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2.
bioRxiv ; 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38168334

ABSTRACT

Tuberculosis (TB) continues to be a major global health burden and kills over a million people annually. New immunization strategies are required for the development of an efficacious TB vaccine that can potentially induce sterilizing immunity. In this study, we first confirmed that various strains of the IKEPLUS vaccine confer a higher survival benefit than BCG in a murine model of intravenous Mycobacterium tuberculosis (Mtb) infection. We have shown that there was a significant increase in the expression of the Rv0282 when IKEPLUS was grown in low zinc and iron containing Sauton medium. We confirmed on biofilm assays that zinc plays a vital role in the growth and formation of Mycobacterium smegmatis ( M. smegmatis ) biofilms. IKEPLUS grown in low zinc media led to better protection of mice after intravenous challenge with very high dosage of Mtb. We also showed that various variants of IKEPLUS induced apoptotic cell-death of infected macrophages at a higher rate than wild type M. smegmatis . We next attempted to determine if zinc containing ribosomal proteins such as rpmb2 could contribute to protective efficacy against Mtb infection. Since BCG has an established role in anti-mycobacterial efficacy, we boosted BCG vaccinated mice with rmpb2 but this did not lead to an increment in the protection mediated by BCG.

3.
bioRxiv ; 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38168250

ABSTRACT

Mycobacterium tuberculosis (Mtb), a successful human pathogen, resides in host sentinel cells and combats the stressful intracellular environment induced by reactive oxygen and nitrogen species during infection. Mtb employs several evasion mechanisms in the face of the host as a survival strategy, including detoxifying enzymes as short-chain dehydrogenases/ reductases (SDRs) to withstand host-generated insults. In this study, using specialized transduction we have generated a Rv0687 deletion mutant and its complemented strain and investigated the functional role of Rv0687, a member of SDRs family genes in Mtb pathogenesis. Wildtype (WT) and mutant Mtb strain lacking Rv0687 (RvΔ0687) were tested for in-vitro stress response and in-vivo survival in macrophages and mice models of infection. The study demonstrates that Rv0687 is crucial for sustaining bacterial growth in nutrition-limited conditions. The deletion of Rv0687 elevated the sensitivity of Mtb to oxidative and nitrosative stress-inducing agents. Furthermore, the lack of Rv0687 compromised the survival of Mtb in primary bone marrow macrophages and led to an increase in the levels of the secreted proinflammatory cytokines TNF-α, and MIP-1α. Interestingly, the growth of WT and RvΔ0687 was similar in the lungs of infected immunocompromised mice however, a significant reduction in RvΔ0687 growth was observed in the spleen of immunocompromised Rag -/- mice at 4 weeks post-infection. Moreover Rag -/- mice infected with RvΔ0687 survived longer compared to WT Mtb strain. Additionally, we observed significant reduction in bacterial burden in spleens and lungs of immunocompetent C57BL/6 mice infected with RvΔ0687 compared to complemented and WT Mtb strains. Collectively, this study reveals that Rv0687 plays a role in Mtb pathogenesis.

4.
Pharmaceuticals (Basel) ; 15(11)2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36422545

ABSTRACT

Tuberculosis (TB) remains a global health problem and the emergence of HIV has further worsened it. Long chemotherapy and the emergence of drug-resistance strains of Mycobacterium tuberculosis as well as HIV has aggravated the problem. This demands urgent the need to develop new anti-tuberculosis and antiretrovirals to treat TB and HIV. The lack of diversity in drugs designed using traditional approaches is a major disadvantage and limits the treatment options. Therefore, new technologies and approaches are required to solve the current issues and enhance the production of drugs. Interestingly, fragment-based drug discovery (FBDD) has gained an advantage over high-throughput screenings as FBDD has enabled rapid and efficient progress to develop potent small molecule compounds that specifically bind to the target. Several potent inhibitor compounds of various targets have been developed using FBDD approach and some of them are under progression to clinical trials. In this review, we emphasize some of the important targets of mycobacteria and HIV. We also discussed about the target-based druggable molecules that are identified using the FBDD approach, use of these druggable molecules to identify novel binding sites on the target and assays used to evaluate inhibitory activities of these identified druggable molecules on the biological activity of the targets.

