Immunological properties of Rv1009 domain from Mycobacterium tuberculosis / 中华检验医学杂志

ABSTRACT

Objective To investigate the immunological properties of Rv1009 domain. Methods BALB/c mice were immunized with Rv1009 domain three times at 2-week interval. ELISA was used to detect the antiRv1009 domain antibody titer in the sera of immunized mice sera. The spleen lymphocytes of the immunized mice were separated and the stimulation index (SI) was measured by MTT colorimetry. Levels of secreted IFN-γ, IL-10 and IL-12 upon specific antigen stimulation were detected by ELISA. The BALB/c mice immunized with Rv1009 domain were intravenously infected with MTB H37Rv. Four weeks after the final injection, the number of CFU in spleens was determined. Results The titer of the specific antibody in sera of the immunized BALB/c mice was 112 800. The SI of Rv1009 domain immunized group (2. 40±0. 18) was significantly higher than that of saline immunized group (0.90±0.21). The IFN-γ,IL-10 and IL-12 levels in culture supematant of spleen lymphecytes from the fusion proteins immunized mice was (1 432±30) ng/L, (503±11) ng/L and (311±11) ng/L respectively, significant different from that of saline immunized group[(256±20) ng/L, (76±6) ng/L and(56±8) ng/L,P<0.01]. Four weeks after the final injection,compared with normal saline immunized mice (6.64±0.13), dramatic reduction in MTB replication was observed in the spleen (4.86±0.14) from BALB/c mice immunized with fusion proteins following a subsequent MTB H37Rv challenge, but the protection efficacy of mice immunized with Rv1009 domain was not as good as that of BCG vaccination group (3.81±0.16). Conclusion Rv1009 domain can be used as a candidate for the new TB vaccine.