tl1a expression in human ibd and animal models
DESCRIPTION
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. Biochem Pharmacol. 2011 Apr 1;81(7):838-47. Nat Rev Rheumatol . 2010 Feb;6(2):67-8. Inflammatory Bowel Disease. - PowerPoint PPT PresentationTRANSCRIPT
TL1A Expression in Human IBD and Animal
ModelsBala Manickam
Pfizer ACVP-STP fellow, Anatomic pathology residentUniversity of Georgia, Athens GA
TL1A & DR3 - Biology
Nat Rev Rheumatol. 2010 Feb;6(2):67-82
Biochem Pharmacol. 2011 Apr 1;81(7):838-47
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Inflammatory Bowel DiseaseHuman IBD IBD represents an important chronic
disease affecting the GI tract of man and domesticated animal species.
The 2 IBD entities in humans are Crohn’s disease (CD) and Ulcerative colitis (UC).
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.
Mouse models of IBD DSS (Dextran sulphate) colitis: Oral administration
of this sulphated polysaccharide to mice induces a self limiting colitis
TNBS (Trinitrobenzene sufonic acid) colitis: Colonic inflammation is induced by intrarectal administration of TNBS dissolved in 50% ethanol
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 PAS-negative macrophages)
Healthy Person CD UC
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TL1A & DR3 expression in human IBD
TL1A
DR3
J Immunol 2003;171;4868-4874
Control anti TL1A
Mucosal Immunology (2011) 4, 172-185;5
TL1A & DR3 : Evidence of Efficacy
TNBS colitis
DSS colitis
Control DR3 KO
Gut bacteria Gut bacteria
GASTROENTEROLOGY 2008;135:552–567
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
subjectsNumber 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 10
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Normal CD UC
Results: TL1A expression
Mice
Naïve DSS TNBS
Human
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Cynomolgus Human Mice
Vasculature(+)
Results: TL1A expression
Germinal center
(-)
DR3 CD Lamina propria
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Mast cells in IBD – Dog, Mice
H&E
Naive IBD
T-blue
Naive DSS TNBS
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B-lymphocytes-Human IBD
Germinal center
Normal CD UC
Lamina propria
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B-lymphocytes-Mice IBD
Germinal center
Naive DSS TNBS
Lamina propria
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T-lymphocytes-Human IBD
Germinal center
Normal CD UC
Lamina propria
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T-lymphocytes-Mice IBD
Germinal center
Naive DSS TNBS
Lamina propria
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B & T lymphocytes- Cynomolgus
Germinal center
B-cells T-cells
Lamina propria
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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 IBDMast 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.
Conclusion
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Acknowledgement 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
Pfizer Internal Use 21
Thank you!