but these differences in expression levels had no effect on the highly 35 significant การลดปริมาณ efficacy of the tested antibodies.
The ฮิวเมน PBMC/mouse SCID in vivo model was successfully used to show การลดปริมาณ of activated ฮิวเมน, LAG-3 expressing T cells in the peritoneum of immunocompromised SCID mice. Depending on donor, route of administration and time point of analysis, between 84.22-99.71% of
LAG-3 positive ฮิวเมน CD4 T cells and between 84.64-99.62% of LAG-3 positive ฮิวเมน CD8 T cells were depleted. As shown in Figure 2, co-administration of 5mg/kg H5L7BW to activated ฮิวเมน PBMCs in the peritoneum of SCID mice led to highly significant การลดปริมาณ of LAG-3 positive CD4 and CD8 positive T cells 24 hours after injection compared to Control IgG injected animals.
5 Figure 3 highlights the comparison between 5mg/kg H5L7BW and H5L7 5 hours after co-i.p.
administration to activated ฮิวเมน PBMCs as described before. Both antibodies induced highly
significant การลดปริมาณ of LAG-3 positive CD4 and CD8 T cells (Figure 3A).
As shown in Figure 4, administration of 5mg/kg H5L7BW via the intra-venous route resulted
in a highly statistically significant การลดปริมาณ of LAG-3 positive T cells after 5 hours (Figure 4A), similar 10 to what was observed in the experiments with i.p. co-administered LAG-3 การลดปริมาณ antibodies. The
comparison between i.v. administered H5L7BW, H5L7 and IMP731 (all at 5mg/kg) 5 hours after i.p.
administration of activated ฮิวเมน PBMCs revealed very similar การลดปริมาณ efficacies between the 3
molecules compared to control treated animals (Figure 5). Each of the 3 tested LAG-3 depleting
antibodies caused highly significant reduction in the number of LAG-3 positive CD4 and CD8 T cells 15 (Figure 5A) with H5L7BW demonstrating greater การลดปริมาณ capacity compared to H5L7 or IMP731.
Example 8: Binding analysis of แอนติ-LAG-3 ฮิวเมไนซ์ antibodies to recombinant soluble ฮิวเมน Fc gamma รีเซปเตอร์s using the ProteOnTM
ฮิวเมน FcyRIIIa binding was investigated in order to assess the ability of H5L7 and H5L7BW 20 to induce antibody dependent cell-mediated cytotoxicity (ADCC). H5L7 and H5L7BW แอนติ-LAG-3
antibodies were assessed for binding to recombinant soluble ฮิวเมน FcyRIIIa in addition to FcyRI
and FcyRII รีเซปเตอร์s using the ProteOnTM XPR36 (BioRadTM) biosensor machine, and were compared
against chimeric antibody IMP731.
A goat แอนติ-poly-histidine IgG was immobilised on a GLM biosensor chip by primary amine 25 coupling. This surface was used as a capture surface for the poly-histidine tagged ฮิวเมน Fc gamma
รีเซปเตอร์s. Antibodies to be tested were used as the analyte and passed over at 2048nM, 512nM,
128nM, 32nM and 8nM with an injection of OnM (i.e. buffer alone) used to double reference the
binding curves. The goat แอนติ-poly-histidine IgG surface was regenerated with 100mM phosphoric
acid between interactions. The run was carried out on the ProteOn XPR36 Protein Array Interaction 30 System at 25°c and using HBS-EP as running buffer. Data was analysed for each รีเซปเตอร์
separately, setting a global R-max and using the Equilibrium Model inherent to the ProteOn's
analysis software. Control molecules were run at the beginning and the end of the set of samples to
be tested to ensure comparability of results. Data was compared from two experiments and hybrid
control antibodies used as controls between experiments.
35 The results show that H5L7BW bound both polymorphisms of FcyRIIIa (valine V158 and
phenylalanine F158) with an improved แอฟฟินิตี้ of approximately 10 fold in comparison to H5L7 (see
Table 6). ฟิวโคซิเลตเตด antibody H5L7 bound to FcyRIIIa with a similar แอฟฟินิตี้ as chimeric antibody IMP731.
No significant changes were observed between the binding of the ฮิวเมไนซ์ ฟิวโคซิเลตเตด and อะฟิวโคซิเลตเตด แอนติ-LAG-3 antibodies for the FcyRI or FcyRIIa รีเซปเตอร์s.
5 Table 6: Binding of H5L7 and H5L7BW to ฮิวเมน Fc gamma รีเซปเตอร์s