1
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Verma NK, Siang Wong BH, Theng Ong S, Min Goay SS, Swan Ho Y, Chen S, Bi X, Shim H, Wulff H, Webster RD, Shelat VG, Chandy KG. Augmenting the activity of calcium-activated potassium channel K Ca3.1 revitalizes T-cell function in the immunosuppressive tumor microenvironment. Biophys J 2023; 122:256a. [PMID: 36783258 DOI: 10.1016/j.bpj.2022.11.1478] [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: 02/12/2023] Open
Affiliation(s)
- Navin K Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
| | - Brandon Han Siang Wong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
| | - Seow Theng Ong
- Nanyang Technological University, Singapore, Republic of Singapore
| | - Stephanie Shee Min Goay
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
| | - Ying Swan Ho
- Bioprocessing Technology Institute, Agency for Science Technology and Research (A∗STAR), Singapore, Republic of Singapore
| | - Shuwen Chen
- Bioprocessing Technology Institute, Agency for Science Technology and Research (A∗STAR), Singapore, Republic of Singapore
| | - Xuezhi Bi
- Bioprocessing Technology Institute, Agency for Science Technology and Research (A∗STAR), Singapore, Republic of Singapore
| | - Heesung Shim
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Heike Wulff
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Richard D Webster
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | | | - K George Chandy
- Molecular Physiology Laboratory, Infection and Immunity Theme, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
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Verma NK, Siang Wong BH, Theng Ong S, Min Goay SS, Swan Ho Y, Chen S, Bi X, Shim H, Wulff H, Chandy KG. A new kCa3.1 channel activator SKA-346 boosts T-cell antitumor response in the immune suppressive microenvironment. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1850] [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: 11/02/2022] Open
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3
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Kottaiswamy A, Kizhakeyil A, Padmanaban AM, Mirza FB, Vijay VR, Lee PS, Verma NK, Kalaiselvan P, Samuel S. The Citrus Flavanone Hesperetin Induces Apoptosis in CTCL Cells via STAT3/Notch1/NFκB-Mediated Signaling Axis. Anticancer Agents Med Chem 2020; 20:1459-1468. [DOI: 10.2174/1871521409666200324110031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/20/2020] [Accepted: 02/07/2020] [Indexed: 12/31/2022]
Abstract
Background:
Hesperetin is a natural compound known for its cholesterol-lowering effect and a wide
range of pharmacological activities.
Objectives:
Investigating the potential anticancer activities of Hesperetin in malignant hematolymphoid cell
lines HuT78 and MJ, derived from patients with Cutaneous T-Cell Lymphomas (CTCL).
Methods:
The cytotoxic effect of Hesperetin on two different CTCL cell lines, HuT78 and MJ, was assessed by
MTS-based colorimetric assay. Apoptosis, cell cycle, ROS (Reactive Oxygen Species) and molecular analysis
were performed using flow-cytometry and immunoblotting.
Results:
Hesperetin-treated CTCL cells were arrested at the sub-G1 phase of cell cycle with the concomitant
decrease in the expression of the cell cycle regulator protein cyclin B. In addition, the study found that the cellular
treatment with Hesperetin caused an induction of apoptosis, which was independent of ROS generation. Hesperetin
caused a significant decrease in the expression level of anti-apoptotic protein Bcl-xL and an increase in cleaved
caspase-3 and PARP proteins in CTCL cells. Furthermore, Hesperetin treatment in CTCL cells down-regulated
the expression of Notch1 and phosphorylation of STAT3 (Tyr705) and inhibited NFκBp65.
Conclusion:
This study highlights the anticancer properties of Hesperetin. Which induces apoptosis in CTCL
cells via STAT3/Notch1/NFκB mediated signaling pathway, suggesting that further development of this novel
class of flavonoid may contribute to new drug discovery for certain hematolymphoid malignancies.
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Affiliation(s)
| | - Atish Kizhakeyil
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11 Mandalay Road, Nanyang Ave, Singapore
| | | | - Fathima B. Mirza
- VRR Institute of Biomedical Science, University of Madras, Chennai, India
| | - Venkatesh R. Vijay
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11 Mandalay Road, Nanyang Ave, Singapore
| | - Pin S. Lee
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11 Mandalay Road, Nanyang Ave, Singapore
| | - Navin K. Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11 Mandalay Road, Nanyang Ave, Singapore
| | | | - Shila Samuel
- VRR Institute of Biomedical Science, University of Madras, Chennai, India
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4
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Diwedi J, Singh AW, Ahlawat S, Sharma R, Arora R, Sharma H, Raja KN, Verma NK, Tantia MS. Comprehensive analysis of mitochondrial DNA based genetic diversity in Indian goats. Gene 2020; 756:144910. [PMID: 32574758 DOI: 10.1016/j.gene.2020.144910] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 04/27/2020] [Revised: 06/01/2020] [Accepted: 06/17/2020] [Indexed: 11/18/2022]
Abstract
Thirty four distinct breeds and many non-descript populations represent the caprine diversity of India. Genetic characterization of breeds is an essential element in designing breeding strategies and preserving genetic diversity. Considering the popularity of mitochondrial DNA for phylogeographical studies, this study involved an extensive analysis of population structure and genetic diversity of 28 defined breeds and 5 lesser known populations representing all four major agro-climatic zones of India using mitochondrial DNA markers. Analysis of hypervariable region 1 of mtDNA control region in 443 goats together with 22 reference sequences, delineated 341 distinct haplotypes belonging to four maternal haplogroups; A, B, C and D, with haplogroup A representing 90% of the individuals. The haplotype and nucleotide diversity indices of Indian goats were 0.998 ± 0.001 and 0.028 ± 0.001, respectively indicating abundant genetic variability. Estimates of population demographic parameters from mismatch analysis suggested a relatively good fit to the model of either spatial or demographic expansion of Indian goats. AMOVA analysis and topology of MJ network suggested lack of phylogeographic structure in domestic goats, which can be attributed to unstructured animal breeding, dwindling pastures and nomadic pastoralism. Genetic differentiation between goats from different agro-ecological regions was in accordance with their geographical propinquity.
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Affiliation(s)
- Jyotsana Diwedi
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
| | | | - Sonika Ahlawat
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India.
| | - Rekha Sharma
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
| | - Reena Arora
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
| | - Himani Sharma
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
| | - K N Raja
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
| | - N K Verma
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
| | - M S Tantia
- ICAR-National Bureau of Animal Genetic Resources, Karnal, India
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5
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Suriyanto S, Ng EYK, Ng CED, Yan XS, Verma NK. 99mTc-MAG 3 diuresis renography in differentiating renal obstruction: Using statistical parameters as new quantifiable indices. Comput Biol Med 2019; 112:103371. [PMID: 31404720 DOI: 10.1016/j.compbiomed.2019.103371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this study was to research, develop and assess the feasibility of using basic statistical parameters derived from renogram, "mean count value (MeanCV) and "median count value (MedianCV)", as novel indices in the diagnosis of renal obstruction through diuresis renography. SUBJECTS AND METHODS First, we re-digitalized and normalized 132 renograms from 74 patients in order to derive the MeanCV and MedianCV. To improve the performance of the parameters, we extrapolated renograms by a two-compartmental modeling. After that, the cutoff points for diagnosis using each modified parameter were set and the sensitivity and specificity were calculated in order to determine the best variants of MeanCV and MedianCV that could differentiate renal obstruction status into 3 distinct classes - i) unobstructed, ii) slightly obstructed, and iii) heavily obstructed. RESULTS The modified MeanCV and MedianCV derived from extended renograms predicted the severity of the renal obstruction. The most appropriate variants of MeanCV and MedianCV were found to be the MeanCV50 and the MedianCV60. The cutoff points of MeanCV50 in separating unobstructed and obstructed classes as well as slightly and heavily obstructed classes were 0.50 and 0.72, respectively. The cutoff points of MedianCV60 in separating unobstructed and obstructed classes as well as slightly and heavily obstructed classes were 0.35 and 0.69, respectively. Notably, MeanCV50 and MedianCV60 were not significantly influenced by either age or gender. CONCLUSIONS The MeanCV50 and the MedianCV60 derived from a renogram could be incorporated with other quantifiable parameters to form a system that could provide a highly accurate diagnosis of renal obstructions.
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Affiliation(s)
- S Suriyanto
- NTU Institute for Health Technologies, Interdisciplinary Graduate School, Nanyang Technological University, Singapore; School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
| | - E Y K Ng
- School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, Singapore.
| | - C E David Ng
- Department of Nuclear Medicine and Molecular Imaging, Singapore General Hospital, Singapore; Duke-NUS Medical School, Singapore.
| | - Xuexian Sean Yan
- Department of Nuclear Medicine and Molecular Imaging, Singapore General Hospital, Singapore; Duke-NUS Medical School, Singapore.
| | - N K Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
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Parmar A, Lakshminarayanan R, Iyer A, Mayandi V, Leng Goh ET, Lloyd DG, Chalasani MLS, Verma NK, Prior SH, Beuerman RW, Madder A, Taylor EJ, Singh I. Design and Syntheses of Highly Potent Teixobactin Analogues against Staphylococcus aureus, Methicillin-Resistant Staphylococcus aureus (MRSA), and Vancomycin-Resistant Enterococci (VRE) in Vitro and in Vivo. J Med Chem 2018; 61:2009-2017. [PMID: 29363971 DOI: 10.1021/acs.jmedchem.7b01634] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The cyclic depsipeptide, teixobactin, kills a number of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and Mycobacterium tuberculosis without detectable resistance. To date, teixobactin is the only molecule in its class that has shown in vivo antibacterial efficacy. In this work, we designed and synthesized 10 new in vivo ready teixobactin analogues. These analogues showed highly potent antibacterial activities against Staphylococcus aureus, MRSA, and vancomycin-resistant enterococci (VRE) in vitro. One analogue, d-Arg4-Leu10-teixobactin, 2, was found to be noncytotoxic in vitro and in vivo. Moreover, topical instillation of peptide 2 in a mouse model of S. aureus keratitis decreased the bacterial bioburden (>99.0% reduction) and corneal edema significantly as compared to untreated mouse corneas. Collectively, our results have established the high therapeutic potential of a teixobactin analogue in attenuating bacterial infections and associated severities in vivo.
