Strain specific analysis of TREM2 gene expression in wild-type mice and B-hTREM2 mice(C) by RT-PCR. Mouse Trem2 mRNA was detectable in wild-type mice (+/+). Human TREM2 mRNA was detectable only in homozygous B-hTREM2 mice(C) (H/H) but not in wild-type mice.

Strain specific TREM2 expression analysis in homozygous B-hTREM2 mice(C) by flow cytometry. Microglia were collected from wild-type mice (+/+) and homozygous B-hTREM2 mice(C) (H/H), and analyzed by flow cytometry with anti-TREM2 antibody. TREM2 was detectable in microglia of wild-type mice and homozygous B-hTREM2 mice(C), as the antibody is crossly reactive with TREM2 in human and mice. 

Antitumor activity of anti-human TREM2 antibody in B-hTREM2 mice(C). (A) Anti-human TREM2 antibody inhibited EMT-6 tumor growth in B-hTREM2 mice(C). Murine breast carcinoma EMT-6 cells were subcutaneously implanted into homozygous B-hTREM2 mice(C) (female, 10 week-old, n=6). Mice were grouped when tumor volume reached approximately 50-80 mm³, and treated with anti-hTREM2 antibody at doses and schedules in panel A. (B) Body weight changes during treatment. As shown in panel A, anti-human TREM2 antibody (in house) were efficacious in controlling tumor growth in B-hTREM2 mice(C), demonstrating they provide a powerful preclinical model for in vivo evaluation of anti-human TREM2 antibody. Values are expressed as mean ± SEM.