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Arthritis Research & Therapy

, 7:P153 | Cite as

Expression of programmed death (PD)-1 and PD-1 ligands (PD-L1, PD-L2) in peripheral blood mononuclear cells of patients with systemic lupus erythematosus

  • G Bertsias
  • A Raptopoulou
  • E Coutala
  • M Mamoulaki
  • H Kritikos
  • P Sidiropoulos
  • DT Boumpas
Poster presentation
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Keywords

Rheumatoid Arthritis Systemic Lupus Erythematosus Peripheral Blood Mononuclear Cell Systemic Lupus Erythematosus Patient Flow Cytometry Analysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Background

Programmed death (PD)-1 is a newly described member of the immunoglobulin super-family that is expressed on activated T lymphocytes and B lymphocytes. Engagement of PD-1 with its specific ligands, PD-L1 (B7-H1) and PD-L2 (B7-DC), inhibits lymphocyte proliferation and cytokine expression, and may play a role in peripheral tolerance and negative regulation of T-cell and B-cell responses in vivo. We sought to investigate the expression profiles of PD-1 and PD-1 ligands in peripheral blood cells of patients with systemic lupus erythematosus (SLE).

Materials and methods

Blood was drawn from patients with SLE (n = 16), rheumatoid arthritis (n = 16), other inflammatory disease (n = 4), and healthy controls (n = 9). Peripheral blood mononuclear cells were separated on a ficoll-density gradient, and flow cytometry analysis was performed using monoclonal antibodies against CD3, CD19, CD14, CD25, CD69, PD-1, PD-L1, and PD-L2.

Results

See Table 1.

Table 1

 

Disease group

 

Healthy controls

Systemic lupus erythematosus

Rheumatoid arthritis

Inflammatory disease

 

Mean

SEM

Mean

SEM

Mean

SEM

Mean

SEM

PD-1+ (%)

        

   in CD3+

0.6

0.2

0.4

0.1

1.6

0.6

0.5

0.1

   in CD19+

1.7

0.9

1.4

0.3

0.9

0.4

1.1

0.4

   in CD25+

3.0

1.0

2.4

0.7

3.3

1.6

8.5

3.4

PD-L1+ (%)

        

   in CD3+

2.8

1.2

4.1

0.9

2.3

0.5

2.0

0.6

   in CD19+

3.9

1.3

5.1

0.9

3.7

1.0

11.3

8.0

   in CD14+

5.1

2.0

14.0

5.4

2.9

0.9

5.7

3.2

PD-L2+ (%)

        

   in CD3+

0.6

0.2

0.5

0.1

0.5

0.2

0.4

0.0

   in CD14+

2.0

0.5

1.4

0.3

1.1

0.5

1.2

0.1

SEM, standard error of the mean. No statistically significant differences were observed.

Conclusions

In this preliminary report, SLE patients showed a trend for lower expression of PD-1 and higher expression of PD-L1 in unstimulated peripheral blood mononuclear cells compared with other disease controls. These results corroborate findings linking SLE with polymorphism of the PD-1 gene resulting in putative altered expression of the PD-L2 [1]. Lower expression of PD-1 in SLE lymphocytes could be related to ineffective suppression of autoreactive lymphocytes and thus to disease evolution. Currently, we investigate expression of PD-1 and its ligands on subpopulations of lymphocytes (CD45RO+, CD27+), as well as the kinetics of expression upon stimulation.

References

  1. 1.
    Prokunina L, Castillejo-Lopez C, Oberg F, Gunnarsson I, Berg L, Magnusson V, et al: A regulatory polymorphism in PDCD1 is associated with susceptibility to systemic lupus erythematosus in humans. Nat Genet. 2002, 32: 666-669. 10.1038/ng1020.CrossRefPubMedGoogle Scholar

Copyright information

© BioMed Central Ltd 2005

Authors and Affiliations

  • G Bertsias
    • 1
  • A Raptopoulou
    • 1
  • E Coutala
    • 1
  • M Mamoulaki
    • 1
  • H Kritikos
    • 1
  • P Sidiropoulos
    • 1
  • DT Boumpas
    • 1
  1. 1.Department of Rheumatology, Clinical Immunology and Allergy, Medical SchoolUniversity of CreteGreece

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