Limits...
Variation of Mycobacterium tuberculosis antigen-specific IFN-γ and IL-17 responses in healthy tuberculin skin test (TST)-positive human subjects.

Fan L, Xiao HP, Hu ZY, Ernst JD - PLoS ONE (2012)

Bottom Line: In addition, we assayed IL-17 secretion in response to the same stimuli, and found less subject-to-subject variation.Analysis of the ratio of IFN-γ to IL-17 secretion on a subject-to-subject basis also revealed a wide range, with the majority of results distributed in a narrow range, and a minority with extreme results all of which were greater than that in the majority of subjects.Variation of IFNγ and IFN-γ/IL-17 responses to mycobacterial antigens exceeds that of responses to the polyclonal stimulus, PHA, in TST positive healthy humans.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, New York University School of Medicine, New York, New York, United States of America.

ABSTRACT

Objective: To determine the variation of IFN-γ and IL-17 responses to M. tuberculosis antigens in healthy TST+ humans.

Methods: We isolated peripheral blood mononuclear cells from 21 TST+ healthy adults, stimulated them with phytohemagglutinin (PHA), PPD, Ag85B, ESAT-6, and live M. bovis BCG, and assayed IFN-γ and IL-17 secretion by ELISA in supernatants after 24 or 72 hours of incubation respectively.

Results: As in other studies, we found a wide range of IFN-γ responses to M. tuberculosis antigens; the variation significantly exceeded that observed in the same donors to the polyclonal T cell stimulus, phytohemagglutinin (PHA). In addition, we assayed IL-17 secretion in response to the same stimuli, and found less subject-to-subject variation. Analysis of the ratio of IFN-γ to IL-17 secretion on a subject-to-subject basis also revealed a wide range, with the majority of results distributed in a narrow range, and a minority with extreme results all of which were greater than that in the majority of subjects. The data suggest that study of exceptional responses to M. tuberculosis antigens may reveal immunologic correlates with specific outcomes of M. tuberculosis infection.

Conclusion: Variation of IFNγ and IFN-γ/IL-17 responses to mycobacterial antigens exceeds that of responses to the polyclonal stimulus, PHA, in TST positive healthy humans. This indicates a quantitative spectrum of human immune responses to infection with M. tuberculosis. Since the outcome of human infection with M. tuberculosis varies greatly, systematic study of multiple immune responses to multiple antigens is likely to reveal correlations between selected immune responses and the outcomes of infection.

Show MeSH

Related in: MedlinePlus

Variation of IFN-γ and IL-17 responses to mycobacterial antigens.PBMC were incubated with the indicated stimuli for 24 h (for IFN-γ responses) or 72 h (for IL-17 responses); cytokine secretion was assayed by ELISA. (A) IFN-γ secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (B) IL-17 secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (C) Ratio of IFN-γ to IL-17 secretion in response to the stimuli in panels A and B. Ratios were calculated using the mean value for IFN-γ and for IL-17 for each subject; the horizontal bar indicates the mean value for the group of subjects.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3412824&req=5

pone-0042716-g001: Variation of IFN-γ and IL-17 responses to mycobacterial antigens.PBMC were incubated with the indicated stimuli for 24 h (for IFN-γ responses) or 72 h (for IL-17 responses); cytokine secretion was assayed by ELISA. (A) IFN-γ secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (B) IL-17 secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (C) Ratio of IFN-γ to IL-17 secretion in response to the stimuli in panels A and B. Ratios were calculated using the mean value for IFN-γ and for IL-17 for each subject; the horizontal bar indicates the mean value for the group of subjects.

Mentions: Since IFN-γ has been widely studied, and since it is essential for control of tuberculosis in mice and in humans, we examined its secretion in response to selected stimuli. As shown in Figure 1A and Table 1, there was a large intersubject range in the amounts of IFN-γ secreted in response to the mycobacterial antigens Purified Protein Derivative (PPD), ESAT-6, and Ag85B, as well as with whole, live, Mycobacterium bovis BCG. For example, PPD stimulated IFN-γ secretion in all 21 subjects, but the amounts varied between individuals over a 500-fold range, from 128 to 64,569 pg/ml (Figure 1A and Table 1). Likewise, IFN-γ responses to Ag85B were detectable in 19 of 21 subjects and varied over a 1,525-fold range, from 28.1 to 42,879 pg/ml. ESAT-6 stimulated detectable quantities of IFN-γ in 14 of 21 subjects, consistent with our inclusion of subjects with a history of BCG vaccination. In the 14 subjects that responded to ESAT-6, IFN-γ secretion varied over an even wider, 4,352-fold range, from 12.9 to 56,147 pg/ml. It is notable that among the donors, the largest quantities of IFN-γ secreted in response to PPD, Ag85B, ESAT-6, and live BCG all occurred in the same subject (donor 12, Table 1), although the lowest IFN-γ responses to these stimuli occurred in 4 different subjects (donors 11, 26, 16, and 23, respectively; Table 1). Notably, despite the heterogeneity of the subjects with respect to their BCG vaccination status or treatment for latent TB infection, the responses of individuals in these specific groups did not account for either the highest or the lowest responses to any of the stimuli, with the exception that cells from 4 of the 7 subjects with a history of BCG vaccination did not respond to stimulation with ESAT-6.


Variation of Mycobacterium tuberculosis antigen-specific IFN-γ and IL-17 responses in healthy tuberculin skin test (TST)-positive human subjects.

