CD11b expression as a marker to distinguish between recently activated effector CD8(+) T cells and memory cells.
CD8(+) T cells in different activation states have been difficult to identify phenotypically. In this study we have investigated whether Mac-1 (CD11b) expression can be used as a criterion to distinguish between recently activated effector cells and memory cells belonging to the CD8(+) T cell subset. Polyclonal virus-specific effector and memory CD8(+) T cells from lymphocytic choriomeningitis- and vesicular stomatitis virus-infected mice were visualized through staining for intracellular IFN-gamma or binding of MHC-peptide tetramers, and Mac-1 expression was evaluated. Naive T cells and most virus-specific memory CD8(+) T cells express little or no Mac-1 independent of the virus model employed. In contrast, the majority of CD8(+) T cells present during acute infection express a significant level of Mac-1 and, similarly, Mac-1 expression is found on secondary effectors generated in response to viral re-exposure. We therefore suggest that high Mac-1 expression defines a subset of circulating effector cells and that the presence of this marker on antigen-specific CD8(+) T cells signifies recent activation.
Institute of Medical Microbiology and Immunology, University of Copenhagen, Panum Institute, 3C Blegdamsvej, 2200 Copenhagen N, Denmark.
J E
JE
Christensen
S O
SO
Andreasen
J P
JP
Christensen
A R
AR
Thomsen
D000208:Acute Disease; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D008216:Lymphocytic Choriomeningitis / Q000276:immunology / Q000821:virology; D008217:Lymphocytic choriomeningitis virus; D016177:Macrophage-1 Antigen / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018353:Rhabdoviridae Infections / Q000276:immunology / Q000821:virology; D014721:Vesicular stomatitis Indiana virus
D015415:Biomarkers; D016177:Macrophage-1 Antigen