Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2010 Mar 1;184(5):2377-85.
doi: 10.4049/jimmunol.0803938. Epub 2010 Jan 29.

Pollen-induced oxidative stress influences both innate and adaptive immune responses via altering dendritic cell functions

Aniko Csillag  1 , Istvan Boldogh, Kitti Pazmandi, Zoltan Magyarics, Peter Gogolak, Sanjiv Sur, Eva Rajnavolgyi, Attila Bacsi
Affiliations

Pollen-induced oxidative stress influences both innate and adaptive immune responses via altering dendritic cell functions

Aniko Csillag et al. J Immunol. .

Abstract

It has been demonstrated that pollen grains contain NAD(P)H oxidases that induce oxidative stress in the airways, and this oxidative insult is critical for the development of allergic inflammation in sensitized mice. On the basis of this observation, we have examined whether pollen grain exposure triggers oxidative stress in dendritic cells (DCs), altering their functions. To test this hypothesis, human monocyte-derived DCs were treated with ragweed pollen grains. Our findings show that exposure to pollen grains induces an increase in the intracellular levels of reactive oxygen species in DCs. Our data also indicate that besides the NAD(P)H oxidases, other component(s) of pollen grains contributes to this phenomenon. Elevated levels of intracellular reactive oxygen species triggered the production of IL-8 as well as proinflammatory cytokines, such as TNF-alpha and IL-6. Treatment with pollen grains initiated the maturation of DCs, strongly upregulated the membrane expression of CD80, CD86, CD83, and HLA-DR, and caused only a slight increase in the expression of CD40. The pollen-treated DCs induced the development of naive T lymphocytes toward effector T cells with a mixed profile of cytokine production. Antioxidant inhibited both the phenotypic and functional changes of DCs, underlining the importance of oxidative stress in these processes. Collectively, these data show that pollen exposure-induced oxidative stress may contribute to local innate immunity and participate in the initiation of adaptive immune responses to pollen Ags.

PubMed Disclaimer

Conflict of interest statement

Disclosures

The authors have no financial conflicts of interest.

Figures

FIGURE 1
FIGURE 1
Exposure to RWPs increases the intracellular ROS levels in cultured monocyte-derived DCs. Cells were loaded with H2DCF-DA and, after removing excess probe, treated as indicated. Changes in DCF fluorescence intensity were detected by means of fluorimetry. Data are presented as means ±SEM of four independent experiments. The p values were calculated with one-way ANOVA followed by Dunnett T3 post hoc test. **p < 0.01; ****p <0.0001 versus IDC control. AU, arbitrary unit; IDC, untreated DCs; RWP, DCs exposed to RWPs; RWPH, DCs exposed to heat-treated RWPs.
FIGURE 2
FIGURE 2
Effect of pollen exposure induced oxidative stress on the chemokine and cytokine-producing capacity of DCs. Levels of IL-8 (A), TNF-α (B), IL-6 (C), IL-12(p70) (D), and IL-10 (E) in the culture supernatants of pollen-treated DCs were determined 24 h after the exposure by means of ELISA. LPS contamination of RWP sample was determined, and the equivalent amount of LPS from E. coli (16 pg/ml) was used as control. Data are presented as means ±SEM of four to five independent experiments. The p values were calculated with one-way ANOVA followed by Bonferroni post hoc test. *p <0.05; **p <0.01; ***p <0.001; ****p <0.0001 versus pollen-treated DCs. IDC, untreated DCs; LPS, LPS-treated DCs; RWP, DCs exposed to RWPs; RWPH, DCs exposed to heat-treated RWPs.
FIGURE 3
FIGURE 3
Pollen exposure-induced oxidative stress contributes to phenotypic maturation of DCs. Immature DCs were treated with RWP for 24 h, and the expression of HLA-DR, costimulatory molecules, or maturation marker was analyzed by flow cytometry. Unfilled histograms indicate isotype controls. Numbers indicate the RFI (upper) and the percentage of positive cells (lower). Results are representative of six independent experiments. IDC, untreated DCs; RWP, DCs exposed to RWPs; RWPH, DCs exposed to heat-treated RWPs; LPS, LPS-treated DCs.
FIGURE 4
FIGURE 4
Increase in the intracellular ROS levels upon pollen exposure alters the T cell-priming capacity of DCs. Pollen-treated DCs were cocultured with CFSE-labeled allogeneic naive CD4+ T cells for 4 d, and then fluorescence intensities were measured by flow cytometry. Numbers indicate the proportion of dividing T cells. Results are representative of four independent experiments. IDC, untreated DCs; LPS, LPS-treated DCs; RWP, DCs exposed to RWPs; RWPH, DCs exposed to heat-treated RWPs.
FIGURE 5
FIGURE 5
Pollen-induced oxidative stress influences the T cell-polarizing capacity of DCs. To investigate the cytokine secretion profile of T lymphocytes primed with pollen-exposed DCs, monocytes as well as naive CD4+ T cells were isolated from buffy coats obtained from three ragweed allergic (□) and three nonallergic blood donors (■). Pollen-exposed DCs were cocultured with autologous naive CD4+ T cells for 4 d, and T cells were then harvested and reactivated for 24 h. Supernatants of T cells were collected, and the levels of IL-3 (A), IL-4 (B), IL-5 (C), GM-CSF (D), and IL-10 (E) were determined by cytometric bead array, whereas concentrations of IFN-γ (F) were measured by means of ELISA. Data are presented as means ± SEM of three independent experiments. The p values were calculated with one-way ANOVA followed by Bonferroni post hoc test. *p < 0.05. IDC, untreated DCs; RWP, DCs exposed to RWPs; RWPH, DCs exposed to heat-treated RWPs.
FIGURE 6
FIGURE 6
Characterization of IL-10–producing autologous T lymphocytes after coculturing with pollen-exposed DCs. The intracellular IL-10 and Foxp3 staining was performed after anti-CD3 reactivation of the DC-primed T cells from ragweed allergic subjects adding monensin in the last 6 h of stimulation. The density plots show staining for CD25-FITC and Foxp3-PE (A), CD25-FITC and IL-10-APC (B), as well as IL-10-APC and Foxp3-PE (C). The quadrant statistics were based on comparison of fluorescence intensities of isotype controls and specific Abs. Results are representative of three independent experiments. IDC, untreated DCs; RWP, DCs exposed to RWPs; RWPH, DCs exposed to heat-treated RWPs.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Banchereau J, Steinman RM. Dendritic cells and the control of immunity. Nature. 1998;392:245–252. - PubMed
    1. Hammad H, Lambrecht BN. Recent progress in the biology of airway dendritic cells and implications for understanding the regulation of asthmatic inflammation. J Allergy Clin Immunol. 2006;118:331–336. - PubMed
    1. Boldogh I, Bacsi A, Choudhury BK, Dharajiya N, Alam R, Hazra TK, Mitra S, Goldblum RM, Sur S. ROS generated by pollen NADPH oxidase provide a signal that augments antigen-induced allergic airway inflammation. J Clin Invest. 2005;115:2169–2179. - PMC - PubMed
    1. Bacsi A, Dharajiya N, Choudhury BK, Sur S, Boldogh I. Effect of pollen-mediated oxidative stress on immediate hypersensitivity reactions and late-phase inflammation in allergic conjunctivitis. J Allergy Clin Immunol. 2005;116:836–843. - PMC - PubMed
    1. Bacsi A, Choudhury BK, Dharajiya N, Sur S, Boldogh I. Sub-pollen particles: carriers of allergenic proteins and oxidases. J Allergy Clin Immunol. 2006;118:844–850. - PMC - PubMed

Publication types

MeSH terms