Cigarette smoke-induced accumulation of lung dendritic cells is interleukin-1α-dependent in mice

Botelho, Nikota, Bauer, Morissette, Iwakura Yoichiro, Kolbeck Roland, Finch Donna, Humbles, Stämpfli

Description

Evidence suggests that dendritic cells accumulate in the lungs of COPD patients and correlate with disease severity. We investigated the importance of IL-1R1 and its ligands IL-1α and β to dendritic cell accumulation and maturation in response to cigarette smoke exposure. Methods Mice were exposed to cigarette smoke using a whole body smoke exposure system. IL-1R1-, TLR4-, and IL-1α-deficient mice, as well as anti-IL-1α and anti-IL-1β blocking antibodies were used to study the importance of IL-1R1 and TLR4 to dendritic cell accumulation and activation. Results Acute and chronic cigarette smoke exposure led to increased frequency of lung dendritic cells. Accumulation and activation of dendritic cells was IL-1R1/IL-1α dependent, but TLR4- and IL-1β-independent. Corroborating the cellular data, expression of CCL20, a potent dendritic cells chemoattractant, was IL-1R1/IL-1α-dependent. Studies using IL-1R1 bone marrow-chimeric mice revealed the importance of IL-1R1 signaling on lung structural cells for CCL20 expression. Consistent with the importance of dendritic cells in T cell activation, we observed decreased CD4 + and CD8 + T cell activation in cigarette smoke-exposed IL-1R1-deficient mice. Conclusion Our findings convey the importance of IL-1R1/IL-1α to the recruitment and activation of dendritic cells in response to cigarette smoke exposure.

Sujets

• List of cigarette smoke carcinogens
• Dendritic cell
• T cell
• CCL20
• Mice (disambiguation)

