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Bhatnagar A, Chopra U, Raja S, Das KD, Mahalingam S, Chakravortty D, Srinivasula SM. TLR-mediated aggresome-like induced structures comprise antimicrobial peptides and attenuate intracellular bacterial survival. Mol Biol Cell 2024; 35:ar34. [PMID: 38170582 PMCID: PMC10916861 DOI: 10.1091/mbc.e23-09-0347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024] Open
Abstract
Immune cells employ diverse mechanisms for host defense. Macrophages, in response to TLR activation, assemble aggresome-like induced structures (ALIS). Our group has shown TLR4-signaling transcriptionally upregulates p62/sequestome1, which assembles ALIS. We have demonstrated that TLR4-mediated autophagy is, in fact, selective-autophagy of ALIS. We hypothesize that TLR-mediated autophagy and ALIS contribute to host-defense. Here we show that ALIS are assembled in macrophages upon exposure to different bacteria. These structures are associated with pathogen-containing phagosomes. Importantly, we present evidence of increased bacterial burden, where ALIS assembly is prevented with p62-specific siRNA. We have employed 3D-super-resolution structured illumination microscopy (3D-SR-SIM) and mass-spectrometric (MS) analyses to gain insight into the assembly of ALIS. Ultra-structural analyses of known constituents of ALIS (p62, ubiquitin, LC3) reveal that ALIS are organized structures with distinct patterns of alignment. Furthermore, MS-analyses of ALIS identified, among others, several proteins of known antimicrobial properties. We have validated MS data by testing the association of some of these molecules (Bst2, IFITM2, IFITM3) with ALIS and the phagocytosed-bacteria. We surmise that AMPs enrichment in ALIS leads to their delivery to bacteria-containing phagosomes and restricts the bacteria. Our findings in this paper support hitherto unknown functions of ALIS in host-defense.
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Affiliation(s)
- Anushree Bhatnagar
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram 695551, Kerala, India
| | - Umesh Chopra
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Sebastian Raja
- Laboratory of Molecular Cell Biology, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600036, India
| | - Krishanu Dey Das
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram 695551, Kerala, India
| | - S. Mahalingam
- Laboratory of Molecular Cell Biology, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600036, India
| | - Dipshikha Chakravortty
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram 695551, Kerala, India
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Srinivasa Murty Srinivasula
- School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram 695551, Kerala, India
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Mirkale K, Jain SK, Oviya TS, Mahalingam S. Optomicrofluidic detection of cancer cells in peripheral blood via metabolic glycoengineering. Lab Chip 2023; 23:5151-5164. [PMID: 37955355 DOI: 10.1039/d3lc00678f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
The currently existing label-based techniques for the detection of circulating tumor cells (CTCs) target natural surface proteins of cells and are therefore applicable to only limited cancer cell types. We report optomicrofluidic detection of cancer cells in the pool of peripheral blood mononuclear cells (PBMCs) by exploiting the difference in their cell metabolism. We employ metabolic glycoengineering as a click chemistry tool for tagging cells that yields several fold-higher fluorescence signals from cancer cells compared to that from PBMCs. The effects of concentrations of the tagging compounds and cell incubation time on the fluorescence signal intensity are studied. The tagged cells were encapsulated in droplets ensuring that cells enter the detection region two-dimensionally focused in single-file and optically detected with a high detection efficiency and low coefficient of variation of the signals. The metabolic tagging approach showed a significantly higher tagging efficiency and average fluorescence signal compared to the well-established and widely adopted anti-EpCAM-FITC-based tagging. We demonstrated the detection of three different cancer cell lines - EpCAM-negative cervical cancer cell, HeLa, weakly EpCAM positive, and triple-negative breast cancer cell, MDA-MB-231, and strongly EpCAM positive breast cancer cell, MCF7, highlighting that the proposed technique is independent of naturally occurring cell surface proteins and widely applicable. The metabolically tagged and optically detected cells were successfully recultured, proving the compatibility of the proposed technique with downstream assays. The proposed technique is then utilised for the detection of CTCs in metastatic cancer patients' blood. The current work provides a new strategy for detecting cancer cells in the blood that can find potential applications in both fundamental research and clinical studies involving CTCs as well as in single-cell sequencing.
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Affiliation(s)
- K Mirkale
- Micro Nano Bio Fluidics Unit, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, Tamilnadu, India.
| | - S K Jain
- Micro Nano Bio Fluidics Unit, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, Tamilnadu, India.
| | - T S Oviya
- Micro Nano Bio Fluidics Unit, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, Tamilnadu, India.
| | - S Mahalingam
- Laboratory of Molecular Cell Biology, National Cancer Tissue Biobank, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai-600036, India
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Mahalingam S, Devanboo A, Pradhan A, Suravaparu A, Sai Kiranmai T, Venkataswamy E, Ramprasad VL, Kadam P. True Fetal Trisomy 22 Detected Using Genome-Wide Noninvasive Prenatal Testing. J Obstet Gynaecol India 2023; 73:180-182. [PMID: 37073230 PMCID: PMC10105796 DOI: 10.1007/s13224-022-01730-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 10/30/2022] [Indexed: 01/14/2023] Open
Affiliation(s)
| | | | | | | | - T. Sai Kiranmai
- Sai Diagnostics and Fetal Medicine Center, Anantapuramu, India
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Mahalingam S, Manap A, Lau K, Omar A, Chelvanathan P, Chia C, Amin N, Mathews I, Afandi N, Rahim N. Mixture deposition method for graphene quantum dots-based dye-sensitized solar cell. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139732] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Rajendran G, Mahalingam S, Kagne R, Nathan B. The South African flag sign-an electrocardiographic sign to predict the culprit artery. QJM 2021; 114:665-666. [PMID: 33989421 DOI: 10.1093/qjmed/hcab137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- G Rajendran
- Department of Emergency Medicine and Trauma, Jawarharlal Institute of Postgraduate Medical Education and Research (JIPMER), Gorimedu, Puducherry 605006, India
| | - S Mahalingam
- Department of Emergency Medicine and Trauma, Jawarharlal Institute of Postgraduate Medical Education and Research (JIPMER), Gorimedu, Puducherry 605006, India
| | - R Kagne
- Department of Emergency Medicine and Trauma, Jawarharlal Institute of Postgraduate Medical Education and Research (JIPMER), Gorimedu, Puducherry 605006, India
| | - B Nathan
- Department of Emergency Medicine and Trauma, Jawarharlal Institute of Postgraduate Medical Education and Research (JIPMER), Gorimedu, Puducherry 605006, India
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Kannan S, Mahalingam S, Srinath S, Sivasankaran M, Kannan S. An experimental study in HCCI combustion of LPG in diesel engine. ACTA ACUST UNITED AC 2021. [DOI: 10.1016/j.matpr.2020.09.774] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Yadav RM, Gupta M, Dalvi A, Bargir UA, Hule G, Shabrish S, Aluri J, Kulkarni M, Kambli P, Uppuluri R, Seshadri S, Jagadeesh S, Suresh B, Raja J, Taur P, Malaischamy S, Ghosh P, Mahalingam S, Kadam P, Lashkari HP, Tamhankar P, Tamhankar V, Mithbawkar S, Bhattad S, Jhawar P, Makam A, Bansal V, Prasad M, Govindaraj G, Guhan B, Bharadwaj Tallapaka K, Desai M, Raj R, Madkaikar MR. Prenatal Diagnosis for Primary Immunodeficiency Disorders-An Overview of the Indian Scenario. Front Immunol 2020; 11:612316. [PMID: 33365035 PMCID: PMC7750517 DOI: 10.3389/fimmu.2020.612316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/04/2020] [Indexed: 01/13/2023] Open
Abstract
Prenatal Diagnosis (PND) forms an important part of primary preventive management for families having a child affected with primary immunodeficiency. Although individually sparse, collectively this group of genetic disorders represents a significant burden of disease. This paper discusses the prenatal services available for affected families at various centers across the country and the challenges and ethical considerations associated with genetic counseling. Mutation detection in the index case and analysis of chorionic villous sampling or amniocentesis remain the preferred procedures for PND and phenotypic analysis of cordocentesis sample is reserved for families with well-characterized index case seeking PND in the latter part of the second trimester of pregnancy. A total of 112 families were provided PND services in the last decade and the presence of an affected fetus was confirmed in 32 families. Post-test genetic counseling enabled the affected families to make an informed decision about the current pregnancy.
