Strain specific TRBC1 expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hTRBC1/hTRBC2 mice by flow cytometry. Splenocytes were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hTRBC1/hTRBC2 mice (H/H), and analyzed by flow cytometry. Mouse TRBC1 was detectable in T cells of wild-type C57BL/6 mice. Human TRBC1 was detectable in T cells of homozygous B-hTRBC1/hTRBC2 mice. Anti-TRBC1 antibody is crossly reactive with TRBC1 in human and mice.

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6 mice and homozygous B-hTRBC1/hTRBC2 mice (n=3, 7-week-old). A. Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. B. Frequency of T cell subpopulations. Percentages of T cells, B cells, NK cells, dendritic cells, granulocytes, monocytes, macrophages, CD4+ T cells, CD8+ T cells and Tregs in B-hTRBC1/hTRBC2 mice were similar to those in C57BL/6 mice, demonstrating that humanization of TRBC1 and TRBC2 do not change the frequency or distribution of these cell types in spleen. The frequency of leukocyte subpopulations in blood and lymph node of B-hTRBC1/hTRBC2 mice were also comparable to wild-type C57BL/6 mice (Data not shown). Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***p < 0.001.