Thyroid Hormones and Their Interactions with

Immune System in Birds

Jianan(Jane)LIU2008-3-3

Objectives

• What are thyroid hormones in birds?

• How do they work?

• What are the effects of thyroid hormones in birds?

• What are the interactions between thyroid hormones and the immune system in birds?

Thyroid Hormones in Birds

Thyroid Hormones

Triiodothyronine

Functionally Active ？

T3Thyroxine

Quantitatively Predominant

T4

Deiodination

O 2CH CH COOH

2NH

HO

I I

I

Thyroxine (T4)

Triiodothyronine (T3)

O 2CH CH COOH

2NH

HO

I I

I

How do they work in birds?

Initiation & Activation

Hypothalamic-Pituitary-Thyroid (HPT) Axis

Hypothalamus

Anterior Pituitary

Thyroid Gland

Plasma

Thyrotropin-releasing hormone (TRH)

Thyrotropin (TSH)

T3 & T4

Feedback

Thyroid Hormone Activation

TR=T3 Receptor

RXR=Retinoid X Receptor

TRE=Thyroid Hormone Response Element

Co?=Co-activator(s) or Co-repressor(s)

Cytoplasm

T3

T3

T3

Nucleus

TRE

TR RXR

Co?

Changing in expression

DNA

What roles do they play in birds?

ThyroidHormones

Multiplicity of Thyroid Hormone Action

ThyroidHormones

Multiplicity of Thyroid Hormone Action

Metabolism（ Thermoregulation ）

Multiplicity of Thyroid Hormone Action

Metabolism（ Thermoregulation ）

ThyroidHormones

Development(Growth+Maturation)

Development(Growth+Maturation)

Metabolism（ Thermoregulation ）

ThyroidHormones

Multiplicity of Thyroid Hormone Action

ReproductionBehavior

Immunity

Development(Growth+Maturation)

Metabolism（ Thermoregulation ）

BehaviorReproduction

ThyroidHormones

Multiplicity of Thyroid Hormone Action

Immune-Thyroid Networks

Studies on Thyroid Hormone & Immune System

Model Organis

msEffects Literature

Zebra FishThymus developmentLymphopoiesis

S.H.Lam et al. (2005)

FrogsMetamorphic-based changes in immune function

Fort et al.(2007)

Birds Suppression in humoral immunity

Bourgeon and Ralot (2007)

MiceLymphocyte proliferative response

Silberman et al. (2002)

Thyroid Hormone & Immune System

Leukocyte

(Cytokine)TSH Thyroid Gland

(T3 & T4)

Immune

SystemHPT Axis

Producing Feedback

stimulatingCytokine-like

Regulating

Summary

• Thyroid homes Thyroxine(T4)

Triiodothyronine (T3)

• Initiation and Activation HPT axis Thyroid hormone receptor (TR) Thyroid hormone response element(TRE)

• Multiplicity in birds’ lives

• Immune-thyroid interactions

Thank You