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Affiliation(s)
- Reetika Malik Yadav
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Maya Gupta
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Aparna Dalvi
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Umair Ahmed Bargir
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Gouri Hule
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Snehal Shabrish
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Jahnavi Aluri
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Manasi Kulkarni
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Priyanka Kambli
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
| | - Ramya Uppuluri
- Department of Pediatric Hematology-Oncology, Blood Marrow Transplantation, Apollo Hospitals, Chennai, India
| | - Suresh Seshadri
- Department of Clinical Genetics & Genetic Counseling, Mediscan Systems, Chennai, India
| | - Sujatha Jagadeesh
- Department of Clinical Genetics & Genetic Counseling, Mediscan Systems, Chennai, India
| | - Beena Suresh
- Department of Clinical Genetics & Genetic Counseling, Mediscan Systems, Chennai, India
| | - Jayarekha Raja
- Department of Clinical Genetics & Genetic Counseling, Mediscan Systems, Chennai, India
| | - Prasad Taur
- Department of Immunology and Department of Pediatric Hemato-Oncology, Bai Jerbai Wadia Hospital for Children, Mumbai, India
| | | | | | | | - Priya Kadam
- MedGenome Labs Private Limited, Bangalore, India
| | - Harsha Prasada Lashkari
- Department of Pediatrics, Kasturba Medical College Hospital, Manipal Academy of Higher Education, Mangalore, India
| | | | | | | | - Sagar Bhattad
- Division of Pediatric Immunology and Rheumatology, Department of Pediatrics, Aster CMI Hospital, Bangalore, India
| | - Prerna Jhawar
- Department of Fetal Medicine, Motherhood Hospital, Bangalore, India
| | - Adinarayan Makam
- Department of Fetal Medicine, Adi Advanced Centre for Fetal Care, Bangalore, India
| | - Vandana Bansal
- Fetal Medicine Department Surya Hospitals, Mumbai, India
| | | | - Geeta Govindaraj
- Department of Pediatrics, Government Medical College, Kozhikode, Calicut, India
| | - Beena Guhan
- Department of Pediatrics, Government Medical College, Kozhikode, Calicut, India
| | | | - Mukesh Desai
- Department of Immunology and Department of Pediatric Hemato-Oncology, Bai Jerbai Wadia Hospital for Children, Mumbai, India
| | - Revathi Raj
- Department of Pediatric Hematology-Oncology, Blood Marrow Transplantation, Apollo Hospitals, Chennai, India
| | - Manisha Rajan Madkaikar
- Center of Excellence for PIDs, Department of Pediatric Immunology and Leucocyte Biology, ICMR-National Institute of Immunohaematology, Mumbai, India
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Mahalingam S, Abdullah H, Manap A. Role of acid-treated CNTs in chemical and electrochemical impedance study of dye-sensitised solar cell. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.01.138] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Eranka Illangakoon U, Mahalingam S, Wang K, Cheong YK, Canales E, Ren G, Cloutman-Green E, Edirisinghe M, Ciric L. Gyrospun antimicrobial nanoparticle loaded fibrous polymeric filters. Materials Science and Engineering: C 2017; 74:315-324. [DOI: 10.1016/j.msec.2016.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 12/04/2016] [Indexed: 11/26/2022]
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10
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Badge R, Kailash K, Dickson DR, Mahalingam S, Raza A, Birch A, Nuttall D, Murali SR, Hayton MJ, Talwalkar S, Watts AC, Trail IA. Medium-term outcomes of the Universal-2 total wrist arthroplasty in patients with rheumatoid arthritis. Bone Joint J 2017; 98-B:1642-1647. [PMID: 27909126 DOI: 10.1302/0301-620x.98b12.37121] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 07/14/2016] [Indexed: 11/05/2022]
Abstract
AIMS The aims of this study were to evaluate the clinical and radiological outcomes of the Universal-2 total wrist arthroplasty (TWA) in patients with rheumatoid arthritis. PATIENTS AND METHODS This was a retrospective review of all 95 Universal-2 TWAs which were performed in our institution between 2003 to 2012 in patients with rheumatoid arthritis. A total of six patients were lost to follow-up and two died of unrelated causes. A total of ten patients had bilateral procedures. Accordingly, 75 patients (85 TWAs) were included in the study. There were 59 women and 16 men with a mean age of 59 years (26 to 86). The mean follow-up was 53 months (24 to 120). Clinical assessment involved recording pain on a visual analogue score, range of movement, grip strength, the Quick Disabilities of the Arm, Shoulder and Hand (DASH) and Wrightington wrist scores. Any adverse effects were documented with particular emphasis on residual pain, limitation of movement, infection, dislocation and the need for revision surgery. Radiographic assessment was performed pre-operatively and at three, six and 12 months post-operatively, and annually thereafter. Arthroplasties were assessed for distal row intercarpal fusion and loosening. Radiolucent zones around the components were documented according to a system developed at our institution. RESULTS The mean worst pain was 8.1 (3 to 10) pre-operatively and 5.4 (0 to 10) at latest follow-up (p < 0.001). Movements were preserved with mean dorsiflexion of 29o (0 o to 70 o) and palmar flexion of 21o (0o to 50o). The mean grip strength was 4.8 kg (1.7 to 11.5) pre-operatively and 10 kg (0 to 28) at final follow-up (p < 0.001). The mean QuickDASH and Wrightington wrist scores improved from 61 (16 to 91) to 46 (0 to 89) and 7.9 (1.8 to 10) to 5.7 (0 to 7.8) (p < 0.001). A total of six patients (7%) had major complications; three required revision arthroplasty and three an arthrodesis. The Kaplan-Meier probability of survival using removal of the components as the endpoint was 91% at 7.8 years (95% confidence interval 84 to 91). CONCLUSION The Universal-2 TWA is recommended for use in patients with rheumatoid arthritis. Cite this article: Bone Joint J 2016;98-B:1642-7.
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Affiliation(s)
- R Badge
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - K Kailash
- Trauma and Orthopaedics, University Hospital Crosshouse, Kilmarnock, KA2 0BE, UK
| | - D R Dickson
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - S Mahalingam
- Hairmyres Hospital, Eaglesham Rd, East Kilbride, Glasgow, G75 8RG, UK
| | - A Raza
- James Cook University Hospital, Marton Road, Middlesbrough, TS4 3BW, UK
| | - A Birch
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - D Nuttall
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - S R Murali
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - M J Hayton
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - S Talwalkar
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - A C Watts
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
| | - I A Trail
- Wrightington Hospital NHS Trust, Hall Lane, Appley Bridge, Wigan, Lancashire, WN6 9EP, UK
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Mahalingam S, Amer I, Ghufoor K, Choudhury N. Patient positioning for direct laryngoscopy--A national survey of 320 UK ENT consultant surgeons: Our experience. Clin Otolaryngol 2016; 40:727-30. [PMID: 25879301 DOI: 10.1111/coa.12442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2015] [Indexed: 11/24/2022]
Affiliation(s)
- S Mahalingam
- Department of Otolaryngology, Head and Neck Surgery, East Surrey Hospital, Redhill, UK
| | - I Amer
- Department of Otolaryngology, Head and Neck Surgery, Royal Sussex County Hospital, Brighton, UK
| | - K Ghufoor
- Department of Otolaryngology, Head and Neck Surgery, St Bartholomew's Hospital, West Smithfield, London, UK
| | - N Choudhury
- Department of Otolaryngology, Head and Neck Surgery, East Surrey Hospital, Redhill, UK
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12
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Abstract
Introduction In 2011 The Royal College of Surgeons of England (RCS) set out best practice standards for emergency surgery. This national pilot audit aimed to determine the compliance of otolaryngology departments in England with these published guidelines. Methods A 26-item online questionnaire was devised that encompassed all the 36 best practices as set out by the RCS for ear, nose and throat (ENT) surgery. This was sent to ENT trainees and consultants based at units in England providing emergency ENT services. Results Data were obtained from 55 of the 102 units (response rate: 54%). A mean compliance of 71% was achieved (range: 25-94%). No units achieved all of the best practices. The standards with the highest compliance included 24-hour availability of blood transfusion and haematology opinion for patients with epistaxis, availability of a consultant or ST3/equivalent for immediate discussion of severe post-tonsillectomy bleeding, 24-hour access to blood transfusion for arrest of haemorrhage and immediate theatre access for arrest of haemorrhage. The areas with the lowest compliance were provision of a pathway for angiography/embolisation for epistaxis and provision of an equipped ENT room on a paediatric ward. Conclusions This audit has highlighted that the majority of departments in England are providing a good standard of ENT emergency care. There is room for improvement in certain areas, such as the provision of an embolisation pathway in the context of refractory epistaxis. We hope that this audit will encourage ENT departments to evaluate their current provision of emergency care and institute changes (where necessary) to maintain and improve their practices.
