B-hVSIG4 mice

Basic Information

Gene Targeting Strategy

Biocytogen replaced the murine Vsig4 gene by inserting human VSIG4 and murine 3’UTR coding sequences into exon 2.

mRNA Expression Analysis

Species-specific VSIG4 gene expression analysis in wild-type C57BL/6 mice and humanized B-hVSIG4 mice. Murine Vsig4 mRNA was detected in liver tissue isolated from wild-type C57BL/6 mice (+/+), while human VSIG4 mRNA was exclusively detected in homozygous B-hVSIG4 mice.

Protein Expression Analysis

Species–specific VSIG4 expression analysis in wild-type and humanized B-hVSIG4 mice. Peritoneal exudate macrophages (PEMs) were isolated from wild-type C57BL/6 (+/+) and homozygous B-hVSIG4 (H/H) mice and analyzed by flow cytometry using species-specific anti-VSIG4 antibodies. Human VSIG4 protein was exclusively detected in B-hVSIG4 mice compared to wild-type mice.

In Vivo Efficacy Evaluation of an Anti-Human VSIG4 Antibody

Anti-tumor activity of an anti-human VSIG4 antibody in humanized B-hVSIG4 mice. Murine colon cancer MC38 cells were subcutaneously implanted into homozygous B-hVSIG4 (H/H) mice (female, 7-week-old, n=5), when the tumor volume reached approximately 100-150 mm3, mice were grouped and treated with isotype control or an anti-human VSIG4 antibody. (A) An anti-human VSIG4 antibody (hVSIG4 Ab-A, in house) slowed tumor growth in B-hVSIG4 mice compared to vehicle control, (B) without negatively impacting body weight changes. This data demonstrates that humanized B-hVSIG4 mice provide a powerful preclinical model for in vivo efficacy evaluation of anti-human VSIG4 antibodies. Values are expressed as mean ± SEM.

Analysis of tumor infiltrating lymphocytes

Analysis of tumor infiltrating lymphocytes (TILs) in humanized B-hVSIG4 mice. Tumor cells were harvested at the experimental endpoint (n=5), and analyzed by flow cytometry to assess lymphocyte cell number and proportion changes in humanized B-hVSIG4 mice treated with either isotype or anti-human VSIG4 antibodies. Percentages of CD8+ T cells, CD4+ T cells, Tregs, M1 macrophages and M1/M2 ratio were increased, while percentages of MDSCs and M2 macrophages were decreased in mice treated with an anti-VSIG4 antibody. Values are expressed as mean ± SEM.

References

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Poster

AACR 2022: Evaluating In Vivo Efficacy of Anti-VSIG4 Antibodies in Humanized B-hVSIG4 Mice