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Affiliation(s)
| | - Rajamani Lakshminarayanan
- Singapore Eye Research Institute , The Academia , Discovery Tower Level 6, 20 College Road , 169857 Singapore
| | - Abhishek Iyer
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry , Ghent University , Krijgslaan 281 (S4) , Ghent B-9000 , Belgium
| | - Venkatesh Mayandi
- Singapore Eye Research Institute , The Academia , Discovery Tower Level 6, 20 College Road , 169857 Singapore
| | - Eunice Tze Leng Goh
- Singapore Eye Research Institute , The Academia , Discovery Tower Level 6, 20 College Road , 169857 Singapore
| | | | | | - Navin K Verma
- Singapore Eye Research Institute , The Academia , Discovery Tower Level 6, 20 College Road , 169857 Singapore.,Lee Kong Chian School of Medicine , Nanyang Technological University , 636921 Singapore
| | | | - Roger W Beuerman
- Singapore Eye Research Institute , The Academia , Discovery Tower Level 6, 20 College Road , 169857 Singapore
| | - Annemieke Madder
- Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry , Ghent University , Krijgslaan 281 (S4) , Ghent B-9000 , Belgium
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7
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Chu TTT, Sinha A, Malleret B, Suwanarusk R, Park JE, Naidu R, Das R, Dutta B, Ong ST, Verma NK, Chan JK, Nosten F, Rénia L, Sze SK, Russell B, Chandramohanadas R. Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol 2017; 180:118-133. [PMID: 29094334 DOI: 10.1111/bjh.14976] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/22/2017] [Indexed: 02/03/2023]
Abstract
Erythropoiesis is marked by progressive changes in morphological, biochemical and mechanical properties of erythroid precursors to generate red blood cells (RBC). The earliest enucleated forms derived in this process, known as reticulocytes, are multi-lobular and spherical. As reticulocytes mature, they undergo a series of dynamic cytoskeletal re-arrangements and the expulsion of residual organelles, resulting in highly deformable biconcave RBCs (normocytes). To understand the significant, yet neglected proteome-wide changes associated with reticulocyte maturation, we undertook a quantitative proteomics approach. Immature reticulocytes (marked by the presence of surface transferrin receptor, CD71) and mature RBCs (devoid of CD71) were isolated from human cord blood using a magnetic separation procedure. After sub-fractionation into triton-extracted membrane proteins and luminal samples (isobaric tags for relative and absolute quantitation), quantitative mass spectrometry was conducted to identify more than 1800 proteins with good confidence and coverage. While most structural proteins (such as Spectrins, Ankyrin and Band 3) as well as surface glycoproteins were conserved, proteins associated with microtubule structures, such as Talin-1/2 and ß-Tubulin, were detected only in immature reticulocytes. Atomic force microscopy (AFM)-based imaging revealed an extended network of spectrin filaments in reticulocytes (with an average length of 48 nm), which shortened during reticulocyte maturation (average spectrin length of 41 nm in normocytes). The extended nature of cytoskeletal network may partly account for increased deformability and shape changes, as reticulocytes transform to normocytes.
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Affiliation(s)
- Trang T T Chu
- Pillar of Engineering Product Development (EPD), Singapore University of Technology & Design (SUTD), Singapore
| | - Ameya Sinha
- Pillar of Engineering Product Development (EPD), Singapore University of Technology & Design (SUTD), Singapore
| | - Benoit Malleret
- Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Singapore Immunology Network (SIgN), Agency for Science & Technology, Singapore
| | - Rossarin Suwanarusk
- Singapore Immunology Network (SIgN), Agency for Science & Technology, Singapore
| | - Jung E Park
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Renugah Naidu
- Pillar of Engineering Product Development (EPD), Singapore University of Technology & Design (SUTD), Singapore
| | - Rupambika Das
- Pillar of Engineering Product Development (EPD), Singapore University of Technology & Design (SUTD), Singapore
| | - Bamaprasad Dutta
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Seow Theng Ong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Navin K Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Jerry K Chan
- Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore.,Duke-NUS Medical School, Singapore
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Oxford, UK
| | - Laurent Rénia
- Singapore Immunology Network (SIgN), Agency for Science & Technology, Singapore
| | - Siu K Sze
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Bruce Russell
- Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Department of Microbiology and Immunology, Otago University, Dunedin, New Zealand
| | - Rajesh Chandramohanadas
- Pillar of Engineering Product Development (EPD), Singapore University of Technology & Design (SUTD), Singapore.,Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore
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8
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Liow SS, Dou Q, Kai D, Li Z, Sugiarto S, Yu CYY, Kwok RTK, Chen X, Wu YL, Ong ST, Kizhakeyil A, Verma NK, Tang BZ, Loh XJ. Long-Term Real-Time In Vivo Drug Release Monitoring with AIE Thermogelling Polymer. Small 2017; 13. [PMID: 27930860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/07/2016] [Indexed: 06/06/2023]
Abstract
A new drug concentration meter is developed. In vivo drug release can be monitored precisely via a self-indicating drug delivery system consisting of a new aggregation-induced emission thermoresponsive hydrogel. By taking the advantage of a self-indicating system, one can easily detect the depletion of drugs, and reinject to maintain a dosage in the optimal therapeutic window.
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Affiliation(s)
- Sing Shy Liow
- Institute of Materials Research and Engineering (IMRE), 2 Fusionopolis Way, #08-03 Innovis, Singapore, 138634, Singapore
| | - Qingqing Dou
- Institute of Materials Research and Engineering (IMRE), 2 Fusionopolis Way, #08-03 Innovis, Singapore, 138634, Singapore
| | - Dan Kai
- Institute of Materials Research and Engineering (IMRE), 2 Fusionopolis Way, #08-03 Innovis, Singapore, 138634, Singapore
| | - Zibiao Li
- Institute of Materials Research and Engineering (IMRE), 2 Fusionopolis Way, #08-03 Innovis, Singapore, 138634, Singapore
| | - Sigit Sugiarto
- Institute of Materials Research and Engineering (IMRE), 2 Fusionopolis Way, #08-03 Innovis, Singapore, 138634, Singapore
| | - Chris Yee Yung Yu
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, China
| | - Ryan Tsz Kin Kwok
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, China
| | - Xiaohong Chen
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian, 361102, P. R. China
| | - Yun-Long Wu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen, Fujian, 361102, P. R. China
| | - Seow Theng Ong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Singapore, 636921, Singapore
| | - Atish Kizhakeyil
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Singapore, 636921, Singapore
| | - Navin K Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Singapore, 636921, Singapore
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, 999077, China
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), 2 Fusionopolis Way, #08-03 Innovis, Singapore, 138634, Singapore
- Singapore Eye Research Institute, 11 Third Hospital Avenue, The Academia 20 College Road, Singapore, 168751, Singapore
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore
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9
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Ahlawat S, Sharma P, Sharma R, Arora R, Verma NK, Brahma B, Mishra P, De S. Evidence of positive selection and concerted evolution in the rapidly evolving PRDM9 zinc finger domain in goats and sheep. Anim Genet 2016; 47:740-751. [PMID: 27621101 DOI: 10.1111/age.12487] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2016] [Indexed: 01/20/2023]
Abstract
Meiotic recombination contributes to augmentation of genetic diversity, exclusion of deleterious alleles and proper segregation of chromatids. PRDM9 has been identified as the gene responsible for specifying the location of recombination hotspots during meiosis and is also the only known vertebrate gene associated with reproductive isolation between species. PRDM9 encodes a protein with a highly variable zinc finger (ZF) domain that varies between as well as within species. In the present study, the ZF domain of PRDM9 on chromosome 1 was characterized for the first time in 15 goat breeds and 25 sheep breeds of India. A remarkable variation in the number and sequence of ZF domains was observed. The number of ZF repeats in the ZF array varied from eight to 12 yielding five homozygous and 10 heterozygous genotypes. The number of different ZF domains was 84 and 52 producing 36 and 26 unique alleles in goats and sheep respectively. The posterior mean of dN/dS or omega values were calculated using the codeml tool of pamlx to identify amino acids that are evolving positively in goats and sheep, as positions -1, +3 and +6 in the ZF domain have been reported to experience strong positive selection across different lineages. Our study identified sites -5, -1, +3, +4 and +6 to be experiencing positive selection. Small ruminant zinc fingers were also found to be evolving under concerted evolution. Our results demonstrate the existence of a vast diversity of PRDM9 in goats and sheep, which is in concert with reports in many metazoans.
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Affiliation(s)
- S Ahlawat
- National Bureau of Animal Genetic Resources, Karnal 132001, Haryana, India.