5.
Am J Physiol Cell Physiol ; 323(5): C1444-C1474, 2022 11 01.
Article in English | MEDLINE | ID: mdl-36189975

ABSTRACT

Mycobacterium tuberculosis (Mtb) is the pathogen that causes tuberculosis (TB), a leading infectious disease of humans worldwide. One of the main histopathological hallmarks of TB is the formation of granulomas comprised of elaborately organized aggregates of immune cells containing the pathogen. Dissemination of Mtb from infected cells in the granulomas due to host and mycobacterial factors induces multiple cell death modalities in infected cells. Based on molecular mechanism, morphological characteristics, and signal dependency, there are two main categories of cell death: programmed and nonprogrammed. Programmed cell death (PCD), such as apoptosis and autophagy, is associated with a protective response to Mtb by keeping the bacteria encased within dead macrophages that can be readily phagocytosed by arriving in uninfected or neighboring cells. In contrast, non-PCD necrotic cell death favors the pathogen, resulting in bacterial release into the extracellular environment. Multiple types of cell death in the PCD category, including pyroptosis, necroptosis, ferroptosis, ETosis, parthanatos, and PANoptosis, may be involved in Mtb infection. Since PCD pathways are essential for host immunity to Mtb, therapeutic compounds targeting cell death signaling pathways have been experimentally tested for TB treatment. This review summarizes different modalities of Mtb-mediated host cell deaths, the molecular mechanisms underpinning host cell death during Mtb infection, and its potential implications for host immunity. In addition, targeting host cell death pathways as potential therapeutic and preventive approaches against Mtb infection is also discussed.


Subject(s)
Mycobacterium tuberculosis , Tuberculosis , Humans , Tuberculosis/microbiology , Tuberculosis/prevention & control , Mycobacterium tuberculosis/metabolism , Cell Death , Macrophages/metabolism , Granuloma/metabolism , Granuloma/microbiology , Granuloma/pathology , Host-Pathogen Interactions
6.
Front Immunol ; 13: 959656, 2022.
Article in English | MEDLINE | ID: mdl-36091032

ABSTRACT

Bacillus Calmette-Guerin (BCG) has been used as a vaccine against tuberculosis since 1921 and remains the only currently approved vaccine for this infection. The recent discovery that BCG protects against initial infection, and not just against progression from latent to active disease, has significant implications for ongoing research into the immune mechanisms that are relevant to generate a solid host defense against Mycobacterium tuberculosis (Mtb). In this review, we first explore the different components of immunity that are augmented after BCG vaccination. Next, we summarize current efforts to improve the efficacy of BCG through the development of recombinant strains, heterologous prime-boost approaches and the deployment of non-traditional routes. These efforts have included the development of new recombinant BCG strains, and various strategies for expression of important antigens such as those deleted during the M. bovis attenuation process or antigens that are present only in Mtb. BCG is typically administered via the intradermal route, raising questions about whether this could account for its apparent failure to generate long-lasting immunological memory in the lungs and the inconsistent level of protection against pulmonary tuberculosis in adults. Recent years have seen a resurgence of interest in the mucosal and intravenous delivery routes as they have been shown to induce a better immune response both in the systemic and mucosal compartments. Finally, we discuss the potential benefits of the ability of BCG to confer trained immunity in a non-specific manner by broadly stimulating a host immunity resulting in a generalized survival benefit in neonates and the elderly, while potentially offering benefits for the control of new and emerging infectious diseases such as COVID-19. Given that BCG will likely continue to be widely used well into the future, it remains of critical importance to better understand the immune responses driven by it and how to leverage these for the design of improved vaccination strategies against tuberculosis.


