I have seen very interesting posts on B7-1 and B7-2 by Lee Wetzler and thierry
sornasse. However I am still a little confused on a couple of experiments that
they did to get at B7-2. My first point of confusion is that if B7-2 is the
major costimulatory protein then what is the function of B7-1 ( since its
m RNA is not even produced till about 24-48hrs after the first signal is
received by the T cell in which case would be to differentiate)?
There could be a couple of possibilities.
1) B7-1 is stimulated under different conditions than B7-2 and that's the
reason for the group seeing low b7-1 under those conditions.
2) B7-1 has other purposes activation is not its major role.
My second point of confusion was that just knowing that B7-1 is not
produced early enough one can't assume that
1) B7-1 is not the major co-stimulatory signal, because different antigens
might preferentially induce one or the other of B7's.
2) Just because B7-2 is produced early that it's the major factor. Because we
all know that there are translational regulations and post translational
modifications that might be going on and this might affect the expression
If B7-1 and B7-2 do have the same function then why is it necessary to have
Thanks again for everybody that responded to my " new discussion in
ShahramI guess posting is better so everyone who is interested can read it.