| | - P Sharma
- National Bureau of Animal Genetic Resources, Karnal 132001, Haryana, India
| | - R Sharma
- National Bureau of Animal Genetic Resources, Karnal 132001, Haryana, India
| | - R Arora
- National Bureau of Animal Genetic Resources, Karnal 132001, Haryana, India
| | - N K Verma
- National Bureau of Animal Genetic Resources, Karnal 132001, Haryana, India
| | - B Brahma
- National Dairy Research Institute, Karnal 132001, Haryana, India
| | - P Mishra
- National Dairy Research Institute, Karnal 132001, Haryana, India
| | - S De
- National Dairy Research Institute, Karnal 132001, Haryana, India
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10
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Verma NK, Fazil MHUT, Ong ST, Chalasani MLS, Low JH, Kottaiswamy A, P P, Kizhakeyil A, Kumar S, Panda AK, Freeley M, Smith SM, Boehm BO, Kelleher D. Correction: LFA-1/ICAM-1 Ligation in Human T Cells Promotes Th1 Polarization through a GSK3β Signaling–Dependent Notch Pathway. J I 2016; 197:2039-40. [DOI: 10.4049/jimmunol.1601160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Verma NK, Fazil MHUT, Ong ST, Chalasani MLS, Low JH, Kottaiswamy A, P P, Kizhakeyil A, Kumar S, Panda AK, Freeley M, Smith SM, Boehm BO, Kelleher D. LFA-1/ICAM-1 Ligation in Human T Cells Promotes Th1 Polarization through a GSK3β Signaling–Dependent Notch Pathway. J I 2016; 197:108-18. [DOI: 10.4049/jimmunol.1501264] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 05/02/2016] [Indexed: 11/19/2022]
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12
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Behl JD, Mishra P, Verma NK, Niranjan SK, Dangi PS, Sharma R, Behl R. Nucleotide polymorphisms in the bovine lymphotoxin A gene and their distribution among Bos indicus zebu cattle breeds. Gene 2016; 579:82-94. [PMID: 26724420 DOI: 10.1016/j.gene.2015.12.049] [Citation(s) in RCA: 2] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 10/12/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022]
Abstract
The present study was undertaken to characterize the genetic variation present in lymphoxin A gene (LTA gene) encoding for the lymphotoxin A protein also known as tumor necrosis factor beta, a cytokine produced by lymphocytes, known to be cytotoxic for a wide range of tumor cells both in vitro and in vivo, and, which is essential for normal immunological development; in 40 animals of 5 diverse Bos indicus Indian zebu cattle breeds. These breeds survive under the harsh and tough tropical climatic conditions of various parts of the Indian subcontinent. The LTA gene in the present study was observed to contain 33 SNPs and 3 small insertion/deletion polymorphisms. Four SNPs occurred in the coding regions of the gene viz. g.1327A>G and g.1400C>T in exon 2 and g.1840C>T and g.1942C>T in exon 3, of which the SNP g.1327A>G in exon 2 resulted in a non-synonymous amino acid change G38D. This amino acid change was however predicted not be affecting the protein function in any manner. The gene contained putative transcription factor binding sites for the c-Re1 and for Pax-4 transcription factors. A putative promoter region was also predicted on the reverse DNA strand from position 894 to 644. Several repeat elements and microsatellite repeats were detected to be occurring across the 3.2kb LTA gene sequence. The study showed the occurrence of 40 genotypes and 48 most probable haplotypes. The genotypes at the observed SNP positions in the LTA gene were in near Hardy-Weinberg equilibrium. A negative Tajima's D value that was not significant statistically at P>0.10 indicated that the neutral mutation hypothesis could not be excluded. The genetic variations observed in the LTA gene in the present study have not been reported earlier and these could possibly be used as molecular markers for further studies involving association of the gene variability with disease resistance/tolerance traits.
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Affiliation(s)
- Jyotsna Dhingra Behl
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India.
| | - Priyanka Mishra
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India
| | - N K Verma
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India
| | - S K Niranjan
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India
| | - P S Dangi
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India
| | - Rekha Sharma
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India
| | - Rahul Behl
- Animal Genetics Division, National Bureau of Animal Genetic Resources, P.O. Box 129, G. T. Bypass Road, Karnal, Haryana 132001, India
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McIntyre J, Verma NK, Smith RJ, Moore C, Nerl H, McEvoy N, Berner N, McGovern I, Khan U, Lyons P, O'Neill L, Nicolosi V, Duesberg GS, Byrne HJ, Coleman J, Volkov Y. A comparison of catabolic pathways induced in primary macrophages by pristine single walled carbon nanotubes and pristine graphene. RSC Adv 2016. [DOI: 10.1039/c6ra02476a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Understanding the correlation between the physico-chemical properties of carbonaceous nanomaterials and how these properties impact on cells and subcelluar mechanisms is critical to their risk assessment and safe translation into engineered devices.
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Pollock JK, Verma NK, Meegan MJ, Zisterer D. Abstract B81: Combretastatin (CA)-4 and its novel analogue CA-432 impair T-cell migration through the Rho/ROCK signalling pathway. Cancer Immunol Res 2015. [DOI: 10.1158/2326-6074.tumimm14-b81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: The capacity of T-cell lymphocytes to migrate and localize in tissues is important in their protective function against infectious agents, however, the ability of these cells to migrate and infiltrate the tumor microenvironment is also a major contributing factor in the development of cancer and cancer metastasis. T-cell migration requires ligand (ICAM-1)/integrin(LFA-1) interaction, activating intracellular signaling pathways which result in a distinct polarized morphology, with an actin-rich lamellipodium and microtubule-rich uropod. Microtubule-targeting agents (MTAs) are amongst some of the most widely used anti-cancer drugs and several have been shown to exhibit anti-inflammatory activity. Combretastatin (CA) A-4 is a MT-destabilizing agent that possesses potent anti-tumor and anti-vascular properties both in vitro and in vivo. CA-432, a novel cis-restriciting analogue containing a β-lactam ring, has recently been synthesized to circumvent the problem of CA-4 isomerisation from a biologically active cis-conformation to a more thermodynamically stable but inactive trans-isomer.
Methods: HuT-78 cell line and peripheral blood lymphocyte (PBL) T-cells were cultured. In this study, the effect of CA-4 and CA-432 on the migratory polarity of T-cells was explored using high content analysis (HCA). The active migration of PBL T-cells was studied using a transwell assay. The mechanistic and signaling pathways involved were examined using western blotting and confocal microscopy. Cytoxicity of both compounds was tested using a viability assay and flow cytometry.
Results: CA-4 and CA-432 treated cells displayed altered T-cell migratory polarity in HuT-78 and peripheral blood T-lymphocyte (PBTL) cells and inhibited active migration of PBTLs. Both compounds induced activation of the RhoA / RhoA associated kinase (ROCK) signaling pathway, leading to the phosphorylation of myosin light chain (MLC), acto-myosin contractility and impaired migration. Disruption of the MT network of T-cells through CA-induced MT depolymerisation was associated with reduced acetylated tubulin expression and decreased MT stability. GEF-H1 is a MT-associated nucleotide exchange factor which activates RhoA upon release from MTs, The siRNA-mediated depletion of GEF-H1 in Hut-78 T cells prevented CA-induced phosphorylation of MLC and attenuated the formation of actin-rich membrane protrusions and cell contractility.
Conclusions: These results suggest an important role for a GEF-H1/RhoA/ROCK/MLC signaling pathway in mediating CA-induced contractility of T cells. Therapeutic agents inhibiting cell migration may open new avenues in the treatment of cancer and metastasis.
Citation Format: Jade Kirstin Pollock, Navin K. Verma, Mary J. Meegan, Daniela Zisterer. Combretastatin (CA)-4 and its novel analogue CA-432 impair T-cell migration through the Rho/ROCK signalling pathway. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr B81.
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15
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Verma NK, Kelleher D. Adaptor regulation of LFA-1 signaling in T lymphocyte migration: Potential druggable targets for immunotherapies? Eur J Immunol 2014; 44:3484-99. [PMID: 25251823 DOI: 10.1002/eji.201344428] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 09/16/2014] [Accepted: 09/22/2014] [Indexed: 01/24/2023]
Abstract
The integrin lymphocyte function associated antigen-1 (LFA-1) plays a key role in leukocyte trafficking and in adaptive immune responses through interactions with adhesive ligands, such as ICAM-1. Specific blockade of these interactions has validated LFA-1 as a therapeutic target in many chronic inflammatory diseases, however LFA-1 antagonists have not been clinically successful due to the development of a general immunosuppression, causing fatal side effects. Growing evidence has now established that LFA-1 mediates an array of intracellular signaling pathways by triggering a number of downstream molecules. In this context, a class of multimodular domain-containing proteins capable of recruiting two or more effector molecules, collectively known as "adaptor proteins," has emerged as important mediators in LFA-1 signal transduction. Here, we provide an overview of the adaptor proteins involved in the intracellular signaling cascades by which LFA-1 regulates T-cell motility and immune responses. The complexity of the LFA-1-associated signaling delineated in this review suggests that it may be an important and challenging focus for future research, enabling the identification of "tunable" targets for the development of immunotherapies.
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Affiliation(s)
- Navin K Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore; Singapore Eye Research Institute, Singapore, Singapore
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16
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Pollock JK, Verma NK, O'Boyle NM, Carr M, Meegan MJ, Zisterer DM. Combretastatin (CA)-4 and its novel analogue CA-432 impair T-cell migration through the Rho/ROCK signalling pathway. Biochem Pharmacol 2014; 92:544-57. [PMID: 25450669 DOI: 10.1016/j.bcp.2014.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 10/24/2022]
Abstract
The capacity of T-lymphocytes to migrate and localise in tissues is important in their protective function against infectious agents, however, the ability of these cells to infiltrate the tumour microenvironment is a major contributing factor in the development of cancer. T-cell migration requires ligand (ICAM-1)/integrin (LFA-1) interaction, activating intracellular signalling pathways which result in a distinct polarised morphology, with an actin-rich lamellipodium and microtubule (MT)-rich uropod. Combretastatin (CA)-4 is a MT-destabilising agent that possesses potent anti-tumour properties. In this study, the effect of CA-4 and its novel analogue CA-432 on human T-cell migration was assessed. Cellular pretreatment with either of CA compounds inhibited the migration and chemotaxis of the T-cell line HuT-78 and primary peripheral blood lymphocyte (PBL) T-cells. This migration-inhibitory effect of CA compounds was due to the disruption of the MT network of T-cells through tubulin depolymerisation, reduced tubulin acetylation and decreased MT stability. In addition, both CA compounds induced the RhoA/RhoA associated kinase (ROCK) signalling pathway, leading to the phosphorylation of myosin light chain (MLC). Furthermore, the siRNA-mediated depletion of GEF-H1, a MT-associated nucleotide exchange factor that activates RhoA upon release from MTs, in T-cells prevented CA-induced phosphorylation of MLC and attenuated the formation of actin-rich membrane protrusions and cell contractility. These results suggest an important role for a GEF-H1/RhoA/ROCK/MLC signalling axis in mediating CA-induced contractility of T-cells. Therapeutic agents that target cytoskeletal proteins and are effective in inhibiting cell migration may open new avenues in the treatment of cancer and metastasis.
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Affiliation(s)
- Jade K Pollock
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland.
| | - Navin K Verma
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
| | - Niamh M O'Boyle
- School of Pharmacy, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland.
| | - Miriam Carr
- School of Pharmacy, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland.
| | - Mary J Meegan
- School of Pharmacy, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland.
| | - Daniela M Zisterer
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin 2, Ireland.
