Strain specific IL5 expression analysis in homozygous B-hIL5/hIL5RA mice by ELISA. Splenocytes were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hIL5/hIL5RA mice (H/H; H/H) stimulated with anti-CD3ε and anti-CD28 in vitro, and cell culture supernatant was analyzed by ELISA with species-specific IL5 ELISA kit. Mouse IL5 was detectable in wild-type mice. Human IL5 was exclusively detectable in homozygous B-hIL5/hIL5RA but not wild-type mice.

Strain specific IL5RA expression analysis in homozygous B-hIL5/hIL5RA mice by FACS. Eosinophils of bone marrow were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hIL5/hIL5RA mice (H/H; H/H), and analyzed by flow cytometry with species-specific anti-IL5RA antibody. Mouse Il5ra was detectable in wild-type mice. Human IL5RA was exclusively detectable in homozygous B-hIL5/hIL5RA mice but not wild-type mice.

The number of BALF immune cells in mouse asthma model 

BALF immune cells were isolated from B-hIL5/hIL5RA mice (n=8). The number of eosinophils was analyzed by flow cytometry under the treatment of PBS, mepolizumab or benralizumab (in house). After treatment of mepolizumab or benralizumab (in house), the number of inflammatory cells was much lower than the positive control in homozygous B-hIL5/hIL5RA mice.

Data was shown as Mean±SEM, and analyzed using One way ANOVA followed Dunnett compared G1/G3/G4 with G2. (**p<0.01, ***p<0.001, ****p<0.0001)

Intraperitoneal (i.p.)

Analysis of eosinophils and basophils in blood by blood routine

Blood was collected at the study endpoint. The results show that the levels of eosinophils in mice treated with mepolizumab or benralizumab (in house) is lower than that in untreated mice.

Data was shown as Mean±SEM, and analyzed using One way ANOVA followed Dunnett compared G1/G3/G4 with G2. (**p<0.01, ***p<0.001, ****p<0.0001)

Intraperitoneal (i.p.)

H&E staining of asthma-like model in B-hIL5/hIL5RA mice 

Lung tissues were collected at the study endpoint. H&E staining results showed that the lung tissues from B-hIL5/hIL5RA mice exposed to PBS aerosols did not show any inflammation. OVA exposure resulted in a significant increase in peribronchial and perivascular inflammation in B-hIL5/hIL5RA mice. A significantly reduction in eosinophils infiltration was observed in mice treated with mepolizumab or benralizumab (in house). 

Data was shown as Mean±SEM, and analyzed using One way ANOVA followed Dunnett compared G1/G3/G4 with G2. (**p<0.01, ***p<0.001, ****p<0.0001)

Functional analysis of eosinophils expression in homozygous B-hIL5/hIL5RA mice by flow cytometry. Human IL5 was injected daily for 4 days, and blood samples were collected one day after the final injection. The number and proportion of eosinophils was then analyzed using flow cytometry. After stimulation with human IL5 recombinant protein, the proportion of eosinophils in the blood of B-hIL5/hIL5RA mice increased.