Poster presented at the Thoracic Society of Australia and New Zealand (TSANZ) Annual Scientific Meeting 2015 (SIG: COPD)

1. Sputum Galectin-3 Expression is
Associated with Eosinophils in COPD
Cell stimulation
with IL-4 and IL-13
Macrophage
Gal-3 oligomers
cross-link CD66 on
neutrophils,
activating them
30% of Gal-3 is
constitutively
secreted
Melanie Erriah1,2, Peng Gao3,4, Katherine J Baines1,2, Peter G Gibson1,2,5, Jodie L Simpson1,2
1 Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, NSW, Australia, 2 Priority Research Centre for
Asthma and Respiratory Disease, The University of Newcastle, NSW, Australia, 3 Second Affiliated Hospital of Jilin University, Jilin,
China, 4 Changchun Central Hospital, Jilin, China, 5 Woolcock Institute of Medical Research, Sydney NSW, Australia
INTRODUCTION
Galectin-3 (Gal-3) is a 35 kDa galactose-binding lectin secreted mainly by
macrophages which has roles in pattern recognition, chemotaxis, neutrophil
activation and phagocytosis1-3 (Fig. 1).
Fig. 1 Schematic summarising the main functions of galectin-3 in macrophages and neutrophils
COPD is characterised by persistent inflammation of the airways with
significant neutrophil infiltration and impaired macrophage efferocytosis of
dead cells4.
Aim:
To determine the expression of sputum Gal-3 in the different COPD
inflammatory phenotypes.
Hypothesis:
Gal-3 levels are reduced in COPD, particularly in the non-eosinophilic
subtype.
RESULTS
•There was a significant difference in age but no difference in gender or BMI between the COPD and healthy
control groups (Table 1).
•Gal-3 levels were similar between the groups (Fig. 3) and did not correlate with age (r=-0.125, p=0.314).
•Sputum Gal-3 was significantly associated with the number and proportion of eosinophils (r=0.404, p<0.001
and r=0.459, p<0.001 respectively) but not with neutrophils (r=-0.197, p=0.113).
•Gal-3 levels in eosinophilic COPD were twice those in non-eosinophilic COPD (Fig. 4).
METHODS
•COPD patients (n=41) and healthy subjects (n=26) underwent a clinical
assessment and sputum induction.
•Sputum was dispersed using dithiothreitol and cytospin slides prepared.
•Cell viability and differential cell counts were performed. Gal-3 was
measured in sputum supernatant using a commercial ELISA kit.
•Eosinophilic COPD was defined as sputum eosinophils ≥3% and
Non-eosinophilic COPD as sputum eosinophils <3%.
CONCLUSIONS
Galectin-3 levels are similar in COPD compared to healthy controls but are significantly associated with
sputum eosinophils.
Significance:
These findings suggest that patients with eosinophilic COPD (and higher levels of Gal-3) may be more
effective at clearing pathogens and apoptotic cells in the airways compared to non-eosinophilic COPD, and
may therefore experience relatively less inflammation.
COPD Healthy control
p
values
N 41 26 -
Gender, male n (%) 18 (44%) 10 (38%) 0.662
Age years, median (q1, q3) 69 (63, 76) 32 (28, 54) <0.001
BMI, mean (SD) 31 (1) 27 (1) 0.083
Ex-smoker n (%) 29 (71%) 8 (31%) 0.002
Pack years, median (q1, q3) 34 (17, 67) 30 (3, 141) 0.660
FEV1 % predicted, mean (SD) 57 (13) 104 (13) <0.001
FEV1/FVC % mean (SD) 56 (9) 81 (7) <0.001
ICS dose µg, median 2000 - -
Sputum % eosinophils, median (q1, q3) 0.8 (0.3, 3.0) 0.3 (0.3, 0.8) 0.075
Sputum % neutrophils, median (q1, q3) 69 (43, 84) 23 (12, 37) <0.001
ACKNOWLEDGEMENTS
This research was supported by an
NHMRC project grant. Gabrielle Le
Brocq, Catherine Delahunty and
Kelly Steel for patient recruitment.
Michelle Gleeson, Kellie Fakes and
Bridgette Ridewood for sputum
processing. Prof Anna Karlsson
and A/Prof Johan Bylund for
feedback on the schematic.
LITERATURE CITED
1. Mey A, Leffler H, Hmama Z, Normier G, Revillard JP. The animal lectin galectin-3 interacts with bacterial
lipopolysaccharides via two independent sites. The Journal of Immunology. 1996;156(4):1572-7.
2. Sano H, Hsu DK, Yu L, Apgar JR, Kuwabara I, Yamanaka T, et al. Human Galectin-3 Is a Novel
Chemoattractant for Monocytes and Macrophages. The Journal of Immunology. 2000;165(4):2156-64.
3. Yamaoka A, Kuwabara I, Frigeri LG, Liu FT: A human lectin, galectin-3 (epsilon bp/Mac-2), stimulates
superoxide production by neutrophils. J Immunol 1995, 154:3479-3487.
4. Hodge S, Hodge G, Scicchitano R, Reynolds PN, Holmes M. Alveolar macrophages from subjects with
chronic obstructive pulmonary disease are deficient in their ability to phagocytose apoptotic airway
epithelial cells. Immunology and cell biology. 2003;81(4):289-96.
CONTACT
MELANIE ERRIAH
Research Higher Degree Student
Centre for Asthma and Respiratory Diseases
Hunter Medical Research Institute
Lot 1 Kookaburra Circuit
New Lambton Heights
NSW 2305
T: +61 2 40420814
E: melanie.erriah@uon.edu.au
Promotes adhesion to laminin
Delays apoptosis
27%
73%
0
10
20
30
40
50
60
70
80
Eosinophilic
COPD
Non-eosinophilic
COPD
Fig. 2 Graph showing the proportion
of eosinophilic to non-eosinophilic
COPD patients.Table 1 summarising the clinical characteristics of the COPD patients and healthy controls.
E o s in o p h ilic N o n -e o s in o p h illic
0
2 0 0
4 0 0
6 0 0
8 0 0
1 0 0 0
F ig . 4
C O P D
Gal-3ng/mL
*
p = 0.012
Fig. 4 Graph showing the median sputum galectin-3 expression in eosinophilic and non-eosinophilic COPD patients
C O P D H e a lth y C o n tr o ls
0
2 0 0
4 0 0
6 0 0
8 0 0
1 0 0 0
F ig . 3
Gal-3ng/ml
p = 0.354
Fig. 3 Graph showing the median sputum galectin-3 levels between the COPD patients and healthy controls.
Cell stimulation
with IL-4 and IL-13
Macrophage
Gal-3 oligomers
cross-link CD66 on
neutrophils,
activating them
30% of Gal-3 is
constitutively
secreted
Acts as a potent
macrophage
chemoattractant
Increases intracellular
availability of the
antioxidant glutathione
Enhances efferocytosis of apoptotic cells
Activates PI3K involved in actin reorganisation
Gal-3
monomers
assemble into
oligomers
Gal-3 oligomers
cross-link CD98 on
macrophages
Galectin-3 monomer
Degranulation
Elastase
Galectin-3
Cleaved
Galectin-3
SuperoxideIL-8
Promotes adhesion to laminin
Delays apoptosis
Enhances phagocytosis
Neutrophil