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Innate immune response to Mycobacterium tuberculosis Beijing and other genotypes.

Wang C, Peyron P, Mestre O, Kaplan G, van Soolingen D, Gao Q, Gicquel B, Neyrolles O - PLoS ONE (2010)

Bottom Line: We analyzed cytokine and chemokine secretion on a semi-global level using antibody arrays allowing the detection of sixty-five immunity-related soluble molecules.However, Beijing strains did not differ relative to each other in their ability to modulate cytokine secretion.The results suggest that the epidemiological success of the Beijing Bmyc10 is unlikely to rely upon any specific ability of this group of strains to impair anti-mycobacterial innate immunity.

View Article: PubMed Central - PubMed

Affiliation: Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France.

ABSTRACT

Background: As a species, Mycobacterium tuberculosis is more diverse than previously thought. In particular, the Beijing family of M. tuberculosis strains is spreading and evaluating throughout the world and this is giving rise to public health concerns. Genetic diversity within this family has recently been delineated further and a specific genotype, called Bmyc10, has been shown to represent over 60% of all Beijing clinical isolates in several parts of the world. How the host immune system senses and responds to various M. tuberculosis strains may profoundly influence clinical outcome and the relative epidemiological success of the different mycobacterial lineages. We hypothesised that the success of the Bmyc10 group may, at least in part, rely upon its ability to alter innate immune responses and the secretion of cytokines and chemokines by host phagocytes.

Methodology/principal findings: We infected human macrophages and dendritic cells with a collection of genetically well-defined M. tuberculosis clinical isolates belonging to various mycobacterial families, including Beijing. We analyzed cytokine and chemokine secretion on a semi-global level using antibody arrays allowing the detection of sixty-five immunity-related soluble molecules. Our data indicate that Beijing strains induce significantly less interleukin (IL)-6, tumor necrosis factor (TNF), IL-10 and GRO-α than the H37Rv reference strain, a feature that is variously shared by other modern and ancient M. tuberculosis families and which constitutes a signature of the Beijing family as a whole. However, Beijing strains did not differ relative to each other in their ability to modulate cytokine secretion.

Conclusions/significance: Our results confirm and expand upon previous reports showing that M. tuberculosis Beijing strains in general are poor in vitro cytokine inducers in human phagocytes. The results suggest that the epidemiological success of the Beijing Bmyc10 is unlikely to rely upon any specific ability of this group of strains to impair anti-mycobacterial innate immunity.

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Related in: MedlinePlus

ELISA confirmation of differences in IL-6, IL-10, GRO-α, and TNF secreted by Mϕ upon infection with either M. tuberculosis H37Rv or Beijing strains.Human Mϕ were infected with M. tuberculosis H37Rv or representive Beijing strains for 18 h and the cell culture supernatants were analyzed for cytokine/chemokine content using dedicated ELISA kits. Data represent the means±s.d. of TNF (A), IL-6 (B), IL-10 (C), GRO-α (D), and MCP-1 (E) concentration in four samples (n = 4) from one representative donor out of four independent donors. Data were analyzed using the Student's t-test. *, P<0.05; **, P<0.01; ***, P<0.001.
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pone-0013594-g002: ELISA confirmation of differences in IL-6, IL-10, GRO-α, and TNF secreted by Mϕ upon infection with either M. tuberculosis H37Rv or Beijing strains.Human Mϕ were infected with M. tuberculosis H37Rv or representive Beijing strains for 18 h and the cell culture supernatants were analyzed for cytokine/chemokine content using dedicated ELISA kits. Data represent the means±s.d. of TNF (A), IL-6 (B), IL-10 (C), GRO-α (D), and MCP-1 (E) concentration in four samples (n = 4) from one representative donor out of four independent donors. Data were analyzed using the Student's t-test. *, P<0.05; **, P<0.01; ***, P<0.001.

