OX40 (Tumor necrosis factor receptor superfamily, member 4, also known as Tnfrsf4), is mainly expressed on the surface of activated CD4+ and CD8+ T cells, and its binding to the OX40L ligand stimulates CD8+ T cell activation. Coactivation of OX40/OX40L enhances T cell functions, including cytokine production, proliferation and survival. OX40 agonistsreduce Regulatory T cells (Tregs) and improve anti-tumor activity.
mRNA expression verification:
Fig 1. Molecular identification of the B-hOX40 humanized mice. Mouse OX-40 mRNA was detected in both the wild type and the B-hOX40 heterozygous mice, while human OX40 mRNA was detected only in theB-hOX40 heterozygous mice.
Protein expression verification:
Fig 2. Spleen cells from both wild type (WT) C57BL/6 and the B-hOX40 homozygous mice were analyzed by flow cytometry. Mouse OX40+ T cells were detected in the WT mice, while human OX40+ T cells were detected in the B-hOX40 homozygous mice.
OX40 antibody pharmacological verification:
Fig 3. Murine colon tumor MC38 cells were subcutaneously injected into B-hOX40 heterozygous mice, which were grouped when the tumor size reached 100 mm3 (n=5). The human OX40 antibody significantly inhibited tumor growth (A), but not body weight (B) at 3 different doses. B-hOX40 mice are powerful tools for human OX40 antibody in vivo pharmacological efficacy test.