Monoclonal antibody to a human leukocyte‐specific membrane glycoprotein probably homologous to the leukocyte‐common (L‐C) antigen of the rat

Abstract

The monoclonal antibody (F 10-89-4) described in this study recognizes an antigen which by quantitative absorption analysis is absent from human brain, kidney, liver, heart, erythrocytes, platelets and normal serum, but is present on spleen, lymph node, chronic lymphatic leukemia cells, bone marrow, thymus and granulocytes at a ratio of 1:1:0.8:0.3:0.1, respectively. Analysis with the fluorescence-activated cell sorter showed that 100% of thymocytes, lymph node lymphocytes, blood mononuclear cells and granulocytes carry the antigen, while 83% of bone marrow cells are positive. There was marked heterogeneity in the amount of labeling of thymocytes, with 3 major peaks. There was also heterogeneity of labeling of blood mononuclear cells and lymph node lymphocytes, with a weakly staining hump containing approximately 20% of the cells in the case of lymph node lymphocytes. Double labeling experiments demonstrated that the weakly staining cells of blood and lymph node were B lymphocytes, while frozen sections of thymus showed that the antigen was expressed most weakly in subcapsular cortical thymocytes, and most strongly on medullary thymocytes. Biochemical studies established that the antigen bound to lentil lectin columns, and sodium dodecyl sulfate polyacrylamide gel electrophoresis studies using NaB3H4-labeled blood mononuclear cells established that the antigen was a major glycoprotein of lymphocytes, and that its molecular weight was in the region of 190000 to 215000.

Demonstration and characterization of Ia-positive dendritic cells in the interstitial connective tissues of rat heart and other tissues, but not brain.

“…The sections were washed three times in phosphate-buffered saline (PBS) (Dulbecco's A and B media, Oxoid Ltd., London) and then incubated 30 min with monoclonal antibody at a dilution known to saturate all the antigen sites on the section. The antibodies raised in this laboratory (F17-23-2, F16-4-4, and F3-20-7) were partially purified from immune ascites by ion-exchange chromatography (22) . Saturating concentrations of antibody were calculated from preliminary titrations of the antibody on lymph node lymphocyte targets, using saturating binding assays (23) .…”

CD44 in hematological neoplasias

“…The class I transmembrane glycoprotein CD44 has first been described in 1980 as a surface molecule on T-lymphocytes, cortical thymocytes, and granulocytes [1]. It plays an important role in cell proliferation, migration, survival, and apoptosis.…”

Biochemical and antigenic characterization of CD45 polypeptides expressed on plasma membrane and internal granules of human neutrophils

“…CD45 (leukocyte common antigen, LCA, T200, Ly5) is a pan-leukocyte phosphotyrosine phosphatase glycoprotein complex showing a marked biochemical and antigenic heterogeneity [1][2][3][4]. This heterogeneity is due to the existence of celltype-specific alternative splicing from a common precursor mRNA that generates several CD45 mature mRNAs coding for proteins with distinct amino acid content of the N-terminal regions [5][6][7][8][9].…”