR gene promoter revealed three kappaB enhancer elements that interacted with Sertoli cell p50 and RelA NF-kappaB proteins, and the overexpression of these NF-kappaB subunits in Sertoli cells stimulated AR promoter activity. Moreover, TNF-alpha, a secretory product of round spermatids, stimulated NF-kappaB binding to the AR promoter, induced AR promoter activity, and increased endogenous AR expression in primary cultures of Sertoli cells. Given the requirement of testosterone for spermatogenesis and the importance of AR in mediating Sertoli cell responsiveness to testosterone, the stimulation of AR expression by NF-kappaB and TNF-alpha may represent an important regulatory mechanism required to maintain efficient spermatogenesis.
Collapse
MESH Headings
- Androgens/pharmacology
- Animals
- Blotting, Northern
- Blotting, Western
- Cells, Cultured
- Enhancer Elements, Genetic
- Gene Expression Regulation
- Male
- NF-kappa B/pharmacology
- Promoter Regions, Genetic/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Sertoli Cells/drug effects
- Sertoli Cells/metabolism
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- Tumor Necrosis Factor-alpha/pharmacology
Collapse
Affiliation(s)
- Frank J Delfino
- Department of Cell Biology and Physiology, University of Pittsburgh, 820 Scaife Hall, 3550 Terrace Street, PA 15261, USA
| | | | | | | |
Collapse
|
25
|
Xiao G, Cvijic ME, Fong A, Harhaj EW, Uhlik MT, Waterfield M, Sun SC. Retroviral oncoprotein Tax induces processing of NF-kappaB2/p100 in T cells: evidence for the involvement of IKKalpha. EMBO J 2001; 20:6805-15. [PMID: 11726516 PMCID: PMC125766 DOI: 10.1093/emboj/20.23.6805] [Citation(s) in RCA: 250] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
IkappaB kinase (IKK) is a key mediator of NF-kappaB activation induced by various immunological signals. In T cells and most other cell types, the primary target of IKK is a labile inhibitor of NF-kappaB, IkappaBalpha, which is responsible for the canonical NF-kappaB activation. Here, we show that in T cells infected with the human T-cell leukemia virus (HTLV), IKKalpha is targeted to a novel signaling pathway that mediates processing of the nfkappab2 precursor protein p100, resulting in active production of the NF-kappaB subunit, p52. This pathogenic action is mediated by the HTLV-encoded oncoprotein Tax, which appears to act by physically recruiting IKKalpha to p100, triggering phosphorylation-dependent ubiquitylation and processing of p100. These findings suggest a novel mechanism by which Tax modulates the NF-kappaB signaling pathway.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Shao-Cong Sun
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA
Corresponding author e-mail:
| |
Collapse
|
26
|
Gilmore TD, Cormier C, Jean-Jacques J, Gapuzan ME. Malignant transformation of primary chicken spleen cells by human transcription factor c-Rel. Oncogene 2001; 20:7098-103. [PMID: 11704834 DOI: 10.1038/sj.onc.1204898] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2001] [Revised: 08/01/2001] [Accepted: 08/07/2001] [Indexed: 02/02/2023]
Abstract
Rel/NF-kappaB transcription factors control a variety of cellular processes, such as cell growth and apoptosis, that are relevant to oncogenesis, and mutations in genes encoding Rel/NF-kappaB transcription factors have been found in several human lymphoid cell cancers. In this study, we have used a sensitive cell outgrowth assay to demonstrate that wild-type human c-Rel can malignantly transform primary chicken spleen cells, and that transformation by c-Rel is accelerated by co-expression of Bc1-2. Full-length mouse c-Rel can also transform chicken spleen cells. These results are the first demonstration of a lymphoid cell malignant transforming ability for mammalian Rel/NF-kappaB transcription factors, and implicate c-Rel as a molecular target for cancer therapeutics.
Collapse
Affiliation(s)
- T D Gilmore
- Department of Biology, Boston University, 5 Cummington Street, Boston, Massachusetts, MA 02215, USA.
| | | | | | | |
Collapse
|
27
|
Fiévez L, Kirschvink N, Dogné S, Jaspar F, Merville MP, Bours V, Lekeux P, Bureau F. Impaired accumulation of granulocytes in the lung during ozone adaptation. Free Radic Biol Med 2001; 31:633-41. [PMID: 11522448 DOI: 10.1016/s0891-5849(01)00621-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Respiratory alterations induced by an acute exposure to ozone (O(3)) paradoxically resolve during multiday exposure. This adaptation is characteristically accompanied by a gradual attenuation of lung neutrophilia. As maintenance of neutrophilia at the site of inflammation is due to cytokine-mediated delayed neutrophil apoptosis, which is associated with reduced levels of Bax, a proapoptotic protein, we sought to determine whether defects in these mechanisms could account for O(3) adaptation. Lung granulocytes obtained at different time points from calves exposed to 0.75 ppm O(3) for 12 h/d for 7 consecutive days neither showed enhancement of survival nor Bax deficiency, when compared to blood granulocytes. To further investigate the effects of an exogenous oxidative stress on neutrophil survival, human granulocytes were treated with hydrogen peroxide alone, or in combination with granulocyte/macrophage colony-stimulating factor, an antiapoptotic cytokine. Both treatments led to rapid apoptosis associated with downregulation of Bcl-x(L) and Bcl-2, two antiapoptotic proteins. This study shows that O(3) adaptation is associated with a failure in the mechanisms leading to accumulation of neutrophils at the site of inflammation, and suggests that this defect is due to direct proapoptotic effects of exogenous oxidative stress on granulocytes.
