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Lipoprotein LprI of Mycobacterium tuberculosis Acts as a Lysozyme Inhibitor.

IR@IMTECH: CSIR-Institute of Microbial Technology, Chandigarh

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Title Lipoprotein LprI of Mycobacterium tuberculosis Acts as a Lysozyme Inhibitor.
 
Creator Sethi, Deepti
Mahajan, Sahil
Singh, Chaahat
Lama, Amrita
Hade, Mangesh Dattu
Gupta, Pawan
Dikshit, Kanak L
 
Subject QR Microbiology
 
Description Mycobacterium tuberculosis executes numerous defense strategies for the successful establishment of infection under a diverse array of challenges inside the host. One such strategy that has been delineated in this study is the abrogation of lytic activity of lysozyme by a novel glycosylated and surface-localized lipoprotein, LprI, which is exclusively present in M. tuberculosis complex. The lprI gene co-transcribes with the glbN gene (encoding hemoglobin (HbN)) and both are synchronously up-regulated in M. tuberculosis during macrophage infection. Recombinant LprI, expressed in Escherichia coli, exhibited strong binding (Kd ≤ 2 nm) with lysozyme and abrogated its lytic activity completely, thereby conferring protection to fluorescein-labeled Micrococcus lysodeikticus from lysozyme-mediated hydrolysis. Expression of the lprI gene in Mycobacterium smegmatis (8-10-fold) protected its growth from lysozyme inhibition in vitro and enhanced its phagocytosis and survival during intracellular infection of peritoneal and monocyte-derived macrophages, known to secrete lysozyme, and in the presence of exogenously added lysozyme in secondary cell lines where lysozyme levels are low. In contrast, the presence of HbN enhanced phagocytosis and intracellular survival of M. smegmatis only in the absence of lysozyme but not under lysozyme stress. Interestingly, co-expression of the glbN-lprI gene pair elevated the invasion and survival of M. smegmatis 2-3-fold in secondary cell lines in the presence of lysozyme in comparison with isogenic cells expressing these genes individually. Thus, specific advantage against macrophage-generated lysozyme, conferred by the combination of LprI-HbN during invasion of M. tuberculosis, may have vital implications on the pathogenesis of tuberculosis.
 
Publisher ASBMB
 
Date 2016-02-05
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://crdd.osdd.net/open/1842/1/78.pdf
Sethi, Deepti and Mahajan, Sahil and Singh, Chaahat and Lama, Amrita and Hade, Mangesh Dattu and Gupta, Pawan and Dikshit, Kanak L (2016) Lipoprotein LprI of Mycobacterium tuberculosis Acts as a Lysozyme Inhibitor. The Journal of biological chemistry, 291 (6). pp. 2938-53. ISSN 1083-351X
 
Relation http://www.jbc.org/content/291/6/2938.long
http://crdd.osdd.net/open/1842/