Guinea-pig alveolar macrophages kill Mycobacterium tuberculosis in vitro, but killing is independent of susceptibility to hydrogen peroxide or triggering of the respiratory burst

O'Brien, Seamus; Jackett, P. S.; Lowrie, Douglas B.; Andrew, Peter W.

doi:10.1016/0882-4010(91)90054-e

Cited by 23 publications

(12 citation statements)

References 19 publications

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“…IFN-␥ is the main macrophage-activating factor, and it has been shown to be essential for protection (5,8). However, substantial killing by the activated macrophages or monocytes has been difficult to demonstrate in vitro (4,16,18,24), and there is increasing evidence for a protective role for antigen-specific cytotoxic T lymphocytes, in both murine and human tuberculoses (2, 17, 22). It is not clear how these cells are protective.…”

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Identification and Characterization of Murine Cytotoxic T Cells That KillMycobacterium tuberculosis

Silva

Lowrie

2000

Infect Immun

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As we seek to develop and evaluate new vaccines against tuberculosis, it is desirable that we understand the mechanisms of protective immunity in our models. Adoptive transfer of protection with hsp65-specific T-cell clones from infected or vaccinated mice into naïve mice had indicated that cytotoxic T cells can make a major contribution to protection. We characterized 28 CD4 ؉ CD8 ؊ and 28 CD4 ؊ CD8 ؉ hsp65-specific T-cell clones derived from infected or vaccinated mice. Half of the CD4 ؉ CD8 ؊ and 64% of the CD4 ؊ CD8 ؉ clones were cytotoxic. Cytotoxicity was associated with high expression of CD44 and gamma interferon production. Most (86%) of the cytotoxic CD4 ؉ CD8 ؊ clones lysed target cells via the Fas-FasL pathway, and most (83%) of the cytotoxic CD4 ؊ CD8 ؉ clones lysed target cells via cytotoxic granules. Only the clones using the granulemediated pathway caused substantial loss of viability of virulent Mycobacterium tuberculosis during lysis of infected macrophages, and the degree of killing closely correlated with the availability of granule marker enzyme activity. Granule-mediated cytotoxicity thus may have a key role in protection against tuberculosis by delivering mycobactericidal granule contents.New vaccines are needed in the fight against tuberculosis (1), but the designing and testing of new vaccines is hampered by our poor understanding of the mechanisms of acquired protective immunity. It is not simply that the key protective antigens have yet to be identified (15); we do not know with certainty what kinds of responses are needed. This knowledge would help both to design vaccines for the best balance of responses and to design clinical tests to monitor or predict vaccine efficacy in the field.Traditionally, protection against tuberculosis has been regarded as due to phagocytosis and killing of Mycobacterium tuberculosis by immunologically activated macrophages and monocytes (12). This is a result of a type 1 cellular response in which gamma interferon (IFN-␥) is produced by antigen-specific T lymphocytes, as distinct from a type 2 response, in which the cells produce interleukin (IL-4) (19). IFN-␥ is the main macrophage-activating factor, and it has been shown to be essential for protection (5,8). However, substantial killing by the activated macrophages or monocytes has been difficult to demonstrate in vitro (4,16,18,24), and there is increasing evidence for a protective role for antigen-specific cytotoxic T lymphocytes, in both murine and human tuberculoses (2, 17, 22). It is not clear how these cells are protective. One possibility is that the cytotoxic T cells are needed to release bacteria from safe havens inside ineffective macrophages so that they can be phagocytosed by fresh, fully activated monocytes or macrophages (7). Alternatively, studies with human peripheral blood cells in vitro have indicated that lysis of infected macrophages by antigen-specific T cells can directly result in death of the bacteria (17, 22). Mycobacterial death can be due to toxic enzymes discharged from lymph...

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Identification and Characterization of Murine Cytotoxic T Cells That KillMycobacterium tuberculosis

Silva

Lowrie

2000

Infect Immun

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“…In these experiments, exogenous catalase protected against the killing of Mycobacterium microti by lymphokine-activated murine macrophages (18). More recent studies have shown, however, that the resistance of M. intracellulare strains to peroxide does not correlate with their catalase content and that the susceptibility of M. tuberculosis to killing by activated macrophages is not related to peroxide susceptibility (14). Therefore, the role of catalase in mycobacterial virulence may be very complex and has not been clearly delineated.…”