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Affiliation(s)
- S Sharma
- University Hospitals of Leicester NHS Trust , UK
| | - A Yao
- Newcastle upon Tyne Hospitals NHS Foundation Trust , UK
| | | | - R Persaud
- Al Zahra Hospital, Sharjah and Dubai , United Arab Emirates
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Mahalingam S, Awad Z, Tolley NS, Khemani S. Ventilation tube insertion simulation: a literature review and validity assessment of five training models. Clin Otolaryngol 2016; 41:321-6. [PMID: 26385050 DOI: 10.1111/coa.12543] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The objective of this study was to identify and investigate the face and content validity of ventilation tube insertion (VTI) training models described in the literature. DESIGN A review of literature was carried out to identify articles describing VTI simulators. Feasible models were replicated and assessed by a group of experts. SETTING Postgraduate simulation centre. PARTICIPANTS Experts were defined as surgeons who had performed at least 100 VTI on patients. Seventeen experts were participated ensuring sufficient statistical power for analysis. MAIN OUTCOME MEASURES A standardised 18-item Likert-scale questionnaire was used. This addressed face validity (realism), global and task-specific content (suitability of the model for teaching) and curriculum recommendation. RESULTS The search revealed eleven models, of which only five had associated validity data. Five models were found to be feasible to replicate. None of the tested models achieved face or global content validity. Only one model achieved task-specific validity, and hence, there was no agreement on curriculum recommendation. CONCLUSIONS The quality of simulation models is moderate and there is room for improvement. There is a need for new models to be developed or existing ones to be refined in order to construct a more realistic training platform for VTI simulation.
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Affiliation(s)
- S Mahalingam
- Department of Otolaryngology, Head and Neck Surgery, East Surrey Hospital, Redhill, UK
| | - Z Awad
- Department of Otolaryngology, Head and Neck Surgery, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - N S Tolley
- Department of Otolaryngology, Head and Neck Surgery, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - S Khemani
- Department of Otolaryngology, Head and Neck Surgery, East Surrey Hospital, Redhill, UK
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Mahalingam S, Srinivasan R, Spielmann P. Quality-of-life and functional outcomes following pharyngolaryngectomy: a systematic review of literature. Clin Otolaryngol 2016; 41:25-43. [DOI: 10.1111/coa.12466] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2015] [Indexed: 11/30/2022]
Affiliation(s)
- S. Mahalingam
- University of Edinburgh; Edinburgh UK
- Department of Otolaryngology; Head and Neck Surgery; East Surrey Hospital; Redhill UK
| | - R. Srinivasan
- Department of Otolaryngology; Head and Neck Surgery; East Surrey Hospital; Redhill UK
| | - P. Spielmann
- Department of Otolaryngology; Head and Neck Surgery; East Surrey Hospital; Redhill UK
- Department of Otolaryngology; Head and Neck Surgery; Ninewells Hospital; University Department of Otolaryngology; Dundee UK
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Mahalingam S, Limb C, Srinivasan R, Riley P, Khemani S. What antibiotics should we administer for paediatric orbital cellulitis? A national survey of NHS trusts. Int J Surg 2015. [DOI: 10.1016/j.ijsu.2015.07.262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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16
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Gupta S, Yao A, Mahalingam S, Persaud R. ENT emergency surgery – Are we complying with the royal college of surgeons of England standards? A national pilot audit. Int J Surg 2015. [DOI: 10.1016/j.ijsu.2015.07.226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Xu Z, Mahalingam S, Rohn J, Ren G, Edirisinghe M. Physio-chemical and antibacterial characteristics of pressure spun nylon nanofibres embedded with functional silver nanoparticles. Materials Science and Engineering: C 2015; 56:195-204. [DOI: 10.1016/j.msec.2015.06.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 06/03/2015] [Accepted: 06/05/2015] [Indexed: 11/29/2022]
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Boddu A, Kumble A, Mahalingam S, Baliga BS, Achappa B. Pulmonary dysfunction in children with beta thalassemia major in relation with iron overload - a cross sectional hospital based study. Asian J Med Sci 2015. [DOI: 10.3126/ajms.v6i5.11782] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background: Previously many patients with thalassemia major died from severe anemia during first decade, but with modern transfusion therapy many now survive beyond childhood. Because of such therapy, however excessive iron deposition occurs in lungs and causing respiratory dysfunction. Respiratory impairment occurs because of defective chelation and repeated transfusions. Objectives: To a) study pattern of respiratory impairment using spirometry, b) estimate iron overload by measuring serum ferritin levels, c) correlate a&b. Methodology:Thalassemia children >7year, on regular blood transfusion were included in the study after getting institutional ethical clearance .Standardised pulmonary function test was done using spirometry. Iron overload was assessed using serum ferritin levels. Severity of pulmonary dysfunction was correlated with serum ferritin levels. Results:Total of 42 children were included 62% were males and 38% were females (with median age 12yrs). By spirometry 95% had restrictive pattern of respiratory dysfunction. Mean ferritin value was 4152. Out of them10 (23.8%) mild, 25(59%) moderate and 5(12%) severe dysfunction based on FEV1 and FVC. The mean ferritin values in severe respiratory dysfunction is 6275 which is significantly higher when compared to moderate (4249) and mild (3066) pattern of respiratory dysfunction. None of the children had evidence of CCF. Significant correlation (p value=0.003) was found between severity of pulmonary dysfunction with ferritin values and also with weight of the child (p value=0.007). No other significant correlation found between severity pattern and transfusion index, age or height. Conclusion:Restrictive pattern is most common pulmonary dysfunction seen in chronic iron overloaded thalassemia major children. Regular blood transfusions with adequate chelation decrease incidence of pulmonary dysfunction. Screening of all thalassemia children using spirometry is need of the hour. DOI: http://dx.doi.org/10.3126/ajms.v6i5.11782Asian Journal of Medical Sciences Vol.6(5) 2015 47-50
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Mahalingam S, Kalia P, Mugilan S. Oral and maxillofacial surgery in medical schools in the United Kingdom. Br J Oral Maxillofac Surg 2015; 53:295-7. [PMID: 25596796 DOI: 10.1016/j.bjoms.2014.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 12/18/2014] [Indexed: 11/18/2022]
Abstract
It has been suggested that oral and maxillofacial surgery (OMFS) is better established in dental schools than in medical schools, and as a result, dental students have a greater insight into the scope of the specialty. We explore how much time is allocated to OMFS in the undergraduate curriculum in medical schools in the UK, and the students' perceptions of the specialty. A total of 186 final year students from 5 medical schools were recruited in a questionnaire-based survey. Of them, 141 (76%) reported no exposure to OMFS, and 37 of the 45 students (82%) who had had some exposure reported that it was not part of their timetabled curriculum. The 2 aspects considered most important by students were the long training pathway (n=38, 20%) and the requirement for dual qualification (n=33, 18%). Our results suggest that UK medical schools provide limited exposure to OMFS. We think it is important that the specialty is included in the compulsory undergraduate curriculum to ensure that medical students gain some awareness. This will not only allow junior doctors to make better informed decisions about their chosen careers, but may also help to reduce the number of inappropriate referrals from doctors in other specialties.
