Human CD8 T cells of the peripheral blood contain a low CD8 expressing cytotoxic/effector subpopulation.
Heterogeneity of lymphocyte populations demonstrates the diversity of cellular immune responses and provide a better understanding of the immune system. CD3+ CD8+ T cells exhibit a low CD8 expressing (CD8low) population in flow cytometric analysis of peripheral blood T cells. In healthy donors, this population consists of 0.2-7.0% of all CD8 T cells. The majority of the CD8low T cell population showed an elevated expression of CD25, CD45RA, and CD95L, and low levels of CD28, CD62L and CD45RO. Circulating CD8low T cells resemble cytotoxic effector cells because they express cytolytic mediators and are able to execute cytotoxicity. A restricted T cell receptor profile with increased Vbeta9, Vbeta14 and Vbeta23 expression was observed and the CD8low T cell population contain Epstein-Barr virus-specific T cells. Therefore, the CD8low population represent a subset of activated CD8 effector T cells, resulting most probably from a continuous and/or balanced immune response to intracellular pathogens.
Trautmann
Axel
A
Swiss Institute of Allergy and Asthma Research (SIAF), Obere Strasse 22, CH-7270 Davos, Switzerland. trautmann_a@klinik.uni-wuerzburg.de
Rückert
Beate
B
Schmid-Grendelmeier
Peter
P
Niederer
Eva
E
Bröcker
Eva-B
EB
Blaser
Kurt
K
Akdis
Cezmi A
CA
D016827:CD8 Antigens / Q000097:blood*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology; D002455:Cell Division / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000097:blood; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000821:virology
D016827:CD8 Antigens; D016207:Cytokines; D011948:Receptors, Antigen, T-Cell