Collapse
Affiliation(s)
- L Fiévez
- Department of Physiology, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Sandersen C, Bureau F, Turlej R, Fiévez L, Dogné S, Kirschvink N, Lekeux P. p65 Homodimer activity in distal airway cells determines lung dysfunction in equine heaves. Vet Immunol Immunopathol 2001; 80:315-26. [PMID: 11457483 DOI: 10.1016/s0165-2427(01)00329-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nuclear factor-kappaB (NF-kappaB) activity, which is a key regulator of inflammatory gene expression, is increased in bronchial epithelial cells from horses suffering from heaves (a hypersensitivity-associated inflammatory condition of the lung). To determine whether this increased activity extends to distal airways and to other pulmonary cells, cells recovered by broncho-alveolar lavage (BAL) in healthy and heaves-affected horses were assessed for NF-kappaB activity. NF-kappaB activity was much higher in BAL cells from heaves-affected horses, especially during crisis (disease exacerbation), than in cells from healthy horses. Moreover, the level of NF-kappaB activity found in BAL cells was positively correlated to total lung resistance and to the proportion of neutrophils present in BAL fluid. Finally, prototypical p65-p50 NF-kappaB heterodimers were absent from BAL cells, which mostly contained p65 homodimers. These results (1) show that increased NF-kappaB activity is a general feature of heaves lung; (2) demonstrate the importance of p65 homodimers in neutrophilic inflammation; and (3) suggest that the use of specific NF-kappaB inhibitors could improve lung function in heaves-affected horses.
Collapse
Affiliation(s)
- C Sandersen
- Department of Physiology, Faculty of Veterinary Medicine, University of Liège, Bât. B42, Sart Tilman, B-4000 Liège, Belgium
| | | | | | | | | | | | | |
Collapse
|
29
|
Shi MJ, Park SR, Kim PH, Stavnezer J. Roles of Ets proteins, NF-kappa B and nocodazole in regulating induction of transcription of mouse germline Ig alpha RNA by transforming growth factor-beta 1. Int Immunol 2001; 13:733-46. [PMID: 11369700 DOI: 10.1093/intimm/13.6.733] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Antibody class switch recombination (CSR) occurs after antigen activation of B cells. CSR is directed to specific heavy chain isotypes by cytokines and B cell activators that induce transcription from the unrearranged, or germline (GL), C(H) region genes. Transforming growth factor (TGF)-beta1 is essential for switch recombination to IgA due to its ability to induce transcription from GL Ig alpha genes. It has been shown that the promoters which regulate transcription of mouse and human GL alpha RNAs contain a TGF-beta1-responsive element that binds Smad and core binding factor (CBFalpha)/AML/PEBPalpha/RUNX: They also contain other elements which bind the transcription factors CREB, BSAP and Ets family proteins. In this manuscript we demonstrate that two tandem Ets sites in the mouse GL alpha promoter bind the transcription factors Elf-1 and PU.1, and that the 3' site is essential for expression of a luciferase reporter gene driven by the GL alpha promoter. Binding of Elf-1 to the GL alpha promoter is inducible by lipopolysaccharide in nuclear extracts from splenic B cells. An NF-kappaB site is identified, although it does not contribute to expression of the promoter in reporter gene assays. Since CSR to IgA is greatly reduced in NF-kappaB/p50-deficient mice, these data support the hypothesis that NF-kappaB has roles in switching in addition to regulation of GL transcription. Finally, we demonstrate that nocodazole, which disrupts microtubules that sequester Smad proteins in the cytoplasm, stimulates transcription from the GL alpha promoter.
Collapse
Affiliation(s)
- M J Shi
- Department of Molecular Genetics and Microbiology, Program in Immunology and Virology, University of Massachusetts Medical School, Worcester, MA 01655-0122, USA
| | | | | | | |
Collapse
|
30
|
Rabson AB, Lin HC. NF-kappa B and HIV: linking viral and immune activation. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2001; 48:161-207. [PMID: 10987091 DOI: 10.1016/s1054-3589(00)48006-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- A B Rabson
- Department of Molecular Genetics and Microbiology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854, USA
| | | |
Collapse
|
31
|
Mann KK, Doerre S, Schlezinger JJ, Sherr DH, Quadri S. The role of NF-kappaB as a survival factor in environmental chemical-induced pre-B cell apoptosis. Mol Pharmacol 2001; 59:302-9. [PMID: 11160867 DOI: 10.1124/mol.59.2.302] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAH) are ubiquitous environmental chemicals that suppress the immune system at multiple levels, including at the level of B cell development in the bone marrow microenvironment. Specifically, PAH induce preB cell apoptosis in primary bone marrow cultures and in cocultures of an early preB cell line (BU-11) and a bone marrow stromal cell line (BMS2). Previous studies focused on the molecular mechanisms through which PAH induce stromal cells to deliver an apoptosis signal to adjacent preB cells. Apoptosis signaling within the preB cell itself was not investigated. Here, the role of NF-kappaB, a lymphocyte survival factor, in PAH-induced preB cell apoptosis was assessed. Analysis of DNA-binding proteins extracted from the nuclei of untreated BU-11 cells indicated DNA-binding complexes comprising NF-kappaB subunits p50, c-Rel, and/or Rel A. NF-kappaB down-regulation with previously described inhibitors induced BU-11 cell apoptosis, demonstrating that the default apoptosis pathway blocked by NF-kappaB is functional at this early stage in B cell development. Similarly, exposure of BU-11/BMS2 cocultures to 7,12-dimethylbenz[a]anthracene (DMBA), a prototypic PAH, down-regulated nuclear Rel A and c-Rel before overt apoptosis. Finally, ectopic expression of Rel A or c-Rel rescued BU-11 cells from DMBA-induced apoptosis. These results extend previous observations by demonstrating that 1) NF-kappaB is a survival factor at an earlier stage of B cell development than previously appreciated and 2) NF-kappaB down-regulation is likely to be part of the molecular mechanism resulting in PAH-induced preB cell apoptosis. These results suggest nonclonally restricted, PAH-mediated suppression of B lymphopoiesis.