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Affiliation(s)
- S Mahalingam
- Department of Surgery, East Surrey Hospital, Canada Avenue, Redhill, Surrey RH1 5RH, United Kingdom.
| | - P Kalia
- Department of Surgery, East Surrey Hospital, Canada Avenue, Redhill, Surrey RH1 5RH, United Kingdom
| | - S Mugilan
- Department of Surgery, East Surrey Hospital, Canada Avenue, Redhill, Surrey RH1 5RH, United Kingdom
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Mahalingam S, Gao L, Nageshwaran S, Vickers C, Bottomley T, Grewal P. Improving pressure ulcer risk assessment and management using the Waterlow scale at a London teaching hospital. J Wound Care 2014; 23:613-22. [DOI: 10.12968/jowc.2014.23.12.613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- S. Mahalingam
- Core Surgical Trainee; Department of Otolaryngology, Head & Neck Surgery, East Surrey Hospital, Canada Avenue, Redhill, Surrey, RHI 5RH
| | - L. Gao
- Resident in Anesthesia; 55 Fruit Street, Boston, MA 02114, USA
| | - S. Nageshwaran
- Wellcome Trust Translational Medicine Fellow; Medical Research Council Clinical Sciences Centre, Du Cane Road, London, W12 0NN
| | - C. Vickers
- Watford General Hospital, Vicarage Road, Watford, Hertfordshire, WD18 0HB
| | - T. Bottomley
- Foundation Doctor; 38 Lower Green Road, Esher, Surrey, KT10 8HD
| | - P. Grewal
- FRCS; Queen Alexandra Hospital, Portsmouth, PO6 3LY
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Mahalingam S, Ren G, Edirisinghe M. Rheology and pressurised gyration of starch and starch-loaded poly(ethylene oxide). Carbohydr Polym 2014; 114:279-287. [DOI: 10.1016/j.carbpol.2014.08.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 07/04/2014] [Accepted: 08/04/2014] [Indexed: 12/28/2022]
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Singh SP, Gupta P, Mahalingam S. HIV-2/SIV Vpx Protein Interacts with Human Nup153 and Regulates Viral Pathogenesis. AIDS Res Hum Retroviruses 2014. [DOI: 10.1089/aid.2014.5497.abstract] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
| | - Pankaj Gupta
- Indian Institute of Technology Madras, Biotechnology, Chennai, India
| | - S Mahalingam
- Indian Institute of Technology Madras, Biotechnology, Chennai, India
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Wijesinghe W, Mantilaka M, Premalal E, Herath H, Mahalingam S, Edirisinghe M, Rajapakse R, Rajapakse R. Facile synthesis of both needle-like and spherical hydroxyapatite nanoparticles: Effect of synthetic temperature and calcination on morphology, crystallite size and crystallinity. Materials Science and Engineering: C 2014; 42:83-90. [DOI: 10.1016/j.msec.2014.05.032] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 03/21/2014] [Accepted: 05/07/2014] [Indexed: 12/25/2022]
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Mahalingam S, Meinders MBJ, Edirisinghe M. Formation, stability, and mechanical properties of bovine serum albumin stabilized air bubbles produced using coaxial electrohydrodynamic atomization. Langmuir 2014; 30:6694-6703. [PMID: 24841724 DOI: 10.1021/la5011715] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Bovine serum albumin (BSA) microbubbles were generated using coaxial electrohydrodynamic atomization (CEDHA) using various concentrations of BSA solutions. The bubble characteristics and the long-term stability of the microbubbles were studied through adjustment of processing parameters and the collection media. Bubbles in the range of 40-800 μm were obtained in a controlled fashion, and increasing the flow rate of the BSA solution reduced the polydispersity of the microbubbles. Use of distilled water-glutaraldehyde, glycerol, and glycerol-Tween 80 collection media allowed a remarkable improvement in bubble stability compared to BSA solution collection medium. Possible physical mechanisms were developed to explain the stability of the microbubbles. The collection distance showed a marked influence on stability of the microbubbles. Near-monodisperse particle-reinforced microbubbles were formed with various concentrations of 2,2'-azobis(isobutyramidine) dihydrochloride (AIBA)-polystyrene particle in BSA solution. The bubble size and the size distribution showed negligible change over a period of time irrespective of the concentration of particles at the bubble surface. The compression stiffness of the microbubbles was determined using nanoindentation at ambient temperature and showed that the stiffness of the microbubbles increased from 8 N/m to 20 N/m upon changing the concentration of BSA solution from 5 wt % to 15 wt %.
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Affiliation(s)
- S Mahalingam
- TopInstitute Food and Nutrition (TIFN) , P.O. Box 557, Wageningen, 6700 AN, The Netherlands
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Bertozzi AI, Munzer C, Fouyssac F, Andre N, Boetto S, Leblond P, Bourdeaut F, Dufour C, Deshpande RK, Bhat KG, Mahalingam S, Muscat A, Cain J, Ferguson M, Popovski D, Algar E, Rossello FJ, Jayasekara S, Watkins DN, Hodge J, Ashley D, Hishii M, Saito M, Arai H, Han ZY, Richer W, Lucchesi C, Freneaux P, Nicolas A, Grison C, Pierron G, Delattre O, Bourdeaut F, Epari S, TS N, Gupta T, Chinnaswamy G, Sastri JG, Shetty P, Moiyadi A, Jalali R, Fay-McClymont T, Johnston D, Janzen L, Guger S, Scheinemann K, Fleming A, Fryer C, Hukin J, Mabbott D, Huang A, Bouffet E, Lafay-Cousin L, Kawamura A, Yamamoto K, Nagashima T, Bartelheim K, Benesch M, Buchner J, Gerss J, Hasselblatt M, Kortmann RD, Fleischack G, Quiroga E, Reinhard H, Schneppenheim R, Seeringer A, Siebert R, Timmermann B, Warmuth-Metz M, Schmid I, Fruhwald MC, Fruhwald MC, Bartelheim K, Seeringer A, Kerl K, Kortmann RD, Warmuth-Metz M, Hasselblatt M, Schneppenheim R, Siebert R, Klingebiel T, Al-Kofide A, Khafaga Y, Al-Hindi H, Dababo M, Ul-Haq A, Anas M, Barria MG, Siddiqui K, Hassounah M, Ayas M, Al-Shail E, Hasselblatt M, Jeibmann A, Eikmeier K, Linge A, Johann P, Koos B, Bartelheim K, Kool M, Pfister SM, Fruhwald MC, Paulus W, Hasselblatt M, Schuller U, Junckerstorff R, Rosenblum MK, Alassiri AH, Rossi S, Bartelheim K, Schmid I, Gottardo N, Toledano H, Viscardi E, Witkowski L, Nagel I, Oyen F, Foulkes WD, Paulus W, Siebert R, Schneppenheim R, Fruhwald MC, Schrey D, Malietzis G, Chi S, Dufour C, Lafay-Cousin L, Marshall L, Carceller F, Moreno L, Zacharoulis S, Bhardwaj R, Chakravadhanula M, Ozals V, Hampton C, Metpally R, Grillner P, Asmundsson J, Gustavsson B, Holm S, Johann PD, Korshunov A, Ryzhova M, Kerl K, Milde T, Witt O, Jones DTW, Hovestadt V, Gajjar A, Hasselblatt M, Fruhwald M, Pfister S, Kool M, Finetti M, Pons ADC, Selby M, Smith A, Crosier S, Wood J, Skalkoyannis B, Bailey S, Clifford S, Williamson D, Seeringer A, Bartelheim K, Kerl K, Hasselblatt M, Rutkowski S, Timmermann B, Kortmann RD, Schneppenheim R, Warmuth-Metz M, Gerss J, Siebert R, Graf N, Boos J, Nysom K, Fruhwald MC, Kerl K, Moreno N, Holsten T, Ahlfeld J, Mertins J, Hotfilder M, Kool M, Bartelheim K, Schleicher S, Handgretinger R, Fruhwald M, Meisterernst M, Kerl K, Schmidt C, Ahlfeld J, Moreno N, Dittmar S, Pfister S, Fruhwald M, Kool M, Meisterernst M, Schuller U, Chan GCF, Shing MMK, Yuen HL, Li RCH, Ling SL, Slavc I, Peyrl A, Chocholous M, Azizi A, Czech T, Dieckmann K, Haberler C, Leiss U, Gotti G, Biassoni V, Schiavello E, Spreafico F, Pecori E, Gandola L, Massimino M, Mertins J, Kornelius K, Moreno N, Holsten T, Fruhwald M, Kool M, Meisterernst M, Yano H, Nakayama N, Ohe N, Ozeki M, Kanda K, Kimura T, Hori T, Fukao T, Iwama T, Weil AG, Diaz A, Gernsback J, Bhatia S, Ragheb J, Niazi T, Khatib Z, Kerl K, Holsten T, Moreno N, Zoghbi A, Meisterernst AM, Birks D, Griesinger A, Amani V, Donson A, Posner R, Dunham C, Kleinschmidt-DeMasters BK, Handler M, Vibhakar R, Foreman N, Bhardwaj R, Ozals V, Hampton C, Zhou L, Catchpoole D, Chakravadhanula M, Kakkar A, Biswas A, Suri V, Sharma M, Kale S, Mahapatra A, Sarkar C, Torchia J, Picard D, Ho KC, Khuong-Quang DA, Louterneau L, Bourgey M, Chan T, Golbourn B, Cousin LL, Taylor MD, Dirks P, Rutka JT, Bouffet E, Hawkins C, Majewski J, Kim SK, Jabado N, Huang A, Chang JHC, Confer M, Chang A, Goldman S, Dunn M, Hartsell W. ATYPICAL TERATOID RHABDOID TUMOUR. