ABSTRACT
Anti-HLA class I monoclonal antibody (mAb) 01.65 inhibited phytohaemagglutinin (PHA)-induced human lymphocyte proliferation. The inhibitory effect was inversely correlated to the strength of the proliferative response. It was increased when lymphocytes were stimulated with suboptimal doses of PHA but it disappeared with supraoptimal doses. Proliferation inhibition was achieved by prolonging the cell cycle time and by slowing down its recruitment rate. The former effect was not restricted to the G1-phase but also included the S phase. These results support the idea that HLA class I molecules are important in the PHA-induced proliferation of human T-lymphocytes.
Subject(s)
Antibodies, Monoclonal/pharmacology , Cell Cycle/immunology , Histocompatibility Antigens Class I/immunology , Lymphocyte Activation , Phytohemagglutinins , T-Lymphocytes/cytology , Antibody Specificity , DNA/biosynthesis , Dose-Response Relationship, Immunologic , Growth Inhibitors/immunology , Growth Inhibitors/pharmacology , Humans , Isoantibodies/pharmacology , Lymphocyte Activation/immunology , T-Lymphocytes/immunology , T-Lymphocytes/metabolismABSTRACT
HLA class I antigens seem to be involved in the proliferative response of PHA-activated human T-lymphocytes. We have previously reported that the treatment of PHA-activated peripheral blood mononuclear cells (PBMC) with an anti-HLA class I monoclonal antibody, 01.65, (i) inhibits the tritiated thymidine incorporation, (ii) inactivates cytosolic protein kinase C (PKC) and (iii) causes an increase in the duration of the cell cycle. Northern Blot kinetic analysis of c-fos, c-myc, cdc2, IL-2R, c-myb, ODC, TK and H3, from 10 minutes to 120 hours, was performed in MAb 01.65 treated cultures. We found that the expression of four genes (c-myc, IL-2R, cdc2 and TK) was depressed 24 hours after PHA stimulation.
Subject(s)
Gene Expression Regulation , Histocompatibility Antigens Class I/physiology , Lymphocyte Activation , T-Lymphocytes/metabolism , Antibodies, Monoclonal/immunology , Blotting, Northern , Cell Cycle , Cells, Cultured , Histocompatibility Antigens Class I/immunology , Humans , Phytohemagglutinins , RNA, Messenger/genetics , T-Lymphocytes/cytology , T-Lymphocytes/immunologyABSTRACT
N-N-Staurosporine (STAR) inhibits in a dose dependent manner Tritiated-Thymidine (3H-TdR) incorporation in phytohemagglutinin (PHA) activated Peripheral Blood Mononuclear Cells (PBMC) treated with anti-HLA class I monoclonal antibody (MAb) 01.65 and its effect results competitive with MAb 01.65. Cytosolic and particulate Protein Kinase C (PKC) have been studied. Only when PKC particulate activity is no more detectable, the effect of STAR on 3H-TdR incorporation is evident.