Mentions: Based on the phylogenetic tree of the Beijing family that has been recently constructed by Mestre et al. [33], a total of nine representative strains were selected from the different subfamilies. These included two strains from the over-represented modern groups Bmyc10 and Bmyc25, two strains from the ancestral group Bmyc4, and three strains from three minor groups, namely Bmyc3, Bmyc9 and Bmyc13 (Table S1). Human monocytes were collected from healthy blood donors and differentiated into Mϕ in the presence of monocyte-colony stimulating factor (M-CSF). Mϕ were infected with the different strains at a multiplicity of infection (MOI) of 5 bacteria per cell. At 4 h and 18 h following infection, the culture medium was collected and analyzed for cytokine/chemokine content using dedicated antibody arrays, which could assay a total of 65 cytokines, chemokines, growth factors and other soluble immune mediators. The signals were captured with X-ray films (Figure 1A), and quantified by densitometry (Figure 1B–F). Thirty-four molecules were detected at varying levels in the supernatants of infected cells at 4 h and 18 h post-infection (Table 1& Table S2). Production of IL-6, IL-10 and GRO-α by Mϕ at 18 h after infection was significantly less for Beijing strains than for H37Rv (Figure 1C–E). The production of other molecules, such as monocyte chemotactic protein (MCP)-1 (Figure 1F) did not differ between H37Rv and Beijing strains, indicating that cells had been infected at comparable MOI. We also confirmed that, as previously reported, Beijing strains induce less TNF than H37Rv in Mϕ after 18 h infection (Figure 1B), although this was barely visible in the protein arrays (Figure 1A). All these results were confirmed by ELISA in two subsequent independent experiments (Figure 2). These findings suggest that, as previously reported, Beijing strains induce less TNF, IL-6 and IL-10 in vitro in Mϕ than H37Rv. In addition we found that Beijing strains also induce less GRO-α than the reference strain, and this has not been previously reported. No differences were observed among the Beijing strains, except minor variations, notably GRO-α production (Figure 1E), which were not confirmed by ELISA quantification.


Innate immune response to Mycobacterium tuberculosis Beijing and other genotypes.

Wang C, Peyron P, Mestre O, Kaplan G, van Soolingen D, Gao Q, Gicquel B, Neyrolles O - PLoS ONE (2010)

ELISA confirmation of differences in IL-6, IL-10, GRO-α, and TNF secreted by Mϕ upon infection with either M. tuberculosis H37Rv or Beijing strains.Human Mϕ were infected with M. tuberculosis H37Rv or representive Beijing strains for 18 h and the cell culture supernatants were analyzed for cytokine/chemokine content using dedicated ELISA kits. Data represent the means±s.d. of TNF (A), IL-6 (B), IL-10 (C), GRO-α (D), and MCP-1 (E) concentration in four samples (n = 4) from one representative donor out of four independent donors. Data were analyzed using the Student's t-test. *, P<0.05; **, P<0.01; ***, P<0.001.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2963601&req=5