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mahalingam S, Kalia P, Nagendran A, Oakeshott P. Undergraduate exposure to plastic surgery: the medical student perspective. J Plast Reconstr Aesthet Surg 2014; 67:e125-6. [PMID: 24444798 DOI: 10.1016/j.bjps.2013.12.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 12/27/2013] [Indexed: 10/25/2022]
Affiliation(s)
- S Mahalingam
- Department of Population Health Sciences & Education, St Georges University of London, Cranmer Terrace, London SW17 0RE, UK.
| | - P Kalia
- Department of Population Health Sciences & Education, St Georges University of London, Cranmer Terrace, London SW17 0RE, UK
| | - A Nagendran
- Department of Population Health Sciences & Education, St Georges University of London, Cranmer Terrace, London SW17 0RE, UK
| | - P Oakeshott
- Department of Population Health Sciences & Education, St Georges University of London, Cranmer Terrace, London SW17 0RE, UK
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Affiliation(s)
- S Mahalingam
- From the George Washington University Medical Center, Department of Radiology, Washington, DC
| | - L M Levy
- From the George Washington University Medical Center, Department of Radiology, Washington, DC.
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Hong R, Finkelstein S, Han B, Komarnicky L, Kuske R, Mahalingam S, Mantz C, Nasr N, Strasser J, Yashar C. Outcomes for APBI With the Strut-Based Brachytherapy Applicator in 430 Patients. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Liang T, Mahalingam S, Edirisinghe M. Creating "hotels" for cells by electrospinning honeycomb-like polymeric structures. Mater Sci Eng C Mater Biol Appl 2013; 33:4384-91. [PMID: 23910357 DOI: 10.1016/j.msec.2013.06.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/28/2013] [Accepted: 06/22/2013] [Indexed: 01/15/2023]
Abstract
It is well established that three-dimensional honeycomb-like nanofibrous structures enhance cell activity. In this work, we report that electrospun polymer nanofibres self-assemble into three-dimensional honeycomb-like structures. The underlying mechanism is studied by varying the polymer solution concentration, collecting substrates and working distance. The polymer solution concentration has a significant effect on the size of the electrospun nanofibres. The collection substrate and working distance affect the electric field strength, the evaporation of solvent and the discharging of nanofibres and consequently these two had a significant influence on the self-assembly of nanofibres.
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Affiliation(s)
- T Liang
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
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Kailash K, Raza A, Mahalingam S, Talwalkar S. AB0296 Outcomes of universal-2 total wrist arthroplasty: Our experience at wrightington hospital. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Hong R, Patel R, Han B, Kuske R, Strasser J, Kormanicky L, Mahalingam S, Mohideen N, Lyden M, Yashar C. Results of the SAVI Research Collaborative Group Registry: Correlating Clinical Toxicity With Dosimetric Parameters in Patients Treated With APBI Using Strut-based Brachytherapy. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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George K, Ahmed N, Fan K, Mahalingam S. Osteomyelitis of the head and neck. Br J Oral Maxillofac Surg 2012. [DOI: 10.1016/j.bjoms.2012.04.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Nakajima-Kambe T, Edwinoliver N, Maeda H, Thirunavukarasu K, Gowthaman M, Masaki K, Mahalingam S, Kamini N. Purification, cloning and expression of an Aspergillus niger lipase for degradation of poly(lactic acid) and poly(ε-caprolactone). Polym Degrad Stab 2012. [DOI: 10.1016/j.polymdegradstab.2011.11.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Boddapati N, Anbarasu K, Suryaraja R, Tendulkar AV, Mahalingam S. Subcellular distribution of the human putative nucleolar GTPase GNL1 is regulated by a novel arginine/lysine-rich domain and a GTP binding domain in a cell cycle-dependent manner. J Mol Biol 2012; 416:346-66. [PMID: 22244851 DOI: 10.1016/j.jmb.2011.12.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 12/21/2011] [Accepted: 12/30/2011] [Indexed: 12/17/2022]
Abstract
GNL1, a putative nucleolar GTPase, belongs to the MMR1-HSR1 family of large GTPases that are emerging as crucial coordinators of signaling cascades in different cellular compartments. Members of this family share very closely related G-domains, but the signals and pathways regulating their subcellular localization with respect to cell growth remain unknown. To understand the nuclear transport mechanism of GNL1, we have identified a novel arginine/lysine-rich nucleolar localization signal in the NH(2)-terminus that is shown to translocate GNL1 and a heterologous protein to the nucleus/nucleolus in a pathway that is independent of importin-α and importin-β. In addition, the present investigation provided evidence that GNL1 localized to the nucleus and the nucleolus only in G2 stage, in contrast to its cytoplasmic localization in the G1 and S phases of the cell cycle. Using heterokaryon assay, we have demonstrated that GNL1 shuttles between the nucleus and the cytoplasm and that the motif between amino acids 201 and 225 is essential for its export from the nucleus by a signal-mediated CRM1-independent pathway. Alanine-scanning mutagenesis of conserved residues within G-domains suggests that the G2 motif is critical for guanine nucleotide triphosphate (GTP) binding of GNL1 and further showed that nucleolar retention of GNL1 is regulated by a GTP-gating-mediated mechanism. Expression of wild-type GNL1 promotes G2/M transition, in contrast to the G-domain mutant (G2m), which fails to localize to the nucleolus. These data suggest that nucleolar translocation during G2 phase may be critical for faster M-phase transition during cell proliferation. Replacement of conserved residues within the G5 motif alters the stability of GNL1 without changing GTP binding activity. Finally, our data suggest that ongoing transcription is essential for the efficient localization of GNL1 to the nucleolus. Overall, the results reported here demonstrate that multiple mechanisms are involved in the translocation of GNL1 to the nucleolus in a cell cycle-dependent manner to regulate cell growth and proliferation.