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17
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Iquebal MA, Ansari MS, Sarika, Dixit SP, Verma NK, Aggarwal RAK, Jayakumar S, Rai A, Kumar D. Locus minimization in breed prediction using artificial neural network approach. Anim Genet 2014; 45:898-902. [PMID: 25183434 DOI: 10.1111/age.12208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2014] [Indexed: 11/26/2022]
Abstract
Molecular markers, viz. microsatellites and single nucleotide polymorphisms, have revolutionized breed identification through the use of small samples of biological tissue or germplasm, such as blood, carcass samples, embryos, ova and semen, that show no evident phenotype. Classical tools of molecular data analysis for breed identification have limitations, such as the unavailability of referral breed data, causing increased cost of collection each time, compromised computational accuracy and complexity of the methodology used. We report here the successful use of an artificial neural network (ANN) in background to decrease the cost of genotyping by locus minimization. The webserver is freely accessible (http://nabg.iasri.res.in/bisgoat) to the research community. We demonstrate that the machine learning (ANN) approach for breed identification is capable of multifold advantages such as locus minimization, leading to a drastic reduction in cost, and web availability of reference breed data, alleviating the need for repeated genotyping each time one investigates the identity of an unknown breed. To develop this model web implementation based on ANN, we used 51,850 samples of allelic data of microsatellite-marker-based DNA fingerprinting on 25 loci covering 22 registered goat breeds of India for training. Minimizing loci to up to nine loci through the use of a multilayer perceptron model, we achieved 96.63% training accuracy. This server can be an indispensable tool for identification of existing breeds and new synthetic commercial breeds, leading to protection of intellectual property in case of sovereignty and bio-piracy disputes. This server can be widely used as a model for cost reduction by locus minimization for various other flora and fauna in terms of variety, breed and/or line identification, especially in conservation and improvement programs.
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Affiliation(s)
- M A Iquebal
- Centre for Agricultural Bioinformatics, Indian Agricultural Statistics Research Institute, Library Avenue, PUSA, New Delhi, 110012, India
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18
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Behl JD, Sharma A, Kataria RS, Verma NK, Kimothi SP, Bhatia AK, Sodhi M, Behl R, Joshi BK. Genetic polymorphisms in the bovine toll-like receptor 4 (TLR4) and monocyte chemo attractant protein-1(CCL2) genes: SNPs distribution analysis in Bos indicus Sahiwal cattle breed. Anim Biotechnol 2014; 25:250-65. [PMID: 24813219 DOI: 10.1080/10495398.2013.868354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Toll-like receptor 4 gene (TLR4) that recognizes the Gram negative bacterial ligand LPS was sequenced in the Bos indicus Sahiwal cattle breed. Ninety four single nucleotide polymorphisms (SNPs) were detected within 10.8 kb gene region. Seventeen of the SNPs were in the coding regions and the one at position 9589(A > G) in exon3 resulted in an amino acid change from Valine to Isoleucine. These SNPs led to generation of 27 TLR4 gene haplotypes. All the Sahiwal animals studied presently showed the occurrence of the genotype CC at gene position 9662, which codes for the amino acid threonine at position 674 of the TLR4 protein, and which had been reported to be associated with lower somatic cell score and, therefore, a lower susceptibility to mastitis, in Taurus cattle. This nucleotide configuration of the Toll-like receptor 4 gene of the Bos indicus Sahiwal cattle breed could possibly indicate toward a lower susceptibility to mastitis in the Sahiwal animals. Monocyte chemo-attractant protein-1 (CCL2) gene encoding for small inducible cytokine A2 that belongs to the CC chemokine family was also sequence characterized in these Sahiwal animals. The CCL2 gene was observed to have 12 polymorphic sites in 3.3 kb region of which one SNP at position 2500 (A > G) in exon 3 resulted in amino acid change from Valine to Isoleucine at position 46 of the mature CCL2 peptide. Seventeen haplotypes of the CCL2 gene were predicted corresponding to 12 genotypes detected.
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19
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Bean C, Verma NK, Yamamoto DL, Chemello F, Cenni V, Filomena MC, Chen J, Bang ML, Lanfranchi G. Ankrd2 is a modulator of NF-κB-mediated inflammatory responses during muscle differentiation. Cell Death Dis 2014; 5:e1002. [PMID: 24434510 PMCID: PMC4040671 DOI: 10.1038/cddis.2013.525] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 11/23/2013] [Accepted: 11/25/2013] [Indexed: 12/29/2022]
Abstract
Adaptive responses of skeletal muscle regulate the nuclear shuttling of the sarcomeric protein Ankrd2 that can transduce different stimuli into specific adaptations by interacting with both structural and regulatory proteins. In a genome-wide expression study on Ankrd2-knockout or -overexpressing primary proliferating or differentiating myoblasts, we found an inverse correlation between Ankrd2 levels and the expression of proinflammatory genes and identified Ankrd2 as a potent repressor of inflammatory responses through direct interaction with the NF-κB repressor subunit p50. In particular, we identified Gsk3β as a novel direct target of the p50/Ankrd2 repressosome dimer and found that the recruitment of p50 by Ankrd2 is dependent on Akt2-mediated phosphorylation of Ankrd2 upon oxidative stress during myogenic differentiation. Surprisingly, the absence of Ankrd2 in slow muscle negatively affected the expression of cytokines and key calcineurin-dependent genes associated with the slow-twitch muscle program. Thus, our findings support a model in which alterations in Ankrd2 protein and phosphorylation levels modulate the balance between physiological and pathological inflammatory responses in muscle.
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Affiliation(s)
- C Bean
- Department of Biology, Innovative Biotechnologies Interdepartmental Research Center, University of Padova, Padova, Italy
| | - N K Verma
- Department of Biology, Innovative Biotechnologies Interdepartmental Research Center, University of Padova, Padova, Italy
| | - D L Yamamoto
- Institute of Biomedical Technologies, National Research Council, Milan, Italy
| | - F Chemello
- Department of Biology, Innovative Biotechnologies Interdepartmental Research Center, University of Padova, Padova, Italy
| | - V Cenni
- Institute of Molecular Genetics, National Research Council, Bologna Unit/IOR, Bologna, Italy
| | - M C Filomena
- 1] Department of Translational Medicine, University of Milan, Milan, Italy [2] Humanitas Clinical and Research Center, Rozzano, Milan, Italy
| | - J Chen
- University of California, San Diego School of Medicine, La Jolla, CA, USA
| | - M L Bang
- 1] Humanitas Clinical and Research Center, Rozzano, Milan, Italy [2] Milan Unit, Institute of Genetic and Biomedical Research, National Research Council, Milan, Italy
| | - G Lanfranchi
- Department of Biology, Innovative Biotechnologies Interdepartmental Research Center, University of Padova, Padova, Italy
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20
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Sharma A, Dutt G, Jayakumar S, Saroha V, Verma NK, Dixit SP. Genetic structuring of nine Indian domestic goat breeds based on SNPs identified in IGF-1 gene. Anim Biotechnol 2013; 24:148-57. [PMID: 23534960 DOI: 10.1080/10495398.2013.763815] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The caprine Insulin like Growth Factor1 (IGF1) gene was analyzed for identification of single nucleotide polymorphisms (SNPs) and genetic structuring of Indian goat breeds. A panel of 80 samples belonging to nine Indian goat breeds (Capra hircus) including three large sized breeds (Jamunapari, Beetal and Jakhrana); three medium sized breeds (Sirohi, Barbari, and Osmanabadi) and three small sized breeds (Black Bengal, Changthangi, and Gaddi) were screened for SNP identification and diversity analysis. The comparative gene sequence analysis of all the nine goat breeds studied revealed a total of 18 SNPs in IGF1 gene. All the nucleotide changes were found to be synonymous. The mean observed heterozygosity was found to be maximum (0.074) in Sirohi, Beetal, Osmanabadi, and Gaddi breeds of goat, whereas it is found to be minimum (0.019) in Black Bengal breed of goat. The rest of the breeds were intermediate in terms of heterozygosity. The same has been confirmed by allele frequency distribution across the studied loci. Barbari and Gaddi were found to be more differentiated (0.0123), Changthangi and Jamunapari were least differentiated (0.00110) based on Nei's genetic distance.
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Affiliation(s)
- Anurodh Sharma
- National Bureau of Animal Genetic Resources, Karnal, Haryana, India
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21
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Verma NK, Conroy J, Lyons PE, Coleman J, O'Sullivan MP, Kornfeld H, Kelleher D, Volkov Y. Autophagy induction by silver nanowires: a new aspect in the biocompatibility assessment of nanocomposite thin films. Toxicol Appl Pharmacol 2012; 264:451-61. [PMID: 22959926 DOI: 10.1016/j.taap.2012.08.023] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 08/22/2012] [Accepted: 08/23/2012] [Indexed: 01/07/2023]
Abstract
Nanomaterials and their enabled products have increasingly been attracting global attention due to their unique physicochemical properties. Among these emerging products, silver nanowire (AgNW)-based thin films are being developed for their promising applications in next generation nanoelectronics and nanodevices. However, serious concerns remain about possible health and safety risks they may pose. Here, we employed a multi-modal systematic biocompatibility assessment of thin films incorporating AgNW. To represent the possible routes of nanomaterial entry during occupational or environmental exposure, we employed four different cell lines of epithelial, endothelial, gastric, and phagocytic origin. Utilizing a cell-based automated image acquisition and analysis procedure in combination with real-time impedance sensing, we observed a low level of cytotoxicity of AgNW, which was dependent on cell type, nanowire lengths, doses and incubation times. Similarly, no major cytotoxic effects were induced by AgNW-containing thin films, as detected by conventional cell viability and imaging assays. However, transmission electron microscopy and Western immunoblotting analysis revealed AgNW-induced autophasosome accumulation together with an upregulation of the autophagy marker protein LC3. Autophagy represents a crucial mechanism in maintaining cellular homeostasis, and our data for the first time demonstrate triggering of such mechanism by AgNW in human phagocytic cells. Finally, atomic force microscopy revealed significant changes in the topology of cells attaching and growing on these films as substrates. Our findings thus emphasize the necessity of comprehensive biohazard assessment of nanomaterials in modern applications and devices and a thorough analysis of risks associated with their possible contact with humans through occupational or environmental exposure.
