scholarly journals Induction of Protective Cellular Immunity against Mycobacterium tuberculosis by Recombinant Attenuated Self-Destructing Listeria monocytogenes Strains Harboring Eukaryotic Expression Plasmids for Antigen 85 Complex and MPB/MPT51

2004 ◽  
Vol 72 (4) ◽  
pp. 2014-2021 ◽  
Author(s):  
Keita Miki ◽  
Toshi Nagata ◽  
Takao Tanaka ◽  
Yeung-Hyen Kim ◽  
Masato Uchijima ◽  
...  

ABSTRACT We report here the induction of specific protective cellular immunity against Mycobacterium tuberculosis by the employment of vaccination with recombinant attenuated Listeria monocytogenes strains. We constructed self-destructing attenuated L. monocytogenes Δ2 strains carrying eukaryotic expression plasmids for the antigen 85 complex (Ag85A and Ag85B) and for MPB/MPT51 (mycobacterial protein secreted by M. bovis BCG/mycobacterial protein secreted by M. tuberculosis) molecules. Infection of these recombinant bacteria allowed expression of the genes in the J774A.1 murine macrophage cell line. Intraperitoneal vaccination of C57BL/6 mice with these recombinant bacteria was capable of inducing purified protein derivative-specific cellular immune responses, such as foot pad reactions, proliferative responses of splenocytes, and gamma interferon production from splenocytes, suggesting the efficacy of vaccination against mycobacterial infection by use of these recombinant L. monocytogenes strains. Furthermore, intravenous vaccination with recombinant bacteria carrying expression plasmids for Ag85A, Ag85B, or MPB/MPT51 in BALB/c mice elicited significant protective responses, comparable to those evoked by a live Mycobacterium bovis BCG vaccine. Notably, this is the first report to show that MPB/MPT51 is a major protective antigen in addition to Ag85A and Ag85B, which have been reported to be major mycobacterial protective antigens.

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 110
Author(s):  
Anna K. Riebisch ◽  
Sabrina Mühlen ◽  
Yan Yan Beer ◽  
Ingo Schmitz

Autophagy is a highly conserved and fundamental cellular process to maintain cellular homeostasis through recycling of defective organelles or proteins. In a response to intracellular pathogens, autophagy further acts as an innate immune response mechanism to eliminate pathogens. This review will discuss recent findings on autophagy as a reaction to intracellular pathogens, such as Salmonella typhimurium, Listeria monocytogenes, Mycobacterium tuberculosis, Staphylococcus aureus, and pathogenic Escherichia coli. Interestingly, while some of these bacteria have developed methods to use autophagy for their own benefit within the cell, others have developed fascinating mechanisms to evade recognition, to subvert the autophagic pathway, or to escape from autophagy.


2008 ◽  
Vol 76 (5) ◽  
pp. 2249-2255 ◽  
Author(s):  
Ying Wu ◽  
Joshua S. Woodworth ◽  
Daniel S. Shin ◽  
Sheldon Morris ◽  
Samuel M. Behar

ABSTRACT The 10-kDa culture filtrate protein (CFP-10) and 6-kDa early secretory antigen of T cells (ESAT-6) are secreted in abundance by Mycobacterium tuberculosis and are frequently recognized by T cells from infected people. The genes encoding these proteins have been deleted from the genome of the vaccine strain Mycobacterium bovis bacillus Calmette-Guérin (BCG), and it is hypothesized that these proteins are important targets of protective immunity. Indeed, vaccination with ESAT-6 elicits protective CD4+ T cells in C57BL/6 mice. We have previously shown that M. tuberculosis infection of C3H mice elicits CFP-10-specific CD8+ and CD4+ T cells. Here we demonstrate that immunization with a CFP-10 DNA vaccine stimulates a specific T-cell response only to the H-2Kk-restricted epitope CFP-1032-39. These CFP-1032-39-specific CD8+ cells undergo a rapid expansion and accumulate in the lung following challenge of immunized mice with aerosolized M. tuberculosis. Protective immunity is induced by CFP-10 DNA vaccination as measured by a CFU reduction in the lung and spleen 4 and 8 weeks after challenge with M. tuberculosis. These data demonstrate that CFP-10 is a protective antigen and that CFP-1032-39-specific CD8+ T cells elicited by vaccination are sufficient to mediate protection against tuberculosis.


2012 ◽  
Vol 19 (5) ◽  
pp. 723-730 ◽  
Author(s):  
Xiaoman Li ◽  
Wei Xu ◽  
Sidong Xiong

ABSTRACTTuberculosis (TB) caused byMycobacterium tuberculosisremains a major infectious disease worldwide. Moreover, latentM. tuberculosisinfection is more likely to progress to active TB and eventually leads to death when HIV infection is involved. Thus, it is urgent to develop a novel TB vaccine with immunogenicity to bothM. tuberculosisand HIV. In this study, four uncharacterized T cell epitopes from MPT64, Ag85A, Ag85B, and TB10.4 antigens ofM. tuberculosiswere predicted, and HIV-1-derived p24, an immunodominant protein that can induce protective responses to HIV-1, was used as an immunogenic backbone.M. tuberculosisepitopes were incorporated separately into the gene backbone of p24, forming a pP24-Mtb DNA vaccine. We demonstrated that pP24-Mtb immunization induced a strongM. tuberculosis-specific cellular response as evidenced by T cell proliferation, cytotoxicity, and elevated frequency of gamma interferon (IFN-γ)-secreting T cells. Interestingly, a p24-specific cellular response and high levels of p24-specific IgG were also induced by pP24-Mtb immunization. When the protective effect was assessed after mycobacterial challenge, pP24-Mtb vaccination significantly reduced tissue bacterial loads and profoundly attenuated the mycobacterial infection-related lung inflammation and injury. Our findings demonstrated that the pP24-Mtb tuberculosis vaccine confers effective protection against mycobacterial challenge with simultaneously elicited robust immune responses to HIV-1, which may provide clues for developing novel vaccines to prevent dual infections.


