• CD3 and CD28 are important markers on the surface of T cells and are related to T cell activation. CD19 is a type I transmembrane protein specifically expressed in normal B cells, tumor B cells, and follicular dendritic cells, and is associated with the activation and proliferation of B cells.
• In B-hCD3E/hCD28/hCD19 mice, the extracellular region of the mouse Cd3e and Cd28 genes is replaced by the extracellular region of the human CD3E and CD28 gene, and a chimeric CD19 coding sequence containing the extracellular region of human CD19 gene is inserted into mouse Cd19 gene.
• Human CD3E, CD28 and CD19 were detectable in homozygous B-hCD3E/hCD28/hCD19 mice. Humanization of CD3E, CD28 and CD19 do not change the overall frequency or distribution of immune cell types in spleen, blood and lymph nodes. 
• This product is used for pharmacodynamics and safety evaluation of B-cell lymphoma and autoimmune diseases.

Strain specific CD3E expression analysis in wild-type C57BL/6JNifdc mice and homozygous humanized B-hCD3E/hCD28/hCD19 mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6JNifdc mice and B-hCD3E/hCD28/hCD19 mice (female, 6-week-old, n=3). 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 C57BL/6JNifdc mice (CD3E+/+CD28+/+CD19+/+). Human CD3E was exclusively detectable in B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/+) and homozygous B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/H), but not in wild-type C57BL/6JNifdc mice.

Strain specific CD28 expression analysis in wild-type C57BL/6JNifdc mice and homozygous humanized B-hCD3E/hCD28/hCD19 mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6JNifdc mice and B-hCD3E/hCD28/hCD19 mice (female, 6-week-old, n=3). Protein expression was analyzed with anti-mouse CD28 antibody (Biolegend, 102105) and anti-human CD28 antibody (Biolegend, 302912) by flow cytometry. Mouse CD28 was only detectable in wild-type C57BL/6JNifdc mice (CD3E+/+CD28+/+CD19+/+). Human CD28 was exclusively detectable in B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/+) and homozygous B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/H), but not in wild-type C57BL/6JNifdc mice.

Strain specific CD19 expression analysis in wild-type C57BL/6JNifdc mice and homozygous humanized B-hCD3E/hCD28/hCD19 mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6JNifdc mice and B-hCD3E/hCD28/hCD19 mice (female, 6-week-old, n=3). Protein expression was analyzed with anti-mouse CD19 antibody (Biolegend, 115507) and anti-human CD19 antibody (Biolegend, 302234) by flow cytometry. Mouse CD19 was detectable in wild-type C57BL/6JNifdc mice (CD3E+/+CD28+/+CD19+/+) and B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/+). Human CD19 was detectable in B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/+) and homozygous B-hCD3E/hCD28/hCD19 mice (CD3EH/HCD28H/HCD19H/H), but not in wild-type C57BL/6JNifdc mice.

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6JNifdc mice and homozygous B-hCD3E/hCD28/hCD19 mice (female, 6-week-old, n=3). A. Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. B. Frequencies of T cell subpopulations. Percentages of T cells, B cells, NK cells, DCs, monocytes, macrophages, neutrophils, CD4+ T cells, CD8+ T cells and Tregs in B-hCD3E/hCD28/hCD19 mice were similar to those in C57BL/6JNifdc mice, demonstrating that humanization of CD3E, CD28 and CD19 do not change the frequency or distribution of these cell types in spleen. Values are expressed as mean ± SEM. 

Frequency of leukocyte subpopulations in blood by flow cytometry. Blood cells were isolated from wild-type C57BL/6JNifdc mice and homozygous B-hCD3E/hCD28/hCD19 mice (female, 6-week-old, n=3). A. Flow cytometry analysis of the blood cells was performed to assess the frequency of leukocyte subpopulations. B. Frequencies of T cell subpopulations. Percentages of T cells, B cells, NK cells, DCs, monocytes, macrophages, neutrophils, CD4+ T cells, CD8+ T cells and Tregs in B-hCD3E/hCD28/hCD19 mice were similar to those in C57BL/6JNifdc mice, demonstrating that humanization of CD3E, CD28 and CD19 do not change the frequency or distribution of these cell types in blood. Values are expressed as mean ± SEM. 

Frequency of leukocyte subpopulations in lymph node by flow cytometry. Leukocytes were isolated from wild-type C57BL/6JNifdc mice and homozygous B-hCD3E/hCD28/hCD19 mice (female, 6-week-old, n=3). A. Flow cytometry analysis of the leukocytes was performed to assess the frequency of leukocyte subpopulations. B. Frequencies of T cell subpopulations. Percentages of T cells, B cells, NK cells, CD4+ T cells, CD8+ T cells and Tregs in B-hCD3E/hCD28/hCD19 mice were similar to those in C57BL/6JNifdc mice, demonstrating that humanization of CD3E, CD28 and CD19 do not change the frequency or distribution of these cell types in lymph node. Values are expressed as mean ± SEM.