background: recent studies have provided evidence that integrins play roles in recognition of mechanical stimuli and its translation into a cellular response. integrin signaling may be regulated by a number of mechanisms including accessory proteins such as cd98 (4f2 antigen). objectives: to determine cd98 expression by human articular chondrocytes and its involvement in human articular mechano...

The 4F2 monoclonal antibody (mAb) has been shown to recognize a 120-kilodalton glycoprotein expressed on the cell surface of human peripheral blood monocytes, activated (but not resting) T or B cells, and T and B lymphoblastoid cell lines. In this report we show that 4F2 mAb specifically binds to the surface of adherent human embryonic fibroblasts but fails to bind to normal adult fibroblasts. ...

Mammalian cells express a transport system known as system x(c)-, which is an exchange agency specific for anionic forms of cystine and glutamate. System x(c)- activity is important to maintain both intracellular glutathione levels and the redox balance between cystine and cysteine in the extracellular milieu. We have shown that the cloned cDNAs encoding the transporter for system x(c)- consist...

Cytotoxic cells are produced in an autologous mixed leukocyte reaction (AMLR). At 1 wk in culture the AMLR killers are mainly IgG Fc- cells and can kill autologous lymphoblastoid cell lines and Raji and Daudi targets that are usually resistant to natural killer cell (NK) lysis. To define the phenotype of these cells, we have used complement (C')-mediated lysis with monoclonal antibodies (MAb). ...

The effects of helper T-cell clone supernatants on resting human B cells were investigated. Four different helper T-cell clones (two T4+ and two T8+) were stimulated by anti-T3 monoclonal antibodies on Sepharose beads or anti-T11(2) plus anti-T11(3) monoclonal antibodies. The supernatants from these activated clones induced the proliferation of highly purified resting B lymphocytes from the per...

Cell surface phenotypes of bronchoalveolar lavage (BAL) and peripheral blood lymphocytes (PBL) obtained from a group of young healthy volunteers, including smokers and nonsmokers were studied. Results indicate that the proportions of T (CD3+) and B (CD19+) lymphocytes were comparable in PBL and BAL lymphocytes, whereas the numbers of cells bearing natural killer cell-associated markers (CD16, C...

A number of cell surface markers are expressed on resting peripheral blood (PB) T cells (1). However, there are a number of surface markers that are expressed only in low proportions or not at all on resting T cells, but that are clearly expressed in varying proportions on activated T cells. Among these markers of activated T cells, the receptors for the Fc portion of IgG (FcyR) are on small fr...

Mixed lymphocyte reaction (MLR)-activated T cells were analyzed according to the expression of various cell surface markers by the specific cytotoxic T lymphocytes (CTL) generated in the MLR. CTL were found exclusively in a population of MLR-activated T cells that lacked detectable Fc gamma R but that expressed a surface antigen recognized by the 4F2 monoclonal antibody. In contrast, CTL were f...