2018 ◽  
Author(s):  
Matt D. Johansen ◽  
Joshua A. Kasparian ◽  
Elinor Hortle ◽  
Warwick J. Britton ◽  
Auriol C. Purdie ◽  
...  

AbstractHost lipid metabolism is an important target for subversion by pathogenic mycobacteria such as Mycobacterium tuberculosis. The appearance of foam cells within the granuloma are well-characterised effects of chronic tuberculosis. The zebrafish-Mycobacterium marinum infection model recapitulates many aspects of human-M. tuberculosis infection and is used as a model to investigate the structural components of the mycobacterial granuloma. Here, we demonstrate that the zebrafish-M. marinum granuloma contains foam cells and that the transdifferentiation of macrophages into foam cells is driven by the mycobacterial ESX1 pathogenicity locus. This report demonstrates conservation of an important aspect of mycobacterial infection across species.


Chest Imaging ◽  
2019 ◽  
pp. 215-219
Author(s):  
Sonia L. Betancourt

Tuberculosis (TB) is an airborne infection caused by Mycobacterium tuberculosis, an obligate aerobe, nonmotile, non-spore-forming bacillus. TB is a major cause of morbidity and mortality especially in developing countries. Patients with impaired cellular immunity including HIV (+), elderly, prisoners, and indigents and homeless patients have an increased susceptibility for active TB disease. Primary infection usually resolves without complications in immunocompetent patients. The most common radiologic manifestations of primary TB in children are consolidation and lymphadenopathy. Progressive primary TB with widespread hamatogenous dissemination may rarely occur. Patchy or nodular opacities in the upper lobes with associated cavitation are characteristic radiologic findings of active infection. While this pattern often correlates with relatively spared immunity, it denotes highly infectious individuals who require isolation.CT is very sensitive for the detection of bronchogenic spread of infection manifesting with discrete nodules, tree-in-bud opacities and cavitation.Miliary TB refers to hematogenous spread of infection.


2014 ◽  
Vol 32 (1) ◽  
pp. 04-10 ◽  
Author(s):  
Marcelo Genofre Vallada ◽  
Thelma Suely Okay ◽  
Gilda Maria B. Del Negro ◽  
Claudio Amaral Antonio ◽  
Lidia Yamamoto ◽  
...  

Objective: To evaluate the accuracy of an interferongamma release assay (QuantiFERON-TB Gold in Tube) for diagnosing Mycobacterium tuberculosis infection in a young pediatric population. Methods: 195 children previously vaccinated with BCG were evaluated, being 184 healthy individuals with no clinical or epidemiological evidence of mycobacterial infection, and 11 with Mycobacterium tuberculosis infection, according to clinical, radiological, and laboratory parameters. A blood sample was obtained from each child and processed according to the manufacturer's instructions. The assay performance was evaluated by a Receiver Operating Characteristic (ROC) curve. Results: In the group of 184 non-infected children, 130 (70.6%) were under the age of four years (mean age of 35 months). In this group, 177 children (96.2%) had negative test results, six (3.2%) had indeterminate results, and one (0.5%) had a positive result. In the group of 11 infected children, the mean age was 58.5 months, and two of them (18%) had negative results. The ROC curve had an area under the curve of 0.88 (95%CI 0.82-0.92; p<0.001), disclosing a predictive positive value of 81.8% for the test (95%CI 46.3-97.4). The assay sensitivity was 81.8% (95%CI 48.2-97.2) and the specificity was 98.8% (95%CI 96-99.8). Conclusions: In the present study, the QuantiFERON-TB Gold in Tube performance for diagnosing M. tuberculosis infection was appropriate in a young pediatric population.


Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1355 ◽  
Author(s):  
Junghwan Lee ◽  
Ji-Ae Choi ◽  
Soo-Na Cho ◽  
Sang-Hun Son ◽  
Chang-Hwa Song

Apoptosis is an important host defense mechanism against mycobacterial infection. However, the molecular mechanisms regulating apoptosis during mycobacterial infection are not well known. Recent reports suggest that bacterial infection regulates mitochondrial fusion and fission in various ways. Here, we investigated the role of mitochondria in Mycobacterium tuberculosis (Mtb)-infected macrophages. Mtb H37Rv (Rv) infection induced mitofusin 2 (MFN2) degradation, leading to mitochondrial fission. Interestingly, Mtb H37Ra (Ra) infection induced significantly greater mitochondrial fragmentation than Rv infection. Mtb-mediated Parkin, an E3 ubiquitin ligase, contributed to the degradation of MFN2. To evaluate the role of endoplasmic reticulum stress in the production of Parkin during Mtb infection, we analyzed Parkin production in 4-phenylbutyric acid (4-PBA)-pretreated macrophages. Pretreatment with 4-PBA reduced Parkin production in Mtb-infected macrophages. In contrast, the level of MFN2 production recovered to a level similar to that of the unstimulated control. In addition, Ra-infected macrophages had reduced mitochondrial membrane potential (MMP) compared to those infected with Rv. Interestingly, intracellular survival of mycobacteria was decreased in siMFN2-transfected macrophages; in contrast, overexpression of MFN2 in macrophages increased Mtb growth compared with the control.


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