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Affiliation(s)
- Navin K Verma
- Institute of Molecular Medicine, Trinity College Dublin, Ireland
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22
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Verma NK, Dempsey E, Long A, Davies A, Barry SP, Fallon PG, Volkov Y, Kelleher D. Leukocyte function-associated antigen-1/intercellular adhesion molecule-1 interaction induces a novel genetic signature resulting in T-cells refractory to transforming growth factor-β signaling. J Biol Chem 2012; 287:27204-16. [PMID: 22707713 DOI: 10.1074/jbc.m112.376616] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The immunesuppressive cytokine TGF-β plays crucial regulatory roles in the induction and maintenance of immunologic tolerance and prevention of immunopathologies. However, it remains unclear how circulating T-cells can escape from the quiescent state maintained by TGF-β. Here, we report that the T-cell integrin leukocyte function-associated antigen-1 (LFA-1) interaction with its ligand intercellular adhesion molecule-1 (ICAM-1) induces a genetic signature associated with reduced TGF-β responsiveness via up-regulation of SKI, E3 ubiquitin-protein ligase SMURF2, and SMAD7 (mothers against decapentaplegic homolog 7) genes and proteins. We confirmed that the expression of these TGF-β inhibitory molecules was dependent on STAT3 and/or JNK activation. Increased expression of SMAD7 and SMURF2 in LFA-1/ICAM-1 cross-linked T-cells resulted in impaired TGF-β-mediated phosphorylation of SMAD2 and suppression of IL-2 secretion. Expression of SKI caused resistance to TGF-β-mediated suppression of IL-2, but SMAD2 phosphorylation was unaffected. Blocking LFA-1 by neutralizing antibody or specific knockdown of TGF-β inhibitory molecules by siRNA substantially restored LFA-1/ICAM-1-mediated alteration in TGF-β signaling. LFA-1/ICAM-1-stimulated human and mouse T-cells were refractory to TGF-β-mediated induction of FOXP3(+) (forkhead box P3) and RORγt(+) (retinoic acid-related orphan nuclear receptor γt) Th17 differentiation. These mechanistic data suggest an important role for LFA-1/ICAM-1 interactions in immunoregulation concurrent with lymphocyte migration that may have implications at the level of local inflammatory response and for anti-LFA-1-based therapies.
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Affiliation(s)
- Navin K Verma
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin 2, Ireland
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23
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Behl JD, Verma NK, Tyagi N, Mishra P, Behl R, Joshi BK. The major histocompatibility complex in bovines: a review. ISRN Vet Sci 2012; 2012:872710. [PMID: 23738132 PMCID: PMC3658703 DOI: 10.5402/2012/872710] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 03/29/2012] [Indexed: 11/23/2022]
Abstract
Productivity in dairy cattle and buffaloes depends on the genetic factors governing the production of milk and milk constituents as well as genetic factors controlling disease resistance or susceptibility. The immune system is the adaptive defense system that has evolved in vertebrates to protect them from invading pathogens and also carcinomas. It is remarkable in the sense that it is able to generate an enormous variety of cells and biomolecules which interact with each other in numerous ways to form a complex network that helps to recognize, counteract, and eliminate the apparently limitless number of foreign invading pathogens/molecules. The major histocompatibility complex which is found to occur in all mammalian species plays a central role in the development of the immune system. It is an important candidate gene involved in susceptibility/resistance to various diseases. It is associated with intercellular recognition and with self/nonself discrimination. It plays major role in determining whether transplanted tissue will be accepted as self or rejected as foreign.
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Affiliation(s)
- Jyotsna Dhingra Behl
- Animal Genetics Division, National Bureau of Animal Genetics Resources, P.O. Box 129, GT Bypass Road, Haryana, Karnal 132001, India
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24
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Mohamed BM, Verma NK, Davies AM, McGowan A, Crosbie-Staunton K, Prina-Mello A, Kelleher D, Botting CH, Causey CP, Thompson PR, Pruijn GJ, Kisin ER, Tkach AV, Shvedova AA, Volkov Y. Citrullination of proteins: a common post-translational modification pathway induced by different nanoparticles in vitro and in vivo. Nanomedicine (Lond) 2012; 7:1181-95. [PMID: 22625207 DOI: 10.2217/nnm.11.177] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AIM Rapidly expanding manufacture and use of nanomaterials emphasize the requirements for thorough assessment of health outcomes associated with novel applications. Post-translational protein modifications catalyzed by Ca(2+)-dependent peptidylargininedeiminases have been shown to trigger immune responses including autoantibody generation, a hallmark of immune complexes deposition in rheumatoid arthritis. Therefore, the aim of the study was to assess if nanoparticles are able to promote protein citrullination. MATERIALS & METHODS Human A549 and THP-1 cells were exposed to silicon dioxide, carbon black or single-walled carbon nanotubes. C57BL/6 mice were exposed to respirable single-walled carbon nanotubes. Protein citrullination, peptidylargininedeiminases activity and target proteins were evaluated. RESULTS The studied nanoparticles induced protein citrullination both in cultured human cells and mouse lung tissues. Citrullination occurred via the peptidylargininedeiminase-dependent mechanism. Cytokeratines 7, 8, 18 and plectins were identified as intracellular citrullination targets. CONCLUSION Nanoparticle exposure facilitated post-translational citrullination of proteins.
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Affiliation(s)
- Bashir M Mohamed
- Department of Clinical Medicine, Trinity College Dublin, Ireland
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25
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Verma NK, Dempsey E, Freeley M, Botting CH, Long A, Kelleher D, Volkov Y. Analysis of dynamic tyrosine phosphoproteome in LFA-1 triggered migrating T-cells. J Cell Physiol 2011; 226:1489-98. [PMID: 20945386 DOI: 10.1002/jcp.22478] [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] [Indexed: 01/23/2023]
Abstract
The ordered, directional migration of T-lymphocytes is a key process during immune surveillance and response. This requires cell adhesion to the high endothelial venules or to the extracellular matrix by a series of surface receptor/ligand interactions involving adhesion molecules of the integrin family including lymphocyte function associated molecule-1 (LFA-1) and intercellular adhesion molecules (ICAMs). Reversible protein phosphorylation is emerging as a key player in the regulation of biological functions with tyrosine phosphorylation playing a crucial role in signal transduction. Thus, the study of this type of post-translational modification at the proteomic level has great biological significance. In this work, phospho-enriched cell lysates from LFA-1-triggered migrating human T-cells were subjected to immunoaffinity purification of tyrosine phosphorylated proteins, mass spectrometric, and bioinformatic analysis. In addition to the identification of several well-documented proteins, the analysis suggested involvement of a number of new and novel proteins in LFA-1 induced T-cell migration. This dataset expands the list of the signaling components of the LFA-1 induced phosphotyrosine protein complexes in migrating T-cells that will be extremely useful in the study of their specific roles within LFA-1 associated signaling pathways. Identification of proteins previously not reported in the context of LFA-1 stimulated signal transduction might provide new insights into understanding the LFA-1 signaling networks and aid in the search for new potential therapeutic targets.
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Affiliation(s)
- Navin K Verma
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College Dublin, Ireland.
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26
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Verma NK, Dourlat J, Davies AM, Long A, Liu WQ, Garbay C, Kelleher D, Volkov Y. STAT3-stathmin interactions control microtubule dynamics in migrating T-cells. J Biol Chem 2009; 284:12349-62. [PMID: 19251695 DOI: 10.1074/jbc.m807761200] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
T-cell migration is a complex highly coordinated process that involves cell adhesion to the high endothelial venules or to the extracellular matrix by surface receptor/ligand interactions, cytoskeletal rearrangements, and phosphorylation-dependent signaling cascades. The mechanism(s) that regulates T-cell migration is of considerable relevance for understanding the pathogenesis of various diseases, such as chronic inflammatory diseases and cancer metastasis. This study was designed to identify potential involvement of STAT3, a latent transcription factor, in mediating integrin-induced T-cell migration. Using our previously characterized in vitro model for lymphocyte migration, we demonstrate that STAT3 is activated and translocated to the nucleus during the process of active motility of Hut78 T-lymphoma cells triggered via LFA-1. Blocking STAT3 signaling by multiple approaches inhibited LFA-1-induced T-cell locomotion via destabilization of microtubules and post-translational modification of tubulin. Here, we show that STAT3 physically interacts with stathmin to regulate microtubule dynamics in migrating T-cells. These observations strongly indicate that STAT3 is critically important for T-cell migration and associated signaling events.
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Affiliation(s)
- Navin K Verma
- Department of Clinical Medicine, Institute of Molecular Medicine, Trinity College Dublin, Dublin 8, Ireland.
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Patel SS, Mohamed Saleem TS, Ravi V, Shrestha B, Verma NK, Gauthaman K. Passiflora incarnataLinn: A phytopharmacological review. ACTA ACUST UNITED AC 2009. [DOI: 10.4103/0973-8258.59731] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [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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28
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Behl JD, Verma NK, Behl R, Mukesh M, Ahlawat SPS. Characterization of genetic polymorphism of the bovine lymphocyte antigen DRB3.2 locus in Kankrej cattle (Bos indicus). J Dairy Sci 2007; 90:2997-3001. [PMID: 17517741 DOI: 10.3168/jds.2006-547] [Citation(s) in RCA: 18] [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] [Indexed: 11/19/2022]
Abstract
Bovine lymphocyte antigen DRB 3.2 (BoLA-DRB3.2) gene encodes for the beta chain of the major histocompatibility complex (MHC) class II molecule in cattle, which is a glycoprotein present on the surface of antigen-presenting cells. This locus shows extensive polymorphism in it. The objective of the present study was to genotype the BoLA-DRB3.2 locus in Kankrej cattle (n = 50) by PCR-RFLP. Bovine DNA was isolated from aliquots of whole blood. Primers specific for exon 2 of the bovine lymphocyte antigen (BoLA)-DRB3 gene were used to amplify the region. The 304-bp amplified product of the DRB3 gene was separately digested with restriction endonucleases RsaI, BstYI, and Hae III. Twenty-four BoLA-DRB 3.2 alleles were identified with frequencies ranging from 1 to 22.0%. Twenty-one alleles of the total 24 alleles were similar to those reported earlier; 3 alleles were new and had not been reported previously. The allele BoLA-DRB3.2*34 occurred at the highest frequency of 22% (approx.) in the Kankrej animals studied. Six alleles (BoLA-DRB3.2 *34, *15, *06, *20, *37, and *20) accounted for almost 71% of the total alleles observed to be present in the Kankrej animals. All the new alleles observed were present at frequencies of 1%. The results obtained in the present study demonstrated that the BoLA DRB3.2 locus is highly polymorphic in the Kankrej cattle.
