It is quite possible that you have picked up the Langerhans cells in the
epidermis- those rogue wandering dendritic cells that are part of the
immunologic protective function in the epidermis (including gingiva).  I
don't recall offhand if the langerhans cells express CD3 constituatively,
but I'm sure there are plenty of situations where CD3 may be upregulated.
Also remember that you may be picking up T cell staining within the arms of
the dendritic cells, which may be difficult to differentiate from the
dendritic cells themselves.  If you're investigating these cells, there are
mouse strains that are immunocompromised in various capacities, and specific
strains are available that lack dendritic cells and langerhans cells.

Hope this helps!

-Mike

Michael Archambault, Research Scientist
Bone and Soft Tissue Program
Osiris Therapeutics Inc.
2001 Aliceanna St  Baltimore, MD 21231
410 522-5005 x 226
marchambault@osiristx.com



-----Original Message-----
From: Cristiano Rumio [mailto:cristiano.rumio@unimi.it]
Sent: Tuesday, January 08, 2002 2:52 AM
To: histonet@pathology.swmed.edu
Subject: CD 3


Dear collegues,

I used CD3 Antibody from DAKO on mouse skin. I was surprised when I found 
dendritic cells stain in the epidermis. HAve you an idea of which kind of 
cells they are? I
In my opinion this antibody does not work well, have you the some
experience?


Thank you in advance.
Cristiano Rumio


Prof. Cristiano Rumio
Department oj Human Anatomy
Via Mangiagalli 31
20133 Milan
Italy
Tel. +39-0258355401
Fax. +39-022364082
e-mail cristiano.rumio@unimi.it