Limits...
The 30-kDa and 38-kDa antigens from Mycobacterium tuberculosis induce partial maturation of human dendritic cells shifting CD4(+) T cell responses towards IL-4 production.

Heuer M, Behlich AS, Lee JS, Ribechini E, Jo EK, Lutz MB - BMC Immunol. (2013)

Bottom Line: DC maturation markers CD80, CD86 and CD83 were readily upregulated by H37Ra- and H37Rv-associated antigens, the 30-kDa (from Ag85 B complex) and 38-KDa Mtb antigens only partially induced these markers.Although the proliferation levels of primary T cell responses were comparable using all the differentially stimulated DC, the 30-kDa and 38-kDa antigens showed a bias towards IL-4 secretion of polarized CD4(+) T cells after secondary stimulation as compared to H37Ra and H37Rv preparations.Together our data indicate that 30-kDa and 38-kDa Mtb antigens induced only partial DC maturation shifting immune responses towards a Th2 profile.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Virology and Immunobiology, University of Würzburg, Würzburg, Germany. m.lutz@vim.uni-wuerzburg.de.

ABSTRACT

Background: Mycobacterium tuberculosis (Mtb) infections are still a major cause of death among all infectious diseases. Although 99% of individuals infected with Mtb develop a CD4(+) Th1 and CD8(+) T cell mediated immunity as measured by tuberculin skin test, this results only in partial protection and Mtb vaccines are not effective. Deviation of immune responses by pathogens towards a Th2 profile is a common mechanism of immune evasion, typically leading to the persistence of the microbes.

Results: Here we tested the stimulatory capacity of selective Mtb antigens on human monocyte-derived dendritic cell (DC) maturation and cytokine production. DC maturation markers CD80, CD86 and CD83 were readily upregulated by H37Ra- and H37Rv-associated antigens, the 30-kDa (from Ag85 B complex) and 38-KDa Mtb antigens only partially induced these markers. All Mtb antigens induced variable levels of IL-6 and low levels of IL-10, there was no release of IL-12p70 detectable. Substantial IL-12p40 production was restricted to LPS or H37Ra and H37Rv preparations. Although the proliferation levels of primary T cell responses were comparable using all the differentially stimulated DC, the 30-kDa and 38-kDa antigens showed a bias towards IL-4 secretion of polarized CD4(+) T cells after secondary stimulation as compared to H37Ra and H37Rv preparations.

Conclusion: Together our data indicate that 30-kDa and 38-kDa Mtb antigens induced only partial DC maturation shifting immune responses towards a Th2 profile.

Show MeSH

Related in: MedlinePlus

DCs stimulated with the 30-kDa and 38-kDa Mtb antigens lead to a Th2 shift in vitro. DCs were stimulated with the different Mtb antigens or LPS or left untreated and simultaneously loaded with the superantigen SEB. After washing the DCs were co-cultured with autologous T cells for 7 days. Then T cells were restimulated for 3 days by PMA/Ionomycin to induce cytokine release. Cytokines were measured by ELISA. Error bars represent the pooled mean data from 4 independent experiments. The IFN-γ/IL-4 ratio was calculated from 4 experiments and the pooled ratios are shown. Statistical significance was tested using one-way ANOVA test with Bonferroni’s post test. * = p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3852591&req=5

Figure 4: DCs stimulated with the 30-kDa and 38-kDa Mtb antigens lead to a Th2 shift in vitro. DCs were stimulated with the different Mtb antigens or LPS or left untreated and simultaneously loaded with the superantigen SEB. After washing the DCs were co-cultured with autologous T cells for 7 days. Then T cells were restimulated for 3 days by PMA/Ionomycin to induce cytokine release. Cytokines were measured by ELISA. Error bars represent the pooled mean data from 4 independent experiments. The IFN-γ/IL-4 ratio was calculated from 4 experiments and the pooled ratios are shown. Statistical significance was tested using one-way ANOVA test with Bonferroni’s post test. * = p < 0.05.

Mentions: Previously we found that a quantitatively weaker T cell stimulation by DC may result in the same T cell proliferation rates but different polarizations into CD4+ T helper (Th) cell subsets [18]. Since the frequency of naive antigen-specific T cells from PBMCs is too low to be followed by any MHC II-restricted peptide stimulation in vitro, we used a superantigen system where higher naive antigen-specific frequencies of T cells can be activated during T cell priming [19]. In this system we explored the Th1 or Th2 subset polarization of the Mtb antigen-matured DC. Primary SEB-stimulated T cells were restimulated after 7 days with PMA/Ionomycin and their supernatants tested for cytokine release. All groups of stimulated T cells released substantial amounts of IFN-γ and IL-10 with no significant differences (Figure 4). However, T cells that were stimulated by 30-kDa- or 38-kDa-matured DC maintained a high IL-4 release as compared to immature (SEB-treated) DC, although the 30-kDa protein showed only as a trend (Figure 4). When the IFN-γ/IL-4 ratio was calculated the 38-kDa antigen showed the strongest IL-4 bias although no significance was achieved by this calculation (Figure 4). These data indicate that DCs matured with the 38-kDa antigen and as a trend also with the 30-kDa antigen, allow SEB-specific T cell responses biased towards a Th2 profile, similar to immature (SEB-treated) DCs.


