QUANTITATIVE CELL METHOD FOR DETERMINATION OF BIOLOGICAL ACTIVITY OF LIGAND OF ANTIBODY AGAINST CD26 Russian patent published in 2022 - IPC G01N33/50 

FIELD: biotechnology.

SUBSTANCE: present invention relates to a quantitative cell method for the in vitro determination of action of ligand of an antibody against CD26, preferably a monoclonal antibody against CD26, such as begelomab. The method for the in vitro determination of the efficiency of ligand of the antibody against CD26 includes following stages: a) incubation at 37°C or at a room temperature of a population of human T-lymphocytes expressing CD26 receptor in a percentage share of more than 75% with ligand of the antibody against CD26 at a concentration in the range from 0.001 mkg/ml to 150 mkg/ml; b) incubation with the antibody against CD26 labeled with fluorochrome, which recognizes CD26 epitope differing from an epitope recognized by ligand of the antibody against CD26, used at the stage a); c) determination of a median fluorescence intensity (hereinafter – MFI) value for CD26, measured for a sample of cells treated with ligand of the antibody against CD26 (MFI_T), and MFI value for non-treated cells (MFI_NT) by cytofluorimetric analysis; d) assessment of a percentage share of internalization of CD26 receptor (hereinafter – %int CD26) or relative fluorescence intensity (hereinafter – RFI) calculated in accordance with the following formula:

where: if the value of %int CD26 is less than 20%, this indicates the low efficiency of ligand of the antibody against CD26; if it is in the range from 20% to 30%, this indicates the average efficiency of ligand of the antibody against CD26; if it is more than 30%, this indicates the high efficiency of ligand of the antibody against CD26.

EFFECT: possibility of quantitative measurement both internalization of CD26 and inhibition of secretion/production of formed cytokines.

11 cl, 14 dwg, 3 tbl