• Sialic acid-binding Ig-like lectin 7 is a protein that in humans is encoded by the SIGLEC7 gene. Sialic acid-binding Ig-like lectin 9 is a protein that in humans is encoded by the SIGLEC9 gene.
• The BAC containing whole human SIGLEC7 and SIGLEC9 genome sequence was inserted into mouse genome randomly in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. The mouse Siglec-E was knocked out B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.
• Human SIGLEC7 and SIGLEC9 were exclusively detectable in NK, T, B, DC, granulocytes, monocytes and macrophages cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Mouse Siglec-E was not detectable in NK, B, T, DCs, granulocytes, monocytes or macrophages cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. 
• B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice provide a powerful preclinical model for in vivo evaluation of anti–Siglec-7 and Siglec-9 antibodies.
• Application: For example, this product is used for pharmacodynamics and safety evaluation of anti–Siglec-7 and Siglec-9 antibodies for cancers.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in NK cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in T cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in B cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in DC cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in granulocytes cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in monocytes cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific anti-hSiglec-7 antibody(Biolegend, 339203) and anti-hSiglec-9 antibody(Biolegend, 351503). Human SIGLEC7 and SIGLEC9 were exclusively detectable in macrophages cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific species-specific anti-mSiglec-E(Biolegend, 677106). Mouse Siglec-E was not detectable in B, T and NK cells of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice or wild-type mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific species-specific anti-mSiglec-E(Biolegend, 677106). Mouse Siglec-E was detectable in DCs and granulocytes of wild-type mice, but not in DCs or granulocytes of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Strain specific Siglec7 and Siglec9 expression analysis in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice. Spleen was collected from wild-type mice (+/+) and B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice, and analyzed by flow cytometry with species-specific species-specific anti-mSiglec-E(Biolegend, 677106). Mouse Siglec-E was detectable in macrophages of wild-type mice, but not in monocytes or macrophages B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice.

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6 mice and homozygous B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice (female, n=3, 6-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, DCs, granulocytes, monocytes, macrophages, CD4+ T cells, CD8+ T cells and Tregs in B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice were similar to those in C57BL/6 mice, demonstrating that transgene of human SIGLEC7 and SIGLEC9 does not change the frequency or distribution of these cell types in spleen. The frequency of leukocyte subpopulations in blood and lymph nodes of B-Tg(hSIGLEC7/hSIGLEC9), Siglec-E KO mice were also comparable to wild-type C57BL/6 mice (Data not shown). Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***P < 0.001.