The 30-kDa and 38-kDa antigens from Mycobacterium tuberculosis induce partial maturation of human dendritic cells shifting CD4(+) T cell responses towards IL-4 production.

Heuer M, Behlich AS, Lee JS, Ribechini E, Jo EK, Lutz MB - BMC Immunol. (2013)

DCs stimulated with the 30-kDa and 38-kDa Mtb antigens lead to a Th2 shift in vitro. DCs were stimulated with the different Mtb antigens or LPS or left untreated and simultaneously loaded with the superantigen SEB. After washing the DCs were co-cultured with autologous T cells for 7 days. Then T cells were restimulated for 3 days by PMA/Ionomycin to induce cytokine release. Cytokines were measured by ELISA. Error bars represent the pooled mean data from 4 independent experiments. The IFN-γ/IL-4 ratio was calculated from 4 experiments and the pooled ratios are shown. Statistical significance was tested using one-way ANOVA test with Bonferroni’s post test. * = p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3852591&req=5

Figure 4: DCs stimulated with the 30-kDa and 38-kDa Mtb antigens lead to a Th2 shift in vitro. DCs were stimulated with the different Mtb antigens or LPS or left untreated and simultaneously loaded with the superantigen SEB. After washing the DCs were co-cultured with autologous T cells for 7 days. Then T cells were restimulated for 3 days by PMA/Ionomycin to induce cytokine release. Cytokines were measured by ELISA. Error bars represent the pooled mean data from 4 independent experiments. The IFN-γ/IL-4 ratio was calculated from 4 experiments and the pooled ratios are shown. Statistical significance was tested using one-way ANOVA test with Bonferroni’s post test. * = p < 0.05.
Mentions: Previously we found that a quantitatively weaker T cell stimulation by DC may result in the same T cell proliferation rates but different polarizations into CD4+ T helper (Th) cell subsets [18]. Since the frequency of naive antigen-specific T cells from PBMCs is too low to be followed by any MHC II-restricted peptide stimulation in vitro, we used a superantigen system where higher naive antigen-specific frequencies of T cells can be activated during T cell priming [19]. In this system we explored the Th1 or Th2 subset polarization of the Mtb antigen-matured DC. Primary SEB-stimulated T cells were restimulated after 7 days with PMA/Ionomycin and their supernatants tested for cytokine release. All groups of stimulated T cells released substantial amounts of IFN-γ and IL-10 with no significant differences (Figure 4). However, T cells that were stimulated by 30-kDa- or 38-kDa-matured DC maintained a high IL-4 release as compared to immature (SEB-treated) DC, although the 30-kDa protein showed only as a trend (Figure 4). When the IFN-γ/IL-4 ratio was calculated the 38-kDa antigen showed the strongest IL-4 bias although no significance was achieved by this calculation (Figure 4). These data indicate that DCs matured with the 38-kDa antigen and as a trend also with the 30-kDa antigen, allow SEB-specific T cell responses biased towards a Th2 profile, similar to immature (SEB-treated) DCs.

Bottom Line: DC maturation markers CD80, CD86 and CD83 were readily upregulated by H37Ra- and H37Rv-associated antigens, the 30-kDa (from Ag85 B complex) and 38-KDa Mtb antigens only partially induced these markers.Although the proliferation levels of primary T cell responses were comparable using all the differentially stimulated DC, the 30-kDa and 38-kDa antigens showed a bias towards IL-4 secretion of polarized CD4(+) T cells after secondary stimulation as compared to H37Ra and H37Rv preparations.Together our data indicate that 30-kDa and 38-kDa Mtb antigens induced only partial DC maturation shifting immune responses towards a Th2 profile.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Virology and Immunobiology, University of Würzburg, Würzburg, Germany. m.lutz@vim.uni-wuerzburg.de.

ABSTRACT

Background: Mycobacterium tuberculosis (Mtb) infections are still a major cause of death among all infectious diseases. Although 99% of individuals infected with Mtb develop a CD4(+) Th1 and CD8(+) T cell mediated immunity as measured by tuberculin skin test, this results only in partial protection and Mtb vaccines are not effective. Deviation of immune responses by pathogens towards a Th2 profile is a common mechanism of immune evasion, typically leading to the persistence of the microbes.

Results: Here we tested the stimulatory capacity of selective Mtb antigens on human monocyte-derived dendritic cell (DC) maturation and cytokine production. DC maturation markers CD80, CD86 and CD83 were readily upregulated by H37Ra- and H37Rv-associated antigens, the 30-kDa (from Ag85 B complex) and 38-KDa Mtb antigens only partially induced these markers. All Mtb antigens induced variable levels of IL-6 and low levels of IL-10, there was no release of IL-12p70 detectable. Substantial IL-12p40 production was restricted to LPS or H37Ra and H37Rv preparations. Although the proliferation levels of primary T cell responses were comparable using all the differentially stimulated DC, the 30-kDa and 38-kDa antigens showed a bias towards IL-4 secretion of polarized CD4(+) T cells after secondary stimulation as compared to H37Ra and H37Rv preparations.

Conclusion: Together our data indicate that 30-kDa and 38-kDa Mtb antigens induced only partial DC maturation shifting immune responses towards a Th2 profile.

Show MeSH
Related in: MedlinePlus