Collapse
Affiliation(s)
- K K Mann
- Boston University Schools of Public Health and Medicine, Department of Environmental Health, Boston, Massachusetts 02118, USA
| | | | | | | | | |
Collapse
|
32
|
Arima N, Tei C. HTLV-I Tax related dysfunction of cell cycle regulators and oncogenesis of adult T cell leukemia. Leuk Lymphoma 2001; 40:267-78. [PMID: 11426548 DOI: 10.3109/10428190109057925] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
HTLV-I is causually related to the oncogenesis of adult T cell leukemia (ATL). However, the precise mechanism of HTLV-I oncogenesis is unclear. HTLV-I Tax protein functions as an activator of various cellular genes, including IL-2, IL-2 receptor-alpha, and c-fos through the activation of nuclear transfer factors such as NF-kappaB and SRF, and also potently activates trascription of viral genes through CREB/ATF sites in the viral LTR. However, Tax activation of HTLV-I infected T cells through the above pathways induces polyclonal proliferation of the cells in vitro; Tax however may function only transiently in the immediate post-infection period following infection in vivo. The long latent period of 60 years from infection to onset of disease suggests other mechanisms for ATL oncogenesis. Recent studies suggest that the malignant transformation of ATL is a multi-hit phenomena, suggesting that discrete genetic events are responsible for ATL oncogenesis. These genetic events could be responsible for the different stages of ATL: smoldering, chronic, lymphoma, and acute type, p16 and p53 genes are important negative regulators of the cell cycle and are often found to be mutated in neoplasms. Recent studies including ours demonstrated a high frequency of alteration of these two genes in primary ATL cells. Furthermore, alteration of the two genes is associated with acute but not chronic type ATL. In addition, p16 gene alteration is linked to the growth rate of ATL cells, suggesting that the alteration of these cell cycle regulatory genes may be related to progression from smoldering or chronic to acute or lymphoma type ATL. Tax may be involved in mutagenesis of these genes through suppression of DNA-beta polymerase gene expression during the process from latent period to acute/lymphoma type. Once transformation occurs, activation of the pathway between Tax and the three nuclear transfer factors, NF-kappaB, SRF, and CREB/ATF, contributes to establish the aggressive manifestations of acute/lymphoma type ATL cells.
Collapse
Affiliation(s)
- N Arima
- First Department Internal Medicine, Faculty of Medicine, Kagoshima University, Japan.
| | | |
Collapse
|
33
|
Agrawal S, Kishore MC. MHC class I gene expression and regulation. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 2000; 9:795-812. [PMID: 11177592 DOI: 10.1089/152581600750062237] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Major histocompatibility complex (MHC) is a conglomerate of genes that play an important role in recognition of self and nonself. These genes are under tight control. In this review we have discussed the transcription processes regulating MHC gene expression. Various biological or chemical modulators can modulate MHC gene expression. The promoter region of class I genes can be activated through several pathways. Hence, these genes are not typical "domestic" genes. Extensive studies on regulation of MHC class I expression, using transfection techniques and transgenic animal models, have resulted in identification of various cis-acting sequences involved in positive and negative regulation of class I genes. Work is in progress to identify the transacting proteins that bind to these sites and to delineate the mechanisms that regulate constitutive and inducible expression of class I genes in normal and diseased cells. It has been seen that various biological molecules (IFN, GM-CSF, IL-2) and other chemicals up-regulate the MHC expression. If the exact mechanisms are known by which the expression of class I genes is up regulated, the efforts can be made to balance the beneficial and toxic effects of biological molecules with one another, which may facilitate the use of combination of these molecules in subpharmacological doses (to eliminate toxicity) for early and better management of neoplastic diseases, as it is well-known that during malignancy MHC gene expression is down-regulated. In the future, the use of transgenic and knockout mice will be useful in acquiring a better understanding, which may further help in cancer therapy.
Collapse
Affiliation(s)
- S Agrawal
- Department of Medical Genetics, Samjay Gandhi Post Graduate Institute of Medical Sciences, Raebareli Road, Lucknow-226014, India.
| | | |
Collapse
|
34
|
Bureau F, Delhalle S, Bonizzi G, Fiévez L, Dogné S, Kirschvink N, Vanderplasschen A, Merville MP, Bours V, Lekeux P. Mechanisms of persistent NF-kappa B activity in the bronchi of an animal model of asthma. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:5822-30. [PMID: 11067942 DOI: 10.4049/jimmunol.165.10.5822] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In most cells trans-activating NF-kappaB induces many inflammatory proteins as well as its own inhibitor, IkappaB-alpha, thus assuring a transient response upon stimulation. However, NF-kappaB-dependent inflammatory gene expression is persistent in asthmatic bronchi, even after allergen eviction. In the present report we used bronchial brushing samples (BBSs) from heaves-affected horses (a spontaneous model of asthma) to elucidate the mechanisms by which NF-kappaB activity is maintained in asthmatic airways. NF-kappaB activity was high in granulocytic and nongranulocytic BBS cells. However, NF-kappaB activity highly correlated to granulocyte percentage and was only abrogated after granulocytic death in cultured BBSs. Before granulocytic death, NF-kappaB activity was suppressed by simultaneous addition of neutralizing anti-IL-1beta and anti-TNF-alpha Abs to the medium of cultured BBSs. Surprisingly, IkappaB-beta, whose expression is not regulated by NF-kappaB, unlike IkappaB-alpha, was the most prominent NF-kappaB inhibitor found in BBSs. The amounts of IkappaB-beta were low in BBSs obtained from diseased horses, but drastically increased after addition of the neutralizing anti-IL-1beta and anti-TNF-alpha Abs. These results indicate that sustained NF-kappaB activation in asthmatic bronchi is driven by granulocytes and is mediated by IL-1beta and TNF-alpha. Moreover, an imbalance between high levels of IL-1beta- and TNF-alpha-mediated IkappaB-beta degradation and low levels of IkappaB-beta synthesis is likely to be the mechanism preventing NF-kappaB deactivation in asthmatic airways before granulocytic death.