Subject(s)
COVID-19 , Mycobacterium bovis , Tuberculosis , Animals , BCG Vaccine , COVID-19/prevention & control , Disease Models, Animal , Vaccination
7.
Int J Mol Sci ; 23(18)2022 Sep 14.
Article in English | MEDLINE | ID: mdl-36142582

ABSTRACT

The emergence of drug-resistant mycobacteria, including Mycobacterium tuberculosis (Mtb) and non-tuberculous mycobacteria (NTM), poses an increasing global threat that urgently demands the development of new potent anti-mycobacterial drugs. One of the approaches toward the identification of new drugs is fragment-based drug discovery (FBDD), which is the most ingenious among other drug discovery models, such as structure-based drug design (SBDD) and high-throughput screening. Specialized techniques, such as X-ray crystallography, nuclear magnetic resonance spectroscopy, and many others, are part of the drug discovery approach to combat the Mtb and NTM global menaces. Moreover, the primary drawbacks of traditional methods, such as the limited measurement of biomolecular toxicity and uncertain bioavailability evaluation, are successfully overcome by the FBDD approach. The current review focuses on the recognition of fragment-based drug discovery as a popular approach using virtual, computational, and biophysical methods to identify potent fragment molecules. FBDD focuses on designing optimal inhibitors against potential therapeutic targets of NTM and Mtb (PurC, ArgB, MmpL3, and TrmD). Additionally, we have elaborated on the challenges associated with the FBDD approach in the identification and development of novel compounds. Insights into the applications and overcoming the challenges of FBDD approaches will aid in the identification of potential therapeutic compounds to treat drug-sensitive and drug-resistant NTMs and Mtb infections.


Subject(s)
Mycobacterium Infections , Mycobacterium tuberculosis , Crystallography, X-Ray , Drug Design , Drug Discovery/methods , Humans , Nontuberculous Mycobacteria
8.
Comput Struct Biotechnol J ; 19: 3491-3506, 2021.
Article in English | MEDLINE | ID: mdl-34194673

ABSTRACT

The L-arginine biosynthesis pathway consists of eight enzymes that catalyse the conversion of L-glutamate to L-arginine. Arginine auxotrophs (argB/argF deletion mutants) of Mycobacterium tuberculosis are rapidly sterilised in mice, while inhibition of ArgJ with Pranlukast was found to clear chronic M. tuberculosis infection in a mouse model. Enzymes in the arginine biosynthetic pathway have therefore emerged as promising targets for anti-tuberculosis drug discovery. In this work, the ligandability of four enzymes of the pathway ArgB, ArgC, ArgD and ArgF is assessed using a fragment-based approach. We identify several hits against these enzymes validated with biochemical and biophysical assays, as well as X-ray crystallographic data, which in the case of ArgB were further confirmed to have on-target activity against M. tuberculosis. These results demonstrate the potential for more enzymes in this pathway to be targeted with dedicated drug discovery programmes.

9.
Environ Sci Pollut Res Int ; 28(18): 22474-22487, 2021 May.
Article in English | MEDLINE | ID: mdl-33415643

ABSTRACT

The present study encompasses a unique concept involving the formation of core-shell particles with surface-activated fly ash (FA) as core and nanoscale zerovalent iron (nZVI) particles as shell, which not only imparts high adsorption efficiency for Cr(VI) but also contributes to fruitful utilization of FA while overcoming the drawbacks associated with ZVI nanoparticles (aggregation, rapid oxidation and less durability). The otherwise inert surface of FA has been modified and activated to achieve a uniform and stable layer of nZVI over FA. The functionalized particles were studied using FE-SEM/EDAX, HR-TEM, XRD and FT-IR studies for its physical, functional and morphological characteristics. The results indicate the strong adsorption ability of nZVI@FA particles, with 100% removal efficiency within 10 min at low initial concentrations of Cr(VI), which is appreciably higher than that of pure fly ash (26%) after 60 min of reaction. Besides, the so-formed structure of composite aids to improve its life, as the synthesized nZVI@FA particles could be efficiently regenerated and reused up to 5 subsequent adsorption-desorption cycles, which is in contrast with the ability of fly ash considering its low desorption potential. Hence, the composite material proves to be an effective and sustainable alternative for treatment of a waste using a waste.


