PD-1:PD-L1/PD-L2 pathway played negative immune role in most tumor and several infectious diseases, but the immune role in tuberculosis (TB) was not explicited. Since the high expression of PD-1:PD-L1/PD-L2 pathway was correlated with MTB infection both in vitro and in vivo, the in vitro negative immune role was indicated by inhibited T cell protective immune function, while the in vivo immune role was not clear. The binding of PD-1 and PD-L1 played an immunosuppression role, the expression of PD-L1 was regulated by Th1-type cytokines. The binding of PD-1 and PD-L2 played protective immune role, and the expression was regulated by Th1-type cytokines. The immune role and mechanism of PD-1, PD-L1 and PD-L2 would be investigated by Cas9-CRISPR technique, which would provide theoretical basis for the tuberculosis prevention and control.