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Affiliation(s)
- Neelima Boddapati
- Laboratory of Molecular Virology and Cell Biology, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600 036, India
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Abstract
BACKGROUND AND OBJECTIVES There is little data on the duration of viraemia following infection with Ross River virus (RRV), the most common cause of arbovirus disease in Australia. In particular, no accurate estimate exists for the duration of pre-symptomatic RRV infection, which is important in assessing the potential for transfusion transmission. MATERIALS AND METHODS We used an established mouse model of RRV infection involving adult Swiss outbred mice to measure viraemia following infection. Applying our experimental data to a published probabilistic model for estimating the risk of dengue transmission by transfused blood, we derived comparable risk estimates for RRV. RESULTS Ross River virus RNA was measured using highly sensitive real-time PCR in serum samples to determine the duration of asymptomatic viraemia, which typically lasted 5 days, but extended to 9 days in some mice. Assuming the potential for transfusion transmission is proven, the risk of RRV transmission by blood during a 2004 outbreak in Cairns, Australia was retrospectively estimated as 1 in 13,542 (range from 1 in 4765 to 47,563). CONCLUSION This study provides updated epidemiological data useful to underpin modelling to assess the potential risk of transfusion-transmitted RRV. Using an established model for dengue, the risk estimate for RRV transmission is comparable in the same geographical region. Should transfusion be proven as a route of transmission, this supports consideration of appropriate mitigation strategies to safeguard blood recipients.
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Affiliation(s)
- G Shang
- Virus and Inflammation Research Group, Faculty of Applied Science, University of Canberra, ACT, Australia
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Gupta P, Singhal PK, Rajendrakumar P, Padwad Y, Tendulkar AV, Kalyanaraman VS, Schmidt RE, Srinivasan A, Mahalingam S. Mechanism of host cell MAPK/ERK-2 incorporation into lentivirus particles: characterization of the interaction between MAPK/ERK-2 and proline-rich-domain containing capsid region of structural protein Gag. J Mol Biol 2011; 410:681-97. [PMID: 21762808 DOI: 10.1016/j.jmb.2011.03.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 03/11/2011] [Accepted: 03/14/2011] [Indexed: 01/11/2023]
Abstract
The characteristic event that follows infection of a cell by retroviruses Including human immunodeficiency virus (HIV)/ simian immunodeficiency virus (SIV) is the formation of a reverse transcription complex in which viral nucleic acids are synthesized. Nuclear transport of newly synthesized viral DNA requires phosphorylation of proteins in the reverse transcription complex by virion-associated cellular kinases. Recently, we demonstrated that disruption of cellular mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 2 (ERK-2) incorporation into SIV virions inhibits virus replication in nonproliferating target cells, indicating that MAPK/ERK-2 plays an important role in HIV /SIV replication. The mechanism of incorporation of MAPK/ERK-2 into virus particles is not defined. In this regard, we hypothesized that a likely interaction of MAPK/ERK-2 with Gag(p55) may enable its packaging into virus particles. In the present investigation, we provided evidence for the first time that MAPK/ERK-2 interacts with the structural Gag polyprotein p55 using a combination of mutagenesis and protein-protein interaction analysis. We further show that MAPK/ERK-2 interacts specifically with the poly-proline motif present in the capsid region of Gag(p55). Utilizing virus-like particles directed by Gag, we have shown that the exchange of conserved proline residues within capsid of Gag(p55) resulted in impaired incorporation of MAPK/ERK-2. In addition, the deletion of a domain comprising amino acids 201 to 255 within host cell MAPK/ERK-2 abrogates its interaction with Gag(p55). The relevance of the poly-proline motif is further evident by its conservation in diverse retroviruses, as noted from the sequence analysis and structural modeling studies of predicted amino acid sequences of the corresponding Gag proteins. Collectively, these data suggest that the interaction of MAPK/ERK-2 with Gag polyprotein results in its incorporation into virus particles and may be essential for retroviral replication.
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Affiliation(s)
- Pankaj Gupta
- Laboratory of Molecular Virology and Cell Biology, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai, India
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Sharma S, Mahalingam S, Nicoli T, Connor S, Fan K. Patterns of cervicofacial infections: comparison of pre- and post-operative computed tomography. Br J Oral Maxillofac Surg 2011. [DOI: 10.1016/j.bjoms.2011.04.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kumari G, Singhal P, Suryaraja R, Mahalingam S. Functional Interaction of the Ras Effector RASSF5 with the Tyrosine Kinase Lck: Critical Role in Nucleocytoplasmic Transport and Cell Cycle Regulation. J Mol Biol 2010; 397:89-109. [DOI: 10.1016/j.jmb.2010.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 12/28/2009] [Accepted: 01/05/2010] [Indexed: 10/20/2022]
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Kumari G, Mahalingam S. Extracellular signal-regulated kinase 2 (ERK-2) mediated phosphorylation regulates nucleo-cytoplasmic shuttling and cell growth control of Ras-associated tumor suppressor protein, RASSF2. Exp Cell Res 2009; 315:2775-90. [PMID: 19555684 DOI: 10.1016/j.yexcr.2009.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 06/16/2009] [Accepted: 06/16/2009] [Indexed: 11/18/2022]
Abstract
Ras GTPase controls the normal cell growth through binding with an array of effector molecules, such as Raf and PI3-kinase in a GTP-dependent manner. RASSF2, a member of the Ras association domain family, is known to be involved in the suppression of cell growth and is frequently down-regulated in various tumor tissues by promoter hypermethylation. In the present study, we demonstrate that RASSF2 shuttles between nucleus and cytoplasm by a signal-mediated process and its export from the nucleus is sensitive to leptomycin B. Amino acids between 240 to 260 in the C-terminus of RASSF2 harbor a functional nuclear export signal (NES), which is necessary and sufficient for efficient export of RASSF2 from the nucleus. Substitution of conserved Ile254, Val257 and Leu259 within the minimal NES impaired RASSF2 export from the nucleus. In addition, wild type but not the nuclear export defective RASSF2 mutant interacts with export receptor, CRM-1 and exported from the nucleus. Surprisingly, we observed nucleolar localization for the nuclear export defective mutant suggesting the possibility that RASSF2 may localize in different cellular compartments transiently in a cell cycle dependent manner and the observed nuclear localization for wild type protein may be due to faster export kinetics from the nucleolus. Furthermore, our data suggest that RASSF2 is specifically phosphorylated by MAPK/ERK-2 and the inhibitors of MAPK pathway impair the phosphorylation and subsequently block the export of RASSF2 from the nucleus. These data clearly suggest that ERK-2 mediated phosphorylation plays an important role in regulating the nucleo-cytoplasmic shuttling of RASSF2. Interestingly, nuclear import defective mutant of RASSF2 failed to induce cell cycle arrest at G1/S phase and apoptosis suggesting that RASSF2 regulates cell growth in a nuclear localization dependent manner. Collectively, these data provided evidence for the first time that MAPK/ERK-2 mediated phosphorylation regulates nucleo-cytoplasmic transport and cell growth arrest activity of RASSF2. Taken together, the present study suggests that active transport between nucleus and cytoplasm may constitute an important regulatory mechanism for RASSF2 function.
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Affiliation(s)
- Gita Kumari
- Laboratory of Molecular Virology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500076, India
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Foong YY, Jans DA, Rolph MS, Gahan ME, Mahalingam S. Interleukin-15 mediates potent antiviral responses via an interferon-dependent mechanism. Virology 2009; 393:228-37. [PMID: 19729181 DOI: 10.1016/j.virol.2009.07.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 04/20/2009] [Accepted: 07/06/2009] [Indexed: 10/20/2022]
Abstract
Interleukin-15 (IL-15) is a potent growth factor for activated T and natural killer (NK) cells, stimulator of memory T cells and plays an important role in viral immunity. To investigate mechanisms underlying the antiviral activity of IL-15, a recombinant vaccinia virus (rVV) encoding murine IL-15 (VV-IL-15) was constructed. Following infection of mice with VV-IL-15, virus titres in the ovaries were significantly reduced compared to mice infected with control VV. Growth of VV-IL-15 was also reduced in nude athymic mice, indicating the antiviral activity of IL-15 does not require T cells. Additionally, VV-IL-15 augmented the cytolytic activity of natural NK cells in the spleen and enhanced interferon (IFN) mRNA expression and transcription factors associated with IFN induction. Using knockout mice and antibody depletion studies, we showed for the first time that the control of VV-IL-15 replication in mice is dependent on NK cells and IFNs and, in their absence, the protective role of IL-15 is abolished.
