VLA-4 expression

[Derya Unutmaz]

Inarticle <199504241143.MAA25039 at miranda.umds.ac.uk>, p.NOrman at umds.ac.UK 
(Fred Titmus) wrote:

>        Concerning adhesion marker VLA4. It appears from textboks and 
>reviews that I've read that the ligand for VLA4 is VCAM-1. Yet peak 
>expression of VCAM on endothelium occurs a few hours after activation, 
>whereas VLA is expressed some days later (hence its name!). Does either of 
>these molecules have a more important ligand, or is their some other 
<mechanism at work?  

I think there is some confusion regarding VLA antigens. In our experience VLA-
4 is expressed by most of the resting human T cells (including cord-blood T 
cells), although it is upregulated after activation. The name "Very Late 
Antigen" (VLA), I suppose mainly refers to VLA-1 and VLA-2 which are, indeed, 
expressed days after activation of resting T cells. All VLAs, however, belong 
to the family of integrins which usually share the beta chain (beta-1).

Derya

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Derya Unutmaz
Immunobiology Research Institute, 
Siena, Italy.
E-mail: Unutmaz at iris02.biocine.it
Fax: +39-577-24 35 64