Gene targeting strategy for B-hIL18BP mice. The mouse Il18bp gene, which encodes the full-length protein, was replaced with the sequence of the human IL18BP counterpart gene in the B-hIL18BP mice.

Strain specific IL18BP expression analysis in homozygous B-hIL18BP mice by ELISA. Serum was collected from wild-type mice (+/+) and homozygous B-hIL18BP mice (H/H) and analyzed by ELISA with species-specific IL18BP ELISA kit. Mouse IL18BP was detectable in wild-type mice. Human IL18BP was exclusively detectable in homozygous B-hIL18BP mice but not in wild-type mice.

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6 mice (female, n=3, 6-week-old) and homozygous B-hIL18BP mice (female, n=3, 6-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, neutrophils, monocytes, macrophages, CD4+ T cells, CD8+ T cells and Tregs in B-hIL18BP mice were similar to those in C57BL/6 mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***p < 0.001.

Frequency of leukocyte subpopulations in blood by flow cytometry. Blood cells were isolated from wild-type C57BL/6 mice (female, n=3, 6-week-old) and homozygous B-hIL18BP mice (female, n=3, 6-week-old). A. Flow cytometry analysis of the blood cells 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, neutrophils, monocytes, macrophages, CD4+ T cells, CD8+ T cells and Tregs in B-hIL18BP mice were similar to those in C57BL/6 mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***p < 0.001.

Frequency of leukocyte subpopulations in lymph nodes by flow cytometry. Lymph nodes cells were isolated from wild-type C57BL/6 mice (female, n=3, 6-week-old) and homozygous B-hIL18BP mice (female, n=3, 6-week-old). A. Flow cytometry analysis of the lymph nodes cells was performed to assess the frequency of leukocyte subpopulations. B. Frequency of T cell subpopulations. Percentages of T cells, B cells, NK cells, CD4+ T cells, CD8+ T cells and Tregs in B-hIL18BP mice were similar to those in C57BL/6 mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***p < 0.001.