In article <M_Doherty-3107951212390001 at db454.niaid.nih.gov> M. Doherty,
M_Doherty at NIH.gov writes:
>> (1) At what point does a CD4+ cell commit to a TH1 vs. a TH2
>> response? Does it "commit," or is the process reversible?
This topic was dealt with in various workshops at the recent congress. I
think Anne O'Garra put it best. The commitment starts very early but is
reversible until the cell is activated several times in the proper LK
milieu then it becomes fixed. This explains why some investigators can
switch an existing response. The switch is usually an outgrowth of
previously unstimulated cells. Since most mouse people work at the
polyclonal/bulk level. Us humanists who use clones do not see switching
in established clones. The LK must be there early but commitment may
take some time to fully reach permanance.