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confidence: 74%

Nucleotide sequence of the Mycobacterium leprae katG region

et al. 1997

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Synthetic oligonucleotide primers based on the DNA sequence data of the Escherichia coli, Mycobacterium tuberculosis, and Mycobacterium intracellulare katG genes encoding the heme-containing enzyme catalaseperoxidase were used to amplify and analyze the Mycobacterium leprae katG region by PCR. A 1.6-kb DNA fragment, which hybridized to an M. tuberculosis katG probe, was obtained from an M. leprae DNA template. Southern hybridization analysis with a probe derived from the PCR-amplified fragment showed that the M. leprae chromosome contains only one copy of the putative katG sequence in a 3.4-kb EcoRI-BamHI DNA segment. Although the nucleotide sequence of the katG region of M. leprae was approximately 70% identical to that of the M. tuberculosis katG gene, no open reading frame encoding a catalase-peroxidase was detectable in the whole sequence. Moreover, two DNA deletions of approximately 100 and 110 bp were found in the M. leprae katG region, and they seemed to be present in all seven M. leprae isolates tested. These results strongly suggest that M. leprae lacks a functional katG gene and catalase-peroxidase activity.Two catalases have been extensively characterized in Escherichia coli. HPI (encoded by katG) is a prokaryotic broadspectrum bifunctional peroxidase-catalase inducible by hydrogen peroxide (7). The E. coli catalase HPII (encoded by katE) is a monofunctional enzyme that has sequence similarities to eukaryotic catalase (17). Biochemical and serological characterizations of mycobacterial lysates have also identified two mycobacterial catalases (20). The mycobacterial T-catalase, which has been identified in most mycobacterial species, has substrate specificities similar to those of the E. coli HPI peroxidase-catalases. The mycobacterial M-catalase is a monofunctional HPII-like catalase which has a limited distribution within the mycobacterial genus. A few species, notably those in the Mycobacterium terrae complex, produce only M-catalase. Mycobacterium tuberculosis and Mycobacterium bovis produce only T-catalase. Mycobacterium avium and Mycobacterium intracellulare produce both classes of catalase (8,9,19,21). Since mycobacteria proliferate inside macrophages, it has been speculated that catalases may protect acid-fast bacilli from the deleterious effects of peroxide and, therefore, may play a crucial role in the in vivo survival of mycobacteria. The virulence of two other intracellular pathogens, Nocardia asteroides and Leishmania donovani, has been related to their catalase content (2). Catalases probably enhance the pathogenicity of these microorganisms by metabolizing hydrogen peroxide, a toxic oxygen metabolite which is released by phagocytes in response to bacterial challenge. There is extensive evidence which suggests that peroxide and its associated toxic oxygen metabolites are responsible, in part, for the antimycobacterial activity of macrophages. The most direct evidence implicating catalases as mycobacterial virulence factors is derived from studies demonstrating the protective effect of exo...

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“…Rouse in the intracellular survival of these acid-fast bacilli (Jackett et al 1981a, 6;Walker & Lowrie, 1981). However, more recent experiments examining the importance of mycobacterial catalases have yielded conflicting results (Gangadharam & Pratt, 1984;O'Brien et al, 1991). We have initiated genetic studies aimed at better defining the role of catalase in mycobacterial virulence.…”

Section: Discussionmentioning

confidence: 99%

“…More recent studies have shown, however, that the resistance of M . intracellulare strains to peroxide does not correlate with their catalase content and that the susceptibility of M. tuberculosis to killing by activated macrophages is not related to peroxide susceptibility (Gangadharam & Pratt, 1984 ;O'Brien et al, 1991). The role of catalase in mycobac-terial virulence, therefore, may be very complex and has not been clearly delineated.…”

Section: Introductionmentioning

confidence: 99%

The catalase-peroxidase of Mycobacterium intracellulare: nucleotide sequence analysis and expression in Escherichia coli

Morris

Nair²,

Rouse³

1992

Journal of General Microbiology

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The activation of catalase genes in response to oxidative stress may contribute to the intracellular survival of mycobacteria. In this report, the nucleotide sequence of a mycobacterial catalase gene is described. The deduced protein sequence of this Mycobacterium intraceflulare gene (MI83 was 60% identical to the Escherichia coli hydroperoxidase I (HPI) protein, 59% identical to the SdmoneZfu typhimurium (HPI) catalase, and 47% identical to a Bacillus stearothermophilus peroxidase. The MI85 protein, expressed in E. coli, has also been shown to have peroxidase and catalase activities. Furthermore, Southern blot hybridizations, which demonstrated that a MI85 gene probe hybridizes with chromosomal DNA from thirteen different strains of mycobacteria, suggest that this catalase-peroxidase gene is prevalent in the mycobacterial genus. The availability of catalase gene probes should permit an evaluation, at the molecular level, of the role of catalase in mycobacterial pathogenesis.

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Guinea-pig alveolar macrophages kill Mycobacterium tuberculosis in vitro, but killing is independent of susceptibility to hydrogen peroxide or triggering of the respiratory burst

Cited by 23 publications

References 19 publications

Identification and Characterization of Murine Cytotoxic T Cells That KillMycobacterium tuberculosis

Identification and Characterization of Murine Cytotoxic T Cells That KillMycobacterium tuberculosis

Nucleotide sequence of the Mycobacterium leprae katG region

The catalase-peroxidase of Mycobacterium intracellulare: nucleotide sequence analysis and expression in Escherichia coli

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