Co-expression of the CD8 receptor in a human CD4+ T-cell clone influences proliferation, cytosolic Ca2+ release and cytokine production.
In normal human subjects a small proportion of peripheral blood T-cells simultaneously express both CD4 and CD8 differentiation antigens. In this study we characterized a subset of CD4+ clones, from a healthy donor, that is specific for the thyrotropin receptor (TSHR) and that showed cells co-expressing the CD8 receptor. To address whether the expression of the CD8 receptor on the cell membrane was associated to differences in the physiology of the T-cells, we isolated, from the same clone, CD4 single positive (SP) cells from those co-expressing CD4/CD8 receptors (DP cells) and stimulated them in vitro with antigen presenting cells (APC) carrying TSHR. The results demonstrated that CD8 co-expression has a profound effect on the physiology of T helper (Th) cells. In comparison to cells expressing the CD4 receptor alone, DP T-cells showed: (1) increased proliferation; (2) higher and more sustained release of free Ca2+ in the cytosol, under stimulus; (3) lower levels of IL-2 and IL-4 released in the supernatants; (4) increased amounts of IFN-gamma released.
Molteni
Monica
M
Department of Internal Medicine, University of Milano, IRCCS Ospedale Maggiore, Milan, Italy. monica.molteni@uninsubria.it
Kohn
Leonard D
LD
Rossetti
Carlo
C
Scrofani
Santo
S
Bonara
Paola
P
Scorza
Raffaella
R
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis*; D006801:Humans; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000502:physiology*
C067361:CD8 receptor; D016207:Cytokines; D011948:Receptors, Antigen, T-Cell; D002118:Calcium