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CD4dullCD8bright double-positive T-lymphocytes have a phenotype of granzyme Bpos CD8pos memory T-lymphocytes
R J Rentenaar1, P C Wever, F N van Diepen
1Department of Internal Medicine, Academic Medical Centre, University of Amsterdam, The Netherlands.
Insights
Cytotoxic T-lymphocytes with a CD4dullCD8bright phenotype were identified in a renal transplant patient with cytomegalovirus infection. This T-cell subset is enriched for memory and effector cytotoxic T cells.
Area of Science:
- Immunology
- Cell Biology
Background:
- T-lymphocytes co-expressing CD4 and CD8 antigens (double-positive T-cells) are typically found in low percentages in healthy individuals.
- A distinct CD4dullCD8bright T-cell phenotype has been observed primarily during viral infections.
Purpose of the Study:
- To investigate the characteristics of CD4dullCD8bright T-lymphocytes in a patient with cytomegalovirus infection.
Main Methods:
- Utilized four-colour flow cytometry to analyze peripheral blood mononuclear cells.
- Focused on a renal transplant recipient diagnosed with cytomegalovirus infection.
Main Results:
- Identified a distinct subpopulation of CD4dullCD8bright double-positive T-lymphocytes.
- These cells displayed phenotypic markers consistent with cytotoxic T-lymphocytes and were granzyme B positive.
- The subpopulation lacked naive T-cells, suggesting a memory or effector function.
Conclusions:
- The CD4dullCD8bright double-positive T-lymphocyte population is significantly enriched for memory and effector cytotoxic T cells.
- This finding highlights a specific T-cell subset involved in antiviral immune responses.
Background:
T-lymphocytes that co-express CD4 and CD8 antigens may be found in small percentages in the peripheral blood of healthy individuals, and have a CD4brightCD8dull phenotype. CD4dullCD8bright T-lymphocytes have been found only in temporal association with some viral infections.
Methods:
Four-colour flow cytometric analysis of peripheral blood mononuclear cells from a renal transplant recipient with cytomegalovirus infection was performed.
Results:
A small but clearly distinguishable subpopulation of CD4dullCD8bright double-positive T-lymphocytes was detected, that exhibited phenotypic characteristics of cytotoxic T-lymphocytes and were granzyme B positive. Furthermore, no naive cells appeared to be present within this subpopulation.
Conclusions:
CD4dullCD8bright double-positive T-lymphocytes are enriched for memory and effector cytotoxic T cells.