In article <noemail-325A33.15594108072003 at cnews.newsguy.com>, Hobo
<URL:mailto:noemail at noemail.com> wrote:
[snip]
> Why don't NK cells kill red blood cells, which don't express MHC Class
> Ones, and why don't red blood cells express MHC Class Ones? Is it
> because without a nucleus MHCs are not needed, or is because without a
> nucleus they can not be produced?
Mammalian red cells develop from a precursor that is nucleated otherwise
they would not be able to encode any proteins!
Not all mammalian species have red cells that lack MHC Class I molecules.
NK cells not only detect low MHC Class I but they also interact with
targets through other adhesion and receptor molecules. Red cells probably
have differences in these other molecules which make them less susceptible
to recognition as targets by NK cells.
Mike <URL:http://www.path.cam.ac.uk/~mrc7/>
--
M.R. Clark, PhD. Division of Immunology
Cambridge University, Dept. Pathology
Tennis Court Rd., Cambridge CB2 1QP
Tel.+44 1223 333705 Fax.+44 1223 333875
