Journal: Frontiers in Immunology
Article Title: Cysteine-specific 89 Zr-labeled anti-CD25 IgG allows immuno-PET imaging of interleukin-2 receptor-α on T cell lymphomas
doi: 10.3389/fimmu.2022.1017132
Figure Lengend Snippet: CD25 expression and 89 Zr-CD25 IgG binding to human lymphoma cells. (A) Western blots of CD25 protein and anti-human 89 Zr-CD25 IgG uptakes in H9, Jurkat, and SUDHL1 lymphoma cells (left). Complete blocking of SUDHL1 cell binding by 0.5 μM of unlabeled anti-CD25 IgG (right). (B) Lindmo binding assays for determining the immunoreactive fraction. Five concentrations of SUDHL1 cells were used, from 0.5 to 16 million cells/ml. The final concentration of 89 Zr-CD25 IgG was 50 ng/ml, and nonspecific binding was assessed with 5 μg of unlabeled anti-CD25 IgG. A conventional plot of specific and nonspecific binding over total applied radioactivity, as a function of increasing cell concentration is shown (left). A double inverse plot was then drawn using the same data as total applied radioactivity over specific binding, as a function of the inverse cell concentration (right). The immunoreactive fraction was determined through linear extrapolation to the ordinate. Data represent the mean ± S.E of values from two independent experiments [total n = 5 per group; uptake in (A) ], or the mean ± S.D of data from a single representative experiment [n = 3 per group; (B) ].
Article Snippet: Mouse monoclonal IgG2a anti- CD25 Ab (7G7/B6) that is specific against human CD25 and does not react with mouse CD25, rat monoclonal IgG1 Ab against mouse CD25 (PC-61.5.3), and IgG2a isotype control Ab were from BioXcell (West Lebanon, NH).
Techniques: Expressing, Binding Assay, Western Blot, Blocking Assay, Concentration Assay, Radioactivity