Enrichment for Th1 cells in the Mel-14+ CD4+ T cell fraction in aged mice.
CD4+ T cells from young and aged mice were sorted into Mel-14+ cells which are regarded as naive cells and Mel-14- cells which are regarded as memory cells. These subsets were stimulated in short-time cultures with anti-CD3 or anti-CD3/anti-CD28 in order to determine the presence of Th1 and/or Th2 cytokines. Based on the simultaneous production of IL-2, IL-4, IL-10, and IFN-gamma upon anti-CD3 stimulation by Mel-14- cells from young and aged mice, it is concluded that this cell population comprises Th1, Th2, and/or Th0 cells. Mel-14+ cells from young mice only secrete substantial amounts of IL-2 in the presence of anti-CD28 as a costimulatory signal and can therefore be regarded as Th precursor cells. By contrast, Mel-14+ cells from aged mice responded to anti-CD3 alone, not only by the production of IL-2 but also by the production of high amounts of IFN-gamma and minute amounts of IL-4 and IL-10, suggesting that these "naive" cells in aged mice are enriched for Th1 cells. This was not due to lack of CD28 triggering since anti-CD28 enhanced IFN-gamma as well as IL-4 and IL-10 to a similar extent. Our data therefore indicate that Mel-14 is not exclusively expressed on naive CD4+ T cells.
Dobber
R
R
Division of Immunological and Infectious Diseases, TNO Prevention and Health, Leiden, The Netherlands.
Tielemans
M
M
Nagelkerken
L
L
D000375:Aging; D000818:Animals; D018106:CD28 Antigens / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000032:analysis; D002469:Cell Separation; D005434:Flow Cytometry; D007156:Immunologic Memory; D019041:L-Selectin; D051379:Mice; D008808:Mice, Inbred CBA; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology
D018106:CD28 Antigens; D015815:Cell Adhesion Molecules; D019041:L-Selectin