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Objective To predict the epitopes of Mycobacterium tuberculosis Rv2657c protein, to understand its immunogenicity Methods The T?cell and B?cell epitopes of Mycobacterium tuberculosis Rv2657c protein were predicted by DNAStar software package. The homology of Rv2657c amino acid sequence with the human protein sequences was prepared using Blast method, then the CTL epitopes were predicted using SYFPEITHI supermotif method, BIMAS quantitative motif method and NetCTL prediction method, and the Th epitopes were predicted by RANKPEP and SYFPEITHI supermotif prediction method. Results The prediction using DNAStar software package showed that Rv2657c protein had 5 B?cell epitopes and 6 T?cell epitopes. The protein had 6 CTL epitopes and there were 38 Th epitopes. Conclusion Rv2657c protein has both B?cell epitopes and T?cell epitopes. It may be a candidate target antigen for the studies of vaccine and diagnosis of tuberculosis.
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Objective To investigate the Mycobacterium tuberculosis infections in 2014 among Beijing army recruits, and evaluate a new method for screening latent tuberculosis infections.Methods A total of 194 army recruits were subjected to chest X-ray examination purified protein derivative(PPD) skin test, antibody detection, and interferon gamma release assay(IGRA) by ELISA combined with recombinant protein CFP10-ESAT6 and latent infection protein Rv2628.Results The positive rates of PPD skin test and antibody test were 49.7% and 15.5%, respectively.The latent infection rate of IGRA test was 22.2% in 194 cases after CFP10-ESAT6 stimulation.After stimulation of latent tuberculosis infection(LTBI) with Rv2628, IFN-γ level was significantly higher than that in healthy control group (P0.05).There was no significant difference between antibody negative and positive groups after stimulation by CFP10-ESAT6 and Rv2628 (P>0.05).The area under the ROC curve of Rv2628 diagnosis of tuberculosis infection was 0.84.When Youden index was 0.621,the specificity was 94.7% and sensitivity was 67.4%.ConclusionCombined detection of antigens Rv2628 and CFP10-ESAT6 specific IFN-γ values can be potentially used for differential diagnosis of active or latent tuberculosis infections.
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Objective To study the therapeutic effects of Ag85A plasmid DNA vaccines in a mouse model of multi-drug resistant-(MDR-) Mycobacterium tuberculosis infection. Methods BALB/c mice were infected with Mycobacterium tuberculosis clinical strain HB361 with isoniazid and rifampin resist-ance by intratail-vein injection and were subsequently divided into 6 groups. At the third day after infection, the mice were treated with saline (group A), vector pVAX1 (greup B), rifampin (group C), vaccae (group D), Ag85A plasmid DNA vaccines (group E),rifampin and Ag85A plasmid DNA vaccines (group F) for 60 d. The lungs and spleens from the mice were taken and their pathological changes, weight and number of myeobacterial colony were examined at the third week after the end of treatment. Results At third week af-ter the end of treatment, the gross pathological observation and histopathological examination in lung showed that the lung lesions were limited, the profile of the alveoli was relatively clear, and normal structure could be seen in 2/3 areas of the lung sections in group D, E and F. The extent of lung lesion was 50% in group D,20% in group E and F. The pathological changes in group A, B, and C were more severer than those in group D, E and F. Compared with group A, the colony-forming units (CFU) in the lungs from mice in group D,E and F decreased 52%, 68%, 78%, respectively. The CFU in the spleens from mice in group D,E and F decreased 48%, 65%, 79%, respectively. Conclusion Ag85A plasmid DNA vaccines alone or Ag85A plasmid DNA vaccines along with chemotherapy have significant therapeutic effects on the mouse model of MDR-Mycobacterium tuberculosis infection.
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Objective To study the expression of MAGE-3 in colorectal cancer (CRC) with different differentiation grades. Method Immunohistochemical technique for MAGE-3 antigen was performed in paraffin embedded sections of 101 CRC specimens. The relationship between differentiation and Dukes classification of CRC and the expression of MAGE-3 antigen was analyzed. Result MAGE-3 was only expressed in tumor tissues with the total positive rate of 31.7%. The rate and intensity of MAGE-3 in poorly differentiated group were higher than that of the well differentiated group (P0.05). Conclusion MAGE-3 may be a specific molecular differentiation related marker of CRC. Its antigen may have potential use as a new peptide vaccine for immunotherapy for CRC.