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Published on: May 6, 2019
PD-1 expression on human CD8 T cells depends on both state of differentiation and activation status
Delphine Sauce1, Jorge R Almeida, Martin Larsen
1Cellular Immunology laboratory, INSERM U543, Avenir Group, Hôpital Pitié-Salpêtrière, Université Pierre et Marie Curie-Paris 6, Paris, France.
Insights
Programmed cell death protein 1 (PD-1) expression on CD8 T cells indicates differentiation and activation status. Understanding PD-1 is crucial for T-cell immunology and monitoring HIV-1 infection and vaccine responses.
Area of Science:
- Immunology
- Virology
- Cellular Biology
Background:
- Programmed cell death protein 1 (PD-1) expression on HIV-specific CD8 T cells is linked to functional exhaustion and uncontrolled HIV-1 replication.
- Assessing PD-1 expression is vital for T-cell immunology and vaccine monitoring.
Purpose of the Study:
- To investigate the significance of PD-1 expression on CD8 T cells in humans.
- To analyze PD-1 expression patterns across different CD8 T cell subsets in healthy and HIV-infected individuals.
Main Methods:
- Detailed analysis of PD-1 expression patterns.
- Examination of CD8 T cell subsets from healthy and HIV-infected donors.
Main Results:
- PD-1 expression is associated with T-cell differentiation, being upregulated in early/intermediate subsets (including HIV-specific CD8 T cells) and downregulated in late stages.
- PD-1 expression also correlates with T-cell activation, with PD-1 positive cells showing increased CD38 and HLA-DR expression.
Conclusions:
- PD-1 expression on CD8 T cells, including those specific for HIV, reflects both differentiation stage and activation status.
- These findings are important for accurate assessment of PD-1 expression in T-cell studies.
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.
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