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Affiliation(s)
- J D Behl
- National Bureau of Animal Genetic Resources, P.O. Box No. 129, G.T. Bypass Road, Karnal, Haryana, India.
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29
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Verma NK, Singh G, Dey CS. Miltefosine induces apoptosis in arsenite-resistant Leishmania donovani promastigotes through mitochondrial dysfunction. Exp Parasitol 2007; 116:1-13. [PMID: 17161839 DOI: 10.1016/j.exppara.2006.10.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [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: 03/13/2006] [Revised: 10/05/2006] [Accepted: 10/13/2006] [Indexed: 11/30/2022]
Abstract
The control of leishmaniasis in absence of vaccine solely depends on the choice of chemotherapy. The major hurdle in successful leishmanial chemotherapy is emergence of drug resistance. Miltefosine, the first orally administrable anti-leishmanial drug, has shown the potential against drug-resistant strains of Leishmania. However, there are discrepancies regarding the involvement of P-glycoprotein (Pgp) and sensitivity of miltefosine in multiple drug-resistant (MDR) cell lines that overexpress Pgp in Leishmania. To address this, the effect of miltefosine in arsenite-resistant Leishmania donovani (Ld-As20) promastigotes displaying an MDR phenotype and overexpressing Pgp-like protein was investigated in the current study. Results indicate that Ld-As20 is sensitive to miltefosine. Miltefosine induces process of programmed cell death in Ld-As20 in a time-dependent manner as determined by cell shrinkage, externalization of phosphatidylserine and DNA fragmentation. Miltefosine treatment leads to loss of mitochondrial membrane potential and the release of cytochrome C with consequent activation of cellular proteases. Activation of cellular proteases resulted in activation of DNase that damaged kinetoplast DNA and induced dyskinetoplasty. These data indicate that miltefosine causes apoptosis-like death in arsenite-resistant L. donovani.
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Affiliation(s)
- Navin K Verma
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER)(1), Punjab 160 062, India
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30
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Abstract
AIMS/HYPOTHESIS Miltefosine, the first oral anti-leishmanial drug, is reported to inhibit phosphatidylinositol 3-kinase (PI3K)/Akt activity in carcinoma cell lines. Inhibition of the PI3K/Akt pathway is known to result in insulin resistance. Therefore, we investigated whether miltefosine has any deleterious effect(s) on insulin sensitivity in L6E9 skeletal muscle cells. MATERIALS AND METHODS L6E9 myotubes were treated with miltefosine and its effect was observed on insulin-signalling proteins such as Akt, PI3K, insulin receptor-beta, IRS-1, c-Jun N-terminal kinase, p38 and glycogen synthase kinase beta, as well as on glucose uptake. RESULTS Miltefosine caused skeletal muscle insulin resistance in vitro by interfering with the insulin-signalling pathway and inhibiting insulin-stimulated glucose uptake. CONCLUSIONS/INTERPRETATION Miltefosine may contribute to the risk of type 2 diabetes and needs further clinical exploration.
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Affiliation(s)
- N K Verma
- Signal Transduction Research Laboratory, Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160062, India
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Dhingra JBN, Verma NK, Behl R, Prasad SK, Ahlawat SPS. Phytomitogen induced changes in levels of inositol phosphates in the bovine lymphocytes. Indian J Biochem Biophys 2005; 42:173-177. [PMID: 23923560] [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] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The changes in levels of inositol phosphates and phosphoinositides were studied in the bovine lymphocytes, in response to phytomitogens (lectins)-concanavalin A (con A) and phytohaemagglutinin (PHA). Addition of con A and PHA resulted in a rapid increase in the cpm of total inositol phosphates (from 8599 +/- 100 cpm/2 x 10(6) cells to 11228 +/- 126 cpm/2 x 10(6) and 9758 +/- 100 cpm/2 x10(6) cells, respectively) at 1 min after mitogen stimulation. There was a concomitant decrease in the phosphatidylinositol levels at 1 min, which continued up to 5 min. At 1 min of stimulation, inositol diphosphate fraction exhibited maximum increase, as compared to inositol mono- and triphosphates, suggesting that it contributed the most towards the overall increase in the total inositol phosphates levels. Results suggest that bovine lymphocytes respond to phytomitogens with a rapid turnover of phosphoinositides.
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Verma NK, Singh J, Dey CS. PPAR-gamma expression modulates insulin sensitivity in C2C12 skeletal muscle cells. Br J Pharmacol 2004; 143:1006-13. [PMID: 15504754 PMCID: PMC1575957 DOI: 10.1038/sj.bjp.0706002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [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: 05/12/2004] [Revised: 08/23/2004] [Accepted: 09/08/2004] [Indexed: 11/09/2022] Open
Abstract
Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) expression is very low in skeletal muscle cells, which is one of the most important target tissues for insulin and plays a predominant role in glucose homeostasis. It has recently been shown that muscle-specific PPAR-gamma deletion in mouse causes insulin resistance. However, it is likely that the observed effects might be due to secondary interaction in whole animal. The aim of the study was to explore the role of muscle PPAR-gamma in insulin sensitivity. We stably transfected C2C12 skeletal muscle cells with plasmids containing sense or antisense constructs of PPAR-gamma and examined the effect of modulation of PPAR-gamma expression in terms of glucose uptake. Effect was also examined in insulin-resistant C2C12 skeletal muscle cells. In transfected C2C12 cell line, the inhibition of PPAR-gamma expression (23.0 +/-0.005%) was observed to induce insulin resistance as determined by functional assessment of 2-deoxyglucose incorporation. Overexpression of PPAR-gamma (28.5 +/- 0.008%) produced an additional effect on insulin (100 nM) and Pioglitazone (50 microM), resulting in 42.7 +/- 3.5% increase in glucose uptake as against 29.2+/-2.8% in wild-type C2C12 skeletal muscle cells differentiated under normal (2% horse serum) condition. Under similar treatment, PPAR-gamma overexpressing cells resistant to insulin exhibited enhanced glucose uptake upto 60.7 +/- 4.08%, as compared to 23.8 +/- 5.1% observed in wild-type C2C12 skeletal muscle cells. These data demonstrate a direct involvement of PPAR-gamma in insulin sensitization of TZD action on skeletal muscle cells, and suggest that pharmacological overexpression of muscle PPAR-gamma gene in skeletal muscle might be a useful strategy for the treatment of insulin resistance.
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Affiliation(s)
- Navin K Verma
- Signal Transduction Research Laboratory, Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
| | - Jaskirat Singh
- Signal Transduction Research Laboratory, Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
| | - Chinmoy S Dey
- Signal Transduction Research Laboratory, Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160 062, India
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Abstract
RNA interference, part of a complicated network of interconnected pathways for cellular defence, RNA surveillance and development, has become a powerful tool for the experimental manipulation of gene expression. It is the process by which double-stranded (dsRNA) silences specific gene expression through homology-dependent degradation of cognate mRNA. The dsRNA is converted into 21nt small interfering RNAs (siRNAs), which directs a complex ribonuclease system to substrate mRNA targets. The degradation of the target mRNA is initiated with the cleavage at a position corresponding to the centre of the siRNA. Dissecting individual cellular pathways to reveal the function of numerous proteins is an approach to drug discovery. Interfering RNA (RNAi) serves as a rapid and convenient tool, which works in various organisms. RNAi technology has the potential to facilitate our understanding of biological processes and potentially lead to exciting new drugs. Here we review various experimental approaches adopted with RNAi and possible therapeutic applications.
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Affiliation(s)
- N K Verma
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
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Abstract
Miltefosine causes leishmanial death, but the possible mechanism(s) of action is not known. The mode of action of miltefosine was investigated in vitro in Leishmania donovani promastigotes as well as in extra- and intracellular amastigotes. Here, we demonstrate that miltefosine induces apoptosis-like death in L. donovani based on observed phenomena such as nuclear DNA condensation, DNA fragmentation with accompanying ladder formation, and in situ labeling of DNA fragments by the terminal deoxyribonucleotidyltransferase-mediated dUTP-biotin nick end labeling method. Understanding of miltefosine-mediated death will facilitate the design of new therapeutic strategies against Leishmania parasites.
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Affiliation(s)
- Navin K Verma
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
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Malhotra S, Grover A, Verma NK, Bhargava VK. A study of drug utilisation and cost of treatment in patients hospitalised with unstable angina. Eur J Clin Pharmacol 2000; 56:755-61. [PMID: 11214788 DOI: 10.1007/s002280000226] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 11/27/2022]
Abstract
OBJECTIVE The current study was designed to investigate drug utilisation in the management of unstable angina in India and to calculate the costs incurred by patients in the treatment of a single episode of unstable angina. METHODS We conducted a prescription survey to examine the use of antianginal drugs in patients with unstable angina in a tertiary care Indian hospital. The use of concurrent medications such as antidiabetic, antihypertensive and lipid-lowering agents was also examined. Data on the cost of treatment, investigations, income, and family size were collected from the case histories or direct interviews with the patients/relatives. RESULTS A total of 336 consecutive prescriptions were evaluated. Aspirin was the most frequently prescribed drug (98%) followed by nitroglycerin infusion (90%) and enoxaparin (52%). One of the heparins was used by 89% of all patients and beta-blockers by up to 62% of the patients. Besides antianginals, antihypertensive (49%) and antidiabetic (16%) drugs were commonly coadministered. The mean (+/- SD) cost of treatment of a single episode of unstable angina in the hospital was US $494 (+/- 271) against an annual per capita income of US $245. The mean (+/- SD) cost incurred by the patients due to drugs alone during the hospital stay was US $70 (+/- 18) and enoxaparin accounted for 60% of the expenditure due to drugs. CONCLUSIONS The results of our study show that low-molecular-weight heparin, enoxaparin, is replacing unfractionated heparin in the treatment of unstable angina. In view of the use of costly new drugs, there is an urgent need for carrying out pharmacoeconomic analysis in developing countries as the treatment of a single episode of unstable angina imparts a considerable economic burden on the patient.
