Functional similarity and differences between selection-independent CD4-CD8- alphabeta T cells and positively selected CD8 T cells expressing the same TCR and the induction of anergy in CD4-CD8- alphabeta T cells in antigen-expressing mice.

摘要: In TCR-alphabeta transgenic mice, CD4-CD8- TCR-alphabeta+ (alphabeta DN) cells arise in the absence of positively selecting MHC molecules and are resistant to clonal deletion Ag-expressing mice. this study activation requirements functional properties alphabeta double-negative (DN) were compared with those selected CD8+ expressing equivalent levels same class I-restricted TCR. We found that required a lower density antigenic ligand for optimal proliferative responses DN derived from nonpositively However, when CD8 coreceptor on was blocked an anti-CD8 mAb, both exhibited dose-response curve dependence CD28/B7 costimulation. Positively also differed they differentiated into more efficient killers IL-2 producers after Ag stimulation, even blockade. Ag-activated equally producing IFN-gamma, suggesting property is independent positive selection. recovered lymph nodes mice functionally anergic. This anergic state associated defective proliferation production response stimulation. These observations indicate can be anergized vivo by physiological ligand.