Abstract: Objective  To study the immunogenicity of three recombinant proteins (Rpfd, Rpfd1, Rpfd2) of Micrococcus luteus resuscitation-promoting factor (Rpf) domain and its mutants in mice.  Methods  Seventy male-BALB/c mice were divided randomly into 5 groups as follow: Rpfd（A）, Rpfd1（A1）, Rpfd2（A2）, BCG（B）and Saline（C）．The mice were immunized subcutaneously at weeks 0, 2 and 4. At 1 week after the final immunization, 7 mice each group were collected and separated sera to detect levels of IFN-γ, IL-2 and antibodies against Rpfd, Rpfd1, Rpfd2 proteins in sera by ELISA. At 4 weeks after the final immunization, the other 7 mice were infected with 1×10⁵CFU Mycobacterium tuberculosis H37Rv by the tail vein injection. At 1 week after infection, the levels of IFN-γ and IL-2 were detected by ELISA.  Results  （1）Antibody levels: ①Rpfd specific antibody levels in mice：group A1（0.990±0.272）were higher than group B（0.631±0.180; t=4.635, P<0.05）; group A2（1.470±0.455）were higher than group B（ t=6.634, P<0.05）. ②Rpfd1 specific antibody levels：group A （1.030±0.304）were higher than group B（0.573±0.004; t=5.276, P<0.05）; group A1（1.368±0.171）were higher than group B（t=17.20, P<0.05）; group A2 （2.766±0.245）were higher than group B（t=31.643, P<0.05）. ③Rpfd2 specific antibody levels：group A1（1.055±0.202）were higher than group B（0.538±0.100; t=8.009, P<0.05）; group A2（1.605±0.544）were higher than group B（t=8.192,P<0.05）. （2）Levels of IFN-γ: Before infection, IFN-γ levels in mice of group A（553.47±132.00) pg/ml were higher than that of group B（385.28±129.07) pg/ml（t=3.150,P<0.05）.After infection, IFN-γ levels in mice of group A1（492.41±211.74）pg/ml were higher than that of group B（335.36±207.72) pg/ml（ t=2.874, P<0.05）; group A2（543.09±223.07）pg/ml were higher than group B（t=3.15, P<0.05）. （3） Levels of IL-2: Before infection, IL-2 levels in mice of group A（1490.05±215.35) pg/ml were higher than that of group B（718.70±269.29) pg/ml（t=7.763,P<0.05）; group A1（1738.91±358.40） pg/ml were higher than group B（t=7.903, P<0.05）; group A2（2270.74±193.40) pg/ml were higher than that of group B（t=16.308,P<0.05）. After infection, IL-2 levels in mice of group A（806.81±306.39) pg/ml were higher than that of group B（335.26±176.81） pg/ml（t=4.627, P<0.05）; group A1（1373.22±143.75） pg/ml were higher than that of group B（t=15.90, P<0.05）. Conclusion  Vaccination with Rpfd、Rpfd1 and Rpfd2 proteins could induce humoral and cellular immune responses in BALB/c mice. They could be used as candidate vaccines.

Key words: Bacterial proteins, Interleukin-2, Interferon type Ⅱ, Recombinant proteins, Antibody formation, Immunity,cellular