Hu Y.,St George's, University of London |
Van Der Geize R.,University of Groningen |
Besra G.S.,University of Birmingham |
Gurcha S.S.,University of Birmingham |
And 4 more authors.
Molecular Microbiology | Year: 2010
Mycobacterium tuberculosis H37Rv contains the kshA (Rv3526) and kshB (Rv3571) genes, encoding 3-ketosteroid 9α-hydroxylase (KSH). Consistent with their predicted roles, the δkshA and δkshB deletion mutants of M. tuberculosis H37Rv were unable to use cholesterol and 4-androstene-3,17-dione as primary carbon and energy sources. Interestingly, δkshA and δkshB mutants were also unable to metabolize the steroid substrate 5α-androstane-3,17-dione, whereas wild-type M. tuberculosis H37Rv could. The deletion of either of these genes lead to rapid death of the microorganism in murine infection models and in macrophages, showing that kshA and kshB are essential factors for M. tuberculosis pathogenesis. Penta-acylated trehalose (PAT) biosynthesis was altered in the δkshB mutant, but not the δkshA mutant. The δkshB mutant synthesizes all other types of lipids. The δkshB mutant had a thickened outer layer in its cell wall. KshB thus appears to be involved in multiple processes, probably as a reductase of different oxygenases. We conclude that an impaired 3-ketosteroid 9α-hydroxylase activity is the cause of the highly attenuated phenotype of our M. tuberculosis H37Rv mutants. © 2009 Blackwell Publishing Ltd.
Dubaniewicz A.,Medical University of Gdańsk |
Holownia A.,Medical University of Bialystok |
Kalinowski L.,Medical University of Gdańsk |
Wybieralska M.,Medical University of Gdańsk |
And 3 more authors.
Human Immunology | Year: 2013
We demonstrated opposite presence of mycobacterial heat shock proteins (Mtb-hsp) 70. kDa, 65. kDa, 16. kDa in sera and lymph nodes in sarcoidosis (SA). Higher occurrence of serum Mtb-hsp70 than Mtb-hsp65 and Mtb-hsp16 could be caused by sequestration of Mtb-hsp65 and Mtb-hsp16 in circulating immune complexes (CIs). It is possible that in genetically different predisposed hosts, Mtb-hsp16 induced by dose-dependent nitrate/nitrite (NOx) may be involved in latent tuberculosis (TB), active TB, or SA development. We evaluated Mtb-hsp70, Mtb-hsp65, Mtb-hsp16 presence in precipitated CIs and serum NOx level in 20 SA patients, 19 TB patients, and 21 healthy volunteers using PEG precipitation, Western Blot, and Griess methods. We revealed higher NOx concentrations in SA and TB than in controls, but lower in SA than TB. Mtb-hsp16, Mtb-hsp65, and Mtb-hsp70 concentrations in precipitated CIs were higher in SA than in TB and controls. In all tested groups, Mtb-hsp16 concentration was higher than Mtb-hsp70 and Mtb-hsp65. We suggest that lower levels of NOx may induce a M. tuberculosis genetic dormancy program via higher Mtb-hsp16 expression in SA. It seems that Mtb-hsp16 may be more important than Mtb-hsp70 and Mtb-hsp65 in CIs formation and initiate an autoimmune response in SA related to mycobacteria's stationary-phase. © 2012 American Society for Histocompatibility and Immunogenetics.
Pukazhvanthen P.,National Institute for Research in Tuberculosis ICMR |
Anbarasu D.,National Institute for Research in Tuberculosis ICMR |
Kabeer Basirudeen S.A.,National Institute for Research in Tuberculosis ICMR |
Raja A.,National Institute for Research in Tuberculosis ICMR |
Singh M.,Lionex Diagnostics and Therapeutics GmbH
Tuberculosis | Year: 2014
Serodiagnostic potential of four recombinant proteins (38 kDa[Rv0934], MPT64[Rv1980c], Adk[Rv0733], and BfrB[Rv3874]) was evaluated in Healthy control subjects (HCS), Healthy household contacts (HHC), Pulmonary tuberculosis patients (PTB), and Human immuno deficiency virus & Tuberculosis co-infected patients (HIV-TB). All the antigens tested individually for the detection of serum IgG by indirect ELISA. All the four antigens have a significantly higher antibody response in PTB compared to healthy controls (P < 0.05). The sensitivity of individual antigens ranged from 20% to 52.5% for the prefixed specificity of 95%. When results of all 4 antigens were combined the sensitivity was increased to 75% and specificity was reduced 89% in HCS. In smear- and culture-positive (S+C+) PTB, four antigen combination gives maximum sensitivity (89.6%) with 89% specificity. In smear negative culture negative (S-C+) PTB, three antigen combination (38 kDa with MPT64 and BfrB) gives maximum sensitivity (69.5%) and specificity (91.6%). In HIV-TB, 4 antigen combinations give the maximum sensitivity of 51.2% with 89% specificity. Combining serology (Four antigen combination) with smear was able to increase the sensitivity from 70% to 92.5% in culture positive PTB. So, we propose that this serology test can be used as adjunct test along with smear for rapid diagnosis of PTB. © 2014 Elsevier Ltd.
