Fig. 4. Oral consumption of selected probiotics increases NK cell activity and antigen-specific leukocyte proliferation in immunodeficient mice.

Experimental scheme of the CPP-induced immunocompromised mouse model is shown in Fig. 3A. (A) After sacrificing mice, splenocytes (1×10⁶ cells/well) and YAC-1 cells (1×10⁴ cell/well) (E:T ratio=100:1) were seeded to a 96-well plate in 200 μL of RPMI-10 and co-incubated at 37°C for 6 h. The cytotoxicity of target cells was then measured with an LDH assay kit. (B) After sacrificing mice, splenocytes (1×10⁶ cells/well) were labeled with CFSE (5 μM) and re-stimulated with each heat-killed probiotics (CJW55-10, CJLP243, CJLP475) at density of 6×10⁶ CFU/mL for 3 d. Relative proliferation of splenocytes was assessed by flow cytometry analyses. No CPP+vehicle, PBS treatment without CPP administration; CPP+vehicle, PBS treatment with CPP administration; CPP+CJW55-10, CJW55-10 treatment with CPP administration; CPP+CJLP243, CJLP243 treatment with CPP administration; CPP+CJLP475, CJLP475 treatment with CPP administration. All results are shown as means±SEM. Significant differences compared with the “CPP+vehicle” group are indicated by ^* p<0.05, ^** p<0.01, and ^*** p<0.001. CPP, cyclophosphamide; MFI, mean fluorescence intensity; CFSE, carboxyfluorescein succinimidyl ester; PBS, phosphate buffered saline.