The Human Cell Surface Glycoprotein Complex (gp 120,200) Recognized by Monoclonal Antibody K20 is a Component Binding to Phytohaemagglutinin on T Cells

Abstract

Monoclonal antibody K20 recognizes a human glycoprotein complex that is not restricted to haematopoietic lineages but is preferentially expressed on early haematopoietic cells, T cells, and monocytes. This glycoprotein complex is made of a constant 120,000-140,000 Mr subunit noncovalently associated at the cell surface with subunits of higher Mr ranging from 150,000 to 200,000 on different cell types. Internal labelling with [35S]methionine and pulse-chase experiments revealed that in the cell the 120,000 Mr glycoprotein of this complex is also noncovalently associated with a 100,000 Mr glycoprotein, and that both glycoproteins are independently biosynthesized. This glycoprotein complex is shown by immunoprecipitation by lectin plus antilectin antibodies and by sequential immunoprecipitations to be one of the cell surface structures bound by phytohaemagglutinin on the surface of normal T cells.

Quantification of integrin receptor agonism by fluorescence lifetime imaging

“…To constrain Journal of Cell Science 121 (3) the location of the clustered integrin for analysis, ␤1-integrin-GFP MEFs expressing talin-rod-mRFP were plated onto PLL and incubated with 4.2 m beads coated with fibronectin ligand or the monoclonal antibodies 12G10 (which detects the high affinity or primed state and stimulates ligand binding) (Mould et al, 1995;Mould et al, 2002), mAb13 (which detects non-ligand-occupied integrin and which blocks ligand binding) (Akiyama et al, 1989) or K20 (which is non-functionaltering and detects all conformational states) (Amiot et al, 1986;Mould et al, 2005). As shown in Fig.…”

“…Anti-␤1 monoclonal antibodies used in the study are: K20 (neutral); (Amiot et al, 1986;Mould et al, 2005), 12G10 (activating) (Mould et al, 1995;Mould et al, 2002) or mAb13 (inactivating) (Akiyama et al, 1989) and were all generated in-house as previously described. Beads were left overnight at 4°C to allow even protein binding, and subsequently washed three times and re-suspended in PBS to form a 50% slurry final concentration.…”

Distinct and overlapping ligand specificities of the alpha 3A beta 1 and alpha 6A beta 1 integrins: recognition of laminin isoforms.

“…Damsky (University of Califomia, San Francisco, CA), respectively. The mouse mAb K20 to #1 (Amiot et al, 1986) was submitted for the 4th International Workshop on Leukocytes.…”

K20 and ICO-10 monoclonal antibodies (gp120/200; Thy-1): immunophenotyping of human solid tumours

“…Their pattern of tissue distribution is quite different (Amiot et al, 1986). ICO-10 and K20 Mabs were shown to have different patterns of reactivity with some tumour cells, subpopulations of B-and T-cells (Baryshnikov, 1984;Amiot et al, 1986). The choice of these two monoclonals was based on the results of pre-screening studies involving various solid tumours and 17 antibodies from the well established clasters of differentiation (CD 1,2,5,7,8,10,11,15 (Baryshnikov, 1984;Baryshnikov et al, 1985b).…”

“…K20 (CD 29) Mab recognising VLA molecular complexes are also helpful for immunophenotyping of tumours and haemoblastoses. Their pattern of tissue distribution is quite different (Amiot et al, 1986). ICO-10 and K20 Mabs were shown to have different patterns of reactivity with some tumour cells, subpopulations of B-and T-cells (Baryshnikov, 1984;Amiot et al, 1986).…”