Elamin A.A.,Helmholtz Center for Infection Research |
Stehr M.,Helmholtz Center for Infection Research |
Spallek R.,Lionex Diagnostics and Therapeutics GmbH |
Rohde M.,Helmholtz Center for Infection Research |
And 2 more authors.
Molecular Microbiology | Year: 2011
Mycobacterium tuberculosis accumulates large amounts of triacylglycerol (TAG) which acts as storage compounds for energy and carbon. The mycobacterial triacylglycerols stored in the form of intracellular lipid droplets are essential for long-term survival of M.tuberculosis during a dormant state. We report here that when the M.tuberculosis mycolytransferase Ag85A is overexpressed in Mycobacterium smegmatis mc 2155, cell morphology was changed and the cells became grossly enlarged. A massive formation of lipid bodies and a change in lipid pattern was observed simultaneously. We suspected a possible role of Ag85A in the acyl lipid metabolism and discovered that the enzyme possesses acyl-CoA:diacylglycerol acyltransferase (DGAT) activity in addition to its well-known function as mycolyltransferase. Ag85A mediates the transesterification of diacylglycerol using long-chain acyl-CoA as acyl donors. The K m and K cat values for palmitoleoyl-coenzyme A were 390μM and 55.54min -1 respectively. A docking model suggests that palmitoleoyl-coenzyme A and 1,2-dipalmitin occupy the same active site as trehalose 6,6'-dimycolate and trehalose 6'-monomycolate. The site-directed Ser126Ala mutation of the active site proved that this residue is involved in the catalytic activity of this enzyme. Although not proven conclusively for dormant stage of M.tuberculosis, our novel finding about the synthesis of TAGs by Ag85A strongly suggests that Ag85A may play a significant role in the formation of lipid storage bodies and thus also in the establishment and maintenance of a persistent tuberculosis infection. © 2011 Blackwell Publishing Ltd.
Chuquimia O.D.,University of Stockholm |
Petursdottir D.H.,University of Stockholm |
Rahman M.J.,University of Stockholm |
Hartl K.,University of Stockholm |
And 2 more authors.
PLoS ONE | Year: 2012
Macrophages and dendritic cells have been recognized as key players in the defense against mycobacterial infection. However, more recently, other cells in the lungs such as alveolar epithelial cells (AEC) have been found to play important roles in the defense and pathogenesis of infection. In the present study we first compared AEC with pulmonary macrophages (PuM) isolated from mice in their ability to internalize and control Bacillus Calmette-Guérin (BCG) growth and their capacity as APCs. AEC were able to internalize and control bacterial growth as well as present antigen to primed T cells. Secondly, we compared both cell types in their capacity to secrete cytokines and chemokines upon stimulation with various molecules including mycobacterial products. Activated PuM and AEC displayed different patterns of secretion. Finally, we analyzed the profile of response of AEC to diverse stimuli. AEC responded to both microbial and internal stimuli exemplified by TLR ligands and IFNs, respectively. The response included synthesis by AEC of several factors, known to have various effects in other cells. Interestingly, TNF could stimulate the production of CCL2/MCP-1. Since MCP-1 plays a role in the recruitment of monocytes and macrophages to sites of infection and macrophages are the main producers of TNF, we speculate that both cell types can stimulate each other. Also, another cell-cell interaction was suggested when IFNs (produced mainly by lymphocytes) were able to induce expression of chemokines (IP-10 and RANTES) by AEC involved in the recruitment of circulating lymphocytes to areas of injury, inflammation, or viral infection. In the current paper we confirm previous data on the capacity of AEC regarding internalization of mycobacteria and their role as APC, and extend the knowledge of AEC as a multifunctional cell type by assessing the secretion of a broad array of factors in response to several different types of stimuli. © 2012 Chuquimia et al.
