B7-H4 KO mice are resistant to Listeria infection, accompanied with increased neutrophils. (A) B7-H4 KO mice are more resistant to Listeria infection than WT mice. Fifteen WT or B7-H4 KO mice were intraperitoneally injected with 2 × 106 CFUs Listeria. Survival of mice was monitored daily. Data represent a pool of 2 independent experiments. *P < .05. (B) Decreased Listeria colony formation in spleens from B7-H4KO mice. WT or B7-H4KO mice (KO) were intravenously injected with 105 CFUs Listeria. Days 1 to 3 after infection, whole spleens were weighted and homogenized in 5 mL PBS, and tissue lysates were plated on agar plates of Listeria enrichment broth for colony counting. The results from individual mice are presented. Data represent at least 3 independently performed experiments. *P < .05. (C) Spleen neutrophils increase after Listeria infection in B7-H4 KO mice. Three B7-H4KO or littermate control mice were grouped and intravenously injected with 105 CFUs Listeria. Splenocytes were isolated 1, 2, and 3 days after infection and were stained with Gr-1 and CD11b mAb. The same numbers of littermates were included as controls. Each point represents results from pool of 3 mice. Data represent at least 3 independent experiments. *P < .05. Error bars indicate SD (n = 3 mice).