Subject(s)
Iron , Water Pollutants, Chemical , Adsorption , Chromium/analysis , Coal Ash , Spectroscopy, Fourier Transform Infrared , Water , Water Pollutants, Chemical/analysis
10.
Vaccine ; 38(45): 7156-7165, 2020 10 21.
Article in English | MEDLINE | ID: mdl-32978002

ABSTRACT

Although vaccination with BCG prevents disseminated forms of childhood tuberculosis (TB), it does not protect against pulmonary infection or Mycobacterium tuberculosis (Mtb) transmission. In this study, we generated a complete deletion mutant of the Mtb Esx-5 type VII secretion system (Mtb Δesx-5). Mtb Δesx-5 was highly attenuated and safe in immunocompromised mice. When tested as a vaccine candidate to boost BCG-primed immunity, Mtb Δesx-5 improved protection against highly virulent Mtb strains in the murine and guinea pig models of TB. Enhanced protection provided by heterologous BCG-prime plus Mtb Δesx-5 boost regimen was associated with increased pulmonary influx of central memory T cells (TCM), follicular helper T cells (TFH) and activated monocytes. Conversely, lower numbers of T cells expressing exhaustion markers were observed in vaccinated animals. Our results suggest that boosting BCG-primed immunity with Mtb Δesx-5 is a potential approach to improve protective immunity against Mtb. Further insight into the mechanism of action of this novel prime-boost approach is warranted.


Subject(s)
Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculosis , Type VII Secretion Systems , Animals , Antigens, Bacterial , BCG Vaccine , Guinea Pigs , Immunization, Secondary , Mice , Mycobacterium tuberculosis/genetics , Tuberculosis/prevention & control , Vaccination
11.
Microbiol Spectr ; 7(3)2019 05.
Article in English | MEDLINE | ID: mdl-31172908

ABSTRACT

Mycobacterium tuberculosis is an ancient master of the art of causing human disease. One important weapon within its fully loaded arsenal is the type VII secretion system. M. tuberculosis has five of them: ESAT-6 secretion systems (ESX) 1 to 5. ESX-1 has long been recognized as a major cause of attenuation of the FDA-licensed vaccine Mycobacterium bovis BCG, but its importance in disease progression and transmission has recently been elucidated in more detail. This review summarizes the recent advances in (i) the understanding of the ESX-1 structure and components, (ii) our knowledge of ESX-1's role in hijacking macrophage function to set a path for infection and dissemination, and (iii) the development of interventions that utilize ESX-1 for diagnosis, drug interventions, host-directed therapies, and vaccines.


Subject(s)
Antigens, Bacterial/immunology , Bacterial Proteins/immunology , Mycobacterium tuberculosis/immunology , Mycobacterium tuberculosis/metabolism , Tuberculosis/immunology , Type VII Secretion Systems/immunology , Type VII Secretion Systems/metabolism , BCG Vaccine/immunology , Bacterial Secretion Systems/metabolism , Chemokines , Host-Pathogen Interactions , Humans , Macrophages/immunology , Mycobacterium tuberculosis/pathogenicity , Necrosis , Phagosomes , Tuberculosis/diagnosis , Tuberculosis/drug therapy , Tuberculosis/prevention & control , Vaccines , Virulence
12.
Proc Natl Acad Sci U S A ; 115(39): 9779-9784, 2018 09 25.
Article in English | MEDLINE | ID: mdl-30143580

ABSTRACT

Reactive oxygen species (ROS)-mediated oxidative stress and DNA damage have recently been recognized as contributing to the efficacy of most bactericidal antibiotics, irrespective of their primary macromolecular targets. Inhibitors of targets involved in both combating oxidative stress as well as being required for in vivo survival may exhibit powerful synergistic action. This study demonstrates that the de novo arginine biosynthetic pathway in Mycobacterium tuberculosis (Mtb) is up-regulated in the early response to the oxidative stress-elevating agent isoniazid or vitamin C. Arginine deprivation rapidly sterilizes the Mtb de novo arginine biosynthesis pathway mutants ΔargB and ΔargF without the emergence of suppressor mutants in vitro as well as in vivo. Transcriptomic and flow cytometry studies of arginine-deprived Mtb have indicated accumulation of ROS and extensive DNA damage. Metabolomics studies following arginine deprivation have revealed that these cells experienced depletion of antioxidant thiols and accumulation of the upstream metabolite substrate of ArgB or ArgF enzymes. ΔargB and ΔargF were unable to scavenge host arginine and were quickly cleared from both immunocompetent and immunocompromised mice. In summary, our investigation revealed in vivo essentiality of the de novo arginine biosynthesis pathway for Mtb and a promising drug target space for combating tuberculosis.