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 11
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Botelho et al. Respiratory Research 2012, 13:81
http://respiratory-research.com/content/13/1/81
RESEARCH Open Access
Cigarette smoke-induced accumulation of lung
dendritic cells is interleukin-1α-dependent
in mice
1 2 2 1 4 5Fernando M Botelho , Jake K Nikota , Carla MT Bauer , Mathieu C Morissette , Yoichiro Iwakura , Roland Kolbeck ,
6 5 1,3*Donna Finch , Alison A Humbles and Martin R Stämpfli
Abstract
Background: Evidence suggests that dendritic cells accumulate in the lungs of COPD patients and correlate with
disease severity. We investigated the importance of IL-1R1 and its ligands IL-1α and β to dendritic cell accumulation
and maturation in response to cigarette smoke exposure.
Methods: Mice were exposed to cigarette smoke using a whole body smoke exposure system. IL-1R1-, TLR4-, and
IL-1α-deficient mice, as well as anti-IL-1α and anti-IL-1β blocking antibodies were used to study the importance of
IL-1R1 and TLR4 to dendritic cell accumulation and activation.
Results: Acute and chronic cigarette smoke exposure led to increased frequency of lung dendritic cells.
Accumulation and activation of dendritic cells was IL-1R1/IL-1α dependent, but TLR4- and IL-1β-independent.
Corroborating the cellular data, expression of CCL20, a potent dendritic cells chemoattractant, was IL-1R1/IL-1α-
dependent. Studies using IL-1R1 bone marrow-chimeric mice revealed the importance of IL-1R1 signaling on lung
structural cells for CCL20 expression. Consistent with the importance of dendritic cells in T cell activation, we
+ +observed decreased CD4 and CD8 T cell activation in cigarette smoke-exposed IL-1R1-deficient mice.
Conclusion: Our findings convey the importance of IL-1R1/IL-1α to the recruitment and activation of dendritic cells
in response to cigarette smoke exposure.
Keywords: Cigarette smoke, Dendritic cells, T cells, CCL20, Mice
Background innate recognition of foreign antigens, fostering activation
The adverse effects of cigarette smoke on human health of adaptive immune responses. Evidence suggests that
are well established [1,2]. Smoking is the leading cause of dendritic cell frequency is increased in the lungs of COPD
chronic obstructive pulmonary disease (COPD), a chronic patients and that expression of maturation markers corre-
lates with worsening of the disease [6]. Dendritic cellslung disorders characterized by progressive and largely
irreversible airflow limitation [3]. It is widely accepted have been suggested to contribute to lung tissue damage
thatchronicinflammationcontributestoairflowlimitation in smokers through activation of autoreactive T cells
and induction of autoantibody responses [7]. In murineobserved in COPD; macrophages, neutrophils and T lym-
phocytes are increased in various parts of the lungs [4]. models, we and others have shown that cigarette smoke
More recently, there is emerging interest in the role of exposure induced the accumulation and maturation of
lung dendritic cells [8,9]. Additionally, dendritic celldendritic cells in COPD [5]. Dendritic cells are highly ef-
ficient antigen presenting cells and key participants in maturation was associated with the development of
emphysema-like lesions [9]. Despite this, mechanisms
underlying the recruitment and maturation of pulmon-* Correspondence: [e-mail]
1
Department of Pathology and Molecular Medicine, McMaster Immunology ary dendritic cells remain poorly understood.
Research Centre, Hamilton, Ontario, Canada
3 IL-1R-type1 (IL-1R1) and its cognate ligands, IL-1αDepartment of Medicine, McMaster University, Hamilton, Ontario, Canada
and β, play a central role in the initiation of inflammatoryFull list of author information is available at the end of the article
© 2012 Botelho et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.Botelho et al. Respiratory Research 2012, 13:81 Page 2 of 10
http://respiratory-research.com/content/13/1/81
processes (reviewed in [10]). IL-1R1 shares homo- (sub-acute exposure), or 5 days/week for 8 weeks
logy and mechanisms of intracellular signaling with toll (chronice). Control animals were exposed to
-like-receptors, key sensors of innate pathogen recogni- room air only by removing the cage lid and limiting
tion. Studies by Doz et al. demonstrated the importance access to food and water. We previously showed that
of IL-1R1, TLR4, and MyD88 (an adaptor signaling mol- expression of the stress hormone corticosterone was
ecule shared by IL-1R1 and TLR4) to cigarette smoke comparable between cigarette smoke and room air-
-induced inflammation [11]; airway neutrophilia was exposed animals [8].
significantly attenuated in IL-1R1-, TLR4- and MyD88-
deficient mouse strains following cigarette smoke expos- Generation of IL-1R1-deficient bone marrow chimeric
ure. While increased expression of IL-1α and β was mice
observed following cigarette smoke exposure, mechanistic 5 million C57BL/6 wild type or IL-1R1-deficient bone
studies revealed that smoke-induced neutrophilic inflam- marrow cells were injected intravenously into irradiated
mation was IL-1α-dependent, but independent of IL-1β, (2 doses of 550Rads (11Gray total)) recipient C57BL/6
and relied on crosstalk between hematopoietic and airway wild type (WT) or IL-1R1-deficient (knockout (KO))
structural cells [12]. Studies by Churg et al. further mice. Recipient mice were on trimethoprim and sulfa-
demonstrated that cigarette smoke-induced emphysema methoxazole antibiotic-treated water one week prior to
formationwas, atleast inpart,IL-1R1-dependent [13]. irradiation and two weeks following irradiation. Mice
The objective of this study was to assess the role of were allowed 8 weeks for reconstitution of hematopoietic
IL-1R1 and TLR4 in cigarette smoke-induced accumula- bone marrow cells.
tion and activation of dendritic cells. We show here that
cigarette smoke mediated activation and accumulation Administration of antibodies
of lung dendritic cells was IL-1R1/IL-1α-dependent Mice were injected intraperitoneally (i.p.) with 400 μgof
and independent of IL-1β and TLR4 signaling. IL-1R1- anti-IL-1α (clone ALF161; R&D Systems, Burlington,
signaling was required in non-hematopoietic lung Canada), anti-IL-1β (clone B122; R&D Systems), or
structural cells for the expression of the dendritic cell Armenian hamster isotype control antibody (Jackson
chemo-attractant and survival factors, CCL20 and Immunoresearch, Burlington, Canada) 12 hours prior to
+ +
GM-CSF. Finally, CD4 and CD8 T cell activation the first smoke exposure, and then daily 1 hour following
was IL-1R1-dependent, implicating IL-1-signaling as a the second smoke exposure. Dosing of the antibodies
mechanism that affects innate and adaptive immune was based on our previous antibody neutralization stud-
processes. ies [12,15]. Specificity of the antibodies was confirmed by
antibody inhibition assays and reported previously [12].
Methods
Animals Isolation of lung mononuclear cells and flow cytometric
BALB/c mice (6–8 weeks old) were purchased from analysis
Charles River Laboratories (Montreal, Canada). IL-1R1- Lung mononuclear cells were isolated as previously
and TLR4-deficient mice both on a C57BL/6 back- described [8]. Briefly, lungs were perfused with 1x
ground, as well as, C57BL/6 wild type control animals phosphate-buffered saline (PBS) and cell suspensions
(6–8 weeks old) were purchased from Jackson Labora- were generated by mechanical mincing and collagenase
tories (Bar Harbor, ME, USA). IL-1α-deficient mice on a digestion. Debris were removed by passage through
C57BL/6 background [14] were bred in-house. Mice nylon mesh and cells were resuspended in 1x PBS con-
were maintained under specific pathogen-free conditions taining 0.3% bovine serum albumin (BSA) (Invitrogen,
in an access-restricted area, on a 12 h light–dark cycle, Burlington, ON, Canada) or in RPMI supplemented with
with food and water provided ad libitum. The Animal 10% FBS (Sigma-Aldrich, Oakville, ON, Canada), 1%
Research Ethics Board of McMaster University approved L-glutamine, and 1% penicillin/streptomycin (Invitrogen,
6
all experiments. Burlington, ON, Canada). 1x10 lung mononuclear cells
were washed once with 1x PBS/0.3% BSA and stained
Cigarette smoke exposure protocol with primary antibodies directly conjugated to fluoro-
5
Mice were exposed to cigarette smoke using a whole chromes for 30 minutes at 4°C. 10 live events were
body smoke exposure system (SIU-48, Promech Lab AB acquiredonanLSRII(BDBiosciences,SanJose,California)
(Vintrie, Sweden)) that was described previously [8]. flow cytometer and data analyzed with FlowJo analysis
Mice were exposed to 12 3R4F reference cigarettes with software (TreeStar Inc., Ashland, Oregon). During flow
filters removed (Tobacco and Health Research Institute, cytometric analysis, side scatter and forward scatter
University of Kentucky, Lexington, KY, USA) for a period parameters were used to define a live cell gate. All anti-
of approximately 50 minutes, twice daily, for 4 days bodies were purchased from BD Biosciences (San Jose,Botelho et al. Respiratory Research 2012, 13:81 Page 3 of 10
http://respiratory-research.com/content/13/1/81
Figure 1 (See legend on next page.)Botelho et al. Respiratory Resea