Study on the cytotoxicity of spleen lymphocytes and immune mechanisms in mice immunized by Mycobacterium tuberculosis H37Ra

    WANG Liª²xian, LU Xianª²yu*, LI Hui, YANG Qiang

    Department of Clinical Immunology, Key Laboratory of Laboratory Medicine Diagnostics, Ministry of Education, Chongqing Medical University, Chongqing 400016, China

    [Abstract] AIM: To explore the specific cytotoxicity of spleen lymphocytes and the immune mechanisms in mice immunized by Mycobacterium tuberculosis(MTB)H37Ra. METHODS: At the various interval (30days, 60days) after the mice were immunized by MTB H37Ra, BCG and PBS, the spleen lymphocytes of the immunized mice were used as the effector cells while the Sp2/0 cells expressing the secreted protein Ag85B were used as the target cells, and the cytotoxicity of spleen lymphocytes in the immunized mice was measured by MTT assay. Spleen lymphocytes were collected at 60 days after immunization and stimulated with PPD, and the expression of perforin, granzyme B on mRNA level was detected by RTª²PCR. RESULTS: The cytotoxicity of spleen lymphocytes in the group immunized by MTB H37Ra was significantly higher than that of PBS control group(P<0ª±05), and slightly higher than that of BCG group. The mRNA expression of perforin, granzyme B in H37Ra group and BCG group was significantly higher than that in PBS control group (P<0ª±05); the expression of perforin mRNA in H37Ra group was significantly higher than that in BCG group (P<0ª±05), but there was no obvious difference with regard to the expression of granzyme B mRNA between H37Ra group and BCG group. CONCLUSION: The cytotoxicity of spleen lymphocytes is enhanced after mice were immunized by MTB H37Ra, which may be related to the expression of perforin and granzyme B. ......