Collapse
Affiliation(s)
- F Bureau
- Departments of Physiology and Immunology/Vaccinology, Faculty of Veterinary Medicine, and Laboratory of Medical Chemistry/Medical Oncology, Faculty of Medicine, University of Liege, Liege, Belgium
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Xiao G, Harhaj EW, Sun SC. Domain-specific interaction with the I kappa B kinase (IKK)regulatory subunit IKK gamma is an essential step in tax-mediated activation of IKK. J Biol Chem 2000; 275:34060-7. [PMID: 10906125 DOI: 10.1074/jbc.m002970200] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human T-cell leukemia virus type 1 Tax oncoprotein deregulates the NF-kappa B signaling pathway by persistently stimulating a key signal transducer, the I kappa B kinase (IKK). Tax physically associates with the IKK regulatory subunit, IKK gamma, although the underlying biochemical mechanism and functional significance remain unclear. We show that the Tax-IKK gamma interaction requires two homologous leucine zipper domains located within IKK gamma. These leucine zipper domains are unique for the presence of a conserved upstream region that is essential for Tax binding. Site-directed mutagenesis analysis revealed that a leucine-repeat region of Tax is important for IKK gamma binding. Interestingly, all the Tax mutants defective in IKK gamma binding failed to engage the IKK complex or stimulate IKK activity, and these functional defects can be rescued by fusing the Tax mutants to IKK gamma. These results provide mechanistic insights into how Tax specifically targets and functionally activates the cellular kinase IKK.
Collapse
Affiliation(s)
- G Xiao
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | | | | |
Collapse
|
36
|
Petro JB, Rahman SJ, Ballard DW, Khan WN. Bruton's tyrosine kinase is required for activation of IkappaB kinase and nuclear factor kappaB in response to B cell receptor engagement. J Exp Med 2000; 191:1745-54. [PMID: 10811867 PMCID: PMC2193161 DOI: 10.1084/jem.191.10.1745] [Citation(s) in RCA: 238] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mutations in the gene encoding Bruton's tyrosine kinase (btk) cause the B cell deficiency diseases X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency (xid) in mice. In vivo and in vitro studies indicate that the BTK protein is essential for B cell survival, cell cycle progression, and proliferation in response to B cell antigen receptor (BCR) stimulation. BCR stimulation leads to the activation of transcription factor nuclear factor (NF)-kappaB, which in turn regulates genes controlling B cell growth. We now demonstrate that a null mutation in btk known to cause the xid phenotype prevents BCR-induced activation of NF-kappaB. This defect can be rescued by reconstitution with wild-type BTK. This mutation also interferes with BCR-directed activation of IkappaB kinase (IKK), which normally targets the NF-kappaB inhibitor IkappaBalpha for degradation. Taken together, these findings indicate that BTK couples IKK and NF-kappaB to the BCR. Interference with this coupling mechanism may contribute to the B cell deficiencies observed in XLA and xid.
Collapse
Affiliation(s)
- James B. Petro
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - S.M. Jamshedur Rahman
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Dean W. Ballard
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| | - Wasif N. Khan
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
| |
Collapse
|
37
|
Schlezinger JJ, Blickarz CE, Mann KK, Doerre S, Stegeman JJ. Identification of NF-kappaB in the marine fish Stenotomus chrysops and examination of its activation by aryl hydrocarbon receptor agonists. Chem Biol Interact 2000; 126:137-57. [PMID: 10862814 DOI: 10.1016/s0009-2797(00)00161-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Members of the Rel family of proteins have been identified in Drosophila, an echinoderm, Xenopus, birds and mammals. Dimers of Rel proteins form the transcription factor nuclear factor kappaB (NF-kappaB) that rapidly activates genes encoding cytokines, cell surface receptors, cell adhesion molecules and acute phase proteins. Evidence suggests that xenobiotic compounds also may alter the activation of NF-kappaB. This study had a dual objective of identifying members of the Rel family and examining their activation by xenobiotic compounds in a marine fish model, scup (Stenotomus chrysops). A DNA-protein crosslinking technique demonstrated that liver, kidney and heart each had at least three nuclear proteins that showed specific binding to an NF-kappaB consensus sequence, with molecular weights suggesting that the proteins potentially corresponded to mouse p50, p65 (RelA) and c-rel. In addition, an approximately 35kD NF-kappaB binding protein was evident in liver and kidney. The 50 kD protein was immunoprecipitated by mammalian p50-specific antibodies. The presence of Rel members in fish implied by those results was confirmed by RT-PCR cloning of a Rel homology domain (an apparent c-rel) from scup liver. NF-kappaB activation occurred in vehicle-treated fish, but this appeared to decrease over time. In fish treated with 0.01 or 1 mg 3,3',4,4', 5-pentachlorobiphenyl per kg, NF-kappaB activation in liver did not decrease, and there was a 6-8-fold increase in activation 16-18 days following treatment. Treatment with 10 mg benzo[a]pyrene/kg had no effect on NF-kappaB-DNA binding, either at 3 or 6 days following treatment. The data show that the Rel family of proteins is present in fish, represented at least by a p50/105 homologue, and support a hypothesis that some aryl hydrocarbon receptor agonists can activate NF-kappaB in vivo.
