• B-Cd11b-EGFP-DTR-Luc mice have the mouse Itgam (Cd11b) promoter to determine the expression of DTR (Diphtheria toxin receptor), EGFP (enhanced green fluorescent protein) and luciferase. 
• Neutrophils, monocytes, macrophages, a part of NK cells and DCs will be traced by EGFP or Luciferase reporting system in B-Cd11b-EGFP-DTR-Luc mice. 
• CD11b+ cells will be depleted in B-Cd11b-EGFP-DTR-Luc mice injected with DT (diphtheria toxin). 
• The mice can be used to study the specific role of CD11b+ cells in immune response.

Gene targeting strategy for B-Cd11b-EGFP-DTR-Luc mice. CD11b co-express EGFP,  the DTR for depletion of CD11b+ cells, and the luciferase for in vivo bioluminescent imaging (BLI) of CD11b+ cells. EGFP-DTR-Luc expression is evident in CD11b+ cells.  

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6 mice (+/+) and heterozygous B-Cd11b-EGFP-DTR-Luc mice (Mut/+) (n=3, 9-week-old) injected with PBS or DT (50 ng/g body weight) for three consecutive days. Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. Values are expressed as mean ± SEM. 

Frequencies of CD11b+ EGFP+ cells and EGFP+ cells in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6 mice (+/+) and heterozygous B-Cd11b-EGFP-DTR-Luc mice (Mut/+) (n=3, 9-week-old) injected with PBS or DT (50 ng/g body weight) for three consecutive days. Flow cytometry analysis of the splenocytes was performed to assess the frequencies of CD11b+ EGFP+ cells in total CD45+ cells. The frequencies of CD11b+ EGFP+ cells were decreased in heterozygous mice injected with DT.