Biosynthesis and post-translational modification of CD6, a T cell signal-transducing molecule.

CD6 (T12) is a 130-kDa glycoprotein present on the surface of human T cells. Previously, we demonstrated that the anti-T12 and anti-2H1 monoclonal antibodies recognized different epitopes on CD6, and both were capable of transducing activation signals to T cells. Anti-T12 augmented suboptimal signaling via the TCR/CD3 complex and directly activated separated CD4+ but not CD8+ cells.

Activation of in vitro proliferation of human T cells by a synthetic peptide of toxic shock syndrome toxin 1.

A 21-mer synthetic peptide (KGEKVDLNTKRTKKSQHTSEG), designated TSST-1(58-78), was constructed from the primary structure of the toxic shock syndrome toxin 1 (TSST-1). The peptide reacted with a panel of neutralizing monoclonal antibodies (MAbs) to whole TSST-1 in solid-phase immunoassays. TSST-1(58-78) promoted the in vitro proliferation of human peripheral blood mononuclear cells (PBMC) in a dose-dependent manner.

Structural characterization of CD6: properties of two distinct epitopes involved in T cell activation.

Studies from our laboratory have shown that anti-T12, a mAb which recognizes CD6, is a macrophage-dependent mitogen for human T cells and can augment T cell autoreactivity in vitro. To obtain additional information regarding the potential biological role of CD6 we sought to further characterize its biochemical properties. The CD6 molecule on 125I-surface-labeled T cells and by Western blot analysis was a monomer of mol.

Anti-T12, an anti-CD6 monoclonal antibody, can activate human T lymphocytes.

Anti-T12 is a murine IgM mAb that recognizes the 130-kDa CD6 glycoprotein on mature human T lymphocytes. Examination of the in vitro effects of this mAb on freshly isolated T cells demonstrates that anti-T12 can induce T cell activation. Such activation is macrophage-dependent, and optimal stimulation occurs with 0.

P1 plasmid replication: measurement of initiator protein concentration in vivo.

To study the functions of the mini-P1 replication initiation protein RepA quantitatively, we have developed a method to measure RepA concentration by using immunoblotting. In vivo, there are about 20 RepA dimers per unit-copy plasmid DNA. RepA was deduced to be a dimer from gel filtration of the purified protein.