Collapse
Affiliation(s)
- J J Schlezinger
- Biology Department, Redfield 342, MS 32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | | | | | | | | |
Collapse
|
38
|
Bureau F, Bonizzi G, Kirschvink N, Delhalle S, Desmecht D, Merville MP, Bours V, Lekeux P. Correlation between nuclear factor-kappaB activity in bronchial brushing samples and lung dysfunction in an animal model of asthma. Am J Respir Crit Care Med 2000; 161:1314-21. [PMID: 10764329 DOI: 10.1164/ajrccm.161.4.9907010] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Asthma is a chronic inflammatory disease of the airways, in which many inflammatory genes are overexpressed. Transcription factor, nuclear factor-kappaB (NF-kappaB), which is thought to control the transcriptional initiation of inflammatory genes, has been poorly investigated in asthma. In the present report, bronchial cells (BCs), recovered by bronchial brushing in healthy and heaves-affected horses (i.e., an animal model of asthma), were assessed for NF-kappaB activity. Small amounts of active NF-kappaB were present in BCs of healthy horses, whereas high levels of NF-kappaB activity was found during crisis (i.e., acute airway obstruction) in all heaves-affected horses. Three weeks after the crisis, the level of NF-kappaB activity found in BCs of heaves-affected horses was highly correlated (p < 0.01) to the degree of residual lung dysfunction. Unexpectedly, active NF- kappaB complexes found in BCs of heaves-affected horses were mainly p65 homodimers, rather than classic p65-p50 heterodimers. At last, intercellular adhesion molecule-1 (ICAM-1) expression paralleled p65 homodimers activity in these cells. These results demonstrate that the kinetics of NF-kappaB activity is strongly related to the course of the disease and confirm the relevance of NF-kappaB as a putative target in asthma therapy. Moreover, uncommon p65 homodimers could transactivate, in BCs, a subset of genes, such as ICAM-1, characteristic of chronic airway inflammation.
Collapse
Affiliation(s)
- F Bureau
- Department of Physiology, Faculty of Veterinary Medicine, and Laboratory of Medical Chemistry, Faculty of Medicine, University of Liège, Liège, Belgium.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Ku PT, You M, Bose HR. Role and regulation of Rel/NF-kappaB activity in anti-immunoglobulin-induced apoptosis in WEHI-231 B lymphoma cells. Cell Signal 2000; 12:245-53. [PMID: 10781932 DOI: 10.1016/s0898-6568(00)00062-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In WEHI-231 cells, anti-immunoglobulin (anti-Ig) treatment leads to both a decrease in the DNA-binding activity of p50/c-Rel/p53 protein complexes and a transient enhancement in the DNA-binding activity of p50 homodimeric complexes. These cells subsequently undergo apoptosis. Because IkappaB-alpha plays a pivotal role in the regulation of Rel/NF-kappaB activity, we have characterized both the nature and kinetics of the expression of IkappaB-alpha following anti-Ig-induced apoptosis in WEHI-231 cells. Anti-Ig treatment of WEHI-231 cells decreased the steady-state level of IkappaB-alpha mRNA, but enhanced the stability of IkappaB-alpha, leading to an accumulation of IkappaB-alpha in both the cytosol and nucleus. Concomitant with the increase in IkappaB-alpha expression there was a gradual decline in the nuclear expression of c-Rel. Because c-Rel plays an important role in the survival of WEHI-231 cells, these results suggest that post-transcriptional regulation of IkappaB-alpha expression might play a role in the anti-Ig-induced apoptosis in WEHI-231 cells.
Collapse
Affiliation(s)
- P T Ku
- Section of Molecular Genetics and Microbiology and the Institute for Cellular and Molecular Biology, The University of Texas at Austin, 78712-1095, USA
| | | | | |
Collapse
|
40
|
Harhaj EW, Good L, Xiao G, Uhlik M, Cvijic ME, Rivera-Walsh I, Sun SC. Somatic mutagenesis studies of NF-kappa B signaling in human T cells: evidence for an essential role of IKK gamma in NF-kappa B activation by T-cell costimulatory signals and HTLV-I Tax protein. Oncogene 2000; 19:1448-56. [PMID: 10723136 DOI: 10.1038/sj.onc.1203445] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
NF-kappa B plays a pivotal role in normal T-cell activation and may also mediate human T-cell leukemia virus (HTLV)-induced T-cell transformation. Activation of NF-kappa B by both T-cell costimulatory signals and the HTLV Tax protein involves stimulation of I kappa B kinase (IKK). As a genetic approach to dissect the intermediate steps involved in NF-kappa B activation in human T cells, we performed somatic cell mutagenesis to isolate signaling-defective mutant Jurkat T-cell lines. One of the mutant cell lines was shown to have a specific blockade in the IKK signaling pathway but remained competent in the c-Jun N-terminal kinase and MAP kinase pathways. Interestingly, this mutant cell line lacks expression of IKK gamma, a non-catalytic component of the IKK complex. Expression of exogenous IKK gamma in the mutant cells restored NF-kappa B activation by both the T-cell costimulation agents and Tax. These findings provide genetic evidence for the requirement of IKK gamma in NF-kappa B signaling triggered by both T-cell costimulatory signals and HTLV-I Tax protein.
Collapse
Affiliation(s)
- E W Harhaj
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, Pennsylvania, PA 17033, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Noda A, Toma-Aiba Y, Fujiwara Y. A unique, short sequence determines p53 gene basal and UV-inducible expression in normal human cells. Oncogene 2000; 19:21-31. [PMID: 10644976 DOI: 10.1038/sj.onc.1203230] [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: 01/08/2023]
Abstract
The p53 tumor suppressor protein plays a central role in the cellular defence against agents which cause genetic damage. The induction and activation of p53 upon stress has been shown at post-transcription level by multiple mechanisms, while the regulatory role of p53 gene transcription is still poorly understood. Here we show that the causative mechanisms underlying this activation are attributed in part to the promoter function of p53. In various normal human cells, p53 gene expression is induced transcriptionally by ultraviolet (UV) but not X-ray irradiation. We determined that, by p53 promoter dissection, the 21 bp element (PE21) responsible for this UV activation resides adjacent to, and upstream to the putative NFkappaB binding site. Moreover, the PE21 sequence was found to be a primary determinant for human p53 gene basal expression carrying bi-directional transcriptional initiation activity, which controls the initiation of RNA synthesis about 50 bases downstream, indicating that the sequence plays a critical role in both basal and inducible transcription. Finally, we detected the putative PE21 binding factor(s) in nuclear extracts from non-irradiated and irradiated cells. Since the PE21 sequence does not show any homologies to the conventional TATA or GC box, or to an 'initiatior', all of which determine the initiation site for transcription, the PE21 sequence appears to be a new class in eukaryotic promoter elements. Our results indicate that the mechanism of PE21-directed p53 mRNA transcription has an important role in the cellular stress response as well as tumor suppression.
