TY - JOUR

T1 - Ligation of MHC class I molecules on peripheral blood T lymphocytes induces new phenotypes and functions

AU - Bregenholt, S

AU - Röpke, M

AU - Skov, S

AU - Claesson, Mogens Helweg

PY - 1996/8/1

Y1 - 1996/8/1

N2 - Microgram concentrations of immobilized anti-MHC class I (MHC-I) Ab induced proliferation of resting CD3+ T cells from peripheral blood. In contrast, soluble Ab did not activate T cells. Exposure of T cells to immobilized anti-MHC-I Ab for only 24 h was followed by proliferation and development of T cell-mediated cytotoxicity. Immediately following MHC-I ligation, the T cells responded with increased protein tyrosine phosphorylation, with new bands appearing in the SDS-PAGE. Exposure of T cells to immobilized anti-MHC-I Ab for 24 h induced an increased surface expression of the TCR/CD3 and CD28 molecules. MHC-I-induced proliferation of purified T cells was dependent on cellular interactions with non-T cells. Under certain conditions, in which MHC-I was ligated by picogram concentrations of immobilized anti-MHC-I Ab, anti-TCR/CD3 Ab-induced proliferation of T cells was strongly inhibited. These data clearly demonstrate that ligation of the MHC-I complex on T cells may induce both positive and negative signals. Since the physiologic ligands for MHC-I molecules are TCR and the CD8 molecules, our data may suggest that MHC-I molecules are instrumental in cellular interactions between T cells.

AB - Microgram concentrations of immobilized anti-MHC class I (MHC-I) Ab induced proliferation of resting CD3+ T cells from peripheral blood. In contrast, soluble Ab did not activate T cells. Exposure of T cells to immobilized anti-MHC-I Ab for only 24 h was followed by proliferation and development of T cell-mediated cytotoxicity. Immediately following MHC-I ligation, the T cells responded with increased protein tyrosine phosphorylation, with new bands appearing in the SDS-PAGE. Exposure of T cells to immobilized anti-MHC-I Ab for 24 h induced an increased surface expression of the TCR/CD3 and CD28 molecules. MHC-I-induced proliferation of purified T cells was dependent on cellular interactions with non-T cells. Under certain conditions, in which MHC-I was ligated by picogram concentrations of immobilized anti-MHC-I Ab, anti-TCR/CD3 Ab-induced proliferation of T cells was strongly inhibited. These data clearly demonstrate that ligation of the MHC-I complex on T cells may induce both positive and negative signals. Since the physiologic ligands for MHC-I molecules are TCR and the CD8 molecules, our data may suggest that MHC-I molecules are instrumental in cellular interactions between T cells.

KW - Antibodies, Monoclonal

KW - Antigens, CD28

KW - Antigens, CD3

KW - Cell Division

KW - Cytotoxicity, Immunologic

KW - Dose-Response Relationship, Immunologic

KW - Histocompatibility Antigens Class I

KW - Humans

KW - Phenotype

KW - Phosphorylation

KW - Protein-Tyrosine Kinases

KW - Receptors, Antigen, T-Cell

KW - T-Lymphocyte Subsets

KW - Time Factors

M3 - Journal article

C2 - 8757602

VL - 157

SP - 993

EP - 999

JO - Journal of Immunology

JF - Journal of Immunology

SN - 0022-1767

IS - 3

ER -