The human LILRB4（CD85K） coding sequence was inserted to mouse Hipp11(H11) allele. Human LILRB4 is highly expressed on the surface of B-hLILRB4 luc EL4 cells.

Gene targeting strategy for B-hLILRB4 luc EL4 cells. The exogenous promoter and human LILRB4 coding sequence was inserted to mouse Hipp11(H11) allele.

The luminescence signal intensity of B-hLILRB4 luc EL4 cells. The luminescence intensity was detected by Bright-GloTM luciferase Assay System (Promega, Cat E2610), and B-hLILRB4 luc EL4 cells have strong luminescence signal.

LILRB4 expression analysis in B-hLILRB4 luc EL4 cells by flow cytometry. Single cell suspensions from B-hLILRB4 luc EL4 cultures were stained with species-specific anti-LILRB4 antibody. Human LILRB4 was detected on the surface of B-hLILRB4 luc EL4 cells but not wild-type EL4 cells. The 10-G04 clone of B-hLILRB4 luc EL4 cells was used for in vivo experiments.

Tumor growth and in vivo imaging of B-hLILRB4 luc EL4. B-hLILRB4 luc EL4 cells (2x10⁵) were injected by tail vein into C57BL/6 mice. Signal intensity and body weight were measured twice a week. (A) Imaging was performed on days 3, 7, 10, 14, and 17, (B) Mice body weight (Mean ± SEM). B-hLILRB4 luc EL4 cells can be used for in vivo efficacy evaluation.

Subcutaneous homograft tumor growth of B-hLILRB4 luc EL4 cells. B-hLILRB4 luc EL4 cells and wild-type EL4 cells were subcutaneously implanted into B-h4-1BB mice (female, 6-week-old, n=6). Tumor volume and body weight were measured twice a week. (A) Average tumor volume. (B) Body weight. Volume was expressed in mm³ using the formula: V=0.5 X long diameter X short diameter². As shown in panel A, B-hLILRB4 luc EL4 cells were able to establish tumors in vivo and can be used for efficacy studies. Values are expressed as mean ± SEM.