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Affiliation(s)
- Y Y Foong
- Division of Immunology and Genetics, The John Curtin School of Medical Research, Australian National University, Canberra ACT 0200, Australia
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41
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Sharkhuu T, Matthaei KI, Forbes E, Mahalingam S, Hogan SP, Hansbro PM, Foster PS. Mechanism of interleukin-25 (IL-17E)-induced pulmonary inflammation and airways hyper-reactivity. Clin Exp Allergy 2007; 36:1575-83. [PMID: 17177681 DOI: 10.1111/j.1365-2222.2006.02595.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND IL-25, a novel member of the IL-17 cytokine family, promotes CD4+ T-helper 2 lymphocyte-like (Th type-2) inflammatory responses in the lung. Although IL-25 up-regulates IL-13 in the lung, the contribution of this and other type 2 cytokine signalling pathways to the induction and persistence of airways hyper-reactivity (AHR) and allergic inflammation are unclear. OBJECTIVE To determine the downstream factors employed by IL-25 to induce Th type-2 pulmonary inflammation and AHR. METHODS IL-25 was delivered to the airways of BALB/c mice by intra-tracheal (i.t.) instillation and AHR and Th type-2 inflammatory responses were characterized in wild type (WT) and Th type-2-cytokine and -signalling pathway-deficient (-/-) mice. RESULTS IL-25 treatment resulted in AHR, eosinophilic inflammation, mucus hypersecretion and a progressive increase in the production of Th type-2 cytokines in the lungs. Levels of arginase-I (arg-I) and eotaxin were also elevated by IL-25 treatment. A significant reduction in AHR, and attenuation of mucus production was observed in IL-25-treated IL-13-/-, IL-4 receptor alpha (IL-4Ralpha-/-)- and signal-transducer-and-activator-of-transcription-factor-6 (STAT6-/-)-deficient mice. AHR was also inhibited in IL-4(-/-)- and IL-5/eotaxin(1)(-/-)- deficient mice treated with IL-25, however, mucus hypersecretion was not completely ablated. IL-25 promoted Th type-2 responses by directly acting on naïve T cells. CONCLUSION IL-25 potently (single dose) induces sustained AHR and acute pulmonary inflammation with eosinophilia. IL-25-induced AHR is dependent on the production of Th type-2 cytokines, and removal of IL-13 and its signal transduction pathway prevents IL-25-induced airways inflammation and AHR. IL-25 potently induces inflammatory cascades that may exacerbate allergic airways inflammation by promoting Th type-2 cytokine responses in conjunction with the up-regulation of factors (eotaxin and arg-I) that can amplify inflammation associated with allergic disorders. Dysregulation in IL-25 production may predispose to features of allergic airways disease.
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Affiliation(s)
- T Sharkhuu
- Division of Molecular Bioscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
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Kumari G, Singhal PK, Rao MRKS, Mahalingam S. Nuclear transport of Ras-associated tumor suppressor proteins: different transport receptor binding specificities for arginine-rich nuclear targeting signals. J Mol Biol 2007; 367:1294-311. [PMID: 17320110 DOI: 10.1016/j.jmb.2007.01.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 12/28/2006] [Accepted: 01/05/2007] [Indexed: 12/30/2022]
Abstract
Ras proteins regulate a wide range of biological processes by interacting with a variety of effector proteins. In addition to the known role in tumorigensis, the activated form of Ras exhibits growth-inhibitory effects by unknown mechanisms. Several Ras effector proteins identified as mediators of apoptosis and cell-cycle arrest also exhibit properties normally associated with tumor suppressor proteins. Here, we show that Ras effector RASSF5/NORE-1 binds strongly to K-Ras but weakly to both N-Ras and H-Ras. RASSF5 was found to localize both in the nucleus and the nucleolus in contrast to other Ras effector proteins, RASSF1C and RASSF2, which are localized in the nucleus and excluded from nucleolus. A 50 amino acid residue transferable arginine-rich nucleolar localization signal (NoLS) identified in RASSF5 is capable of interacting with importin-beta and transporting the cargo into the nucleolus. Surprisingly, similar arginine-rich signals identified in RASSF1C and RASSF2 interact with importin-alpha and transport the heterologous cytoplasmic proteins to the nucleus. Interestingly, mutation of arginine residues within these nuclear targeting signals prevented interaction of Ras effector proteins with respective transport receptors and abolished their nuclear translocation. These results provide evidence for the first time that arginine-rich signals are able to recognize different nuclear import receptors and transport the RASSF proteins into distinct sub-cellular compartments. In addition, our data suggest that the nuclear localization of RASSF5 is critical for its cell growth control activity. Together, these data suggest that the transport of Ras effector superfamily proteins into the nucleus/nucleolus may play a vital role in modulating Ras-mediated cell proliferation during tumorigenesis.
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Affiliation(s)
- Gita Kumari
- Laboratory of Molecular Virology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500076, India
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Rao MRKS, Kumari G, Balasundaram D, Sankaranarayanan R, Mahalingam S. A novel lysine-rich domain and GTP binding motifs regulate the nucleolar retention of human guanine nucleotide binding protein, GNL3L. J Mol Biol 2006; 364:637-54. [PMID: 17034816 DOI: 10.1016/j.jmb.2006.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 09/01/2006] [Accepted: 09/01/2006] [Indexed: 01/13/2023]
Abstract
A variety of G-proteins and GTPases are known to be involved in nucleolar function. We describe here a new evolutionarily conserved putative human GTPase, guanine nucleotide binding protein-like 3-like (GNL3L). Genes encoding proteins related to GNL3L are present in bacteria and yeast to metazoa and suggests its critical role in development. Conserved domain search analysis revealed that the GNL3L contains a circularly permuted G-motif described by a G5-G4-G1-G2-G3 pattern similar to the HSR1/MMR1 GTP-binding protein subfamily. Highly conserved and critical residues were identified from a three-dimensional structural model obtained for GNL3L using the crystal structure of an Ylqf GTPase from Bacillus subtilis. We demonstrate here that GNL3L is transported into the nucleolus by a novel lysine-rich nucleolar localization signal (NoLS) residing within 1-50 amino acid residues. NoLS identified here is necessary and sufficient to target the heterologous proteins to the nucleolus. We show for the first time that the lysine-rich targeting signal interacts with the nuclear transport receptor, importin-beta and transports GNL3L into the nucleolus. Interestingly, depletion of intracellular GTP blocks GNL3L accumulation into the nucleolar compartment. Furthermore, mutations within the G-domains alter the GTP binding ability of GNL3L and abrogate wild-type nucleolar retention even in the presence of functional NoLS, suggesting that the efficient nucleolar retention of GNL3L involves activities of both basic NoLS and GTP-binding domains. Collectively, these data suggest that GNL3L is composed of distinct modules, each of which plays a specific role in molecular interactions for its nucleolar retention and subsequent function(s) within the nucleolus.