Subject(s)
Arginine/deficiency , Mycobacterium tuberculosis/metabolism , Oxidative Stress , Antioxidants/metabolism , Antitubercular Agents/pharmacology , Arginine/metabolism , DNA Damage , Drug Resistance, Bacterial , Flow Cytometry , Gene Expression Profiling , In Vitro Techniques , Metabolic Networks and Pathways , Reactive Oxygen Species/metabolism , Sulfhydryl Compounds/metabolism
13.
ACS Appl Mater Interfaces ; 8(19): 12520-7, 2016 05 18.
Article in English | MEDLINE | ID: mdl-27093055

ABSTRACT

Zeolite has been surface modified to form novel multifunctional materials having capability for simultaneous and facile removal of heavy metals [Pb(II)], organic pollutants [methylene blue dye], and microorganisms [E. Coli, S. Aureus, and Pseudomonas] from contaminated water. The unique concept involves formation of core-shell particles with a functional core of zeolite and a porous shell of ZnO nanoflakes which not only imparts photocatalytic and antibacterial properties but also renders the surface negatively charged, thereby facilitating rapid adsorption of Pb(II) and MB. The uniform formation of ZnO nanoflakes (shell) on the zeolite (core) surface has been confirmed by XRD, DRS, FE-SEM, and TEM studies. Metal ion adsorption studies under varying conditions of time and concentration indicate that the material follows the Langmuir isotherm model and pseudo-second-order kinetics with good correlation to the experimental data. The rapid and high adsorption capacity of the material for both Pb (II) and MB has been established while factors responsible for enhanced adsorption have been discussed. The antibacterial studies against Gram negative bacteria (E. Coli and Pseudomonas) and Gram positive bacteria (S. Aureus) showed good zone inhibition characteristics. The material can be regenerated and reused besides having ease of separation using simple techniques. Being multifunctional, efficient, nontoxic, energy neutral, and recyclable with no effluent generation, the material is an efficient and sustainable alternative for water purification.


Subject(s)
Anti-Bacterial Agents , Bacteria/growth & development , Nanoparticles/chemistry , Water Purification/methods , Zeolites , Zinc Oxide , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Surface Properties , Zeolites/chemistry , Zeolites/pharmacology , Zinc Oxide/chemistry , Zinc Oxide/pharmacology
14.
Aging Cell ; 14(4): 582-94, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25982749

ABSTRACT

The role of lymphatic vessels is to transport fluid, soluble molecules, and immune cells to the draining lymph nodes. Here, we analyze how the aging process affects the functionality of the lymphatic collectors and the dynamics of lymph flow. Ultrastructural, biochemical, and proteomic analysis indicates a loss of matrix proteins, and smooth muscle cells in aged collectors resulting in a decrease in contraction frequency, systolic lymph flow velocity, and pumping activity, as measured in vivo in lymphatic collectors. Functionally, this impairment also translated into a reduced ability for in vivo bacterial transport as determined by time-lapse microscopy. Ultrastructural and proteomic analysis also indicates a decrease in the thickness of the endothelial cell glycocalyx and loss of gap junction proteins in aged lymph collectors. Redox proteomic analysis mapped an aging-related increase in the glycation and carboxylation of lymphatic's endothelial cell and matrix proteins. Functionally, these modifications translate into apparent hyperpermeability of the lymphatics with pathogen escaping from the collectors into the surrounding tissue and a decreased ability to control tissue fluid homeostasis. Altogether, our data provide a mechanistic analysis of how the anatomical and biochemical changes, occurring in aged lymphatic vessels, compromise lymph flow, tissue fluid homeostasis, and pathogen transport.


