Transcript Drug Safety Research & Development

TL1A Expression in
Human IBD and Animal Models
Bala Manickam
Pfizer ACVP-STP fellow, Anatomic pathology resident
University of Georgia, Athens GA
TL1A & DR3 - Biology
Nat Rev Rheumatol. 2010 Feb;6(2):67-8
Biochem Pharmacol. 2011 Apr 1;81(7):838-47
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Inflammatory Bowel Disease
Human IBD
Mouse models of IBD
 IBD represents an important chronic
disease affecting the GI tract of man
and domesticated animal species.
 DSS (Dextran sulphate) colitis: Oral administration
of this sulphated polysaccharide to mice induces a
self limiting colitis
 The 2 IBD entities in humans are
Crohn’s disease (CD) and
Ulcerative colitis (UC).
 TNBS (Trinitrobenzene sufonic acid) colitis: Colonic
inflammation is induced by intrarectal
administration of TNBS dissolved in 50% ethanol
 Immune mediated - responds to
immunomodulatory drugs
 The pathogenesis of IBD involves:
1. Failure of immune regulation.
2. Genetic susceptibility.
3. Environmental triggers
(microbial flora).
4. Disruption of the mucosal
barrier.
Canine IBD
 Small intestine: Lymphocytic-plasmacytic enteritis
(LPE), eosinophilic enteritis and eosinophilic
gastro-enteritis (EGE)
 Large intestine; Lymphocytic-plasmacytic colitis,
eosinophilic colitis, histiocytic ulcerative colitis
(HUC) (mainly PAS-positive macrophages), and
regional granulomatous colitis (mainly PASnegative macrophages)
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TL1A & DR3 expression in human IBD
Healthy Person
CD
UC
TL1A
DR3
J Immunol 2003;171;4868-4874
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TL1A & DR3 : Evidence of Efficacy
Gut bacteria
Control
Gut bacteria
anti TL1A
TNBS
colitis
DSS
colitis
Control
GASTROENTEROLOGY 2008;135:552–567
DR3 KO
Mucosal Immunology (2011) 4, 172-185;
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Rationale for current study
 Up-regulation of TL1A and DR3 in human CD and UC
and in rodent IBD models
 TL1A and DR3 deficiency attenuates murine IBD
 IBD occurs spontaneously in dogs. Because of this, and
because it shares a similar immunopathology, it may
provide valuable mechanistic insight into the disease in
humans.
 Studying IBD in spontaneous and induced models may
provide insights into how we model the disease in
laboratory mice
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Hypothesis
 By characterizing and comparing expression
profile of TL1A and other critical immunological
markers in murine IBD to people, we may
further validate (and perhaps even uncover)
therapeutic targets for human IBD.
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Objectives
Compare and characterize the staining of TL1A & DR3 in
intestinal tissues obtained from DSS and TNBS mouse
colitis models, human IBD, canine IBD and normal colons
from cynomolgus monkeys.
Compare the staining characteristics of mast cells in
intestinal tissues obtained from DSS and TNBS mouse
colitis models, human IBD and canine IBD.
Compare the expression of T&B cells in different models
of IBD.
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Experimental design
Groups
Number of
subjects
Number of
slides/subject
Total number of
slides
DSS (Mouse)
5
10
50
TNBS (Mouse)
5
10
50
Normal colon (Mouse)
5
10
50
UC (Human)
6
6
36
CD (Human)
6
6
36
Normal colon (Human)
6
6
36
Normal colon (Primate)
5
5
25
IBD (Dog)
5
10
50
Normal colon (Dog)
5
10
50
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Reagents
• Anti-human TL1A mAb (made by Pfizer, optimized for
IHC)
– Homology to mouse, rat: 92%
– Homology to dog (predicted): 86%
• Anti-human DR3 mAb (made by Novus Biol)
– The immunogenic peptide shares
– 44% homology with canine DR3 (XP_546752 )
– 88% homology with primate DR3 (XM_003274297
• CD3, CD45RB220, CD20, Toluidine blue
Pfizer Internal Use
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Results: TL1A expression
Normal
CD
UC
Naïve
DSS
TNBS
Human
Mice
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Results: TL1A expression
Cynomolgus
Human
Mice
Vasculature
(+)
Germinal
center
(-)
DR3
CD
Lamina propria
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Mast cells in IBD – Dog, Mice
Naive
IBD
Naive
DSS
H&E
T-blue
TNBS
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B-lymphocytes-Human IBD
Normal
CD
UC
Germinal
center
Lamina
propria
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B-lymphocytes-Mice IBD
Naive
DSS
TNBS
Germinal
center
Lamina
propria
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T-lymphocytes-Human IBD
Normal
CD
UC
Germinal
center
Lamina
propria
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T-lymphocytes-Mice IBD
Naive
DSS
TNBS
Germinal
center
Lamina
propria
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B & T lymphocytes- Cynomolgus
B-cells
T-cells
Germinal
center
Lamina
propria
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Conclusion
TL1A:
 The expression of TL1A was similar and consistent across the species
 TL1A was up regulated in IBD when compared to the Naive/healthy patients
 This data not only validates the existing murine IBD models but also indicates
that TL1A could be a druggable target in IBD
 We also uncovered that Cynomolgus shares similar staining characteristics
with human and murine IBD tissues and thus can probably be a good model to
study human IBD
B&T-lymphocytes:
 Increased numbers of both B & T cells in the lamina propria in cases of IBD,
suggests a potential role for immune activation in IBD
Mast cells:
 In our study, We could not detect any difference in the expression of mast
cells in both naïve and or IBD patients in both murine and Dog cases.
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Acknowledgement
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Dr. Timothy LaBranche (Industry Mentor)
Dr. Elizabeth Howerth (Academic Mentor)
Dr. Zaher Radi (Pfizer)
Dr. Shawn O’ Neil (Pfizer)
Jameel Syed (Pfizer)
Zachery Stewart (Pfizer)
University of Georgia
ACVP-STP Coalition
Studies were funded and supported by DRSD, Pfizer
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Thank you!
Pfizer Internal Use
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