[Antiphospholipid and anti beta 2-glycoprotein I antibodies].

Recent studies have shown that beta 2glycoprotein I (beta 2GPI), a plasma inhibitor of coagulation with affinity for anionic phospholipids, is frequently required for the formation of the epitopes recognized by some anti-phospholipid antibodies. Six murine monoclonal antibodies directed against human beta 2GPI were compared with anti-beta 2GPI antibodies associated with systemic lupus erythematosus and primary anti-phospholipid syndrome. The beta 2GPI-dependent binding properties to neutral and anionic phospholipids were studied, as well as the target epitopes on the beta 2GPI molecule and the effect of various beta 2GPI treatments to get rid of contaminating phospholipids or to block the beta 2GPI-phospholipid interaction.

CD45RA expression by CD4 T lymphocytes in tumors invaded by B-cell non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD).

Little is known about the role of tumor infiltrating T lymphocytes (TIL-T) in the pathogenesis of malignant diseases and collaboration between normal and malignant cells has not yet been proved. In the present work, we have investigated whether immune T lymphocytes exist in tumors invaded by B-cell non-Hodgkin's lymphoma (NHL) or Hodgkin's disease (HD). Therefore, we have studied the reactivity of the CD45RA monoclonal antibody, which discriminates between naive and memory CD4 T lymphocytes.

Membrane cell permeabilization with saponin and multiparametric analysis by flow cytometry.

Saponin, a detergent like molecule, can permeabilize cell membranes without destroying them, and thus can be used for the detection of intracellular antigens on intact cells with a flow cytometer. First experiments were reported that demonstrated the detection of intracytoplasmic antigens such as intermediate filaments and CD3 in T acute lymphoblastic leukemia (ALL). Further experiments were also performed to prove that intranuclear structures were equally accessible: dyes such as propidium iodide (PI) and monoclonal antibodies (mAb) such as Ki67 could penetrate the nucleus and lead to the analysis of DNA content and to the discrimination between the different cell cycle phases (G0, G1, S, G2-M).