Subject(s)
Aging/metabolism , Lymph Nodes/metabolism , Lymph/metabolism , Lymphatic Vessels/chemistry , Proteome/metabolism , Amino Acid Sequence , Animals , Connexins/genetics , Connexins/metabolism , Endothelial Cells/metabolism , Endothelial Cells/ultrastructure , Extracellular Matrix Proteins/genetics , Extracellular Matrix Proteins/metabolism , Gap Junctions/metabolism , Gap Junctions/ultrastructure , Glycocalyx/chemistry , Glycocalyx/metabolism , Glycosylation , Gram-Positive Bacterial Infections/metabolism , Gram-Positive Bacterial Infections/microbiology , Homeostasis , Lymph Nodes/microbiology , Lymph Nodes/ultrastructure , Lymphatic Vessels/metabolism , Lymphatic Vessels/microbiology , Lymphatic Vessels/ultrastructure , Male , Mesentery/metabolism , Mesentery/microbiology , Mesentery/ultrastructure , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Mycobacterium smegmatis/physiology , Myocytes, Smooth Muscle/metabolism , Myocytes, Smooth Muscle/ultrastructure , Proteome/genetics , Rats , Rats, Inbred F344 , Staphylococcus aureus/physiology , Time-Lapse Imaging
15.
PLoS Pathog ; 10(5): e1004115, 2014 May.
Article in English | MEDLINE | ID: mdl-24809459

ABSTRACT

Mycobacterium tuberculosis bacilli display two signature features: acid-fast staining and the capacity to induce long-term latent infections in humans. However, the mechanisms governing these two important processes remain largely unknown. Ser/Thr phosphorylation has recently emerged as an important regulatory mechanism allowing mycobacteria to adapt their cell wall structure/composition in response to their environment. Herein, we evaluated whether phosphorylation of KasB, a crucial mycolic acid biosynthetic enzyme, could modulate acid-fast staining and virulence. Tandem mass spectrometry and site-directed mutagenesis revealed that phosphorylation of KasB occurred at Thr334 and Thr336 both in vitro and in mycobacteria. Isogenic strains of M. tuberculosis with either a deletion of the kasB gene or a kasB_T334D/T336D allele, mimicking constitutive phosphorylation of KasB, were constructed by specialized linkage transduction. Biochemical and structural analyses comparing these mutants to the parental strain revealed that both mutant strains had mycolic acids that were shortened by 4-6 carbon atoms and lacked trans-cyclopropanation. Together, these results suggested that in M. tuberculosis, phosphorylation profoundly decreases the condensing activity of KasB. Structural/modeling analyses reveal that Thr334 and Thr336 are located in the vicinity of the catalytic triad, which indicates that phosphorylation of these amino acids would result in loss of enzyme activity. Importantly, the kasB_T334D/T336D phosphomimetic and deletion alleles, in contrast to the kasB_T334A/T336A phosphoablative allele, completely lost acid-fast staining. Moreover, assessing the virulence of these strains indicated that the KasB phosphomimetic mutant was attenuated in both immunodeficient and immunocompetent mice following aerosol infection. This attenuation was characterized by the absence of lung pathology. Overall, these results highlight for the first time the role of Ser/Thr kinase-dependent KasB phosphorylation in regulating the later stages of mycolic acid elongation, with important consequences in terms of acid-fast staining and pathogenicity.


Subject(s)
3-Oxoacyl-(Acyl-Carrier-Protein) Synthase/metabolism , Bacterial Proteins/metabolism , Mycobacterium tuberculosis/metabolism , Mycobacterium tuberculosis/pathogenicity , Mycolic Acids/metabolism , Protein Serine-Threonine Kinases/metabolism , 3-Oxoacyl-(Acyl-Carrier-Protein) Synthase/genetics , Animals , Bacterial Proteins/genetics , Catalytic Domain/genetics , Cell Wall/metabolism , Lipid Metabolism/genetics , Mice , Mice, Inbred C57BL , Mice, SCID , Microbiological Techniques/methods , Models, Molecular , Mycobacterium tuberculosis/genetics , Mycolic Acids/chemistry , Phosphorylation , Staining and Labeling/methods , Tuberculosis/diagnosis , Tuberculosis/metabolism , Tuberculosis/microbiology , Virulence
16.
PLoS One ; 8(11): e78639, 2013.
Article in English | MEDLINE | ID: mdl-24250805