Rahman M.J.,University of Stockholm |
Degano I.R.,University of Stockholm |
Singh M.,Lionex Diagnostics and Therapeutics GmbH |
Fernandez C.,University of Stockholm
PLoS ONE | Year: 2010
Background: It has been proposed that the immune system could be primed as early as during the fetal life and this might have an impact on postnatal vaccination. Therefore, we addressed in murine models whether gestational treatment with mycobacterial antigens could induce better immune responses in the postnatal life. Methods/Findings: BALB/c mice were treated subcutaneously (s.c.) at the second week of gestation with antigen (Ag)85A or heparin-binding hemagglutinin (HBHA) in the absence of adjuvant. Following birth, offspring mice were immunized intranasally (i.n.) with the same antigens formulated with the adjuvant cholera toxin (CT) at week 1 and week 4. One week after the last immunization, we assessed antigen-specific recall interferon gamma (IFN-γ) responses by in vitro restimulation of lung-derived lymphocytes. Protection against infection was assessed by challenge with high dose Mycobacterium bovis Bacille Calmette-Gué rin (BCG) given i.n. We found that recall IFN-γ responses were higher in the offspring born to the treated mother compared to the untreated-mother. More importantly, we observed that the offspring born to the treated mother controlled infection better than the offspring born to the untreated mother. Since the gestational treatment was done in absence of adjuvant, essentially there was no antibody production observed in the pregnant mice and therefore no influence of maternal antibodies was expected. We hypothesized that the effect of maternal treatment with antigen on the offspring occurred due to antigen transportation through placenta. To trace the antigens, we conjugated fluorescent nanocrystals with Ag85A (Qdot-ITK-Ag85A). After inoculation in the pregnant mice, Qdot-ITK-Ag85A conjugates were detected in the liver, spleen of pregnant females and in all the fetuses and placentas examined. Conclusion: The fetal immune system could be primed in utero by mycobacterial antigens transported through the placenta. © 2010 Rahman et al.
Lionex Diagnostics and Therapeutics GmbH | Date: 2014-03-26
In the first aspect, the present invention relates to mycobacterial thiolperoxidase for use in diagnosing or determining tuberculosis infection in an individual. In a further aspect, methods are provided for diagnosing or determining the status of tuberculosis infection in individuals infected or suspected to be afflicted with tuberculosis infection comprising the step of determining the level or amount of antibodies against mycobacterial thioperoxidase in a sample of an individual. Moreover, methods are provided for the stratification of the treatment regimen of said individual as well as for monitoring the change from latent to active status of tuberculosis infection. Moreover, the present invention provides kits for use in diagnosing or detecting tuberculosis infection as well as the status of the same based on the level or amount of mycobacterial thiolperoxidase.
Lionex Diagnostics and Therapeutics GmbH | Date: 2014-07-16
The present invention relates in a first aspect to isolated sigma factor C(SigC) of bacteria, in particular, of mycobacteria for use in a pharmaceutical composition, e.g., for use in a prophylactic or therapeutic vaccine. The present invention provides the use of SigC of bacteria, in particular, of mycobacteria for use in a prime-boost-vaccination strategy, e.g. as a vaccine against Mycobacterium tuberculosis and other types of mycobacteria based diseases. In a further aspect, the present invention relates to pharmaceutical compositions containing SigC whereby said pharmaceutical composition is in form of a vaccine. Finally, methods for treating or preventing infections as well as for modulating or reducing innate immune responses are provided based on administration of Sig C.
Lionex Diagnostics and Therapeutics GmbH | Date: 2015-01-28
The present invention relates to new 4-nitro-5-dichloromethylpyrazol derivatives. These new derivatives are particularly useful in the treatment of infectious diseases including bacterial infection. In particular, the compounds according to the present invention are useful in the treatment of mycobacterial infections including tuberculosis.
Lionex Diagnostics and Therapeutics GmbH | Date: 2014-06-18
The present invention relates to a pharmaceutical composition comprising a combination of ethambutol with at least one additional anti-bacterial agent, in particular, anti-mycobacterial agent for use in the treatment of bacterial infection, in particular, mycobacterial infection.