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Affiliation(s)
- M R K Subba Rao
- Laboratory of Molecular Virology, Centre for DNA Fingerprinting and Diagnostics, ECIL Road, Nacharam, Hyderabad 500076, India
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Hamilton NHR, Mahalingam S, Banyer JL, Ramshaw IA, Thomson SA. A recombinant vaccinia virus encoding the interferon-inducible T-cell alpha chemoattractant is attenuated in vivo. Scand J Immunol 2004; 59:246-54. [PMID: 15030574 DOI: 10.1111/j.0300-9475.2004.01391.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Murine interferon-inducible T-cell alpha chemoattractant (I-TAC) is a potent non-ELR CXC chemokine that predominantly attracts activated T lymphocytes, binds to the receptor CXCR3 and is induced by interferon-gamma (IFN-gamma). We analysed I-TAC expression by reverse transcriptase-polymerase chain reaction during three different virus-infection models in mice, respiratory syncytial virus (RSV), influenza A and vaccinia virus western reserve (VV-WR). In the lungs from mice infected with RSV or influenza A viruses, peak expression of I-TAC coincided with peak viraemia. Surprisingly, there was no expression in the lungs of mice infected with vaccinia, unlike the elevated expression shown previously for other interferon-regulated chemokines, such as Crg2 and Mig. To further investigate the importance of this difference during vaccinia infection in mice, a recombinant virus encoding I-TAC (rVV I-TAC) was generated. Studies in C57BL/6 and Swiss nude mice showed that I-TAC expression caused increased mononuclear cell infiltration and significantly attenuated the VV. Infection of the footpads of naïve or already immune (with VV-WR) mice with either rVV I-TAC or VV-WR demonstrated that I-TAC expression reduced overall inflammation during infection and that this reduction was more pronounced in already immune mice. The data presented here show that I-TAC can have an important role during virus infections and that vaccinia has evolved ways to avoid inducing I-TAC expression.
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Affiliation(s)
- N H R Hamilton
- John Curtin School of Medical Research (JCSMR), Australian National University, Canberra, Australian Capital Territory, Australia
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45
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Rajendra Kumar P, Singhal PK, Vinod SS, Mahalingam S. A non-canonical transferable signal mediates nuclear import of simian immunodeficiency virus Vpx protein. J Mol Biol 2003; 331:1141-56. [PMID: 12927548 DOI: 10.1016/s0022-2836(03)00853-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Protein transport into the nucleus is generally considered to involve specific nuclear localization signals (NLS) though it is becoming increasingly evident that efficient and well controlled import of proteins which lack a canonical NLS also occurs in cells. Vpx, a 112 amino acid protein from human immunodeficiency virus type 2 (HIV-2) and the closely related simian immunodeficiency virus (SIV) is one such protein, which does not have an identifiable canonical NLS and is yet efficiently imported to the nuclear compartment. Here we report that Vpx protein is imported to the nucleus independently of virus-encoded cofactors. When fusions of truncated versions of Vpx with full-length beta-galactosidase (beta-Gal) were tested, the region from Vpx 61 to 80 was found to be sufficient to mediate the import of the heterologous cytoplasmic protein to the nucleus. Inactivation of Vpx NLS precluded nuclear import of Vpx and reduced virus replication in non-dividing macrophage cultures, even when functional integrase and Gag matrix proteins implicated in viral nuclear import were present. Importantly, we identified and characterized a novel type of 20 amino acid transferable nuclear import signal in Vpx that is distinct from other import signals described. In addition, we show that the minimal nuclear targeting domain identified here overlaps with helical domain III (amino acid (aa) 64-82) and the structural integrity of this helical motif is critical for the nuclear import of Vpx. Taken together, these data suggest that Vpx is imported to the nucleus via a novel import pathway that is dependent on its 20 amino acid unique nuclear targeting signal, and that the nuclear import property of Vpx is critical for the optimal virus replication in non-dividing cells such as macrophages.
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Affiliation(s)
- P Rajendra Kumar
- Laboratory of Molecular Virology, Centre for DNA Fingerprinting and Diagnostics, (CDFD), ECIL Road, Nacharam, 500 076, Hyderabad, India
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Kampmeier JA, Mahalingam S, Liu TZ. A catalytic procedure for the preparation of carbonyl-labeled acyl chlorides: more mechanistic insights into decarbonylation reactions promoted by rhodium(I) complexes. Organometallics 2002. [DOI: 10.1021/om00135a040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hamilton NHR, Banyer JL, Hapel AJ, Mahalingam S, Ramsay AJ, Ramshaw IA, Thomson SA. IFN-gamma regulates murine interferon-inducible T cell alpha chemokine (I-TAC) expression in dendritic cell lines and during experimental autoimmune encephalomyelitis (EAE). Scand J Immunol 2002; 55:171-7. [PMID: 11896933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Murine interferon-inducible T cell alpha chemokine (I-TAC) is a potent non-ELR Cys-X-Cys (CXC) chemokine that predominantly attracts activated T lymphocytes and binds to the receptor CXCR3. Using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) we analysed murine I-TAC expression in two different progenitor dendritic cell (DC) lines, MTHC-D2 and JAWS II which were exposed to various cytokines, and Con A-activated splenocytes from a panel of knockout mice. Analysis of the progenitor DC lines and Con A cultures demonstrated that murine I-TAC is primarily regulated by interferon (IFN)-gamma via interferon regulatory factor (IRF)-1. It has been proposed that I-TAC may have a role in autoimmune diseases such as multiple sclerosis (MS). Because I-TAC appears to be secreted from antigen-presenting cells (APCs) and attracts activated T cells, we examined the level of murine I-TAC mRNA in the central nervous system (CNS) of wild-type and IFN-gamma-receptor knockout (IFN-gammaR-/-) mice with myelin oligodendrocyte glycoprotein (MOG)35-55 peptide-induced experimental autoimmune encephalomyelitis (EAE). Peak I-TAC expression was detected in wild-type mice on day 14 when the mice begin to recover, whereas very low levels of I-TAC were detected in the CNS of IFN-gammaR-/- mice which develop severe EAE and die. The expression characteristics of murine I-TAC suggest an important mediator of immune cell communication that could augment vaccines and autoimmune therapies.
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MESH Headings
- Animals
- Antibodies/pharmacology
- CD40 Antigens/metabolism
- Cell Line
- Central Nervous System/immunology
- Chemokine CXCL11
- Chemokines, CXC/genetics
- Cytokines/pharmacology
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Encephalomyelitis, Autoimmune, Experimental/genetics
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Female
- Gene Expression/drug effects
- Glycoproteins/toxicity
- Interferon-gamma/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myelin-Oligodendrocyte Glycoprotein
- Peptide Fragments/toxicity
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Interferon/deficiency
- Receptors, Interferon/genetics
- Interferon gamma Receptor
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Affiliation(s)
- N H R Hamilton
- John Curtin School of Medical Research (JCSMR), Australian National University, Canberra, Australian Capital Territory, Australia
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50
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Vanitharani R, Mahalingam S, Rafaeli Y, Singh SP, Srinivasan A, Weiner DB, Ayyavoo V. HIV-1 Vpr transactivates LTR-directed expression through sequences present within -278 to -176 and increases virus replication in vitro. Virology 2001; 289:334-42. [PMID: 11689055 DOI: 10.1006/viro.2001.1153] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) Vpr, a 14-kDa virion-associated protein, plays an important role in the viral life cycle. Using a panel of truncated HIV-1 LTR-CAT constructs and Vpr expression plasmid, we have identified sequences from nucleotide -278 to -176 in LTR as Vpr-mediated transactivation domain. This region includes the glucocorticoid response element (GRE) in HIV-1 LTR. Transactivation by Vpr was noted with the HIV-1 LTR reporter constructs containing CAT or luciferase. A similar effect was also observed with a construct in which the GRE motif was linked to CAT. Studies involving Vpr mutants identified that helical domains I and III, and amino acid residues at G75 and C76, are responsible for GRE-mediated LTR transactivation. The transactivation function of Vpr is independent of its cell cycle arrest activity. Further, viral replication studies indicated that Vpr-mediated increase in viral replication is directly correlated with the ability of Vpr to transactivate HIV-1 LTR. The results presented here demonstrate that Vpr activates HIV-1 LTR through the host GR pathway and suggest that an intact GRE in the LTR is critical for Vpr activity.
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Affiliation(s)
- R Vanitharani
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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