ABSTRACT

The development of a new vaccine as a substitute for Bacillus Calmette-Guerin or to improve its efficacy is one of the many World Health Organization goals to control tuberculosis. Mycobacterial vectors have been used successfully in the development of vaccines against tuberculosis. To enhance the potential utility of Mycobacterium smegmatis as a vaccine, it was transformed with a recombinant plasmid containing the partial sequences of the genes Ag85c, MPT51, and HspX (CMX) from M. tuberculosis. The newly generated recombinant strain mc(2)-CMX was tested in a murine model of infection. The recombinant vaccine induced specific IgG1 or IgG2a responses to CMX. CD4(+) and CD8(+) T cells from the lungs and spleen responded ex vivo to CMX, producing IFN-γ, IL17, TNF-α, and IL2. The vaccine thus induced a significant immune response in mice. Mice vaccinated with mc(2)-CMX and challenged with M. tuberculosis showed better protection than mice immunized with wild-type M. smegmatis or BCG. To increase the safety and immunogenicity of the CMX antigens, we used a recombinant strain of M. smegmatis, IKE (immune killing evasion), to express CMX. The recombinant vaccine IKE-CMX induced a better protective response than mc(2)-CMX. The data presented here suggest that the expression of CMX antigens improves the immune response and the protection induced in mice when M. smegmatis is used as vaccine against tuberculosis.


Subject(s)
Mycobacterium smegmatis/immunology , Tuberculosis Vaccines/administration & dosage , Tuberculosis/prevention & control , Vaccines, Synthetic/administration & dosage , Animals , BCG Vaccine/administration & dosage , Bacterial Proteins/genetics , CD8-Positive T-Lymphocytes/immunology , Humans , Mice , Mycobacterium smegmatis/genetics , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/pathogenicity , Tuberculosis/microbiology , Tuberculosis Vaccines/immunology , Tumor Necrosis Factor-alpha/biosynthesis , Vaccines, Synthetic/immunology
17.
Indian J Exp Biol ; 51(2): 116-23, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23923604

ABSTRACT

Viral gene oncotherapy is emerging as a biotherapeutic cancer treatment modality based on targeted killing of cancer cells by viral genes. Newcastle disease virus (NDV) has the property to cause selective oncolysis of tumor cells sparing normal cells. NDV has a single stranded negative sense RNA genome, which is 15,186 nucleotide long and consists of six genes, which codes for eight proteins. NDV like other paramyxoviruses has the ability to generate multiple proteins from the P gene. P protein is encoded by an unedited transcript of the P gene, whereas the V and W protein are the results of RNA editing event in which one and two G residues are inserted at a conserved editing site within the P gene mRNA resulting in V and W transcripts, respectively. Although NDV is known to cause oncolysis by triggering apoptosis, the role of different viral proteins in selective oncolysis is still unclear. P gene edited products are known for its anti-apoptotic property in homologous host. In the present study, NDV P gene and its RNA edited products were amplified, cloned, sequenced and in vitro expression was done in HeLa cells. Further constructs were assayed for their apoptosis inducing ability in HeLa cells. Preliminary study suggested that P, V and W proteins are not apoptotic to HeLa cells.


Subject(s)
Genes, Viral/genetics , Newcastle disease virus/genetics , Phosphoproteins/genetics , Phosphoproteins/metabolism , Viral Proteins/genetics , Viral Proteins/metabolism , Amino Acid Sequence , Animals , Annexin A5/metabolism , Base Sequence , Chickens , Cloning, Molecular , Gene Expression Regulation, Viral , HeLa Cells , Humans , Molecular Sequence Data , Open Reading Frames/genetics , Phosphoproteins/chemistry , Reproducibility of Results , Viral Proteins/chemistry
18.
J Minim Access Surg ; 9(2): 65-71, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23741111