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Affiliation(s)
- S Malhotra
- Department of Pharmacology, Postgraduate Insitute of Medical Education and Research, Chandigarh, India
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36
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de Jersey J, Bird PH, Verma NK, Bradley MP. Antigen-specific systemic and reproductive tract antibodies in foxes immunized with Salmonella typhimurium expressing bacterial and sperm proteins. Reprod Fertil Dev 2000; 11:219-28. [PMID: 10898286 DOI: 10.1071/rd99072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 11/23/2022] Open
Abstract
Attenuated Salmonella typhimurium strains are potential 'safe' delivery vectors of an oral immunocontraceptive vaccine for the European red fox (Vulpes vulpes). In the present study, model bacterial (Escherichia coli heat-labile enterotoxin B subunit, LTB) and fox sperm (fSP10) antigens were expressed in S. typhimurium SL3261 (delta aroA) under the control of the trc promoter. Adult female foxes were given three oral immunizations with SL3261 containing either LTB (SL3261/pLTB), fSP10 (SL3261/pFSP10) or a control plasmid (pKK233-2 or pTrc99A). All foxes raised serum (IgG) and vaginal (IgG and IgA) antibodies against S. typhimurium lipopolysaccharide (LPS). Each fox that received SL3261/pLTB raised high titre LTB-specific serum and vaginal IgG antibodies. However, only one of four foxes immunized with SL3261/pFSP10 raised an anti-fSP10 immune response, in the form of low titre serum and vaginal IgG antibodies. No vaginal IgA antibodies were raised against either LTB or fSP10 in these experiments. The immune responses against recombinant LTB and fSP10 resulted chiefly from the initial dose of antigen in the inocula and were minimally influenced by continued in vivo antigen expression. This study demonstrates for the first time in the female red fox that oral Salmonella can elicit specific systemic and reproductive tract antibodies against heterologous, recombinant proteins.
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Affiliation(s)
- J de Jersey
- Vertebrate Biocontrol Cooperative Research Centre, CSIRO Wildlife and Ecology, Canberra, ACT, Australia.
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Abstract
O-antigen modification (serotype conversion) in Shigella flexneri, which is an important virulence determinant, is conferred by temperate bacteriophages. Several serotype-converting phages have been isolated and preliminary characterization has identified the genes involved in O-antigen modification, and has also provided insight into the molecular biology of these phages.
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Affiliation(s)
- G E Allison
- Divn of Biochemistry and Molecular Biology, Faculty of Science, Australian National University, Canberra, ACT, 0200, Australia
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38
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Abstract
An attenuated strain of Shigella flexneri was utilised to express viral protein (VP) 4 of rotavirus and the immunogenicity of the recombinant constructs was studied in BALB/c mice. VP4 was expressed as a fusion with maltose binding protein (MBP) in both the cytoplasm and periplasm, with a much higher level of expression occurring in the former. While all constructs induced a Shigella-specific response in mice, only the construct expressing MBP-VP4 in the cytoplasm of Shigella stimulated an immune response specific to rotavirus. This study demonstrates that Shigella can be used to deliver rotavirus antigens and induces an immune response directed towards both rotavirus and Shigella.
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Affiliation(s)
- A L Loy
- Division of Biochemistry and Molecular Biology, Faculty of Science, The Australian National University, Canberra, ACT
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Adhikari P, Allison G, Whittle B, Verma NK. Serotype 1a O-antigen modification: molecular characterization of the genes involved and their novel organization in the Shigella flexneri chromosome. J Bacteriol 1999; 181:4711-8. [PMID: 10419979 PMCID: PMC103612 DOI: 10.1128/jb.181.15.4711-4718.1999] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [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: 11/20/2022] Open
Abstract
The factors responsible for serotype 1a O-antigen modification in Shigella flexneri were localized to a 5.8-kb chromosomal HindIII fragment of serotype 1a strain Y53. The entire 5.8-kb fragment and regions up- and downstream of it (10.6-kb total) were sequenced. A putative three-gene operon, which showed homology with other serotype conversion genes, was identified and shown to confer serotype 1a O-antigen modification. The serotype conversion genes were flanked on either side by phage DNA. Multiple insertion sequence (IS) elements were located within and upstream of the phage DNA in a composite transposon-like structure. Host DNA homologous to the dsdC and the thrW proA genes was located upstream of the IS elements and downstream of the phage DNA, respectively. The sequence analysis indicates that the organization of the 10.6-kb region of the Y53 chromosome is unique and suggests that the serotype conversion genes were originally brought into the host by a bacteriophage. Several features of this region are also characteristic of pathogenicity islands.
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Affiliation(s)
- P Adhikari
- Division of Biochemistry and Molecular Biology, Faculty of Science, The Australian National University, Canberra, ACT 0200, Australia
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40
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Abstract
Shigella flexneri SFL124 (serotype Y) is a promising live oral vaccine candidate, which has been shown to be safe and immunogenic in human volunteers. To change the serotype of this vaccine strain, we inserted a serotype conversion gene cluster into the chromosome of SFL124 by using a bacteriophage-based site-specific integration system. By cloning an integrase gene (int), an attachment site (attP) and a glucosyl transfer gene cluster from bacteriophage SfX into a suicide vector, and subsequently introducing this construct into S. flexneri SFL124, we obtained a S. flexneri strain (designated SFL1213) expressing the serotype X somatic antigen specificity. The strain retained other characteristics of the parent strain, such as colony shape, growth rate, and Congo red binding property. Stability test showed that the serotype X O-antigen specificity in SFL1213 was 100% stable after being cultured approximately 72 successive hours under non-selective condition. In a mouse pulmonary model, the recombinant strain elicited a significant level of humoral antibodies which recognized the lipopolysaccharide (LPS) of a wild-type S. flexneri serotype X strain. The site-specific insertion system will be useful when stable expression of a cloned single copy gene is desired in the chromosome of S. flexneri vaccine candidate, SFL124.
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Affiliation(s)
- S Guan
- Division of Biochemistry and Molecular Biology, Faculty of Science, Australian National University, Canberra, Australia
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41
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Abstract
The aroA and aroD genes from Shigella dysenteriae type 1, encoding 5-enolpyruvylshikimate 3-phosphate synthase and 3-dehydroquinase, respectively, were cloned by polymerase chain reaction (PCR). Their nucleotide sequences were determined and predicted to code for 46 kDa and 27.5 kDa proteins, respectively. Protein expressed from these genes using the minicell system, corresponded to the size of the predicted protein products. The cloned genes were shown to be functional by complementation of Escherichia coli aroA- and aroD- mutants. The predicted amino acid sequences of the cloned aroA (427 amino acids) and aroD (252 amino acids) genes of S. dysenteriae type 1 were found to be highly homologous to the corresponding genes in other bacterial species, indicating the high conservation of these housekeeping genes. The use of the cloned aroA and aroD genes in the development of a vaccine strain against S. dysenteriae is discussed.
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Affiliation(s)
- J C Walker
- Division of Biochemistry and Molecular Biology, Faculty of Science, School of Life Sciences, The Australian National University, Canberra.
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Whittle BL, Smith RM, Matthaei KI, Young IG, Verma NK. Enhancement of the specific mucosal IgA response in vivo by interleukin-5 expressed by an attenuated strain of Salmonella serotype Dublin. J Med Microbiol 1997; 46:1029-38. [PMID: 9402925 DOI: 10.1099/00222615-46-12-1029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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: 02/05/2023] Open
Abstract
It has been shown that cytokines have potential as therapeutic adjuvants in vaccination. Interleukin-5 (IL-5) is a cytokine that regulates antibody production, in particular enhancing IgA production by activated mucosal B cells. This study examined the expression of a cloned cytokine gene encoding murine IL-5 (mIL-5) by an attenuated aroA strain (SL5631) of Salmonella serotype Dublin. The resulting strain, SL5631(pTRXFUS-mIL-5), expressed mIL-5 as a fusion with thioredoxin as demonstrated by immunological and biological assays. When strain SL5631(pTRXFUS-mIL-5) was used as a live vaccine in BALB/c mice, it colonised and multiplied at higher levels in spleens and livers than the strain carrying the empty plasmid. A reduction in invasiveness of SL5631(pTRXFUS-mIL-5) was observed in in-vitro invasion assays. Enhanced IgA response against salmonella LPS in mucosal secretions and enhanced IgA and IgG responses were detected by ELISA and ELISPOT methods in sera of mice immunised with the strain expressing mIL-5. Results with IL-5-deficient mice showed that the enhanced IgA response was due to Salmonella-expressed mIL-5 rather than endogenous mIL-5.
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MESH Headings
- Animals
- Antibodies, Bacterial/biosynthesis
- Bacterial Vaccines/immunology
- Cloning, Molecular
- Disease Models, Animal
- Electrophoresis, Polyacrylamide Gel
- Enzyme-Linked Immunosorbent Assay
- Female
- Gene Expression
- Genetic Vectors
- Immunity, Mucosal
- Immunoglobulin A, Secretory/biosynthesis
- Immunoglobulin G/biosynthesis
- Interleukin-5/deficiency
- Interleukin-5/genetics
- Interleukin-5/immunology
- Lipopolysaccharides/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Plasmids
- Salmonella/genetics
- Salmonella/immunology
- Salmonella Infections, Animal/immunology
- Vaccines, Attenuated/immunology
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Affiliation(s)
- B L Whittle
- Division of Biochemistry and Molecular Biology, Faculty of Science, Canberra, Australia
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Abstract
The O-antigen of most Shigella flexneri serotypes contains an identical tetrasaccharide repeating unit. Apart from serotype Y, the O-antigen is modified by addition of a glucosyl and/or O-acetyl residue to a specific position in the O-unit. In this study the glucosyl transferase gene from a serotype 1 a has been cloned and identified. The bacteriophage SfV integrase (int) gene was used to probe a S. flexneri Y53 (serotype 1 a) cosmid library and 18 unique clones were identified. Southern hybridisation of these clones indicated two unlinked regions of the chromosome contained the int homologue. When expressed in a live candidate vaccine strain of S. flexneri serotype Y (SFL124), clones with one region produced type I antigen, whereas clones containing the other region produced mainly type Y antigen. One of the cosmid clones positive for type I antigen by agglutination and Western blotting was selected for further study. Genes involved in O-antigen glucosyl modification were mapped on a 5.8 kb fragment and subclones were produced which fully or partially expressed the type I antigen, depending on the extent of the clone. Fully and partially expressing clones may be useful vaccine candidate strains for protection against disease caused by two serotypes of S. flexneri.
