TL1A Expression in - PowerPoint Presentation

Slide1

TL1A Expression in Human IBD and Animal Models

Bala

Manickam

Pfizer ACVP-STP fellow, Anatomic pathology resident

University of Georgia, Athens GASlide2

TL1A & DR3 - Biology

Nat Rev

Rheumatol

. 2010 Feb;6(2):67-8

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Biochem Pharmacol. 2011 Apr 1;81(7):838-47Slide3

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Inflammatory Bowel Disease

Human 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

drugsThe

pathogenesis of IBD involves:Failure of immune regulation.Genetic susceptibility.Environmental triggers (microbial flora).Disruption of the mucosal barrier

.Mouse models of IBDDSS

(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% ethanolCanine 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

)Slide4

Healthy Person CD UC

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TL1A & DR3 expression in human IBD

TL1A

DR3

J

Immunol

2003;171;4868-4874Slide5

C

ontrol anti TL1A

Mucosal Immunology

(2011)

4,

172-185;

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TL1A & DR3 : Evidence of Efficacy

TNBS

colitis

DSS

colitis

Control DR3 KO

Gut bacteria

Gut bacteriaGASTROENTEROLOGY 2008;135:552–567Slide6

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.

7Slide8

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.8Slide9

Experimental design

Groups

Number

of subjects

Number

of slides/subject

Total number of slides

DSS (Mouse)

5

1050

TNBS (Mouse)510

50Normal colon (Mouse)

51050

UC (Human)66

36CD (Human)

6636

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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ReagentsAnti-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

shares44% homology with canine DR3 (XP_546752 )88% homology with primate DR3 (XM_003274297CD3, CD45RB220, CD20, Toluidine blue

Pfizer Internal Use

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Normal CD UC

Results: TL1A expression

Mice

Naïve DSS TNBS

HumanSlide12

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Cynomolgus

Human

Mice

Vasculature

(+)

Results: TL1A expression

Germinal

center

(-)

DR3

CD

Lamina

propria

Slide13

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Mast cells in IBD – Dog, Mice

H&E

Naive IBD

T-blue

Naive DSS TNBSSlide14

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B-lymphocytes-Human IBD

Germinal center

Normal CD UC

Lamina

propriaSlide15

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B

-lymphocytes-Mice IBD

Germinal center

Naive DSS TNBS

Lamina

propriaSlide16

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T-lymphocytes-Human IBD

Germinal center

Normal CD UC

Lamina

propriaSlide17

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T-lymphocytes-Mice IBD

Germinal center

Naive DSS TNBS

Lamina

propriaSlide18

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B & T lymphocytes-

Cynomolgus

Germinal center

B-cells T-cells

Lamina

propriaSlide19

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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.

ConclusionSlide20

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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 GeorgiaACVP-STP Coalition

Studies were funded and supported by DRSD, PfizerSlide21

Pfizer Internal Use21

Thank

you!