ABSTRACT

CONTEXT: Spinal anaesthesia has been reported as an alternative to general anaesthesia for performing laparoscopic cholecystectomy (LC). AIMS: Study aimed to evaluate efficacy, safety and cost benefit of conducting laparoscopic cholecystectomy under spinal anaesthesia (SA) in comparison to general anaesthesia(GA). SETTINGS AND DESIGN: A prospective, randomised study conducted over a two year period at an urban, non teaching hospital. MATERIALS AND METHODS: Patients meeting inclusion criteria e randomised into two groups. Group A and Group B received general and spinal anaesthesia by standardised techniques. Both groups underwent standard four port laparoscopic cholecystectomy. Mean anaesthesia time, pneumoperitoneum time and surgery time defined primary outcome measures. Intraoperative events and post operative pain score were secondary outcome measure. STATISTICAL ANALYSIS USED: The Student t test, Pearson's chi-square test and Fisher exact test. RESULTS: Out of 235 cases enrolled in the study, 114 cases in Group A and 110 in Group B analysed. Mean anaesthesia time appeared to be more in the GA group (49.45 vs. 40.64, P = 0.02) while pneumoperitoneum time and corresponding the total surgery time was slightly longer in the SA group. 27/117 cases who received SA experienced intraoperative events, four significant enough to convert to GA. No postoperative complications noted in either group. Pain relief significantly more in SA group in immediate post operative period (06 and 12 hours) but same as GA group at time of discharge (24 hours). No late postoperative complication or readmission noted in either group. CONCLUSION: Laparoscopic cholecystectomy done under spinal anaesthesia as a routine anaesthesia of choice is feasible and safe. Spinal anaesthesia can be recommended to be the anaesthesia technique of choice for conducting laparoscopic cholecystectomy in hospital setups in developing countries where cost factor is a major factor.

19.
J Cancer Res Ther ; 9(1): 135-7, 2013.
Article in English | MEDLINE | ID: mdl-23575096

ABSTRACT

Branchiogenic carcinoma, which is squamous cell carcinoma arising in a branchial cyst, is extremely rare and a highly contentious clinicopathologic entity. A 56-year-old male presented with a well-defined, fluctuant, painless mass on the right side of the neck which was excised with a diagnosis of branchial cyst. The pathological diagnosis was branchial cleft squamous cell carcinoma, which was characterized microscopically by a branchial cleft cyst with a tumour and a non-tumour transitional zone. The report highlights the controversy surrounding this entity and establishes the diagnosis based ona set of histopathologic criteria proposed by Martin et al. and later modified by Khafif et al.


Subject(s)
Branchioma/pathology , Carcinoma, Squamous Cell/diagnosis , Head and Neck Neoplasms/diagnosis , Fluorodeoxyglucose F18 , Humans , Male , Middle Aged , Multimodal Imaging , Positron-Emission Tomography , Tomography, X-Ray Computed , Ultrasonography
20.
Appl Biochem Biotechnol ; 167(7): 2005-22, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22644640

ABSTRACT

Cancer is one of the killer diseases in humans and needs alternate curative measures despite recent improvement in modern treatment modalities. Oncolytic virotherapy seems to be a promising nonconventional way to treat cancers. Newcastle disease virus (NDV), a poultry virus, is nonpathogenic to human and domestic animals and has a long history of being used in oncotherapy research in several preclinical studies. The ability of NDV to successfully infect and destroy cancer cells is dependent on the strain and the pathotype of the virus. Adaptation of viruses to heterologous hosts without losing its replicative and oncolytic potential is prerequisite for use as cancer virotherapeutics. In the present study, velogenic NDV was adapted for replication in HeLa cells, and its cytotoxic potential was evaluated by observing morphological, biochemical, and nuclear landmarks of apoptosis. Our results indicated that the NDV-induced apoptosis in HeLa cells was dependent on upregulation of TNF-related apoptosis-inducing ligand (TRAIL) and caspases activation. Different determinants of apoptosis evaluated in the present study indicated that this strain could be a promising candidate for cancer therapy in future.


Subject(s)
Newcastle disease virus/physiology , Oncolytic Virotherapy/methods , Adaptation, Physiological , Animals , Annexin A5/metabolism , Biological Transport , Caspases/metabolism , Cell Nucleus/metabolism , Cell Survival , Chickens , Chromatin/metabolism , DNA Fragmentation , G1 Phase , HeLa Cells , Hemagglutination , Hemagglutination Inhibition Tests , Humans , Kinetics , Membrane Potential, Mitochondrial , Newcastle Disease/virology , Newcastle disease virus/growth & development , Phosphatidylserines/metabolism , Propidium/metabolism , Real-Time Polymerase Chain Reaction , Staining and Labeling , TNF-Related Apoptosis-Inducing Ligand/metabolism , Up-Regulation
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