pone-0013594-g002: ELISA confirmation of differences in IL-6, IL-10, GRO-α, and TNF secreted by Mϕ upon infection with either M. tuberculosis H37Rv or Beijing strains.Human Mϕ were infected with M. tuberculosis H37Rv or representive Beijing strains for 18 h and the cell culture supernatants were analyzed for cytokine/chemokine content using dedicated ELISA kits. Data represent the means±s.d. of TNF (A), IL-6 (B), IL-10 (C), GRO-α (D), and MCP-1 (E) concentration in four samples (n = 4) from one representative donor out of four independent donors. Data were analyzed using the Student's t-test. *, P<0.05; **, P<0.01; ***, P<0.001.
Mentions: Based on the phylogenetic tree of the Beijing family that has been recently constructed by Mestre et al. [33], a total of nine representative strains were selected from the different subfamilies. These included two strains from the over-represented modern groups Bmyc10 and Bmyc25, two strains from the ancestral group Bmyc4, and three strains from three minor groups, namely Bmyc3, Bmyc9 and Bmyc13 (Table S1). Human monocytes were collected from healthy blood donors and differentiated into Mϕ in the presence of monocyte-colony stimulating factor (M-CSF). Mϕ were infected with the different strains at a multiplicity of infection (MOI) of 5 bacteria per cell. At 4 h and 18 h following infection, the culture medium was collected and analyzed for cytokine/chemokine content using dedicated antibody arrays, which could assay a total of 65 cytokines, chemokines, growth factors and other soluble immune mediators. The signals were captured with X-ray films (Figure 1A), and quantified by densitometry (Figure 1B–F). Thirty-four molecules were detected at varying levels in the supernatants of infected cells at 4 h and 18 h post-infection (Table 1& Table S2). Production of IL-6, IL-10 and GRO-α by Mϕ at 18 h after infection was significantly less for Beijing strains than for H37Rv (Figure 1C–E). The production of other molecules, such as monocyte chemotactic protein (MCP)-1 (Figure 1F) did not differ between H37Rv and Beijing strains, indicating that cells had been infected at comparable MOI. We also confirmed that, as previously reported, Beijing strains induce less TNF than H37Rv in Mϕ after 18 h infection (Figure 1B), although this was barely visible in the protein arrays (Figure 1A). All these results were confirmed by ELISA in two subsequent independent experiments (Figure 2). These findings suggest that, as previously reported, Beijing strains induce less TNF, IL-6 and IL-10 in vitro in Mϕ than H37Rv. In addition we found that Beijing strains also induce less GRO-α than the reference strain, and this has not been previously reported. No differences were observed among the Beijing strains, except minor variations, notably GRO-α production (Figure 1E), which were not confirmed by ELISA quantification.

Bottom Line: We analyzed cytokine and chemokine secretion on a semi-global level using antibody arrays allowing the detection of sixty-five immunity-related soluble molecules.However, Beijing strains did not differ relative to each other in their ability to modulate cytokine secretion.The results suggest that the epidemiological success of the Beijing Bmyc10 is unlikely to rely upon any specific ability of this group of strains to impair anti-mycobacterial innate immunity.

View Article: PubMed Central - PubMed

Affiliation: Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, Toulouse, France.

ABSTRACT

Background: As a species, Mycobacterium tuberculosis is more diverse than previously thought. In particular, the Beijing family of M. tuberculosis strains is spreading and evaluating throughout the world and this is giving rise to public health concerns. Genetic diversity within this family has recently been delineated further and a specific genotype, called Bmyc10, has been shown to represent over 60% of all Beijing clinical isolates in several parts of the world. How the host immune system senses and responds to various M. tuberculosis strains may profoundly influence clinical outcome and the relative epidemiological success of the different mycobacterial lineages. We hypothesised that the success of the Bmyc10 group may, at least in part, rely upon its ability to alter innate immune responses and the secretion of cytokines and chemokines by host phagocytes.

Methodology/principal findings: We infected human macrophages and dendritic cells with a collection of genetically well-defined M. tuberculosis clinical isolates belonging to various mycobacterial families, including Beijing. We analyzed cytokine and chemokine secretion on a semi-global level using antibody arrays allowing the detection of sixty-five immunity-related soluble molecules. Our data indicate that Beijing strains induce significantly less interleukin (IL)-6, tumor necrosis factor (TNF), IL-10 and GRO-α than the H37Rv reference strain, a feature that is variously shared by other modern and ancient M. tuberculosis families and which constitutes a signature of the Beijing family as a whole. However, Beijing strains did not differ relative to each other in their ability to modulate cytokine secretion.

Conclusions/significance: Our results confirm and expand upon previous reports showing that M. tuberculosis Beijing strains in general are poor in vitro cytokine inducers in human phagocytes. The results suggest that the epidemiological success of the Beijing Bmyc10 is unlikely to rely upon any specific ability of this group of strains to impair anti-mycobacterial innate immunity.

Show MeSH
Related in: MedlinePlus