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In vivo and in vitro effects of antituberculosis treatment on mycobacterial interferon-gamma T cell response.

Sauzullo I, Mengoni F, Lichtner M, Massetti AP, Rossi R, Iannetta M, Marocco R, Del Borgo C, Soscia F, Vullo V, Mastroianni CM - PLoS ONE (2009)

Bottom Line: In these patients the release of IFN-gamma is absent even after a prolonged 6-day incubation with both ESAT-6 and CFP-10 antigens and the percentage of effector/memory T-cells phenotype was markedly lower than subjects with persistent positive QFT-G results.The in vitro study showed that antituberculous drugs did not exert any inhibitory effect on IFN-gamma production within the range of therapeutically achievable concentrations.In addition, the antituberculous drugs do not have any direct down-regulatory effect on the specific IFN-gamma response.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious and Tropical Diseases, Sapienza University, Rome, Italy.

ABSTRACT

Background: In recent years, the impact of antituberculous treatment on interferon (IFN)-gamma response to Mycobacterium tuberculosis antigens has been widely investigated, but the results have been controversial. The objective of the present study was: i) to evaluate longitudinal changes of IFN-gamma response to M. tuberculosis-specific antigens in TB patients during antituberculous treatment by using the QuantiFERON-TB Gold (QFT-G) assay; ii) to compare the differences in T-cell response after a short or prolonged period of stimulation with mycobacterial antigens; iii) to assess the CD4+ and CD8+ T cells with effector/memory and central/memory phenotype; iv) to investigate the direct in vitro effects of antituberculous drugs on the secretion of IFN-gamma.

Principal findings: 38 TB patients was evaluated at baseline and at month 2 and 4 of treatment and at month 6 (treatment completion). 27 (71%) patients had a QFT-G reversion (positive to negative) at the end of therapy, while 11 (29%) TB patients remained QFT-G positive at the end of therapy. Among the 11 patients with persistent positive QFT-G results, six had a complete response to the treatment, while the remaining 5 patients did not have a resolution of the disease. All 27 patients who became QFT-G negative had a complete clinical and microbiological recovery of the TB disease. In these patients the release of IFN-gamma is absent even after a prolonged 6-day incubation with both ESAT-6 and CFP-10 antigens and the percentage of effector/memory T-cells phenotype was markedly lower than subjects with persistent positive QFT-G results. The in vitro study showed that antituberculous drugs did not exert any inhibitory effect on IFN-gamma production within the range of therapeutically achievable concentrations.

Conclusions: The present study suggests that the decrease in the M. tuberculosis-specific T cells responses following successful anti-TB therapy may have a clinical value as a supplemental tool for the monitoring of the efficacy of pharmacologic intervention for active TB. In addition, the antituberculous drugs do not have any direct down-regulatory effect on the specific IFN-gamma response.

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Effect of antituberculous drugs on IFN-γ release in vitro.The IFN-γ production was evaluated after overnight incubation with the combination of four drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) at three different concentrations of solution. C1: INH 5 µg/ml, RIF 7 µg/ml, ETB 5 µg/ml, PZA 40 µg/ml; C2: INH 10 µg/ml, RIF 14 µg/ml, ETB 10 µg/ml, PZA 80 µg/ml; C3: INH 15 µg/ml, RIF 21 µg/ml, ETB 15 µg/ml, PZA 120 µg/ml. Controls wells contained only PHA at 5 µg/ml. The concentrations of IFN-γ produced in the presence of drug concentrations compatible with those achieved in the serum of treated patients (C1) were not significantly different from controls containing only PHA (p = 0,071). In contrast, a significant inhibitory effect was found at more elevated drug concentrations (C2 and C3) (p<0.001 for both). Student's t test was used for statistical analysis.
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pone-0005187-g004: Effect of antituberculous drugs on IFN-γ release in vitro.The IFN-γ production was evaluated after overnight incubation with the combination of four drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) at three different concentrations of solution. C1: INH 5 µg/ml, RIF 7 µg/ml, ETB 5 µg/ml, PZA 40 µg/ml; C2: INH 10 µg/ml, RIF 14 µg/ml, ETB 10 µg/ml, PZA 80 µg/ml; C3: INH 15 µg/ml, RIF 21 µg/ml, ETB 15 µg/ml, PZA 120 µg/ml. Controls wells contained only PHA at 5 µg/ml. The concentrations of IFN-γ produced in the presence of drug concentrations compatible with those achieved in the serum of treated patients (C1) were not significantly different from controls containing only PHA (p = 0,071). In contrast, a significant inhibitory effect was found at more elevated drug concentrations (C2 and C3) (p<0.001 for both). Student's t test was used for statistical analysis.

Mentions: To determine whether antituberculous drugs had an inhibitory effect on the IFN-γ release by T cells, the heparinized blood samples were incubated in vitro with a combination of INH, RIF, ETB, STR. The concentrations of IFN-γ (mean±SE, UI/ml) measured at the three different used concentrations were as follows: C1, 3.767±0.18; C2, 1.85±0.21; C3, 0.667±0.286 (Figure 4). IFN-γ release was inhibited in a dose-dependent manner. It is important to point out that a significant inhibitory effect was seen only at more elevated drug concentrations if compared to controls containing only PHA (4.04±0.07) (p<0.001, for both C2 and C3). On the other hand, when antituberculous drugs were used at concentrations which are compatible with those achieved in the serum of treated patients (C1), the concentrations of IFN-γ were not significantly different from controls (p = 0.071). No evidence of toxic effect of the combined drugs on the cellular survival was found (data not shown).


