Characterization of Mce4A protein of Mycobacterium tuberculosis: role in invasion and survival

Saini, Neeraj Kumar; Sharma, Monika; Chandolia, Amita; Pasricha, Rashmi; Brahmachari, Vani; Bose, Mridula

doi:10.1186/1471-2180-8-200

Cited by 60 publications

(51 citation statements)

References 29 publications

(30 reference statements)

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“…To assist in the effort to treat latent TB, this study was conducted in order to test the hypothesis that a molecular beacon siRNA designed against the mce4 operon, which has been shown to be responsible for latent TB infection (Arruda et al, 1993;Saini et al, 2008;Rathor et al, 2013), especially mce4A (Saini et al, 2008;Xu et al, 2007), could be used for the attenuation of mycobacterial infection. This hypothesis was tested in differentiated U937 cells infected with recombinant E. coli expressing mce4A gene or M. smegmatis.…”

Section: Discussionmentioning

confidence: 99%

A Short Interfering Rna Molecular Beacon for the Attenuation of Mycobacterial Infection

George¹

2014

American Journal of Biochemistry and Biotechnology

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The ability of the pathogen Mycobacterium Tuberculosis (MTB) to invade and survive within macrophages of granulomas is attributed to the product of the Mammalian Cell Entry (MCE) operon whose gene, mce4A, encodes a cholesterol transporter that transports host lipids into the bacterium that allows the bacterium to survive during chronic infection. Here, we proposed and tested the hypothesis that a mce4A siRNA molecular beacon can be used to attenuate mycobacterial infection in macrophages. Mce4A gene was cloned and expressed in E. coli (E. coli-4A) and differentiated U937 cells were transduced with piLenti-siRNA-GFP phage expressing the mce4A siRNA for 24 h. This was followed by infection with either E. coli-4A or M. smegmatis for 3 h followed by incubation for 0, 3, 6, 24 and 48 h. The cells were lysed and the lysates were plated on LB agar plates containing ampicillin (100 µg mL −1 ) or on 7H11 media and incubated at 37°C overnight. Our results showed that the siRNA treatment attenuated E.coli-4A infection in macrophages at 3, 6, 24 and 48 h by 0, 77, 59.6 and 99.7%, respectively. Our results also showed that the siRNA treatment attenuated M. smegmatis infection in macrophages at 3, 6, 24 and 48 h. by 94.8, 70.3, 98.9 and 93.4%, respectively. In conclusion, a mce4A siRNA molecular beacon was successfully delivered and stably expressed in macrophages which attenuated E. coli expressing mce4A (E. coli-4A) and M. smegmatis infection in macrophages.

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Section: Discussionmentioning

confidence: 99%

A Short Interfering Rna Molecular Beacon for the Attenuation of Mycobacterial Infection

George¹

2014

American Journal of Biochemistry and Biotechnology

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“…MAM7 is a relatively small and constitutively expressed surface adhesin that is widely distributed in Gram-negative bacteria including S. enterica (Krachler & Orth, 2011). It is anchored in the outer membrane and contains seven of the mammalian cell entry (mce) domains responsible for host cell binding (Chitale et al, 2001;Saini et al, 2008). MAM7 seems to bind to fibronectin with a low-affinity interaction, which is complemented by a second receptor, phosphatidic acid, resulting in an overall affinity that is very high.…”

Section: Other Proteinaceous Adhesionsmentioning

confidence: 99%

Surface adhesins and exopolymers of selected foodborne pathogens

et al. 2014

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The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalization, avoidance of an immune response, and survival and persistence in the environment. A variety of bacterial surface structures are involved in this process and these promote bacterial adhesion in a more or less specific manner. In this review, we will focus on those surface adhesins and exopolymers in selected foodborne pathogens that are involved mainly in primary adhesion. Their role in biofilm development will also be considered when appropriate. Both the clinical impact and the implications for food safety of such adhesion will be discussed.

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“…Among them, the deduced amino acid sequences with some similarity to mycobacterial mammalian cell entry (MCE) proteins are defined as belonging to the "MCE-related" or "MCE family" domain, which is widely found in bacterial genomes (EMBL-EBI database [http://ebi.ac.uk]). MCE proteins in Mycobacterium tuberculosis (the etiologic agent of tuberculosis) are identified as invasion factors while the biological functions of the MCE-related proteins remain unclear (24,35,38).…”

mentioning

confidence: 99%

Meningococcal Internalization into Human Endothelial and Epithelial Cells Is Triggered by the Influx of Extracellular l -Glutamate via GltT l -Glutamate ABC Transporter in Neisseria meningitidis

2011

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Meningococcal internalization into human cells is likely to be a consequence of meningococcal adhesion to human epithelial and endothelial cells. Here, we identified three transposon mutants of Neisseria meningitidis that were primarily defective in the internalization of human brain microvascular endothelial cells (HBMEC), with insertions occurring in the gltT (a sodium-independent L-glutamate transporter) gene or its neighboring gene, NMB1964 (unknown function). NMB1964 was tentatively named gltM in this study because of the presence of a mammalian cell entry (MCE)-related domain in the deduced amino acid sequences. The null ⌬gltT-⌬gltM N. meningitidis mutant was also defective in the internalization into human umbilical vein endothelial cells and the human lung carcinoma epithelial cell line A549, and the defect was suppressed by transcomplementation of the mutants with gltT ؉ -gltM ؉ genes. The intracellular survival of the ⌬gltT-⌬gltM mutant in HBMEC was not largely different from that of the wild-type strain under our experimental conditions. Introduction of a1-bp deletion and amber or ochre mutations in gltT-gltM genes resulted in the loss of efficient internalization into HBMEC. The defect in meningococcal internalization into HBMEC and L-glutamate uptake in the ⌬gltT-⌬gltM mutant were suppressed only in strains expressing both GltT and GltM proteins. The efficiency of meningococcal invasion to HBMEC decreased under L-glutamate-depleted conditions. Furthermore, ezrin, a key membrane-cytoskeleton linker, accumulated beneath colonies of the gltT ؉ -gltM ؉ N. meningitidis strain but not of the ⌬gltT-⌬gltM mutant. These findings suggest that L-glutamate influx via the GltT-GltM L-glutamate ABC transporter serves as a cue for N. meningitidis internalization into host cells.

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Characterization of Mce4A protein of Mycobacterium tuberculosis: role in invasion and survival

Cited by 60 publications

References 29 publications

A Short Interfering Rna Molecular Beacon for the Attenuation of Mycobacterial Infection

A Short Interfering Rna Molecular Beacon for the Attenuation of Mycobacterial Infection

Surface adhesins and exopolymers of selected foodborne pathogens

Meningococcal Internalization into Human Endothelial and Epithelial Cells Is Triggered by the Influx of Extracellular l -Glutamate via GltT l -Glutamate ABC Transporter in Neisseria meningitidis

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