德晋贵宾厅

• PMN-MDSCs are a type of pathologically activated neutrophils that exert immunosuppressive effects.
• CD300LD is expressed in normal neutrophils and upregulated in tumor-bearing PMN-MDSCs, serving as a key immunosuppressive factor.
• Knockout of Cd300ld can reverse the tumor immunosuppressive microenvironment.
• CD300ld is upregulated in human cancers and correlates with poor patient survival.
• Blocking CD300ld activity can inhibit tumor progression and exhibits a synergistic effect with anti-PD1 therapy.
• The exons 1~4 of mouse Cd300ld gene that encode signal peptide, extracellular domain, transmembrane domain and cytoplasmic region are replaced by human counterparts in B-hCD300LD mice.
• Mouse Cd300ld mRNA was only detectable in wild-type mice. Human CD300LD mRNA was exclusively detectable in homozygous B-hCD300LD mice but not in wild-type mice.
• Human CD300LD expression was detected in Neutrophils and Macrophages of spleen in homozygous B-hCD300LD mice and wild-type mice, as the antibody was cross-reactive between human and mouse
• This product is used for tumor pharmacology and safety evaluation of anti-human CD300LD antibodies.

Gene targeting strategy for B-hCD300LD mice

• The exons 1~4 of mouse Cd300ld gene that encode signal peptide, extracellular domain, transmembrane domain and cytoplasmic region are replaced by human counterparts in B-hCD300LD mice.
• The promoter and 5’UTR region of the mouse gene are retained, and the mouse 3’UTR is replaced by the human 3’UTR.

Strain specific analysis of CD300LD mRNA expression in wild-type C57BL/6JNifdc mice and B-hCD300LD mice by RT-PCR. Spleen RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and B-hCD300LD mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CD300LD primers. Mouse Cd300ld mRNA was detectable in wild-type mice. Human CD300LD mRNA was exclusively detectable in B-hCD300LD mice but not in wild-type mice.

CD300LD expression analysis in homozygous B-hCD300LD mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6JNifdc mice (+/+), homozygous B-hCD300LD mice (H/H), and analyzed by flow cytometry with CD300LD antibody(provided by a client, cross-reactive between human and mouse ).

CD300LD expression analysis in homozygous B-hCD300LD mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6JNifdc mice (+/+), homozygous B-hCD300LD mice (H/H), and analyzed by flow cytometry with CD300LD antibody(provided by a client, cross-reactive between human and mouse ).

CD300LD expression analysis in homozygous B-hCD300LD mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6JNifdc mice (+/+), homozygous B-hCD300LD mice (H/H), and analyzed by flow cytometry with CD300LD antibody(provided by a client, cross-reactive between human and mouse ).

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6JNifdc mice (female, n=3, 8-week-old), homozygous B-hCD300LD mice (female, n=3, 8-week-old). A. Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. B. Frequency of T cell subpopulations. Percentages of T cells, B cells, NK cells, dendritic cells, neutrophils, monocytes, macrophages, CD4+ T cells, CD8+ T cells and Tregs in B-hCD300LD mice were similar to those in C57BL/6JNifdc. Values are expressed as mean ± SEM.

FACS plots of T cells, B cells, CD4+ T cells, CD8+ T cells and Tregs in spleen. Splenocytes were isolated from wild-type C57BL/6JNifdc mice (female, n=3, 8-week-old) and homozygous B-hCD300LD mice (female, n=3, 8-week-old).

FACS plots of DCs, NK cells, neutrophils, macrophages and monocytes in spleen. Splenocytes were isolated from wild-type C57BL/6JNifdc mice (female, n=3, 8-week-old) and homozygous B-hCD300LD mice (female, n=3, 8-week-old).