Collapse
Affiliation(s)
- A Noda
- Department of Radiation Biophysics, Kobe University School of Medicine, 7-5-1 Kusunokicho, Chuo-ku, Kobe 650-0017, Japan
| | | | | |
Collapse
|
42
|
Delfino FJ, Walker WH. NF-kappaB induces cAMP-response element-binding protein gene transcription in sertoli cells. J Biol Chem 1999; 274:35607-13. [PMID: 10585438 DOI: 10.1074/jbc.274.50.35607] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Spermatogenesis is dependent upon Sertoli cells, which relay hormonal signals and provide factors required for the differentiation and proliferation of germ cells. NF-kappaB transcription factors are constitutively expressed in the nuclei of Sertoli cells in rodent testis. Electrophoretic mobility shift assays demonstrated that Sertoli NF-kappaB proteins specifically bind to kappaB enhancer motifs within the promoter of the cAMP-response element-binding protein (CREB) gene, an important mediator of hormonal signals that control spermatogenesis. Overexpression of NF-kappaB proteins in primary Sertoli and NIH 3T3 fibroblast cells induced the CREB promoter in transient transfection assays. Stimulation of Sertoli cells with tumor necrosis factor-alpha, an NF-kappaB-activating cytokine produced by round spermatids located adjacent to Sertoli cells, stimulated the elimination of IkappaB, the translocation of additional NF-kappaB to the nucleus, and increased NF-kappaB binding to CREB promoter kappaB enhancer elements. Tumor necrosis factor-alpha also stimulated transcription from the CREB promoter. These data demonstrate that NF-kappaB contributes to the up-regulation of CREB expression in Sertoli cells and raises the possibility that NF-kappaB may induce other Sertoli genes required for spermatogenesis. Furthermore, the CREB promoter is also inducible by NF-kappaB in NIH 3T3 cells suggesting that NF-kappaB may be a general regulator of CREB in non-testis tissues.
Collapse
Affiliation(s)
- F J Delfino
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | | |
Collapse
|
43
|
Abstract
The avian Rev-T retrovirus encodes the v-Rel oncoprotein, which is a member of the Rel/NF-kappaB transcription factor family. v-Rel induces a rapidly fatal lymphoma/leukemia in young birds, and v-Rel can transform and immortalize a variety of avian cell types in vitro. Although Rel/NF-kappaB transcription factors have been associated with oncogenesis in mammals, v-Rel is the only member of this family that is frankly oncogenic in animal model systems. The potent oncogenicity of v-Rel is the consequence of a number of mutations that have altered its activity and regulation: for example, certain mutations decrease its ability to be regulated by IkappaBalpha, change its DNA-binding site specificity, and endow it with new transactivation properties. The study of v-Rel will continue to increase our knowledge of how cellular Rel proteins contribute to oncogenesis by affecting cell growth, altering cell-cycle regulation, and blocking apoptosis. This review will discuss biological and molecular activities of v-Rel, with particular attention to how these activities relate to structure - function aspects of the Rel/NF-kappaB transcription factors.
Collapse
Affiliation(s)
- T D Gilmore
- Biology Department, Boston University, 5 Cummington Street, Boston, Massachusetts, MA 02215-2406, USA
| |
Collapse
|
44
|
de Martin R, Schmid JA, Hofer-Warbinek R. The NF-kappaB/Rel family of transcription factors in oncogenic transformation and apoptosis. Mutat Res 1999; 437:231-43. [PMID: 10592330 DOI: 10.1016/s1383-5742(99)00089-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent progress in the identification and functional analysis of protein kinases and adapter molecules that lead to activation of NF-kappaB family transcription factors has lead to a quite detailed understanding of one of the major signalling pathways that mediate a cell's response to environmental stress in a variety of host-defense situations. NF-kappaB is recognized as a key regulatory factor mediating the coordinate expression of genes which are part of the cellular machinery that functions to protect an organism against damage posed by physical, chemical or microbial noxae. In a wide variety of patho-physiological situations such as immune and inflammatory reactions, the expression of cytokines, interleukins and adhesion molecules in cells of the immune system including T and B cells, endothelial as well as phagocytic/antigen presenting cells is to a large extent regulated by NF-kappaB. Moreover, this transcription factor appears to play a central role in the regulation of apoptosis, an important cellular program that decides upon a cell's fate not only during embryonic development but also on its way from normal to the transformed phenotype. Thus, NF-kappaB has emerged also as an attractive target for therapeutic interference in a variety of pathological situations, including chronic inflammatory and autoimmune diseases, HIV infection and cancer.
