PD-1 expression on human CD8 T cells depends on both state of differentiation and activation status

AIDS. 2007 Oct 1;21(15):2005-13. doi: 10.1097/QAD.0b013e3282eee548.


Objective and design: PD-1 expression on HIV-specific CD8 T cells was recently reported to reflect functional exhaustion, resulting in uncontrolled HIV-1 replication. Assessing PD-1 expression on T cells may be highly relevant in T-cell immunology and vaccine monitoring. However, this requires us to gain further insights into the significance of PD-1 expression on CD8 T cells in humans.

Methods: We performed a detailed analysis of PD-1 expression pattern on various CD8 T cell subsets from healthy or HIV infected donors.

Results: PD-1 expression has two facets in vivo. On the one hand, it is linked to T-cell differentiation: PD-1 is up-regulated on early/intermediate differentiated subsets, which include HIV and Epstein-Barr virus-specific CD8 T-cell populations, but is down-regulated during late stages of differentiation. On the other hand, it is linked to T-cell activation: on PD-1 positive cells, PD-1 over-expression occurs along with the up-regulation of activation markers such as CD38 or HLA-DR.

Conclusions: PD-1 expression on CD8 T cells, including those specific for HIV, can be related both to their differentiation stage and their activation status. It is important to consider these findings when assessing the expression of PD-1 on T cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-ribosyl Cyclase 1 / biosynthesis
  • Antigens, CD / metabolism*
  • Apoptosis Regulatory Proteins / metabolism*
  • CD8-Positive T-Lymphocytes / metabolism*
  • Case-Control Studies
  • Cell Differentiation*
  • HIV Infections / metabolism*
  • Herpesvirus 4, Human / metabolism
  • Humans
  • Lymphocyte Activation*
  • Programmed Cell Death 1 Receptor


  • Antigens, CD
  • Apoptosis Regulatory Proteins
  • PDCD1 protein, human
  • Programmed Cell Death 1 Receptor
  • ADP-ribosyl Cyclase 1