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Affiliation(s)
- D A Bastin
- Division of Biochemistry and Molecular Biology, School of Life Sciences, Faculty of Science, Australian National University, Canberra, Australia
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Abstract
Attenuated, heterologous strains of Salmonella have shown potential as live, recombinant vaccines against foreign pathogens. Studies in animal models have demonstrated that immunization with these heterologous vaccines is an effective way to induce both cellular and humoral immune responses against Salmonella and the foreign antigen. We studied the consequence of priming mice with Salmonella dublin 3-6 months before intraperitoneal administration with the same strain carrying a model B-cell epitope. Mice primed with the carrier strain demonstrated enhanced serum Ig titres against the foreign antigen. This immune enhancement was observed up to approximately 6 months after priming. These findings suggest that previous immunological experience with Salmonella does not limit the immune response to a foreign antigen carried by the same organism. In fact, prior exposure to Salmonella appears to enhance the response to the foreign antigen.
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Affiliation(s)
- B L Whittle
- Division of Biochemistry and Molecular Biology, Australian National University, Canberra, Australia.
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45
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Mahwar RS, Verma NK, Chakrabarti SP, Biswas DK. Environmental auditing programme in India. Sci Total Environ 1997; 204:11-26. [PMID: 9299766 DOI: 10.1016/s0048-9697(97)00161-7] [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: 05/22/2023]
Abstract
The concept of environmental auditing in industrial units in India was formally introduced in March 1992 with the overall objective minimising consumption of resources and promoting use of clean technologies in industrial production to minimise generation of wastes. A series of discussions were held among the concerned regulatory agencies before and after making environmental auditing and submission of Annual Environmental Statements, a mandatory requirement for the industries. This followed organisation of a number of workshops, seminars and training programmers all over the country by different agencies dealing with environment protection, conducting of audit studies in 125 selected polluting industries in the country by the Central Pollution Control Board (CPCB), Delhi, and a number of other activities. The present paper gives the details of the activities before and after the introduction of this requirement in the country. The aspects covered include (i) the evolution of the concept, (ii) the history of the introduction of the scheme in the country and the organisational structure, (iii) the mandatory requirement and its applicability, (iv) the implementing agencies and their responsibilities, (v) summary of the training programmes/workshops organised in the country, (vi) case studies conducted by CPCB in selected polluting industries and the major findings, (vii) development of guidelines for conducting environmental audit in different categories of polluting industries, and (viii) the current status of the scheme and plans for its effective implementation.
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Affiliation(s)
- R S Mahwar
- Central Pollution Control Board, Ministry of Environment and Forests, East Arjun Nagar, Delhi, India
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Huan PT, Bastin DA, Whittle BL, Lindberg AA, Verma NK. Molecular characterization of the genes involved in O-antigen modification, attachment, integration and excision in Shigella flexneri bacteriophage SfV. Gene 1997; 195:217-27. [PMID: 9305767 DOI: 10.1016/s0378-1119(97)00143-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bacteriophage SfV is a temperate phage of Shigella flexneri responsible for converting serotype Y (3,4) to serotype 5a (V; 3,4) through its glucosyl transferase gene. The glucosyl transferase (gtr) gene of SfV has been cloned and shown to partially convert S. flexneri serotype Y to serotype 5a. In this study, we found that the serotype-converting region of SfV was approximately 2.5 kb in length containing three continuous ORFs. The recombinant strain carrying the three complete ORFs expressed the type V and group antigen 3,4, both indistinguishable from that of S. flexneri 5a wild-type strain. The interruption of orf5 or orf6 gave partial conversion in the S. flexneri recombinant strain indicated by the incomplete replacement of group antigen 3,4. The region adjacent to the serotype-conversion genes was found to be identical to the attP-int-xis region of phage P22. Altogether, an approximately 2.2-kb sequence covering a portion of the serotype-conversion (approximately 500 nt)-attP-int-xis regions of SfV was remarkably similar to that of P22.
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Affiliation(s)
- P T Huan
- Division of Biochemistry and Molecular Biology, School of Life Sciences, The Australian National University, Canberra
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Huan PT, Whittle BL, Bastin DA, Lindberg AA, Verma NK. Shigella flexneri type-specific antigen V: cloning, sequencing and characterization of the glucosyl transferase gene of temperate bacteriophage SfV. Gene 1997; 195:207-16. [PMID: 9305766 DOI: 10.1016/s0378-1119(97)00144-3] [Citation(s) in RCA: 37] [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] [Indexed: 02/05/2023]
Abstract
With lysogeny by bacteriophage SfV, Shigella flexneri serotype Y is converted to serotype 5a. The glucosyl transferase gene (gtr) from bacteriophage SfV of S. flexneri, involved in serotype-specific conversion, was cloned and characterized. The DNA sequence of a 3.7 kb EcoRI-BamHI fragment of bacteriophage SfV which includes the gtr gene was determined. This gene, encoding a polypeptide of 417 aa with 47.67 kDa molecular mass, caused partial serotype conversion of S. flexneri from serotype Y to type V antigen as demonstrated by Western blotting and the sensitivity of the hybrid strain to phage Sf6. The deduced protein of the partially sequenced open reading frame upstream of the gtr showed similarity to various glycosyl transferases of other bacteria. Orf3, separated from the gtr by a non-coding region and transcribed convergently, codes for a 167 aa (18.8 kDa) protein found to have homology with tail fibre genes of phage lambda and P2.
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Affiliation(s)
- P T Huan
- Division of Biochemistry and Molecular Biology, School of Life Sciences, The Australian National University, Canberra
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Whittle BL, Lee E, Weir RC, Verma NK. Immune response to a Murray Valley encephalitis virus epitope expressed in the flagellin of an attenuated strain of Salmonella. J Med Microbiol 1997; 46:129-38. [PMID: 9060872 DOI: 10.1099/00222615-46-2-129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [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: 02/03/2023] Open
Abstract
Recent developments in vaccine construction include the use of attenuated, avirulent strains of Salmonella as carriers of foreign antigens. These recombinant strains can elicit a heterologous immune response when injected into animals, demonstrating potential for their use in the construction of many vaccines. In the present study, a B-cell epitope of Murray Valley encephalitis virus (MVE) was identified and expressed in a Salmonella strain to evaluate its potential to induce a specific immune response to MVE. A synthetic oligonucleotide encoding the B-cell epitope (residues E201-224) of the envelope protein of MVE was inserted into the cloned flagellin gene of the Salmonella strain. The construct was sequenced to ensure correct orientation of the epitope. Expression of the epitope was demonstrated by Western blot analysis and immunogold electron microscopy with monoclonal antibody specific to the epitope. Electron microscopy analysis revealed multiple copies of the epitope along the flagella. The recombinant Salmonella carrying the hybrid flagellin gene elicited an immune response to the MVE epitope in a mouse model. The MVE-specific antibodies partially neutralised the virus in vitro. The significance of this system for engineering vaccines for other medically important flaviviruses is discussed.
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Affiliation(s)
- B L Whittle
- Division of Biochemistry and Molecular Biology, Faculty of Science, Australian National University, Canberra, Australia
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Huan PT, Taylor R, Lindberg AA, Verma NK. Immunogenicity of the Shigella flexneri serotype Y (SFL 124) vaccine strain expressing cloned glucosyl transferase gene of converting bacteriophage SfX. Microbiol Immunol 1995; 39:467-72. [PMID: 8569531 DOI: 10.1111/j.1348-0421.1995.tb02230.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [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: 01/31/2023]
Abstract
The glucosyl transferase gene (gtr) from bacteriophage phage X (SfX) caused partial conversion of serotype Y (group antigen 3, 4) to X (group antigen 7, 8) when introduced into a candidate vaccine strain of Shigella flexneri serotype Y (SFL124). The gtr gene caused conversion of O-antigens but did not eliminate the adsorption of the corresponding phage SfX. The hybrid strain expressing both group antigens 7, 8 and 3, 4 showed 75% protection when immunized guinea pigs were challenged with a wild-type S. flexneri serotype X strain. No protection was observed against serotype Y challenge, although group antigen 3, 4 was detected in the LPS of the hybrid strain. This suggests the importance of O-antigen immunity in the host defense against shigellosis.
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Affiliation(s)
- P T Huan
- Division of Biochemistry and Molecular Biology, Faculty of Science, School of Life Sciences, Australian National University, Canberra, Australia
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Verma NK, Ziegler HK, Wilson M, Khan M, Safley S, Stocker BA, Schoolnik GK. Delivery of class I and class II MHC-restricted T-cell epitopes of listeriolysin of Listeria monocytogenes by attenuated Salmonella. Vaccine 1995; 13:142-50. [PMID: 7625107 DOI: 10.1016/0264-410x(95)93127-u] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Using a Salmonella vaccine-Listeria infection model of intracellular infection, we studied the capacity of an attenuated strain of Salmonella carrying T-cell epitopes of listeriolysin (LLO) of L. monocytogenes to elicit epitope-specific T-cell responses. Class II (LLO 215-226) or class I (LLO 91-99) MHC-restricted T-cell epitopes of LLO were inserted within a central, hypervariable domain of the flagellin protein of an attenuated delta aroA Salmonella dublin strain. T cells from Listeria-immunized mice were activated by lysates or heat-killed preparations of Salmonella construct expressing the LLO 215-226 epitope, indicating that LLO 215-226 is processed and presented to T cells when offered to antigen-presenting cells as part of a flagellin-epitope fusion protein. The chimeric flagellin genes were integrated into the chromosome of the flagellin-negative S. dublin strain to obtain stable expression of the epitopes. Immunization with the living, chromosomally integrated Salmonella construct carrying LLO 215-226 epitope as part of the flagellin protein generated T cells reactive with the corresponding LLO peptide, indicating that this chimera can stimulate a class-specific immune response in vitro. The effect of flanking residues on the processing and presentation of MHC class I LLO 91-99 epitope was studied using Salmonella vaccine strains that express chimeric flagellins containing one of three LLO 91-99 inserts: 91-99 (normal flagellin amino acids as flanking residues); KK91-99KK (Lys-Lys flanking residues); and AAA91-99AAA (Ala-Ala-Ala flanking residues).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- N K Verma
- Howard Hughes Medical Institute, Stanford University School of Medicine, CA 94305, USA
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