The Complex of α2‐Macroglobulin with CD2 in the Plasma of Gastric Carcinoma Patients

Abstract

alpha 2-macroglobulin (alpha 2M) preparations purified from the plasma of healthy persons and gastric carcinoma patients were further analysed by immunochemical techniques. It was found that only alpha 2M from the plasma of gastric carcinoma patients gave a positive reaction with E-receptor sheep antiserum in rocket immunoelectrophoresis. The alpha 2M fraction giving the positive reaction with E-receptor sheep antiserum was isolated and analysed by the immunoblotting technique with monoclonal antibodies to T11 antigen. The presence of the alpha 2M-CD2 complex in the plasma of gastric carcinoma patients was demonstrated. This finding may explain the immunosuppressive effect of the plasma alpha 2M in cancer patients.

Association of CD2 with Fibrinogen in Human Plasma: Depletion of the Soluble E‐Receptor in Blood Clotting

“…[5] Rocket Immunoelectrophoresis Rocket immunoelectrophoresis was performed by the Laurell technique in 1.2% agarose with a veronal buffer (pH 8.5) containing 50 mL of ERSA per mL of the gel. [10] Six mL of serum or one mL of plasma were applied to the gel.…”

“…[5] Polyacrylamide Gel Electrophoresis A discontinuous PAGE was performed in 5% gel. [5] Sodium dodecyl sulfate (SDS) gel electrophoresis was performed in a 4 -20% linear gradient of PAG according to Laemmli.…”

“…The fractions were purified on immunosorbents with immobilized antibodies to immunoglobulins, haptoglobins, and apolipoprotein B100 as described earlier. [5] Finally, the heparin-binding proteins were removed on heparin-agarose (Kemotex, Estonia). [12] In all steps, the fractions were controlled with ERSA and antiserum to fibrinogen by rocket immunoelectrophoresis.…”

“…[5] Rabbit antisera to such human plasma proteins as fibrinogen, haptoglobins (Dakopatts, Denmark), fibronectin, sheep antiserum to IgG (HþL chains) (Institute of Molecular Pathology, Estonia), apo-B100 and apo-A1 lipoproteins (Orion Diagnostica, Espoo, Finland) were used.…”

“…The complex was purified and partially characterized. [5] To determine the level of the soluble E-receptor (SER) in different pathological conditions, sheep antiserum to the E-receptor (ERSA) was prepared by immunization of the sheep with the E-receptor coated autologous erythrocytes. [6] An elevated serum level of SER and CD2 was found in HIV-1 positive and AIDS patients.…”