Collapse
Affiliation(s)
- R de Martin
- Department of Vascular Biology and Thrombosis Research, University of Vienna, Vienna International Research Cooperation Center (VIRCC), Brunnerstr. 59, A-1235, Vienna, Austria.
| | | | | |
Collapse
|
45
|
Doerre S, Corley RB. Constitutive Nuclear Translocation of NF-κB in B Cells in the Absence of IκB Degradation. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.1.269] [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
Members of the NF-κB/Rel family of transcription factors are involved in many aspects of B lymphocyte development and function. NF-κB is constitutively active in these cells, in contrast with most other cell types. In the inactive form, NF-κB/Rel proteins are sequestered in the cytoplasm by members of the IκB family of NF-κB inhibitors. When activated, NF-κB is translocated to the nucleus, a process that involves the phosphorylation and proteasomal degradation of IκB proteins. Thus, NF-κB activation is accompanied by the rapid turnover of IκB proteins. We show that while this “classical” mode of NF-κB activation is a uniform feature of IgM+ B cell lines, all IgG+ B cells analyzed contain nuclear NF-κB yet have stable IκBα, IκBβ, and IκBε. Furthermore, Iκβε levels are at least 10 times lower in IgG+ B cells than in IgM+ B cells, an additional indication that the regulation of constitutive NF-κB activity in these two types of B cells is fundamentally different. These data imply the existence of a novel mechanism of NF-κB activation in IgG+ B cells that operates independently of IκB degradation. They further suggest that different isoforms of the B cell receptor may have distinct roles in regulating NF-κB activity.
Collapse
Affiliation(s)
- Stefan Doerre
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118
| | - Ronald B. Corley
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118
| |
Collapse
|
46
|
Arima N, Matsushita K, Obata H, Ohtsubo H, Fujiwara H, Arimura K, Kukita T, Suruga Y, Wakamatsu S, Hidaka S, Tei C. NF-kappaB involvement in the activation of primary adult T-cell leukemia cells and its clinical implications. Exp Hematol 1999; 27:1168-75. [PMID: 10390192 DOI: 10.1016/s0301-472x(99)00053-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The HTLV-I provirus-encoded Tax protein induces NF-kappaB in Tax-transfected Jurkat T cells or HTLVL-I- infected T cells in vitro. Tax induction of NF-kappaB is presumed to be involved in proliferation and activation of primary leukemia cells in vivo. Recent studies have demonstrated that NF-kappaB activities in human T cells are mediated by at least four c-Rel-related DNA binding proteins - p50, p55, p75 and p85. We examined the significance of NF-kappaB induction in primary adult T cell leukemia cells and the induction kinetics of each of the four NF-kappaB species. Marked NF-kappaB activity was detected using an electrophoretic mobility shift assay (EMSA) in the primary cells of patients with acute disease, but little activity was noted in the cells of chronic patients. NF-kappaB activity was enhanced in a time-dependent manner in acute type cells cultured with mitogen-free medium; there was no induction of activity in chronic type cells. UV crosslinking demonstrated all four species of NFkappaB complex - high levels of p50 and lower levels of p55 and p75, in acute type cells; chronic type cells showed only the p50. As a control, normal resting T cells similarly showed only p50; control cells showed little change in activity when cultured without mitogenic stimulation, analogous to chronic type ATL. Northern blotting revealed enhancement of c-rel (encoding p85) and KBFI (encoding p50 and p55) expression in acute type cells during culture, while there was no significant enhancement of mRNAs in chronic type ATL cells or unstimulated normal T cells. Northern blotting also revealed that Tax is upregulated at the mRNA level in acute- but not chronic-type cells during culture. Expression of c-rel and KBF1 mRNAs in acute type cells appeared to be related to Tax mRNA expression. These results suggest that Tax is capable of inducing nuclear expression of all four NF-kappaB species in primary ATL cells of acute type patients, with marked effects on p55, p75, and p85. Tax induction of NF-kappaB species is regulated, at least in part, at a pretranslational level involving increases in c-rel and KBF1 mRNA.
Collapse
MESH Headings
- Acute Disease
- Aged
- Aged, 80 and over
- Chronic Disease
- DNA-Binding Proteins/biosynthesis
- DNA-Binding Proteins/genetics
- Disease Progression
- Female
- Gene Expression Regulation, Leukemic
- Gene Expression Regulation, Viral
- Gene Products, tax/physiology
- Genes, pX
- Human T-lymphotropic virus 1/genetics
- Humans
- Jurkat Cells
- Kinetics
- Leukemia-Lymphoma, Adult T-Cell/genetics
- Leukemia-Lymphoma, Adult T-Cell/pathology
- Male
- Middle Aged
- NF-kappa B/biosynthesis
- NF-kappa B/genetics
- NF-kappa B/physiology
- NF-kappa B p50 Subunit
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Neoplastic Stem Cells/metabolism
- Protein Isoforms/biosynthesis
- Protein Isoforms/genetics
- Proto-Oncogene Proteins/biosynthesis
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins c-rel
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Transcription Factors/biosynthesis
- Transcription Factors/genetics
- Transcriptional Activation
- Transfection
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- N Arima
- First Department of Internal Medicine, Faculty of Medicine, Kagoshima University, Sakuragaoka, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Bendall HH, Sikes ML, Ballard DW, Oltz EM. An intact NF-kappa B signaling pathway is required for maintenance of mature B cell subsets. Mol Immunol 1999; 36:187-95. [PMID: 10403484 DOI: 10.1016/s0161-5890(99)00031-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Members of the NF-kappaB/Rel transcription factor family are expressed constitutively during B cell development and are further induced by mitogen activation. Mice harboring germline disruptions in individual NF-kappaB subunits exhibit distinct defects in B lymphocyte activation and survival. However, the role of NF-kappaB in the production and maintenance of B cell subsets has been difficult to dissect in these knockout animals due to functional impairment of other immune cells. To directly address the cell autonomous requirements for NF-kappaB in humoral immune compartments, transgenic mice were generated that express a transdominant form of Ikappa-Balpha in B lineage cells. Whereas expression of the inhibitor had only modest effects on basal or LPS-induced levels of NF-kappaB, transgenic B cells were significantly impaired for cellular proliferation and NF-kappaB induction in response to B cell receptor (BCR) crosslinking. Furthermore, the trans-dominant inhibitor produced a dose-dependent reduction in the population of mature splenic B cells. This cellular defect was more pronounced in long-lived B lymphocyte subsets that recirculate to the adult bone marrow. Together, these results indicate that BCR-mediated signaling must maintain NF-kappaB levels above a stringent threshold for proper regulation of B cell homeostasis.