In vivo and in vitro effects of antituberculosis treatment on mycobacterial interferon-gamma T cell response.

Sauzullo I, Mengoni F, Lichtner M, Massetti AP, Rossi R, Iannetta M, Marocco R, Del Borgo C, Soscia F, Vullo V, Mastroianni CM - PLoS ONE (2009)

Effect of antituberculous drugs on IFN-γ release in vitro.The IFN-γ production was evaluated after overnight incubation with the combination of four drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) at three different concentrations of solution. C1: INH 5 µg/ml, RIF 7 µg/ml, ETB 5 µg/ml, PZA 40 µg/ml; C2: INH 10 µg/ml, RIF 14 µg/ml, ETB 10 µg/ml, PZA 80 µg/ml; C3: INH 15 µg/ml, RIF 21 µg/ml, ETB 15 µg/ml, PZA 120 µg/ml. Controls wells contained only PHA at 5 µg/ml. The concentrations of IFN-γ produced in the presence of drug concentrations compatible with those achieved in the serum of treated patients (C1) were not significantly different from controls containing only PHA (p = 0,071). In contrast, a significant inhibitory effect was found at more elevated drug concentrations (C2 and C3) (p<0.001 for both). Student's t test was used for statistical analysis.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2664463&req=5

pone-0005187-g004: Effect of antituberculous drugs on IFN-γ release in vitro.The IFN-γ production was evaluated after overnight incubation with the combination of four drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) at three different concentrations of solution. C1: INH 5 µg/ml, RIF 7 µg/ml, ETB 5 µg/ml, PZA 40 µg/ml; C2: INH 10 µg/ml, RIF 14 µg/ml, ETB 10 µg/ml, PZA 80 µg/ml; C3: INH 15 µg/ml, RIF 21 µg/ml, ETB 15 µg/ml, PZA 120 µg/ml. Controls wells contained only PHA at 5 µg/ml. The concentrations of IFN-γ produced in the presence of drug concentrations compatible with those achieved in the serum of treated patients (C1) were not significantly different from controls containing only PHA (p = 0,071). In contrast, a significant inhibitory effect was found at more elevated drug concentrations (C2 and C3) (p<0.001 for both). Student's t test was used for statistical analysis.
Mentions: To determine whether antituberculous drugs had an inhibitory effect on the IFN-γ release by T cells, the heparinized blood samples were incubated in vitro with a combination of INH, RIF, ETB, STR. The concentrations of IFN-γ (mean±SE, UI/ml) measured at the three different used concentrations were as follows: C1, 3.767±0.18; C2, 1.85±0.21; C3, 0.667±0.286 (Figure 4). IFN-γ release was inhibited in a dose-dependent manner. It is important to point out that a significant inhibitory effect was seen only at more elevated drug concentrations if compared to controls containing only PHA (4.04±0.07) (p<0.001, for both C2 and C3). On the other hand, when antituberculous drugs were used at concentrations which are compatible with those achieved in the serum of treated patients (C1), the concentrations of IFN-γ were not significantly different from controls (p = 0.071). No evidence of toxic effect of the combined drugs on the cellular survival was found (data not shown).

Bottom Line: In these patients the release of IFN-gamma is absent even after a prolonged 6-day incubation with both ESAT-6 and CFP-10 antigens and the percentage of effector/memory T-cells phenotype was markedly lower than subjects with persistent positive QFT-G results.The in vitro study showed that antituberculous drugs did not exert any inhibitory effect on IFN-gamma production within the range of therapeutically achievable concentrations.In addition, the antituberculous drugs do not have any direct down-regulatory effect on the specific IFN-gamma response.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious and Tropical Diseases, Sapienza University, Rome, Italy.

ABSTRACT

Background: In recent years, the impact of antituberculous treatment on interferon (IFN)-gamma response to Mycobacterium tuberculosis antigens has been widely investigated, but the results have been controversial. The objective of the present study was: i) to evaluate longitudinal changes of IFN-gamma response to M. tuberculosis-specific antigens in TB patients during antituberculous treatment by using the QuantiFERON-TB Gold (QFT-G) assay; ii) to compare the differences in T-cell response after a short or prolonged period of stimulation with mycobacterial antigens; iii) to assess the CD4+ and CD8+ T cells with effector/memory and central/memory phenotype; iv) to investigate the direct in vitro effects of antituberculous drugs on the secretion of IFN-gamma.

Principal findings: 38 TB patients was evaluated at baseline and at month 2 and 4 of treatment and at month 6 (treatment completion). 27 (71%) patients had a QFT-G reversion (positive to negative) at the end of therapy, while 11 (29%) TB patients remained QFT-G positive at the end of therapy. Among the 11 patients with persistent positive QFT-G results, six had a complete response to the treatment, while the remaining 5 patients did not have a resolution of the disease. All 27 patients who became QFT-G negative had a complete clinical and microbiological recovery of the TB disease. In these patients the release of IFN-gamma is absent even after a prolonged 6-day incubation with both ESAT-6 and CFP-10 antigens and the percentage of effector/memory T-cells phenotype was markedly lower than subjects with persistent positive QFT-G results. The in vitro study showed that antituberculous drugs did not exert any inhibitory effect on IFN-gamma production within the range of therapeutically achievable concentrations.

Conclusions: The present study suggests that the decrease in the M. tuberculosis-specific T cells responses following successful anti-TB therapy may have a clinical value as a supplemental tool for the monitoring of the efficacy of pharmacologic intervention for active TB. In addition, the antituberculous drugs do not have any direct down-regulatory effect on the specific IFN-gamma response.

Show MeSH
Related in: MedlinePlus