I thought if the cell expresses phoshatidylserine (PS), ie an insult to
the
cell membrane has caused PS to flip from inside the membrane to outside
the membrane. This PS is then a signal for macrophage processing.
Just a thought. And it may not be right.
On 13 Feb 1998, Axel Boldt wrote:
> Marc Buhler <mbuhler at STOP_SPAMmail.usyd.edu.au> said:
>> Axel> Neither B- nor T-cells nor anybody else will take any action unless a
> Axel> new antigen has been engulfed, processed and presented by a macrophage
> Axel> (let's talk about thymus-dependant antigens only for now); so the most
> Axel> central question of all should be: how do macrophages know what to
> Axel> engulf?
>> Marc> If antibodies are stuck to it, the macrophage can use Fc receptors (tail
> Marc> end of the antibody, as it were) to "know" they should engulf
> Marc> it.
>> At this point, we don't have antibodies. Before the B-cell can produce
> antibodies, it has to be stimulated by a Th cell, which has to find
> something on a macrophage surface. So the macrophage must know what to
> eat without the help of antibodies.
>> Marc> is no need for the macrophage to choose between "self" and
> Marc> "non-self".... most *everything* should be taken in, digested and
> Marc> presented.
>> That would be a possibility of course, but wouldn't that mean that
> macrophages chew on the good stuff all day and destroy valuable
> proteins and cells along the way?
>> Axel
>>
