Eun Young Choi's group from the Seoul National University College of Medicine have discovered that CD4 T cell help is not required to initiate differentiation of CD8 T cells into central memory T cells during an immune response.
CD8 T cells activated without CD4 T cell help are impaired in memory expansion. To understand the underlying cellular mechanism, Dr. Young Choi's group used a CD4 helper cell-deficient congenic mouse system. Surprisingly, they found that initiation of the memory differentiation program is CD8 T cell-intrinsic and not encoded by CD4 help. Instead, CD4 T cells helped to sustain the intrinsic CD8 T cell memory program which allowed for increased numbers of central memory T cells and efficient antigen clearance.
The authors used Bio X Cell's anti-mouse CD4 antibody (clone GK1.5) to deplete CD4 T cells in vivo. Additionally, the authors used Bio X Cell's anti-mouse PD-L1 antibody (clone 10F.9G2) to block PD-L1/PD-1 signaling in vivo resulting in restoration of the proliferative and functional activity of exhausted CD8 T cells in CD4 helper cell-deficient hosts. Lastly, the authors used Bio X Cell's anti-Thy1.1 antibody (clone 19E12) to deplete Thy1.1 expressing cells in vivo.
See the article in Nature Communications:
http://www.nature.com/ncomms/2015/150814/ncomms8994/full/ncomms8994.html