• CD3 consists of four protein chains (CD3ε, CD3δ, CD3γ, and CD3ζ), which are important biological markers on the T cell membrane. CD3 can form a TCR/CD3 complex with the T cell receptor, participating in the regulation of T cell antigen recognition, signal transduction, and T cell development.
• B-hCD3EDG mice(C.B6) were obtained by backcrossing B-hCD3EDG mice (strain 110039). In B-hCD3EDG mice(C.B6), human CD3EDG is expressed, while mouse Cd3edg is knocked out.
• Human CD3E can be detected on T cells from the spleen and blood of homozygous B-hCD3EDG mice (C.B6), but not in wild-type mice. Humanization of CD3EDG does not change the overall frequency or distribution of immune cell types in the spleen, blood, thymus, and lymph nodes. T cells can be activated by anti-hCD3E antibody and anti-mCD28 antibody in B-hCD3EDG mice (C.B6) in vitro.
• This product is used for the pharmacological and safety evaluation of therapeutic drugs for cancer and autoimmune diseases.

Strain specific analysis of CD3EDG mRNA expression in wild-type BALB/cCrSlcNifdc mice and B-hCD3EDG mice(C.B6) by RT-PCR. Thymus RNA were isolated from wild-type BALB/cCrSlcNifdc mice (+/+) and homozygous B-hCD3EDG mice(C.B6) (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CD3EDG primers. Mouse Cd3edg mRNA was only detectable in wild-type mice. Human CD3EDG mRNA was exclusively detectable in homozygous B-hCD3EDG mice(C.B6), but not in wild-type mice. 

Strain specific CD3E expression analysis in wild-type BALB/cCrSlcNifdc mice and homozygous humanized B-hCD3EDG mice(C.B6) by flow cytometry. Splenocytes were collected from wild-type BALB/cCrSlcNifdc mice and homozygous B-hCD3EDG mice(C.B6) (female, n=3, 6-week-old). Protein expression was analyzed with anti-mouse CD3e antibody (Biolegend, 100312) and anti-human CD3e antibody (BD Horizon™ , 562426) by flow cytometry. Mouse CD3E was only detectable in wild-type BALB/cCrSlcNifdc mice. Human CD3E was exclusively detectable in homozygous B-hCD3EDG mice(C.B6), but not in wild-type BALB/cCrSlcNifdc mice.

Strain specific CD3E expression analysis in wild-type BALB/cCrSlcNifdc mice and homozygous humanized B-hCD3EDG mice(C.B6) by flow cytometry. Blood cells were collected from wild-type BALB/cCrSlcNifdc mice and homozygous B-hCD3EDG mice(C.B6) (female, n=3, 6-week-old). Protein expression was analyzed with anti-mouse CD3e antibody (Biolegend, 100312) and anti-human CD3e antibody (BD Horizon™ , 562426) by flow cytometry. Mouse CD3E was only detectable in wild-type BALB/cCrSlcNifdc mice. Human CD3E was exclusively detectable in homozygous B-hCD3EDG mice (C.B6), but not in wild-type BALB/cCrSlcNifdc mice.

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type BALB/cCrSIcNifdc mice and homozygous B-hCD3EDG mice(C.B6) (female, 6-week-old, n=3). A. Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. B. Frequency of T cell subpopulations. Frequencies of T cells, B cells, NK cells, DCs, neutrophils, monocytes, macrophages, CD4+ T cells, CD8+ T cells and Tregs in B-hCD3EDG mice(C.B6) were similar to those in BALB/cCrSIcNifdc. The frequency of leukocyte subpopulations in thymus, lymph node and blood of B-hCD3EDG mice (C.B6) were also comparable to wild-type BALB/cCrSIcNifdc mice (Data not shown). Values are expressed as mean ± SEM. 

CD25 and CD69 expression analysis in wild-type BALB/cCrSlcNifdc mice and homozygous humanized B-hCD3EDG mice(C.B6) by flow cytometry. T cells were isolated from splenocytes of BALB/cCrSlcNifdc and B-hCD3EDG mice(C.B6) (n=3, 6-week-old), and were incubated in the presence of anti-mCD3ε antibody (2ug/ml，BioXcell，BE0001-2) , anti-hCD3ε antibody (2ug/ml，BioXcell，BE0001-1) and anti-mCD28 antibody (5ug/ml，BioXcell，BE0015-1) for 24h. T cell proliferation was tested by flow cytometry. T cell activation in B-hCD3EDG mice(C.B6)  was significantly up-regulated by anti-hCD3ε antibody or anti-hCD3ε antibody and anti-mCD28 antibody.

CD25 and CD69 expression analysis in wild-type BALB/cCrSlcNifdc mice and homozygous humanized B-hCD3EDG mice(C.B6) by flow cytometry. T cells were isolated from splenocytes of BALB/cCrSlcNifdc and B-hCD3EDG mice(C.B6) (n=3, 6-week-old), and were incubated in the presence of anti-mCD3ε antibody (2ug/ml，BioXcell，BE0001-2) , anti-hCD3ε antibody (2ug/ml，BioXcell，BE0001-1) and anti-mCD28 antibody (5ug/ml，BioXcell，BE0015-1) for 48h. T cell proliferation was tested by flow cytometry. T cell activation in B-hCD3EDG mice(C.B6)  was significantly up-regulated by anti-hCD3ε antibody or anti-hCD3ε antibody and anti-mCD28 antibody.

CD25 and CD69 expression analysis in wild-type BALB/cCrSlcNifdc mice and homozygous humanized B-hCD3EDG mice(C.B6) by flow cytometry. T cells were isolated from splenocytes of BALB/cCrSlcNifdc and B-hCD3EDG mice(C.B6) (n=3, 6-week-old), and were incubated in the presence of anti-mCD3ε antibody(2ug/ml，BioXcell，BE0001-2) , anti-hCD3ε antibody (2ug/ml，BioXcell，BE0001-1) and anti-mCD28 antibody (5ug/ml，BioXcell，BE0015-1) for 72h. T cell proliferation was tested by flow cytometry. T cell activation in B-hCD3EDG mice(C.B6)  was significantly up-regulated by anti-hCD3ε antibody or anti-hCD3ε antibody and anti-mCD28 antibody.

The proliferation of CD4+T cells and CD8+T cells was analyzed by flow cytometry. T cells were isolated from splenocytes of BALB/cCrSlcNifdc and B-hCD3EDG mice(C.B6) (n=3, 6-week-old), and were incubated in the presence of anti-mCD3ε antibody(2ug/ml，BioXcell，BE0001-2) , anti-hCD3ε antibody (2ug/ml，BioXcell，BE0001-1) and anti-mCD28 antibody (5ug/ml，BioXcell，BE0015-1) for 24h. T cell proliferation was tested by flow cytometry. T cell activation in B-hCD3EDG mice(C.B6)  was significantly up-regulated by anti-hCD3ε antibody and anti-mCD28 antibody.

The proliferation of CD4+T cells and CD8+T cells was analyzed by flow cytometry. T cells were isolated from splenocytes of BALB/cCrSlcNifdc and B-hCD3EDG mice(C.B6) (n=3, 6-week-old), and were incubated in the presence of anti-mCD3ε antibody(2ug/ml，BioXcell，BE0001-2) , anti-hCD3ε antibody (2ug/ml，BioXcell，BE0001-1) and anti-mCD28 antibody (5ug/ml，BioXcell，BE0015-1) for 48h. T cell proliferation was tested by flow cytometry. T cell activation in B-hCD3EDG mice(C.B6)  was significantly up-regulated by anti-hCD3ε antibody and anti-mCD28 antibody.