title: Human memory T lymphocytes express increased levels of three cell adhesion molecules (LFA-3, CD2, and LFA-1) and three other molecules (UCHL1, CDw29, and Pgp-1) and have enhanced IFN-gamma production.
abstract: Studies of cell-surface molecules involved in human T cell interaction reveal that differential expression of each of three adhesion molecules (LFA-3, CD2, and LFA-1) subdivides human peripheral blood T cells into major subpopulations. Systematic analysis of the relationship between expression of these and other markers of T cell subsets demonstrates a single major subset of human peripheral blood T lymphocytes distinguished by enhanced expression of LFA-3, CD2, LFA-1, and three other markers (CDw29 [4B4], UCHL1, and Pgp-1). Large differences in relative expression are observed for UCHL1 (29-fold) and LFA-3 (greater than 8-fold), and smaller differences (2- to 4-fold) are seen for CDw29, CD2, LFA-1, and Pgp-1. Bimodal distribution of LFA-3 is found on both CD4+ cells and on CD8+ cells as well as on B lymphocytes (CD19+). Neonatal T cells (CD3+) are comprised almost exclusively of the subset expressing low LFA-3, CD2, LFA-1, CDw29, and UCHL1. Activation of cord peripheral blood mononuclear leukocytes with PHA leads to uniform enhanced expression of each of these molecules on CD3+ cells. Functional analyses of these T cell subsets were performed after sorting of adult T cells based on differential LFA-3 expression. Only the LFA-3+ subset proliferated in response to the Ag tetanus toxoid, even though the LFA-3- subset proliferated more strongly to PHA. Furthermore, the LFA-3+ subset made greater than fivefold more IFN-gamma than the LFA-3- subset in response to PHA, despite the fact that both subsets made equivalent amounts of IL-2. This phenotypic and functional analysis of resting and activated newborn and adult T cells indicates that human memory T cells express enhanced levels of LFA-3, CD2, LFA-1, UCHL1, CDw29, and Pgp-1; we speculate that the increase in expression of T cell adhesion molecules LFA-3, CD2, and LFA-1 on memory cells is functionally important in their enhanced responsiveness.
mesh_terms: D000328:Adult; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis* / Q000096:biosynthesis; D018801:CD2 Antigens; D002352:Carrier Proteins / Q000032:analysis; D015815:Cell Adhesion Molecules; D005312:Fetal Blood / Q000032:analysis; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins / Q000032:analysis; D009000:Monocytes / Q000032:analysis; D011971:Receptors, Immunologic / Q000032:analysis; D013601:T-Lymphocytes / Q000032:analysis / Q000145:classification* / Q000378:metabolism; D013745:Tetanus Toxoid / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D018801:CD2 Antigens; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D013745:Tetanus Toxoid; D007371:Interferon-gamma