An Eosinophil Immunoregulatory Activity

1
An Eosinophil Immunoregulatory Activity

• Sameer K. Mathur, MD, PhD
• Assistant Professor
• University of Wisconsin- Madison

2
Mediators in Asthma

• Cytokines are capable of eliciting key
  pathophysiological changes in asthma
• For example, IL-13
• Airway hyperreactivity
• Mucus secretion
• Goblet cell hyperplasia
• Subepithelial basement membrane thickening

3
Are EOS important for IL-13 in the airway?

• IL-5 and eotaxin-2 mediated EOS accumulation in
  airway necessary for IL-13 in BAL and AHR (Yang
  et al., JACI 2003)
• EOS are required for T-cell recruitment into
  airway and enhanced cytokine production (E.
  Jacobsen, unpublished, presented at IES 2007)

4
Research Hypothesis

• EOS regulate CD4 T-cell expression of key
  inflammatory cytokines, such as IL-13?

5
EOS Interaction With T-cells

• Models of Interaction
• Cytokine Secretion (Capron lab and others)
• Antigen Presenting Cell (Weller lab)
• Indoleamine Dioxygenase (IDO) (Moqbel lab)

6
Co-culture Experimental System


Staphylococcal enterotoxin B (SEB)
CD4 T-Cell
Eosinophil (EOS)
7
Enhanced Th2/Th1 Cytokine Secretion
IFN-g
IL-13
20000
600
15000
400
pg/mL
10000
200
5000
0
0
T-Cells EOS SEB
- -
- -
-
-

-
- -
- -
-
-

-
p 8
Enhanced Proliferation

20000
15000
CPM
10000
5000
0
T-Cells EOS SEB
- -
-
-

p 9
Do EOS and T-cells require cell contact?
Transwell Experiment

• Two compartments
• Semi-permeable membrane (0.4mM)
• Free diffusion of cytokines and molecular
  mediators
• No cell migration across membrane
• No cell-cell contact

10
EOS Immunoregulation Requires Cell Contact
IFN-g
IL-13
1200
p0.019
NS
p0.034
p0.022
4000
800
pg/mL
2000
400
0
0
CD4 T-Cells EOS Transwell
- -
-

- -
-

SEB
SEB
11
(No Transcript)
12
Flow Cytometry of Integrins
EOS
CD4 T-cell
of Max
of Max
ICAM-1 (CD54)
LFA-1 (CD11a)
Grey- isotype control Blue- cells cultured
alone Red- cells in co-culture
13
Neutralization of ICAM-1 Inhibits Enhancement of
IL-13 Secretion
IL-13
1200
p0.003
p800
pg/mL
n12
400
0
Control IgG a-ICAM-1 mAb
- -
-
-
- -
-
-
CD4 T-cells SEB
CD4 T-cells EOS SEB
14
ICAM-1 Neutralization Has No Effect on IFN-g
Regulation
IFN-g
10000
p8000
6000
pg/mL
4000
n13
2000
0
Control IgG a-ICAM-1 mAb
- -
-
-
- -
-
-
CD4 T-cells SEB
CD4 T-cells EOS SEB
15
Model for Integrin Interaction
SEB
Increased CD4 T-cell activity
T-Cell
LFA-1
ICAM-1
EOS
16

• Since ICAM-1 on EOS is induced during co-culture,
  what are the signals involved?

17
Model for Bidirectional Interaction
SEB
SEB
T-Cell
Increased CD4 T-cell activity
LFA-1
LFA-1
IL-1a
ICAM-1
EOS
18
Specific Aims

• Aim 1. Define the T-cell derived factor(s)
  stimulating the eosinophil regulatory activity
  mediated by cell adhesion molecules.
• Aim 2. Establish the mechanism(s) for the
  eosinophil-CD4 T cell interaction and the
  consequences on CD4 T-cell function.
• Aim 3. Evaluate the relationship of eosinophil
  regulatory activity to clinical characteristics
  of asthma.

19
The Major Critiques

• Concern about relevance of SEB in model
• In aim 3, concern that the complexities of airway
  inflammation will not allow us to observe a
  relationship between the signaling molecules and
  readouts of asthma
• Lack of publications

20
Acknowledgements

• Mathur Lab
• Beth Schwantes
• Robyn Brandau
• Andrea Marquardt

• Mentors
• Dr. Nizar Jarjour
• Dr. William Busse
• Dr. James Gern

• Busse Lab
• Dr. Julie Sedgwick
• Jarjour Lab
• Dr. Becky Kelly
• Dr. Lin-Ying Liu

Funding Clinical Research Scholar Award (UW K12,
PI Graziano) AMA Seed Grant