Fan L, Xiao HP, Hu ZY, Ernst JD - PLoS ONE (2012)

Variation of IFN-γ and IL-17 responses to mycobacterial antigens.PBMC were incubated with the indicated stimuli for 24 h (for IFN-γ responses) or 72 h (for IL-17 responses); cytokine secretion was assayed by ELISA. (A) IFN-γ secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (B) IL-17 secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (C) Ratio of IFN-γ to IL-17 secretion in response to the stimuli in panels A and B. Ratios were calculated using the mean value for IFN-γ and for IL-17 for each subject; the horizontal bar indicates the mean value for the group of subjects.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3412824&req=5

pone-0042716-g001: Variation of IFN-γ and IL-17 responses to mycobacterial antigens.PBMC were incubated with the indicated stimuli for 24 h (for IFN-γ responses) or 72 h (for IL-17 responses); cytokine secretion was assayed by ELISA. (A) IFN-γ secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (B) IL-17 secretion in response to PHA, PPD, ESAT-6, Ag85B, or live M. bovis BCG. Each symbol reflects responses of a single subject whose responses were assayed in triplicate. The horizontal bar indicates the mean value for the group. (C) Ratio of IFN-γ to IL-17 secretion in response to the stimuli in panels A and B. Ratios were calculated using the mean value for IFN-γ and for IL-17 for each subject; the horizontal bar indicates the mean value for the group of subjects.
Mentions: Since IFN-γ has been widely studied, and since it is essential for control of tuberculosis in mice and in humans, we examined its secretion in response to selected stimuli. As shown in Figure 1A and Table 1, there was a large intersubject range in the amounts of IFN-γ secreted in response to the mycobacterial antigens Purified Protein Derivative (PPD), ESAT-6, and Ag85B, as well as with whole, live, Mycobacterium bovis BCG. For example, PPD stimulated IFN-γ secretion in all 21 subjects, but the amounts varied between individuals over a 500-fold range, from 128 to 64,569 pg/ml (Figure 1A and Table 1). Likewise, IFN-γ responses to Ag85B were detectable in 19 of 21 subjects and varied over a 1,525-fold range, from 28.1 to 42,879 pg/ml. ESAT-6 stimulated detectable quantities of IFN-γ in 14 of 21 subjects, consistent with our inclusion of subjects with a history of BCG vaccination. In the 14 subjects that responded to ESAT-6, IFN-γ secretion varied over an even wider, 4,352-fold range, from 12.9 to 56,147 pg/ml. It is notable that among the donors, the largest quantities of IFN-γ secreted in response to PPD, Ag85B, ESAT-6, and live BCG all occurred in the same subject (donor 12, Table 1), although the lowest IFN-γ responses to these stimuli occurred in 4 different subjects (donors 11, 26, 16, and 23, respectively; Table 1). Notably, despite the heterogeneity of the subjects with respect to their BCG vaccination status or treatment for latent TB infection, the responses of individuals in these specific groups did not account for either the highest or the lowest responses to any of the stimuli, with the exception that cells from 4 of the 7 subjects with a history of BCG vaccination did not respond to stimulation with ESAT-6.

Bottom Line: In addition, we assayed IL-17 secretion in response to the same stimuli, and found less subject-to-subject variation.Analysis of the ratio of IFN-γ to IL-17 secretion on a subject-to-subject basis also revealed a wide range, with the majority of results distributed in a narrow range, and a minority with extreme results all of which were greater than that in the majority of subjects.Variation of IFNγ and IFN-γ/IL-17 responses to mycobacterial antigens exceeds that of responses to the polyclonal stimulus, PHA, in TST positive healthy humans.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, New York University School of Medicine, New York, New York, United States of America.

ABSTRACT

Objective: To determine the variation of IFN-γ and IL-17 responses to M. tuberculosis antigens in healthy TST+ humans.

Methods: We isolated peripheral blood mononuclear cells from 21 TST+ healthy adults, stimulated them with phytohemagglutinin (PHA), PPD, Ag85B, ESAT-6, and live M. bovis BCG, and assayed IFN-γ and IL-17 secretion by ELISA in supernatants after 24 or 72 hours of incubation respectively.

Results: As in other studies, we found a wide range of IFN-γ responses to M. tuberculosis antigens; the variation significantly exceeded that observed in the same donors to the polyclonal T cell stimulus, phytohemagglutinin (PHA). In addition, we assayed IL-17 secretion in response to the same stimuli, and found less subject-to-subject variation. Analysis of the ratio of IFN-γ to IL-17 secretion on a subject-to-subject basis also revealed a wide range, with the majority of results distributed in a narrow range, and a minority with extreme results all of which were greater than that in the majority of subjects. The data suggest that study of exceptional responses to M. tuberculosis antigens may reveal immunologic correlates with specific outcomes of M. tuberculosis infection.

Conclusion: Variation of IFNγ and IFN-γ/IL-17 responses to mycobacterial antigens exceeds that of responses to the polyclonal stimulus, PHA, in TST positive healthy humans. This indicates a quantitative spectrum of human immune responses to infection with M. tuberculosis. Since the outcome of human infection with M. tuberculosis varies greatly, systematic study of multiple immune responses to multiple antigens is likely to reveal correlations between selected immune responses and the outcomes of infection.

Show MeSH
Related in: MedlinePlus