Collapse
Affiliation(s)
- H H Bendall
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | | | | | | |
Collapse
|
48
|
Hettmann T, DiDonato J, Karin M, Leiden JM. An essential role for nuclear factor kappaB in promoting double positive thymocyte apoptosis. J Exp Med 1999; 189:145-58. [PMID: 9874571 PMCID: PMC1887697 DOI: 10.1084/jem.189.1.145] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/1998] [Revised: 10/05/1998] [Indexed: 12/15/2022] Open
Abstract
To examine the role of nuclear factor (NF)-kappaB in T cell development and activation in vivo, we produced transgenic mice that express a superinhibitory mutant form of inhibitor kappaB-alpha (IkappaB-alphaA32/36) under the control of the T cell-specific CD2 promoter and enhancer (mutant [m]IkappaB-alpha mice). Thymocyte development proceeded normally in the mIkappaB-alpha mice. However, the numbers of peripheral CD8(+) T cells were significantly reduced in these animals. The mIkappaB-alpha thymocytes displayed a marked proliferative defect and significant reductions in interleukin (IL)-2, IL-3, and granulocyte/macrophage colony-stimulating factor production after cross-linking of the T cell antigen receptor. Perhaps more unexpectedly, double positive (CD4(+)CD8(+); DP) thymocytes from the mIkappaB-alpha mice were resistant to alpha-CD3-mediated apoptosis in vivo. In contrast, they remained sensitive to apoptosis induced by gamma-irradiation. Apoptosis of wild-type DP thymocytes after in vivo administration of alpha-CD3 mAb was preceded by a significant reduction in the level of expression of the antiapoptotic gene, bcl-xL. In contrast, the DP mIkappaB-alpha thymocytes maintained high level expression of bcl-xL after alpha-CD3 treatment. Taken together, these results demonstrated important roles for NF-kappaB in both inducible cytokine expression and T cell proliferation after TCR engagement. In addition, NF-kappaB is required for the alpha-CD3-mediated apoptosis of DP thymocytes through a pathway that involves the regulation of the antiapoptotic gene, bcl-xL.
Collapse
Affiliation(s)
- T Hettmann
- Departments of Medicine and Pathology, University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | |
Collapse
|
49
|
Chen C, Agnès F, Gélinas C. Mapping of a serine-rich domain essential for the transcriptional, antiapoptotic, and transforming activities of the v-Rel oncoprotein. Mol Cell Biol 1999; 19:307-16. [PMID: 9858554 PMCID: PMC83888 DOI: 10.1128/mcb.19.1.307] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/1998] [Accepted: 09/23/1998] [Indexed: 11/20/2022] Open
Abstract
The v-Rel oncoprotein belongs to the Rel/NF-kappaB family of transcription factors and induces aggressive lymphomas in chickens and transgenic mice. Current models for cell transformation by v-Rel invoke the combined activation of gene expression and the dominant inhibition of transcription mediated by its cellular homologs. Here, we mapped a serine-rich transactivation domain in the C terminus of v-Rel that is necessary for its biological activity. Specific serine-to-alanine substitutions within this region impaired the transcriptional activity of v-Rel, whereas a double mutant abolished its function. In contrast, substitutions with phosphomimetic aspartate residues led to a complete recovery of the transcriptional potential. The transforming activity of v-Rel mutants correlated with their ability to inhibit programmed cell death. The transforming and antiapoptotic activities of v-Rel were abolished by defined Ser-to-Ala mutations and restored by most Ser-to-Asp substitutions. However, one Ser-to-Asp mutant showed wild-type transactivation ability but failed to block apoptosis and to transform cells. These results show that the transactivation function of v-Rel is necessary but not sufficient for cell transformation, adding an important dimension to the transformation model. It is possible that defined protein-protein interactions are also required to block apoptosis and transform cells. Since v-Rel is an acutely oncogenic member of the Rel/NF-kappaB family, our data raise the possibility that phosphorylation of its serine-rich transactivation domain may regulate its unique biological activity.
Collapse
Affiliation(s)
- C Chen
- Center for Advanced Biotechnology and Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854-5638, USA
| | | | | |
Collapse
|
50
|
Uhlik M, Good L, Xiao G, Harhaj EW, Zandi E, Karin M, Sun SC. NF-kappaB-inducing kinase and IkappaB kinase participate in human T-cell leukemia virus I Tax-mediated NF-kappaB activation. J Biol Chem 1998; 273:21132-6. [PMID: 9694868 DOI: 10.1074/jbc.273.33.21132] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The tax gene product of human T-cell leukemia virus I induces aberrant expression of various cellular genes, which contributes to transformation of host cells. Induction of many Tax target genes is mediated through transcription factor NF-kappaB. Here we show that Tax triggers activation of cellular protein kinases, IkappaB kinase alpha (IKKalpha) and IKKbeta, which phosphorylate the NF-kappaB inhibitory protein IkappaB alpha, resulting in its degradation and NF-kappaB activation. Constitutive IKK activation occurs in both Tax-transfected and human T-cell leukemia virus I-infected T cells. We further demonstrate that Tax-mediated NF-kappaB signaling also requires the NF-kappaB-inducing kinase (NIK). Consistently, inactive forms of either IKKs or NIK attenuate Tax-mediated NF-kappaB activation. Therefore, Tax activates NF-kappaB by targeting cellular signaling molecules, including both IKKs and NIK.
Collapse
Affiliation(s)
- M Uhlik
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | | | | | | | | | | | | |
Collapse
|