Knowledge of dendritic cells branches out

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Public release date: 8-May-2006

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Research Australia

Knowledge of dendritic cells branches out

A new type of cell that generates crucial cells of the immune system

has been discovered at The Walter and Eliza Hall Institute. With this

new knowledge, medical researchers can begin to consider the

development of customized immune therapies using this new cell to

target specific infections such as HIV, malaria and influenza;

certain cancers; and even autoimmune diseases.

Dendritic cells (or " DC " ) are specialised white blood cells that

patrol the body, searching for infections. DC seize and then

internally break apart any infectiousorganisms that they find. These

fragments are then presented on the waving branches or " dendrites " of

the DC to activate the immune system's killer T cells. These

activated T cells then eliminate the existing infection and resist

any future attack by memorizing that infection.

DC also have an important educative role to play in preventing

autoimmune diseases, such as type 1 diabetes and Multiple Sclerosis,

where the body's immune system mistakes " self " for " foreign " and

launches an attack. Since DC are central to many immune responses,

they are potential targets for the development of new immune therapies.

Since their discovery in the US in 1975, it has been known that DC,

like other white blood cells, develop from stem cells in the bone

marrow. Exactly how that process happens has been a mystery – until

now. Using a mouse model, PhD student Shalin Naik, group leader

Professor Ken Shortman and a team of colleagues at The Walter and

Eliza Hall Institute have discovered the different " precursors "

that produce DC. In doing so, they have also determined that the

practical operations of DC are more specialized than previously

believed. Rather than being generalized " police " within the body, it

seems that DC are effectively organized as specialized squads that

deal with specific problems – just as a police force might have

different departments to deal with armed robberies, homicides and

fraud. These discoveries at WEHI have profoundly altered our

understanding of this important aspect of the immune system.

The research received advance online publication on the Nature

Immunology website on 7 May 2006.